Implement `super` expressions (#2116)

This Pull Request changes the following:

- Implement `super` expression parsing / execution.
- Implement early errors for `super` expressions.
- Refactor / add internal slot representation for environment and function objects.

boa_engine/src/builtins/eval/mod.rs

@@ -79,16 +79,10 @@ impl Eval {
 
         // Because of implementation details the following code differs from the spec.
 
-        // Parse the script body (11.a - 11.d)
+        // Parse the script body and handle early errors (6 - 11)
-        // TODO: Implement errors for 11.e - 11.h
+        let body = match context.parse_eval(x.as_bytes(), direct, strict) {
-        let parse_result = if strict {
-            context.parse_strict(x.as_bytes())
-        } else {
-            context.parse(x.as_bytes())
-        };
-        let body = match parse_result.map_err(|e| e.to_string()) {
             Ok(body) => body,
-            Err(e) => return context.throw_syntax_error(e),
+            Err(e) => return context.throw_syntax_error(e.to_string()),
         };
 
         // 12 - 13 are implicit in the call of `Context::compile_with_new_declarative`.

boa_engine/src/builtins/function/mod.rs

@@ -19,7 +19,7 @@ use crate::{
         internal_methods::get_prototype_from_constructor, JsObject, NativeObject, Object,
         ObjectData,
     },
-    object::{ConstructorBuilder, FunctionBuilder, Ref, RefMut},
+    object::{ConstructorBuilder, FunctionBuilder, JsFunction, PrivateElement, Ref, RefMut},
     property::{Attribute, PropertyDescriptor, PropertyKey},
     symbol::WellKnownSymbols,
     syntax::{ast::node::FormalParameterList, Parser},
@@ -108,7 +108,13 @@ impl ThisMode {
     }
 }
 
-#[derive(Debug, PartialEq, Clone, Copy)]
+/// Represents the `[[ConstructorKind]]` internal slot of function objects.
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#sec-ecmascript-function-objects
+#[derive(Clone, Copy, Debug, PartialEq)]
 pub enum ConstructorKind {
     Base,
     Derived,
@@ -126,6 +132,18 @@ impl ConstructorKind {
     }
 }
 
+/// Record containing the field definition of classes.
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#sec-classfielddefinition-record-specification-type
+#[derive(Clone, Debug, Trace, Finalize)]
+pub enum ClassFieldDefinition {
+    Public(PropertyKey, JsFunction),
+    Private(Sym, JsFunction),
+}
+
 /// Wrapper for `Gc<GcCell<dyn NativeObject>>` that allows passing additional
 /// captures through a `Copy` closure.
 ///
@@ -191,6 +209,19 @@ pub enum Function {
     Ordinary {
         code: Gc<crate::vm::CodeBlock>,
         environments: DeclarativeEnvironmentStack,
+
+        /// The `[[ConstructorKind]]` internal slot.
+        #[unsafe_ignore_trace]
+        constructor_kind: ConstructorKind,
+
+        /// The `[[HomeObject]]` internal slot.
+        home_object: Option<JsObject>,
+
+        /// The `[[Fields]]` internal slot.
+        fields: Vec<ClassFieldDefinition>,
+
+        /// The `[[PrivateMethods]]` internal slot.
+        private_methods: Vec<(Sym, PrivateElement)>,
     },
     Generator {
         code: Gc<crate::vm::CodeBlock>,
@@ -207,14 +238,85 @@ impl fmt::Debug for Function {
 impl Function {
     /// Returns true if the function object is a constructor.
     pub fn is_constructor(&self) -> bool {
-        self.constructor().is_some()
+        match self {
+            Self::Native { constructor, .. } | Self::Closure { constructor, .. } => {
+                constructor.is_some()
+            }
+            Self::Generator { .. } => false,
+            Self::Ordinary { code, .. } => !(code.this_mode == ThisMode::Lexical),
+        }
     }
 
-    /// Returns the constructor kind if the function is constructable, or `None` otherwise.
+    /// Returns true if the function object is a derived constructor.
-    pub fn constructor(&self) -> Option<ConstructorKind> {
+    pub(crate) fn is_derived_constructor(&self) -> bool {
-        match self {
+        if let Self::Ordinary {
-            Self::Native { constructor, .. } | Self::Closure { constructor, .. } => *constructor,
+            constructor_kind, ..
-            Self::Ordinary { code, .. } | Self::Generator { code, .. } => code.constructor,
+        } = self
+        {
+            constructor_kind.is_derived()
+        } else {
+            false
+        }
+    }
+
+    /// Returns a reference to the function `[[HomeObject]]` slot if present.
+    pub(crate) fn get_home_object(&self) -> Option<&JsObject> {
+        if let Self::Ordinary { home_object, .. } = self {
+            home_object.as_ref()
+        } else {
+            None
+        }
+    }
+
+    ///  Sets the `[[HomeObject]]` slot if present.
+    pub(crate) fn set_home_object(&mut self, object: JsObject) {
+        if let Self::Ordinary { home_object, .. } = self {
+            *home_object = Some(object);
+        }
+    }
+
+    /// Returns the values of the `[[Fields]]` internal slot.
+    pub(crate) fn get_fields(&self) -> &[ClassFieldDefinition] {
+        if let Self::Ordinary { fields, .. } = self {
+            fields
+        } else {
+            &[]
+        }
+    }
+
+    /// Pushes a value to the `[[Fields]]` internal slot if present.
+    pub(crate) fn push_field(&mut self, key: PropertyKey, value: JsFunction) {
+        if let Self::Ordinary { fields, .. } = self {
+            fields.push(ClassFieldDefinition::Public(key, value));
+        }
+    }
+
+    /// Pushes a private value to the `[[Fields]]` internal slot if present.
+    pub(crate) fn push_field_private(&mut self, key: Sym, value: JsFunction) {
+        if let Self::Ordinary { fields, .. } = self {
+            fields.push(ClassFieldDefinition::Private(key, value));
+        }
+    }
+
+    /// Returns the values of the `[[PrivateMethods]]` internal slot.
+    pub(crate) fn get_private_methods(&self) -> &[(Sym, PrivateElement)] {
+        if let Self::Ordinary {
+            private_methods, ..
+        } = self
+        {
+            private_methods
+        } else {
+            &[]
+        }
+    }
+
+    /// Pushes a private method to the `[[PrivateMethods]]` internal slot if present.
+    pub(crate) fn push_private_method(&mut self, name: Sym, method: PrivateElement) {
+        if let Self::Ordinary {
+            private_methods, ..
+        } = self
+        {
+            private_methods.push((name, method));
         }
     }
 }

boa_engine/src/bytecompiler.rs

@@ -1,5 +1,5 @@
 use crate::{
-    builtins::function::{ConstructorKind, ThisMode},
+    builtins::function::ThisMode,
     environments::{BindingLocator, CompileTimeEnvironment},
     syntax::ast::{
         node::{
@@ -11,7 +11,8 @@ use crate::{
             object::{MethodDefinition, PropertyDefinition, PropertyName},
             operator::assign::AssignTarget,
             template::TemplateElement,
-            Class, Declaration, FormalParameterList, GetConstField, GetField, StatementList,
+            Class, Declaration, FormalParameterList, GetConstField, GetField, GetSuperField,
+            StatementList,
         },
         op::{AssignOp, BinOp, BitOp, CompOp, LogOp, NumOp, UnaryOp},
         Const, Node,
@@ -81,7 +82,7 @@ impl<'b> ByteCompiler<'b> {
     #[inline]
     pub fn new(name: Sym, strict: bool, context: &'b mut Context) -> Self {
         Self {
-            code_block: CodeBlock::new(name, 0, strict, None),
+            code_block: CodeBlock::new(name, 0, strict),
             literals_map: FxHashMap::default(),
             names_map: FxHashMap::default(),
             bindings_map: FxHashMap::default(),
@@ -1003,7 +1004,7 @@ impl<'b> ByteCompiler<'b> {
                     self.compile_expr(node.obj(), true)?;
                     self.emit_opcode(Opcode::Swap);
                     let index = self.get_or_insert_name(node.field());
-                    self.emit(Opcode::SetPrivateValue, &[index]);
+                    self.emit(Opcode::AssignPrivateField, &[index]);
                 }
                 AssignTarget::GetConstField(node) => {
                     self.access_set(Access::ByName { node }, Some(assign.rhs()), use_expr)?;
@@ -1032,6 +1033,24 @@ impl<'b> ByteCompiler<'b> {
                 let access = Access::ByValue { node };
                 self.access_get(access, use_expr)?;
             }
+            Node::GetSuperField(get_super_field) => match get_super_field {
+                GetSuperField::Const(field) => {
+                    let index = self.get_or_insert_name(*field);
+                    self.emit_opcode(Opcode::Super);
+                    self.emit(Opcode::GetPropertyByName, &[index]);
+                    if !use_expr {
+                        self.emit_opcode(Opcode::Pop);
+                    }
+                }
+                GetSuperField::Expr(expr) => {
+                    self.compile_expr(expr, true)?;
+                    self.emit_opcode(Opcode::Super);
+                    self.emit_opcode(Opcode::GetPropertyByValue);
+                    if !use_expr {
+                        self.emit_opcode(Opcode::Pop);
+                    }
+                }
+            },
             Node::ConditionalOp(op) => {
                 self.compile_expr(op.cond(), true)?;
                 let jelse = self.jump_if_false();
@@ -1181,6 +1200,24 @@ impl<'b> ByteCompiler<'b> {
                 self.emit(Opcode::Call, &[(template.exprs().len() + 1) as u32]);
             }
             Node::ClassExpr(class) => self.class(class, true)?,
+            Node::SuperCall(super_call) => {
+                for arg in super_call.args() {
+                    self.compile_expr(arg, true)?;
+                }
+
+                let last_is_rest_parameter =
+                    matches!(super_call.args().last(), Some(Node::Spread(_)));
+
+                if last_is_rest_parameter {
+                    self.emit(Opcode::SuperCallWithRest, &[super_call.args().len() as u32]);
+                } else {
+                    self.emit(Opcode::SuperCall, &[super_call.args().len() as u32]);
+                }
+
+                if !use_expr {
+                    self.emit_opcode(Opcode::Pop);
+                }
+            }
             _ => unreachable!(),
         }
         Ok(())
@@ -1194,10 +1231,6 @@ impl<'b> ByteCompiler<'b> {
                     match decl {
                         Declaration::Identifier { ident, .. } => {
                             let ident = ident.sym();
-                            if ident == Sym::ARGUMENTS {
-                                self.code_block.lexical_name_argument = true;
-                            }
-
                             if let Some(expr) = decl.init() {
                                 self.compile_expr(expr, true)?;
                                 self.emit_binding(BindingOpcode::InitVar, ident);
@@ -1206,10 +1239,6 @@ impl<'b> ByteCompiler<'b> {
                             }
                         }
                         Declaration::Pattern(pattern) => {
-                            if pattern.idents().contains(&Sym::ARGUMENTS) {
-                                self.code_block.lexical_name_argument = true;
-                            }
-
                             if let Some(init) = decl.init() {
                                 self.compile_expr(init, true)?;
                             } else {
@@ -1225,10 +1254,6 @@ impl<'b> ByteCompiler<'b> {
                 for decl in list.as_ref() {
                     match decl {
                         Declaration::Identifier { ident, .. } => {
-                            if ident.sym() == Sym::ARGUMENTS {
-                                self.code_block.lexical_name_argument = true;
-                            }
-
                             if let Some(expr) = decl.init() {
                                 self.compile_expr(expr, true)?;
                                 self.emit_binding(BindingOpcode::InitLet, ident.sym());
@@ -1237,10 +1262,6 @@ impl<'b> ByteCompiler<'b> {
                             }
                         }
                         Declaration::Pattern(pattern) => {
-                            if pattern.idents().contains(&Sym::ARGUMENTS) {
-                                self.code_block.lexical_name_argument = true;
-                            }
-
                             if let Some(init) = decl.init() {
                                 self.compile_expr(init, true)?;
                             } else {
@@ -1256,9 +1277,6 @@ impl<'b> ByteCompiler<'b> {
                 for decl in list.as_ref() {
                     match decl {
                         Declaration::Identifier { ident, .. } => {
-                            if ident.sym() == Sym::ARGUMENTS {
-                                self.code_block.lexical_name_argument = true;
-                            }
                             let init = decl
                                 .init()
                                 .expect("const declaration must have initializer");
@@ -1266,10 +1284,6 @@ impl<'b> ByteCompiler<'b> {
                             self.emit_binding(BindingOpcode::InitConst, ident.sym());
                         }
                         Declaration::Pattern(pattern) => {
-                            if pattern.idents().contains(&Sym::ARGUMENTS) {
-                                self.code_block.lexical_name_argument = true;
-                            }
-
                             if let Some(init) = decl.init() {
                                 self.compile_expr(init, true)?;
                             } else {
@@ -1927,22 +1941,12 @@ impl<'b> ByteCompiler<'b> {
     ) -> JsResult<Gc<CodeBlock>> {
         let strict = strict || body.strict();
         let length = parameters.length();
-        let mut code = CodeBlock::new(
+        let mut code = CodeBlock::new(name.unwrap_or(Sym::EMPTY_STRING), length, strict);
-            name.unwrap_or(Sym::EMPTY_STRING),
-            length,
-            strict,
-            Some(ConstructorKind::Base),
-        );
 
         if let FunctionKind::Arrow = kind {
-            code.constructor = None;
             code.this_mode = ThisMode::Lexical;
         }
 
-        if generator {
-            code.constructor = None;
-        }
-
         let mut compiler = ByteCompiler {
             code_block: code,
             literals_map: FxHashMap::default(),
@@ -2541,17 +2545,7 @@ impl<'b> ByteCompiler<'b> {
     /// A class declaration binds the resulting class object to it's identifier.
     /// A class expression leaves the resulting class object on the stack for following operations.
     fn class(&mut self, class: &Class, expression: bool) -> JsResult<()> {
-        let mut code = CodeBlock::new(
+        let code = CodeBlock::new(class.name(), 0, true);
-            class.name(),
-            0,
-            true,
-            Some(if class.super_ref().is_some() {
-                ConstructorKind::Derived
-            } else {
-                ConstructorKind::Base
-            }),
-        );
-        code.computed_field_names = Some(gc::GcCell::new(vec![]));
         let mut compiler = ByteCompiler {
             code_block: code,
             literals_map: FxHashMap::default(),
@@ -2562,47 +2556,6 @@ impl<'b> ByteCompiler<'b> {
         };
         compiler.context.push_compile_time_environment(true);
 
-        for element in class.elements() {
-            match element {
-                ClassElement::FieldDefinition(name, field) => {
-                    compiler.emit_opcode(Opcode::This);
-                    match name {
-                        PropertyName::Literal(name) => {
-                            if let Some(node) = field {
-                                compiler.compile_stmt(node, true)?;
-                            } else {
-                                compiler.emit_opcode(Opcode::PushUndefined);
-                            }
-                            compiler.emit_opcode(Opcode::Swap);
-                            let index = compiler.get_or_insert_name(*name);
-                            compiler.emit(Opcode::DefineOwnPropertyByName, &[index]);
-                        }
-                        PropertyName::Computed(_) => {
-                            compiler.emit_opcode(Opcode::Swap);
-                            compiler.emit_opcode(Opcode::ToPropertyKey);
-                            if let Some(node) = field {
-                                compiler.compile_stmt(node, true)?;
-                            } else {
-                                compiler.emit_opcode(Opcode::PushUndefined);
-                            }
-                            compiler.emit_opcode(Opcode::DefineOwnPropertyByValue);
-                        }
-                    }
-                }
-                ClassElement::PrivateFieldDefinition(name, field) => {
-                    compiler.emit_opcode(Opcode::This);
-                    if let Some(node) = field {
-                        compiler.compile_stmt(node, true)?;
-                    } else {
-                        compiler.emit_opcode(Opcode::PushUndefined);
-                    }
-                    let index = compiler.get_or_insert_name(*name);
-                    compiler.emit(Opcode::SetPrivateValue, &[index]);
-                }
-                _ => {}
-            }
-        }
-
         if let Some(expr) = class.constructor() {
             compiler.code_block.length = expr.parameters().length();
             compiler.code_block.params = expr.parameters().clone();
@@ -2667,8 +2620,12 @@ impl<'b> ByteCompiler<'b> {
                     .compile_environments
                     .push(compile_environment);
                 compiler.code_block.num_bindings = num_bindings;
+                compiler.code_block.is_class_constructor = true;
             }
         } else {
+            if class.super_ref().is_some() {
+                compiler.emit_opcode(Opcode::SuperCallDerived);
+            }
             let (num_bindings, compile_environment) =
                 compiler.context.pop_compile_time_environment();
             compiler
@@ -2676,6 +2633,7 @@ impl<'b> ByteCompiler<'b> {
                 .compile_environments
                 .push(compile_environment);
             compiler.code_block.num_bindings = num_bindings;
+            compiler.code_block.is_class_constructor = true;
         }
 
         compiler.emit_opcode(Opcode::PushUndefined);
@@ -2686,6 +2644,16 @@ impl<'b> ByteCompiler<'b> {
         self.code_block.functions.push(code);
         self.emit(Opcode::GetFunction, &[index]);
 
+        self.emit_opcode(Opcode::Dup);
+        if let Some(node) = class.super_ref() {
+            self.compile_expr(node, true)?;
+            self.emit_opcode(Opcode::PushClassPrototype);
+        } else {
+            self.emit_opcode(Opcode::PushUndefined);
+        }
+        self.emit_opcode(Opcode::SetClassPrototype);
+        self.emit_opcode(Opcode::Swap);
+
         for element in class.elements() {
             match element {
                 ClassElement::StaticMethodDefinition(name, method_definition) => {
@@ -2767,22 +2735,91 @@ impl<'b> ByteCompiler<'b> {
                         MethodDefinition::Ordinary(expr) => {
                             self.function(&expr.clone().into(), true)?;
                             let index = self.get_or_insert_name(*name);
-                            self.emit(Opcode::SetPrivateValue, &[index]);
+                            self.emit(Opcode::SetPrivateMethod, &[index]);
                         }
                         MethodDefinition::Generator(expr) => {
                             self.function(&expr.clone().into(), true)?;
                             let index = self.get_or_insert_name(*name);
-                            self.emit(Opcode::SetPrivateValue, &[index]);
+                            self.emit(Opcode::SetPrivateMethod, &[index]);
                         }
                         // TODO: implement async
                         MethodDefinition::AsyncGenerator(_) | MethodDefinition::Async(_) => {}
                     }
                 }
-                ClassElement::FieldDefinition(PropertyName::Computed(name_node), _) => {
+                ClassElement::FieldDefinition(name, field) => {
                     self.emit_opcode(Opcode::Dup);
-                    self.compile_stmt(name_node, true)?;
+                    match name {
-                    self.emit_opcode(Opcode::Swap);
+                        PropertyName::Literal(name) => {
-                    self.emit_opcode(Opcode::PushClassComputedFieldName);
+                            self.emit_push_literal(Literal::String(
+                                self.interner().resolve_expect(*name).into(),
+                            ));
+                        }
+                        PropertyName::Computed(name) => {
+                            self.compile_expr(name, true)?;
+                        }
+                    }
+                    let field_code = CodeBlock::new(Sym::EMPTY_STRING, 0, true);
+                    let mut field_compiler = ByteCompiler {
+                        code_block: field_code,
+                        literals_map: FxHashMap::default(),
+                        names_map: FxHashMap::default(),
+                        bindings_map: FxHashMap::default(),
+                        jump_info: Vec::new(),
+                        context: self.context,
+                    };
+                    field_compiler.context.push_compile_time_environment(true);
+                    if let Some(node) = field {
+                        field_compiler.compile_stmt(node, true)?;
+                    } else {
+                        field_compiler.emit_opcode(Opcode::PushUndefined);
+                    }
+                    let (num_bindings, compile_environment) =
+                        field_compiler.context.pop_compile_time_environment();
+                    field_compiler
+                        .code_block
+                        .compile_environments
+                        .push(compile_environment);
+                    field_compiler.code_block.num_bindings = num_bindings;
+                    field_compiler.emit_opcode(Opcode::Return);
+
+                    let code = Gc::new(field_compiler.finish());
+                    let index = self.code_block.functions.len() as u32;
+                    self.code_block.functions.push(code);
+                    self.emit(Opcode::GetFunction, &[index]);
+                    self.emit_opcode(Opcode::PushClassField);
+                }
+                ClassElement::PrivateFieldDefinition(name, field) => {
+                    self.emit_opcode(Opcode::Dup);
+                    let name_index = self.get_or_insert_name(*name);
+                    let field_code = CodeBlock::new(Sym::EMPTY_STRING, 0, true);
+                    let mut field_compiler = ByteCompiler {
+                        code_block: field_code,
+                        literals_map: FxHashMap::default(),
+                        names_map: FxHashMap::default(),
+                        bindings_map: FxHashMap::default(),
+                        jump_info: Vec::new(),
+                        context: self.context,
+                    };
+                    field_compiler.context.push_compile_time_environment(true);
+                    if let Some(node) = field {
+                        field_compiler.compile_stmt(node, true)?;
+                    } else {
+                        field_compiler.emit_opcode(Opcode::PushUndefined);
+                    }
+                    let (num_bindings, compile_environment) =
+                        field_compiler.context.pop_compile_time_environment();
+                    field_compiler
+                        .code_block
+                        .compile_environments
+                        .push(compile_environment);
+                    field_compiler.code_block.num_bindings = num_bindings;
+                    field_compiler.emit_opcode(Opcode::Return);
+
+                    let code = Gc::new(field_compiler.finish());
+                    let index = self.code_block.functions.len() as u32;
+                    self.code_block.functions.push(code);
+                    self.emit(Opcode::GetFunction, &[index]);
+                    self.emit(Opcode::PushClassFieldPrivate, &[name_index]);
                 }
                 ClassElement::StaticFieldDefinition(name, field) => {
                     self.emit_opcode(Opcode::Dup);
@@ -2817,7 +2854,7 @@ impl<'b> ByteCompiler<'b> {
                         self.emit_opcode(Opcode::PushUndefined);
                     }
                     let index = self.get_or_insert_name(*name);
-                    self.emit(Opcode::SetPrivateValue, &[index]);
+                    self.emit(Opcode::SetPrivateField, &[index]);
                 }
                 ClassElement::StaticBlock(statement_list) => {
                     self.emit_opcode(Opcode::Dup);
@@ -2837,25 +2874,43 @@ impl<'b> ByteCompiler<'b> {
                     let index = self.code_block.functions.len() as u32;
                     self.code_block.functions.push(code);
                     self.emit(Opcode::GetFunction, &[index]);
+                    self.emit_opcode(Opcode::SetHomeObject);
                     self.emit(Opcode::Call, &[0]);
                     self.emit_opcode(Opcode::Pop);
                 }
-                ClassElement::MethodDefinition(..)
+                ClassElement::PrivateMethodDefinition(name, method_definition) => {
-                | ClassElement::PrivateMethodDefinition(..)
+                    self.emit_opcode(Opcode::Dup);
-                | ClassElement::PrivateFieldDefinition(..)
+                    match method_definition {
-                | ClassElement::FieldDefinition(..) => {}
+                        MethodDefinition::Get(expr) => {
+                            self.function(&expr.clone().into(), true)?;
+                            let index = self.get_or_insert_name(*name);
+                            self.emit(Opcode::PushClassPrivateGetter, &[index]);
                         }
+                        MethodDefinition::Set(expr) => {
+                            self.function(&expr.clone().into(), true)?;
+                            let index = self.get_or_insert_name(*name);
+                            self.emit(Opcode::PushClassPrivateSetter, &[index]);
+                        }
+                        MethodDefinition::Ordinary(expr) => {
+                            self.function(&expr.clone().into(), true)?;
+                            let index = self.get_or_insert_name(*name);
+                            self.emit(Opcode::PushClassPrivateMethod, &[index]);
+                        }
+                        MethodDefinition::Generator(expr) => {
+                            self.function(&expr.clone().into(), true)?;
+                            let index = self.get_or_insert_name(*name);
+                            self.emit(Opcode::PushClassPrivateMethod, &[index]);
+                        }
+                        // TODO: implement async
+                        MethodDefinition::AsyncGenerator(_) | MethodDefinition::Async(_) => {}
+                    }
+                }
+                ClassElement::MethodDefinition(..) => {}
             }
-
-        self.emit_opcode(Opcode::Dup);
-
-        if let Some(node) = class.super_ref() {
-            self.compile_expr(node, true)?;
-            self.emit_opcode(Opcode::PushClassPrototype);
-        } else {
-            self.emit_opcode(Opcode::PushEmptyObject);
         }
 
+        self.emit_opcode(Opcode::Swap);
+
         for element in class.elements() {
             match element {
                 ClassElement::MethodDefinition(name, method_definition) => {
@@ -2918,37 +2973,13 @@ impl<'b> ByteCompiler<'b> {
                             }
                         },
                         // TODO: implement async
-                        MethodDefinition::AsyncGenerator(_) | MethodDefinition::Async(_) => {}
+                        MethodDefinition::AsyncGenerator(_) | MethodDefinition::Async(_) => {
-                    }
+                            self.emit_opcode(Opcode::Pop);
-                }
-                ClassElement::PrivateMethodDefinition(name, method_definition) => {
-                    self.emit_opcode(Opcode::Dup);
-                    match method_definition {
-                        MethodDefinition::Get(expr) => {
-                            self.function(&expr.clone().into(), true)?;
-                            let index = self.get_or_insert_name(*name);
-                            self.emit(Opcode::SetPrivateGetter, &[index]);
-                        }
-                        MethodDefinition::Set(expr) => {
-                            self.function(&expr.clone().into(), true)?;
-                            let index = self.get_or_insert_name(*name);
-                            self.emit(Opcode::SetPrivateSetter, &[index]);
-                        }
-                        MethodDefinition::Ordinary(expr) => {
-                            self.function(&expr.clone().into(), true)?;
-                            let index = self.get_or_insert_name(*name);
-                            self.emit(Opcode::SetPrivateValue, &[index]);
                         }
-                        MethodDefinition::Generator(expr) => {
-                            self.function(&expr.clone().into(), true)?;
-                            let index = self.get_or_insert_name(*name);
-                            self.emit(Opcode::SetPrivateValue, &[index]);
                     }
-                        // TODO: implement async
-                        MethodDefinition::AsyncGenerator(_) | MethodDefinition::Async(_) => {}
                 }
-                }
+                ClassElement::PrivateMethodDefinition(..)
-                ClassElement::PrivateFieldDefinition(..)
+                | ClassElement::PrivateFieldDefinition(..)
                 | ClassElement::StaticFieldDefinition(..)
                 | ClassElement::PrivateStaticFieldDefinition(..)
                 | ClassElement::StaticMethodDefinition(..)
@@ -2958,9 +2989,7 @@ impl<'b> ByteCompiler<'b> {
             }
         }
 
-        self.emit_opcode(Opcode::Swap);
+        self.emit_opcode(Opcode::Pop);
-        let index = self.get_or_insert_name(Sym::PROTOTYPE);
-        self.emit(Opcode::SetPropertyByName, &[index]);
 
         if !expression {
             self.emit_binding(BindingOpcode::InitVar, class.name());

boa_engine/src/context/mod.rs

@@ -167,14 +167,21 @@ impl Context {
         parser.parse_all(self)
     }
 
-    /// Parse the given source text in strict mode.
+    /// Parse the given source text with eval specific handling.
-    pub(crate) fn parse_strict<S>(&mut self, src: S) -> Result<StatementList, ParseError>
+    pub(crate) fn parse_eval<S>(
+        &mut self,
+        src: S,
+        direct: bool,
+        strict: bool,
+    ) -> Result<StatementList, ParseError>
     where
         S: AsRef<[u8]>,
     {
         let mut parser = Parser::new(src.as_ref());
+        if strict {
             parser.set_strict();
-        parser.parse_all(self)
+        }
+        parser.parse_eval(direct, self)
     }
 
     /// `Call ( F, V [ , argumentsList ] )`
@@ -705,22 +712,20 @@ impl Context {
     #[inline]
     pub fn execute(&mut self, code_block: Gc<CodeBlock>) -> JsResult<JsValue> {
         let _timer = Profiler::global().start_event("Execution", "Main");
-        let global_object = self.global_object().clone().into();
 
         self.vm.push_frame(CallFrame {
             prev: None,
             code: code_block,
-            this: global_object,
             pc: 0,
             catch: Vec::new(),
             finally_return: FinallyReturn::None,
             finally_jump: Vec::new(),
             pop_on_return: 0,
-            loop_env_stack: vec![0],
+            loop_env_stack: Vec::from([0]),
-            try_env_stack: vec![crate::vm::TryStackEntry {
+            try_env_stack: Vec::from([crate::vm::TryStackEntry {
                 num_env: 0,
                 num_loop_stack_entries: 0,
-            }],
+            }]),
             param_count: 0,
             arg_count: 0,
             generator_resume_kind: GeneratorResumeKind::Normal,

boa_engine/src/environments/mod.rs

@@ -29,7 +29,9 @@ mod runtime;
 
 pub(crate) use {
     compile::CompileTimeEnvironment,
-    runtime::{BindingLocator, DeclarativeEnvironment, DeclarativeEnvironmentStack},
+    runtime::{
+        BindingLocator, DeclarativeEnvironment, DeclarativeEnvironmentStack, EnvironmentSlots,
+    },
 };
 
 #[cfg(test)]

boa_engine/src/environments/runtime.rs

@@ -1,4 +1,4 @@
-use crate::{environments::CompileTimeEnvironment, Context, JsResult, JsValue};
+use crate::{environments::CompileTimeEnvironment, object::JsObject, Context, JsResult, JsValue};
 use boa_gc::{Cell, Finalize, Gc, Trace};
 use boa_interner::Sym;
 use rustc_hash::FxHashSet;
@@ -26,12 +26,161 @@ use rustc_hash::FxHashSet;
 #[derive(Debug, Trace, Finalize)]
 pub(crate) struct DeclarativeEnvironment {
     bindings: Cell<Vec<Option<JsValue>>>,
-    this: Option<JsValue>,
     compile: Gc<Cell<CompileTimeEnvironment>>,
     poisoned: Cell<bool>,
+    slots: Option<EnvironmentSlots>,
+}
+
+/// Describes the different types of internal slot data that an environment can hold.
+#[derive(Clone, Debug, Trace, Finalize)]
+pub(crate) enum EnvironmentSlots {
+    Function(Cell<FunctionSlots>),
+    Global,
+}
+
+impl EnvironmentSlots {
+    /// Return the slots if they are part of a function environment.
+    pub(crate) fn as_function_slots(&self) -> Option<&Cell<FunctionSlots>> {
+        if let Self::Function(env) = &self {
+            Some(env)
+        } else {
+            None
+        }
+    }
+}
+
+/// Holds the internal slots of a function environment.
+#[derive(Clone, Debug, Trace, Finalize)]
+pub(crate) struct FunctionSlots {
+    /// The `[[ThisValue]]` internal slot.
+    this: JsValue,
+
+    /// The `[[ThisBindingStatus]]` internal slot.
+    #[unsafe_ignore_trace]
+    this_binding_status: ThisBindingStatus,
+
+    /// The `[[FunctionObject]]` internal slot.
+    function_object: JsObject,
+
+    /// The `[[NewTarget]]` internal slot.
+    new_target: Option<JsObject>,
+}
+
+impl FunctionSlots {
+    /// Returns the value of the `[[FunctionObject]]` internal slot.
+    pub(crate) fn function_object(&self) -> &JsObject {
+        &self.function_object
+    }
+
+    /// Returns the value of the `[[NewTarget]]` internal slot.
+    pub(crate) fn new_target(&self) -> Option<&JsObject> {
+        self.new_target.as_ref()
+    }
+
+    /// `BindThisValue`
+    ///
+    /// Sets the given value as the `this` binding of the environment.
+    /// Returns `false` if the `this` binding has already been initialized.
+    ///
+    /// More information:
+    ///  - [ECMAScript specification][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-bindthisvalue
+    pub(crate) fn bind_this_value(&mut self, this: &JsObject) -> bool {
+        // 1. Assert: envRec.[[ThisBindingStatus]] is not lexical.
+        debug_assert!(self.this_binding_status != ThisBindingStatus::Lexical);
+
+        // 2. If envRec.[[ThisBindingStatus]] is initialized, throw a ReferenceError exception.
+        if self.this_binding_status == ThisBindingStatus::Initialized {
+            return false;
+        }
+
+        // 3. Set envRec.[[ThisValue]] to V.
+        self.this = this.clone().into();
+
+        // 4. Set envRec.[[ThisBindingStatus]] to initialized.
+        self.this_binding_status = ThisBindingStatus::Initialized;
+
+        // 5. Return V.
+        true
+    }
+
+    /// `HasThisBinding`
+    ///
+    /// Returns if the environment has a `this` binding.
+    ///
+    /// More information:
+    ///  - [ECMAScript specification][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-function-environment-records-hasthisbinding
+    pub(crate) fn has_this_binding(&self) -> bool {
+        // 1. If envRec.[[ThisBindingStatus]] is lexical, return false; otherwise, return true.
+        self.this_binding_status != ThisBindingStatus::Lexical
+    }
+
+    /// `HasSuperBinding`
+    ///
+    /// Returns if the environment has a `super` binding.
+    ///
+    /// More information:
+    ///  - [ECMAScript specification][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-function-environment-records-hassuperbinding
+    ///
+    /// # Panics
+    ///
+    /// Panics if the function object of the environment is not a function.
+    pub(crate) fn has_super_binding(&self) -> bool {
+        // 1.If envRec.[[ThisBindingStatus]] is lexical, return false.
+        if self.this_binding_status == ThisBindingStatus::Lexical {
+            return false;
+        }
+
+        // 2. If envRec.[[FunctionObject]].[[HomeObject]] is undefined, return false; otherwise, return true.
+        self.function_object
+            .borrow()
+            .as_function()
+            .expect("function object must be function")
+            .get_home_object()
+            .is_some()
+    }
+
+    /// `GetThisBinding`
+    ///
+    /// Returns the `this` binding on the function environment.
+    ///
+    /// More information:
+    ///  - [ECMAScript specification][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-function-environment-records-getthisbinding
+    pub(crate) fn get_this_binding(&self) -> Option<&JsValue> {
+        // 1. Assert: envRec.[[ThisBindingStatus]] is not lexical.
+        debug_assert!(self.this_binding_status != ThisBindingStatus::Lexical);
+
+        // 2. If envRec.[[ThisBindingStatus]] is uninitialized, throw a ReferenceError exception.
+        if self.this_binding_status == ThisBindingStatus::Uninitialized {
+            return None;
+        }
+
+        // 3. Return envRec.[[ThisValue]].
+        Some(&self.this)
+    }
+}
+
+/// Describes the status of a `this` binding in function environments.
+#[derive(Clone, Copy, Debug, PartialEq)]
+enum ThisBindingStatus {
+    Lexical,
+    Initialized,
+    Uninitialized,
 }
 
 impl DeclarativeEnvironment {
+    /// Returns the internal slot data of the current environment.
+    pub(crate) fn slots(&self) -> Option<&EnvironmentSlots> {
+        self.slots.as_ref()
+    }
+
     /// Get the binding value from the environment by it's index.
     ///
     /// # Panics
@@ -79,9 +228,9 @@ impl DeclarativeEnvironmentStack {
         Self {
             stack: vec![Gc::new(DeclarativeEnvironment {
                 bindings: Cell::new(Vec::new()),
-                this: None,
                 compile: global_compile_environment,
                 poisoned: Cell::new(false),
+                slots: Some(EnvironmentSlots::Global),
             })],
         }
     }
@@ -91,7 +240,7 @@ impl DeclarativeEnvironmentStack {
     /// This is only useful when compiled bindings are added after the initial compilation (eval).
     pub(crate) fn extend_outer_function_environment(&mut self) {
         for env in self.stack.iter().rev() {
-            if env.this.is_some() {
+            if let Some(EnvironmentSlots::Function(_)) = env.slots {
                 let compile_bindings_number = env.compile.borrow().num_bindings();
                 let mut bindings_mut = env.bindings.borrow_mut();
 
@@ -163,15 +312,34 @@ impl DeclarativeEnvironmentStack {
         }
     }
 
-    /// Get the `this` value of the most outer function environment.
+    /// `GetThisEnvironment`
+    ///
+    /// Returns the environment that currently provides a `this` biding.
+    ///
+    /// More information:
+    ///  - [ECMAScript specification][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-getthisenvironment
+    ///
+    /// # Panics
+    ///
+    /// Panics if no environment exists on the stack.
     #[inline]
-    pub(crate) fn get_last_this(&self) -> Option<JsValue> {
+    pub(crate) fn get_this_environment(&self) -> &EnvironmentSlots {
         for env in self.stack.iter().rev() {
-            if let Some(this) = &env.this {
+            if let Some(slots) = &env.slots {
-                return Some(this.clone());
+                match slots {
+                    EnvironmentSlots::Function(function_env) => {
+                        if function_env.borrow().has_this_binding() {
+                            return slots;
                         }
                     }
-        None
+                    EnvironmentSlots::Global => return slots,
+                }
+            }
+        }
+
+        panic!("global environment must exist")
     }
 
     /// Push a declarative environment on the environments stack.
@@ -195,9 +363,9 @@ impl DeclarativeEnvironmentStack {
 
         self.stack.push(Gc::new(DeclarativeEnvironment {
             bindings: Cell::new(vec![None; num_bindings]),
-            this: None,
             compile: compile_environment,
             poisoned: Cell::new(poisoned),
+            slots: None,
         }));
     }
 
@@ -211,29 +379,78 @@ impl DeclarativeEnvironmentStack {
         &mut self,
         num_bindings: usize,
         compile_environment: Gc<Cell<CompileTimeEnvironment>>,
-        this: JsValue,
+        this: Option<JsValue>,
+        function_object: JsObject,
+        new_target: Option<JsObject>,
+        lexical: bool,
     ) {
-        let poisoned = self
+        let outer = self
             .stack
             .last()
-            .expect("global environment must always exist")
+            .expect("global environment must always exist");
-            .poisoned
+
-            .borrow()
+        let poisoned = outer.poisoned.borrow().to_owned();
-            .to_owned();
+
+        let this_binding_status = if lexical {
+            ThisBindingStatus::Lexical
+        } else if this.is_some() {
+            ThisBindingStatus::Initialized
+        } else {
+            ThisBindingStatus::Uninitialized
+        };
+
+        let this = if let Some(this) = this {
+            this
+        } else {
+            JsValue::Null
+        };
 
         self.stack.push(Gc::new(DeclarativeEnvironment {
             bindings: Cell::new(vec![None; num_bindings]),
-            this: Some(this),
             compile: compile_environment,
             poisoned: Cell::new(poisoned),
+            slots: Some(EnvironmentSlots::Function(Cell::new(FunctionSlots {
+                this,
+                this_binding_status,
+                function_object,
+                new_target,
+            }))),
+        }));
+    }
+
+    /// Push a function environment that inherits it's internal slots from the outer environment.
+    ///
+    /// # Panics
+    ///
+    /// Panics if no environment exists on the stack.
+    pub(crate) fn push_function_inherit(
+        &mut self,
+        num_bindings: usize,
+        compile_environment: Gc<Cell<CompileTimeEnvironment>>,
+    ) {
+        let outer = self
+            .stack
+            .last()
+            .expect("global environment must always exist");
+
+        let poisoned = outer.poisoned.borrow().to_owned();
+        let slots = outer.slots.clone();
+
+        self.stack.push(Gc::new(DeclarativeEnvironment {
+            bindings: Cell::new(vec![None; num_bindings]),
+            compile: compile_environment,
+            poisoned: Cell::new(poisoned),
+            slots,
         }));
     }
 
     /// Pop environment from the environments stack.
     #[inline]
-    pub(crate) fn pop(&mut self) {
+    pub(crate) fn pop(&mut self) -> Gc<DeclarativeEnvironment> {
         debug_assert!(self.stack.len() > 1);
-        self.stack.pop();
+        self.stack
+            .pop()
+            .expect("environment stack is cannot be empty")
     }
 
     /// Get the most outer environment.

boa_engine/src/object/jsobject.rs

@@ -52,29 +52,14 @@ impl JsObject {
     /// internal slots from the `data` provided.
     #[inline]
     pub fn from_proto_and_data<O: Into<Option<Self>>>(prototype: O, data: ObjectData) -> Self {
-        let prototype: Option<Self> = prototype.into();
-        if let Some(prototype) = prototype {
-            let private = {
-                let prototype_b = prototype.borrow();
-                prototype_b.private_elements.clone()
-            };
-            Self::from_object(Object {
-                data,
-                prototype: Some(prototype),
-                extensible: true,
-                properties: PropertyMap::default(),
-                private_elements: private,
-            })
-        } else {
         Self::from_object(Object {
             data,
-                prototype: None,
+            prototype: prototype.into(),
             extensible: true,
             properties: PropertyMap::default(),
             private_elements: FxHashMap::default(),
         })
     }
-    }
 
     /// Immutably borrows the `Object`.
     ///

boa_engine/src/object/mod.rs

@@ -124,8 +124,9 @@ pub struct Object {
 
 /// The representation of private object elements.
 #[derive(Clone, Debug, Trace, Finalize)]
-pub(crate) enum PrivateElement {
+pub enum PrivateElement {
-    Value(JsValue),
+    Field(JsValue),
+    Method(JsObject),
     Accessor {
         getter: Option<JsObject>,
         setter: Option<JsObject>,

boa_engine/src/syntax/ast/node/declaration/mod.rs

@@ -4,7 +4,7 @@ use crate::syntax::ast::node::{
     join_nodes,
     object::PropertyName,
     statement_list::StatementList,
-    Identifier, Node,
+    ContainsSymbol, Identifier, Node,
 };
 use boa_interner::{Interner, Sym, ToInternedString};
 
@@ -229,6 +229,30 @@ impl Declaration {
             Self::Pattern(pattern) => pattern.init(),
         }
     }
+
+    /// Returns `true` if the node contains the given token.
+    ///
+    /// More information:
+    ///  - [ECMAScript specification][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-static-semantics-contains
+    pub(crate) fn contains(&self, symbol: ContainsSymbol) -> bool {
+        match self {
+            Self::Identifier { init, .. } => {
+                if let Some(node) = init {
+                    if node.contains(symbol) {
+                        return true;
+                    }
+                }
+            }
+            Self::Pattern(pattern) => {
+                if pattern.contains(symbol) {
+                    return true;
+                }
+            }
+        }
+        false
+    }
 }
 
 /// `DeclarationPattern` represents an object or array binding pattern.
@@ -383,6 +407,99 @@ impl DeclarationPattern {
         }
         false
     }
+
+    /// Returns `true` if the node contains the given token.
+    ///
+    /// More information:
+    ///  - [ECMAScript specification][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-static-semantics-contains
+    pub(crate) fn contains(&self, symbol: ContainsSymbol) -> bool {
+        match self {
+            DeclarationPattern::Object(object) => {
+                if let Some(node) = object.init() {
+                    if node.contains(symbol) {
+                        return true;
+                    }
+                }
+                for binding in &object.bindings {
+                    match binding {
+                        BindingPatternTypeObject::SingleName {
+                            default_init: Some(node),
+                            ..
+                        } => {
+                            if node.contains(symbol) {
+                                return true;
+                            }
+                        }
+                        BindingPatternTypeObject::RestGetConstField {
+                            get_const_field, ..
+                        } => {
+                            if get_const_field.obj().contains(symbol) {
+                                return true;
+                            }
+                        }
+                        BindingPatternTypeObject::BindingPattern {
+                            pattern,
+                            default_init,
+                            ..
+                        } => {
+                            if let Some(node) = default_init {
+                                if node.contains(symbol) {
+                                    return true;
+                                }
+                            }
+                            if pattern.contains(symbol) {
+                                return true;
+                            }
+                        }
+                        _ => {}
+                    }
+                }
+            }
+            DeclarationPattern::Array(array) => {
+                if let Some(node) = array.init() {
+                    if node.contains(symbol) {
+                        return true;
+                    }
+                }
+                for binding in array.bindings() {
+                    match binding {
+                        BindingPatternTypeArray::SingleName {
+                            default_init: Some(node),
+                            ..
+                        } => {
+                            if node.contains(symbol) {
+                                return true;
+                            }
+                        }
+                        BindingPatternTypeArray::GetField { get_field }
+                        | BindingPatternTypeArray::GetFieldRest { get_field } => {
+                            if get_field.obj().contains(symbol)
+                                || get_field.field().contains(symbol)
+                            {
+                                return true;
+                            }
+                        }
+                        BindingPatternTypeArray::GetConstField { get_const_field }
+                        | BindingPatternTypeArray::GetConstFieldRest { get_const_field } => {
+                            if get_const_field.obj().contains(symbol) {
+                                return true;
+                            }
+                        }
+                        BindingPatternTypeArray::BindingPattern { pattern }
+                        | BindingPatternTypeArray::BindingPatternRest { pattern } => {
+                            if pattern.contains(symbol) {
+                                return true;
+                            }
+                        }
+                        _ => {}
+                    }
+                }
+            }
+        }
+        false
+    }
 }
 
 /// `DeclarationPatternObject` represents an object binding pattern.

boa_engine/src/syntax/ast/node/field/get_super_field/mod.rs

@@ -0,0 +1,47 @@
+use crate::syntax::ast::node::Node;
+use boa_interner::{Interner, Sym, ToInternedString};
+
+#[cfg(feature = "deser")]
+use serde::{Deserialize, Serialize};
+
+/// The `super` keyword is used to access fields on an object's parent.
+///
+/// More information:
+///  - [ECMAScript reference][spec]
+///  - [MDN documentation][mdn]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-SuperProperty
+/// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/super
+#[cfg_attr(feature = "deser", derive(Serialize, Deserialize))]
+#[derive(Clone, Debug, PartialEq)]
+pub enum GetSuperField {
+    Const(Sym),
+    Expr(Box<Node>),
+}
+
+impl From<Sym> for GetSuperField {
+    fn from(field: Sym) -> Self {
+        Self::Const(field)
+    }
+}
+
+impl From<Node> for GetSuperField {
+    fn from(field: Node) -> Self {
+        Self::Expr(Box::new(field))
+    }
+}
+
+impl ToInternedString for GetSuperField {
+    fn to_interned_string(&self, interner: &Interner) -> String {
+        match self {
+            GetSuperField::Const(field) => format!("super.{}", interner.resolve_expect(*field)),
+            GetSuperField::Expr(field) => format!("super[{}]", field.to_interned_string(interner)),
+        }
+    }
+}
+
+impl From<GetSuperField> for Node {
+    fn from(get_super_field: GetSuperField) -> Self {
+        Self::GetSuperField(get_super_field)
+    }
+}

boa_engine/src/syntax/ast/node/field/mod.rs

@@ -3,8 +3,12 @@
 pub mod get_const_field;
 pub mod get_field;
 pub mod get_private_field;
+pub mod get_super_field;
 
-pub use self::{get_const_field::GetConstField, get_field::GetField};
+pub use self::{
+    get_const_field::GetConstField, get_field::GetField, get_private_field::GetPrivateField,
+    get_super_field::GetSuperField,
+};
 
 #[cfg(test)]
 mod tests;

boa_engine/src/syntax/ast/node/mod.rs

@@ -17,6 +17,7 @@ pub mod operator;
 pub mod return_smt;
 pub mod spread;
 pub mod statement_list;
+pub mod super_call;
 pub mod switch;
 pub mod template;
 pub mod throw;
@@ -35,7 +36,7 @@ pub use self::{
         ArrowFunctionDecl, AsyncFunctionDecl, AsyncFunctionExpr, Declaration, DeclarationList,
         DeclarationPattern, FunctionDecl, FunctionExpr,
     },
-    field::{get_private_field::GetPrivateField, GetConstField, GetField},
+    field::{get_private_field::GetPrivateField, GetConstField, GetField, GetSuperField},
     identifier::Identifier,
     iteration::{Break, Continue, DoWhileLoop, ForInLoop, ForLoop, ForOfLoop, WhileLoop},
     new::New,
@@ -46,6 +47,7 @@ pub use self::{
     return_smt::Return,
     spread::Spread,
     statement_list::StatementList,
+    super_call::SuperCall,
     switch::{Case, Switch},
     template::{TaggedTemplate, TemplateLit},
     throw::Throw,
@@ -55,6 +57,7 @@ use self::{
     declaration::class_decl::ClassElement,
     iteration::IterableLoopInitializer,
     object::{MethodDefinition, PropertyDefinition},
+    operator::assign::AssignTarget,
 };
 
 pub(crate) use self::parameters::FormalParameterListFlags;
@@ -146,6 +149,9 @@ pub enum Node {
     /// Provides access to object fields. [More information](./declaration/struct.GetField.html).
     GetField(GetField),
 
+    /// Provides access to super fields. [More information](./declaration/struct.GetSuperField.html).
+    GetSuperField(GetSuperField),
+
     /// A `for` statement. [More information](./iteration/struct.ForLoop.html).
     ForLoop(ForLoop),
 
@@ -240,6 +246,9 @@ pub enum Node {
 
     /// A class declaration. [More information](./declaration/struct.class_decl.Class.html).
     ClassExpr(Class),
+
+    /// A call of the super constructor. [More information](./super_call/struct.SuperCall.html).
+    SuperCall(SuperCall),
 }
 
 impl From<Const> for Node {
@@ -314,6 +323,9 @@ impl Node {
                 get_private_field.to_interned_string(interner)
             }
             Self::GetField(ref get_field) => get_field.to_interned_string(interner),
+            Self::GetSuperField(ref get_super_field) => {
+                get_super_field.to_interned_string(interner)
+            }
             Self::WhileLoop(ref while_loop) => while_loop.to_indented_string(interner, indentation),
             Self::DoWhileLoop(ref do_while) => do_while.to_indented_string(interner, indentation),
             Self::If(ref if_smt) => if_smt.to_indented_string(interner, indentation),
@@ -345,6 +357,7 @@ impl Node {
             Self::AsyncGeneratorDecl(ref decl) => decl.to_indented_string(interner, indentation),
             Self::ClassDecl(ref decl) => decl.to_indented_string(interner, indentation),
             Self::ClassExpr(ref expr) => expr.to_indented_string(interner, indentation),
+            Self::SuperCall(ref super_call) => super_call.to_interned_string(interner),
         }
     }
 
@@ -880,6 +893,361 @@ impl Node {
         }
         false
     }
+
+    /// Returns `true` if the node contains the given token.
+    ///
+    /// More information:
+    ///  - [ECMAScript specification][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-static-semantics-contains
+    pub(crate) fn contains(&self, symbol: ContainsSymbol) -> bool {
+        match self {
+            Node::ArrayDecl(array) => {
+                for node in array.as_ref() {
+                    if node.contains(symbol) {
+                        return true;
+                    }
+                }
+            }
+            Node::Assign(assign) => {
+                match assign.lhs() {
+                    AssignTarget::GetPrivateField(field) => {
+                        if field.obj().contains(symbol) {
+                            return true;
+                        }
+                    }
+                    AssignTarget::GetConstField(field) => {
+                        if field.obj().contains(symbol) {
+                            return true;
+                        }
+                    }
+                    AssignTarget::GetField(field) => {
+                        if field.obj().contains(symbol) || field.field().contains(symbol) {
+                            return true;
+                        }
+                    }
+                    AssignTarget::DeclarationPattern(pattern) => {
+                        if pattern.contains(symbol) {
+                            return true;
+                        }
+                    }
+                    AssignTarget::Identifier(_) => {}
+                }
+                if assign.rhs().contains(symbol) {
+                    return true;
+                }
+            }
+            Node::AwaitExpr(expr) => {
+                if expr.expr().contains(symbol) {
+                    return true;
+                }
+            }
+            Node::BinOp(bin_op) => {
+                if bin_op.lhs().contains(symbol) || bin_op.rhs().contains(symbol) {
+                    return true;
+                }
+            }
+            Node::Block(block) => {
+                for node in block.items() {
+                    if node.contains(symbol) {
+                        return true;
+                    }
+                }
+            }
+            Node::Call(call) => {
+                if call.expr().contains(symbol) {
+                    return true;
+                }
+                for node in call.args() {
+                    if node.contains(symbol) {
+                        return true;
+                    }
+                }
+            }
+            Node::ConditionalOp(conditional) => {
+                if conditional.cond().contains(symbol)
+                    || conditional.if_true().contains(symbol)
+                    || conditional.if_false().contains(symbol)
+                {
+                    return true;
+                }
+            }
+            Node::ConstDeclList(decl_list)
+            | Node::LetDeclList(decl_list)
+            | Node::VarDeclList(decl_list) => match decl_list {
+                DeclarationList::Const(declarations)
+                | DeclarationList::Let(declarations)
+                | DeclarationList::Var(declarations) => {
+                    for declaration in declarations.iter() {
+                        if declaration.contains(symbol) {
+                            return true;
+                        }
+                    }
+                }
+            },
+            Node::DoWhileLoop(do_while_loop) => {
+                if do_while_loop.cond().contains(symbol) || do_while_loop.body().contains(symbol) {
+                    return true;
+                }
+            }
+            Node::GetConstField(field) => {
+                if field.obj().contains(symbol) {
+                    return true;
+                }
+            }
+            Node::GetPrivateField(field) => {
+                if field.obj().contains(symbol) {
+                    return true;
+                }
+            }
+            Node::GetField(field) => {
+                if field.obj().contains(symbol) || field.field().contains(symbol) {
+                    return true;
+                }
+            }
+            Node::ForLoop(for_loop) => {
+                if let Some(node) = for_loop.init() {
+                    if node.contains(symbol) {
+                        return true;
+                    }
+                }
+                if let Some(node) = for_loop.condition() {
+                    if node.contains(symbol) {
+                        return true;
+                    }
+                }
+                if let Some(node) = for_loop.final_expr() {
+                    if node.contains(symbol) {
+                        return true;
+                    }
+                }
+                if for_loop.body().contains(symbol) {
+                    return true;
+                }
+            }
+            Node::ForInLoop(for_in_loop) => {
+                match for_in_loop.init() {
+                    IterableLoopInitializer::Var(declaration)
+                    | IterableLoopInitializer::Let(declaration)
+                    | IterableLoopInitializer::Const(declaration) => {
+                        if declaration.contains(symbol) {
+                            return true;
+                        }
+                    }
+                    IterableLoopInitializer::DeclarationPattern(pattern) => {
+                        if pattern.contains(symbol) {
+                            return true;
+                        }
+                    }
+                    IterableLoopInitializer::Identifier(_) => {}
+                }
+                if for_in_loop.body().contains(symbol) || for_in_loop.expr().contains(symbol) {
+                    return true;
+                }
+            }
+            Node::ForOfLoop(for_of_loop) => {
+                match for_of_loop.init() {
+                    IterableLoopInitializer::Var(declaration)
+                    | IterableLoopInitializer::Let(declaration)
+                    | IterableLoopInitializer::Const(declaration) => {
+                        if declaration.contains(symbol) {
+                            return true;
+                        }
+                    }
+                    IterableLoopInitializer::DeclarationPattern(pattern) => {
+                        if pattern.contains(symbol) {
+                            return true;
+                        }
+                    }
+                    IterableLoopInitializer::Identifier(_) => {}
+                }
+                if for_of_loop.body().contains(symbol) || for_of_loop.iterable().contains(symbol) {
+                    return true;
+                }
+            }
+            Node::If(if_node) => {
+                if if_node.cond().contains(symbol) || if_node.body().contains(symbol) {
+                    return true;
+                }
+                if let Some(node) = if_node.else_node() {
+                    if node.contains(symbol) {
+                        return true;
+                    }
+                }
+            }
+            Node::New(new) => {
+                if new.call().expr().contains(symbol) {
+                    return true;
+                }
+                for node in new.call().args() {
+                    if node.contains(symbol) {
+                        return true;
+                    }
+                }
+            }
+            Node::Return(expr) => {
+                if let Some(expr) = expr.expr() {
+                    if expr.contains(symbol) {
+                        return true;
+                    }
+                }
+            }
+            Node::Switch(switch) => {
+                if switch.val().contains(symbol) {
+                    return true;
+                }
+                for case in switch.cases() {
+                    if case.condition().contains(symbol) {
+                        return true;
+                    }
+                    for node in case.body().items() {
+                        if node.contains(symbol) {
+                            return true;
+                        }
+                    }
+                }
+                if let Some(default) = switch.default() {
+                    for node in default {
+                        if node.contains(symbol) {
+                            return true;
+                        }
+                    }
+                }
+            }
+            Node::Spread(spread) => {
+                if spread.val().contains(symbol) {
+                    return true;
+                }
+            }
+            Node::TaggedTemplate(template) => {
+                if template.tag().contains(symbol) {
+                    return true;
+                }
+                for node in template.exprs() {
+                    if node.contains(symbol) {
+                        return true;
+                    }
+                }
+            }
+            Node::TemplateLit(template) => {
+                for element in template.elements() {
+                    if let template::TemplateElement::Expr(node) = element {
+                        if node.contains(symbol) {
+                            return true;
+                        }
+                    }
+                }
+            }
+            Node::Throw(expr) => {
+                if expr.expr().contains(symbol) {
+                    return true;
+                }
+            }
+            Node::Try(try_node) => {
+                for node in try_node.block().items() {
+                    if node.contains(symbol) {
+                        return true;
+                    }
+                }
+                if let Some(catch) = try_node.catch() {
+                    if let Some(declaration) = catch.parameter() {
+                        if declaration.contains(symbol) {
+                            return true;
+                        }
+                    }
+                    for node in catch.block().items() {
+                        if node.contains(symbol) {
+                            return true;
+                        }
+                    }
+                }
+            }
+            Node::UnaryOp(unary) => {
+                if unary.target().contains(symbol) {
+                    return true;
+                }
+            }
+            Node::WhileLoop(while_loop) => {
+                if while_loop.cond().contains(symbol) || while_loop.body().contains(symbol) {
+                    return true;
+                }
+            }
+            Node::SuperCall(_) if symbol == ContainsSymbol::SuperCall => return true,
+            Node::GetSuperField(_) if symbol == ContainsSymbol::SuperProperty => return true,
+            Node::ArrowFunctionDecl(arrow) => {
+                for parameter in arrow.params().parameters.iter() {
+                    if parameter.declaration().contains(symbol) {
+                        return true;
+                    }
+                }
+                for node in arrow.body().items() {
+                    if node.contains(symbol) {
+                        return true;
+                    }
+                }
+            }
+            Node::Object(object) => {
+                for property in object.properties() {
+                    match property {
+                        PropertyDefinition::IdentifierReference(_) => {}
+                        PropertyDefinition::Property(name, init) => {
+                            if let Some(node) = name.computed() {
+                                if node.contains(symbol) {
+                                    return true;
+                                }
+                            }
+                            if init.contains(symbol) {
+                                return true;
+                            }
+                        }
+                        PropertyDefinition::SpreadObject(spread) => {
+                            if spread.contains(symbol) {
+                                return true;
+                            }
+                        }
+                        PropertyDefinition::MethodDefinition(_, name) => {
+                            if let Some(node) = name.computed() {
+                                if node.contains(symbol) {
+                                    return true;
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+            Node::ClassDecl(class) | Node::ClassExpr(class) => {
+                if let Some(node) = class.super_ref() {
+                    if node.contains(symbol) {
+                        return true;
+                    }
+                }
+                for element in class.elements() {
+                    match element {
+                        ClassElement::MethodDefinition(name, _)
+                        | ClassElement::StaticMethodDefinition(name, _)
+                        | ClassElement::FieldDefinition(name, _)
+                        | ClassElement::StaticFieldDefinition(name, _) => {
+                            if let Some(node) = name.computed() {
+                                if node.contains(symbol) {
+                                    return true;
+                                }
+                            }
+                        }
+                        _ => {}
+                    }
+                }
+            }
+            _ => {}
+        }
+        false
+    }
+}
+
+/// Represents the possible symbols that can be use the the `Node.contains` function.
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub(crate) enum ContainsSymbol {
+    SuperProperty,
+    SuperCall,
 }
 
 impl ToInternedString for Node {
@@ -946,3 +1314,44 @@ fn test_formatting(source: &'static str) {
         panic!("parsing test did not give the correct result (see above)");
     }
 }
+
+/// Helper function to check if a function contains a super call or super property access.
+pub(crate) fn function_contains_super(
+    body: &StatementList,
+    parameters: &FormalParameterList,
+) -> bool {
+    for param in parameters.parameters.iter() {
+        if param.declaration().contains(ContainsSymbol::SuperCall)
+            || param.declaration().contains(ContainsSymbol::SuperProperty)
+        {
+            return true;
+        }
+    }
+    for node in body.items() {
+        if node.contains(ContainsSymbol::SuperCall) || node.contains(ContainsSymbol::SuperProperty)
+        {
+            return true;
+        }
+    }
+    false
+}
+
+/// Returns `true` if the function parameters or body contain a direct `super` call.
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#sec-static-semantics-hasdirectsuper
+pub(crate) fn has_direct_super(body: &StatementList, parameters: &FormalParameterList) -> bool {
+    for param in parameters.parameters.iter() {
+        if param.declaration().contains(ContainsSymbol::SuperCall) {
+            return true;
+        }
+    }
+    for node in body.items() {
+        if node.contains(ContainsSymbol::SuperCall) {
+            return true;
+        }
+    }
+    false
+}

boa_engine/src/syntax/ast/node/object/mod.rs

@@ -3,7 +3,7 @@
 use crate::syntax::ast::{
     node::{
         declaration::block_to_string, join_nodes, AsyncFunctionExpr, AsyncGeneratorExpr,
-        FunctionExpr, GeneratorExpr, Node,
+        FormalParameterList, FunctionExpr, GeneratorExpr, Node, StatementList,
     },
     Const,
 };
@@ -321,6 +321,32 @@ pub enum MethodDefinition {
     Async(AsyncFunctionExpr),
 }
 
+impl MethodDefinition {
+    /// Return the body of the method.
+    pub(crate) fn body(&self) -> &StatementList {
+        match self {
+            MethodDefinition::Get(expr)
+            | MethodDefinition::Set(expr)
+            | MethodDefinition::Ordinary(expr) => expr.body(),
+            MethodDefinition::Generator(expr) => expr.body(),
+            MethodDefinition::AsyncGenerator(expr) => expr.body(),
+            MethodDefinition::Async(expr) => expr.body(),
+        }
+    }
+
+    /// Return the parameters of the method.
+    pub(crate) fn parameters(&self) -> &FormalParameterList {
+        match self {
+            MethodDefinition::Get(expr)
+            | MethodDefinition::Set(expr)
+            | MethodDefinition::Ordinary(expr) => expr.parameters(),
+            MethodDefinition::Generator(expr) => expr.parameters(),
+            MethodDefinition::AsyncGenerator(expr) => expr.parameters(),
+            MethodDefinition::Async(expr) => expr.parameters(),
+        }
+    }
+}
+
 /// `PropertyName` can be either a literal or computed.
 ///
 /// More information:
@@ -348,6 +374,7 @@ pub enum PropertyName {
 }
 
 impl PropertyName {
+    /// Returns the literal property name if it exists.
     pub(in crate::syntax) fn literal(&self) -> Option<Sym> {
         if let Self::Literal(sym) = self {
             Some(*sym)
@@ -356,6 +383,16 @@ impl PropertyName {
         }
     }
 
+    /// Returns the expression node if the property name is computed.
+    pub(in crate::syntax) fn computed(&self) -> Option<&Node> {
+        if let Self::Computed(node) = self {
+            Some(node)
+        } else {
+            None
+        }
+    }
+
+    /// Returns either the literal property name or the computed const string property name.
     pub(in crate::syntax) fn prop_name(&self) -> Option<Sym> {
         match self {
             PropertyName::Literal(sym)

boa_engine/src/syntax/ast/node/super_call/mod.rs

@@ -0,0 +1,46 @@
+use crate::syntax::ast::node::{join_nodes, Node};
+use boa_interner::{Interner, ToInternedString};
+
+#[cfg(feature = "deser")]
+use serde::{Deserialize, Serialize};
+
+/// The `super` keyword is used to access and call functions on an object's parent.
+///
+/// More information:
+///  - [ECMAScript reference][spec]
+///  - [MDN documentation][mdn]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-SuperCall
+/// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/super
+#[cfg_attr(feature = "deser", derive(Serialize, Deserialize))]
+#[derive(Clone, Debug, PartialEq)]
+pub struct SuperCall {
+    args: Box<[Node]>,
+}
+
+impl SuperCall {
+    /// Creates a new `SuperCall` AST node.
+    pub(crate) fn new<A>(args: A) -> Self
+    where
+        A: Into<Box<[Node]>>,
+    {
+        Self { args: args.into() }
+    }
+
+    /// Retrieves the arguments of the super call.
+    pub(crate) fn args(&self) -> &[Node] {
+        &self.args
+    }
+}
+
+impl ToInternedString for SuperCall {
+    fn to_interned_string(&self, interner: &Interner) -> String {
+        format!("super({})", join_nodes(interner, &self.args))
+    }
+}
+
+impl From<SuperCall> for Node {
+    fn from(call: SuperCall) -> Self {
+        Self::SuperCall(call)
+    }
+}

boa_engine/src/syntax/parser/expression/left_hand_side/member.rs

@@ -10,7 +10,7 @@ use crate::syntax::{
     ast::{
         node::{
             field::{get_private_field::GetPrivateField, GetConstField, GetField},
-            Call, New, Node,
+            Call, GetSuperField, New, Node,
         },
         Keyword, Punctuator,
     },
@@ -66,7 +66,7 @@ where
 
         let token = cursor.peek(0, interner)?.ok_or(ParseError::AbruptEnd)?;
         let mut lhs = match token.kind() {
-            TokenKind::Keyword((Keyword::New, true)) => {
+            TokenKind::Keyword((Keyword::New | Keyword::Super, true)) => {
                 return Err(ParseError::general(
                     "keyword must not contain escaped characters",
                     token.span().start(),
@@ -86,6 +86,55 @@ where
 
                 Node::from(New::from(call_node))
             }
+            TokenKind::Keyword((Keyword::Super, _)) => {
+                cursor.next(interner).expect("token disappeared");
+                let token = cursor.next(interner)?.ok_or(ParseError::AbruptEnd)?;
+                match token.kind() {
+                    TokenKind::Punctuator(Punctuator::Dot) => {
+                        let token = cursor.next(interner)?.ok_or(ParseError::AbruptEnd)?;
+                        let field = match token.kind() {
+                            TokenKind::Identifier(name) => GetSuperField::from(*name),
+                            TokenKind::Keyword((kw, _)) => GetSuperField::from(kw.to_sym(interner)),
+                            TokenKind::BooleanLiteral(true) => {
+                                GetSuperField::from(Keyword::True.to_sym(interner))
+                            }
+                            TokenKind::BooleanLiteral(false) => {
+                                GetSuperField::from(Keyword::False.to_sym(interner))
+                            }
+                            TokenKind::NullLiteral => {
+                                GetSuperField::from(Keyword::Null.to_sym(interner))
+                            }
+                            TokenKind::PrivateIdentifier(_) => {
+                                return Err(ParseError::general(
+                                    "unexpected private identifier",
+                                    token.span().start(),
+                                ));
+                            }
+                            _ => {
+                                return Err(ParseError::unexpected(
+                                    token.to_string(interner),
+                                    token.span(),
+                                    "expected super property",
+                                ))
+                            }
+                        };
+                        field.into()
+                    }
+                    TokenKind::Punctuator(Punctuator::OpenBracket) => {
+                        let expr = Expression::new(None, true, self.allow_yield, self.allow_await)
+                            .parse(cursor, interner)?;
+                        cursor.expect(Punctuator::CloseBracket, "super property", interner)?;
+                        GetSuperField::from(expr).into()
+                    }
+                    _ => {
+                        return Err(ParseError::unexpected(
+                            token.to_string(interner),
+                            token.span(),
+                            "expected super property",
+                        ))
+                    }
+                }
+            }
             _ => PrimaryExpression::new(self.name, self.allow_yield, self.allow_await)
                 .parse(cursor, interner)?,
         };

boa_engine/src/syntax/parser/expression/left_hand_side/mod.rs

@@ -12,11 +12,15 @@ mod call;
 mod member;
 mod template;
 
-use self::{call::CallExpression, member::MemberExpression};
 use crate::syntax::{
-    ast::{Node, Punctuator},
+    ast::{node::SuperCall, Keyword, Node, Punctuator},
     lexer::{InputElement, TokenKind},
-    parser::{AllowAwait, AllowYield, Cursor, ParseResult, TokenParser},
+    parser::{
+        expression::left_hand_side::{
+            arguments::Arguments, call::CallExpression, member::MemberExpression,
+        },
+        AllowAwait, AllowYield, Cursor, ParseResult, TokenParser,
+    },
 };
 use boa_interner::{Interner, Sym};
 use boa_profiler::Profiler;
@@ -64,6 +68,19 @@ where
 
         cursor.set_goal(InputElement::TemplateTail);
 
+        if let Some(next) = cursor.peek(0, interner)? {
+            if let TokenKind::Keyword((Keyword::Super, _)) = next.kind() {
+                if let Some(next) = cursor.peek(1, interner)? {
+                    if next.kind() == &TokenKind::Punctuator(Punctuator::OpenParen) {
+                        cursor.next(interner).expect("token disappeared");
+                        let args = Arguments::new(self.allow_yield, self.allow_await)
+                            .parse(cursor, interner)?;
+                        return Ok(SuperCall::new(args).into());
+                    }
+                }
+            }
+        }
+
         // TODO: Implement NewExpression: new MemberExpression
         let lhs = MemberExpression::new(self.name, self.allow_yield, self.allow_await)
             .parse(cursor, interner)?;

boa_engine/src/syntax/parser/expression/primary/async_function_expression/mod.rs

@@ -2,7 +2,10 @@
 mod tests;
 
 use crate::syntax::{
-    ast::{node::AsyncFunctionExpr, Keyword, Position, Punctuator},
+    ast::{
+        node::{function_contains_super, AsyncFunctionExpr},
+        Keyword, Position, Punctuator,
+    },
     lexer::{Error as LexError, TokenKind},
     parser::{
         expression::BindingIdentifier,
@@ -132,6 +135,13 @@ where
             params_start_position,
         )?;
 
+        if function_contains_super(&body, &params) {
+            return Err(ParseError::lex(LexError::Syntax(
+                "invalid super usage".into(),
+                params_start_position,
+            )));
+        }
+
         Ok(AsyncFunctionExpr::new(name, params, body))
     }
 }

boa_engine/src/syntax/parser/expression/primary/async_generator_expression/mod.rs

@@ -11,7 +11,10 @@
 mod tests;
 
 use crate::syntax::{
-    ast::{node::AsyncGeneratorExpr, Keyword, Position, Punctuator},
+    ast::{
+        node::{function_contains_super, AsyncGeneratorExpr},
+        Keyword, Position, Punctuator,
+    },
     lexer::{Error as LexError, TokenKind},
     parser::{
         expression::BindingIdentifier,
@@ -148,6 +151,13 @@ where
             params_start_position,
         )?;
 
+        if function_contains_super(&body, &params) {
+            return Err(ParseError::lex(LexError::Syntax(
+                "invalid super usage".into(),
+                params_start_position,
+            )));
+        }
+
         //implement the below AsyncGeneratorExpr in ast::node
         Ok(AsyncGeneratorExpr::new(name, params, body))
     }

boa_engine/src/syntax/parser/expression/primary/function_expression/mod.rs

@@ -11,7 +11,10 @@
 mod tests;
 
 use crate::syntax::{
-    ast::{node::FunctionExpr, Keyword, Position, Punctuator},
+    ast::{
+        node::{function_contains_super, FunctionExpr},
+        Keyword, Position, Punctuator,
+    },
     lexer::{Error as LexError, TokenKind},
     parser::{
         expression::BindingIdentifier,
@@ -124,6 +127,13 @@ where
             params_start_position,
         )?;
 
+        if function_contains_super(&body, &params) {
+            return Err(ParseError::lex(LexError::Syntax(
+                "invalid super usage".into(),
+                params_start_position,
+            )));
+        }
+
         Ok(FunctionExpr::new(name, params, body))
     }
 }

boa_engine/src/syntax/parser/expression/primary/generator_expression/mod.rs

@@ -11,7 +11,10 @@
 mod tests;
 
 use crate::syntax::{
-    ast::{node::GeneratorExpr, Position, Punctuator},
+    ast::{
+        node::{function_contains_super, GeneratorExpr},
+        Position, Punctuator,
+    },
     lexer::{Error as LexError, TokenKind},
     parser::{
         expression::BindingIdentifier,
@@ -128,6 +131,13 @@ where
             params_start_position,
         )?;
 
+        if function_contains_super(&body, &params) {
+            return Err(ParseError::lex(LexError::Syntax(
+                "invalid super usage".into(),
+                params_start_position,
+            )));
+        }
+
         Ok(GeneratorExpr::new(name, params, body))
     }
 }

boa_engine/src/syntax/parser/expression/primary/object_initializer/mod.rs

@@ -13,6 +13,7 @@ mod tests;
 use crate::syntax::{
     ast::{
         node::{
+            function_contains_super, has_direct_super,
             object::{self, MethodDefinition},
             AsyncFunctionExpr, AsyncGeneratorExpr, FormalParameterList, FunctionExpr,
             GeneratorExpr, Node, Object,
@@ -173,10 +174,18 @@ where
                 cursor.peek_expect_no_lineterminator(0, "Async object methods", interner)?;
 
                 let token = cursor.peek(0, interner)?.ok_or(ParseError::AbruptEnd)?;
+                let position = token.span().start();
+
                 if let TokenKind::Punctuator(Punctuator::Mul) = token.kind() {
                     let (property_name, method) =
                         AsyncGeneratorMethod::new(self.allow_yield, self.allow_await)
                             .parse(cursor, interner)?;
+
+                    // It is a Syntax Error if HasDirectSuper of MethodDefinition is true.
+                    if has_direct_super(method.body(), method.parameters()) {
+                        return Err(ParseError::general("invalid super usage", position));
+                    }
+
                     return Ok(object::PropertyDefinition::method_definition(
                         method,
                         property_name,
@@ -184,6 +193,12 @@ where
                 }
                 let (property_name, method) =
                     AsyncMethod::new(self.allow_yield, self.allow_await).parse(cursor, interner)?;
+
+                // It is a Syntax Error if HasDirectSuper of MethodDefinition is true.
+                if has_direct_super(method.body(), method.parameters()) {
+                    return Err(ParseError::general("invalid super usage", position));
+                }
+
                 return Ok(object::PropertyDefinition::method_definition(
                     method,
                     property_name,
@@ -206,6 +221,11 @@ where
             let (class_element_name, method) =
                 GeneratorMethod::new(self.allow_yield, self.allow_await).parse(cursor, interner)?;
 
+            // It is a Syntax Error if HasDirectSuper of MethodDefinition is true.
+            if has_direct_super(method.body(), method.parameters()) {
+                return Err(ParseError::general("invalid super usage", position));
+            }
+
             match class_element_name {
                 object::ClassElementName::PropertyName(property_name) => {
                     return Ok(object::PropertyDefinition::method_definition(
@@ -241,6 +261,12 @@ where
         match property_name {
             // MethodDefinition[?Yield, ?Await] -> get ClassElementName[?Yield, ?Await] ( ) { FunctionBody[~Yield, ~Await] }
             object::PropertyName::Literal(str) if str == Sym::GET && !ordinary_method => {
+                let position = cursor
+                    .peek(0, interner)?
+                    .ok_or(ParseError::AbruptEnd)?
+                    .span()
+                    .start();
+
                 property_name = PropertyName::new(self.allow_yield, self.allow_await)
                     .parse(cursor, interner)?;
 
@@ -267,6 +293,11 @@ where
                     interner,
                 )?;
 
+                // It is a Syntax Error if HasDirectSuper of MethodDefinition is true.
+                if has_direct_super(&body, &FormalParameterList::default()) {
+                    return Err(ParseError::general("invalid super usage", position));
+                }
+
                 Ok(object::PropertyDefinition::method_definition(
                     MethodDefinition::Get(FunctionExpr::new(
                         None,
@@ -320,6 +351,14 @@ where
                     )));
                 }
 
+                // It is a Syntax Error if HasDirectSuper of MethodDefinition is true.
+                if has_direct_super(&body, &parameters) {
+                    return Err(ParseError::general(
+                        "invalid super usage",
+                        params_start_position,
+                    ));
+                }
+
                 Ok(object::PropertyDefinition::method_definition(
                     MethodDefinition::Set(FunctionExpr::new(None, parameters, body)),
                     property_name,
@@ -391,6 +430,14 @@ where
                     }
                 }
 
+                // It is a Syntax Error if HasDirectSuper of MethodDefinition is true.
+                if has_direct_super(&body, &params) {
+                    return Err(ParseError::general(
+                        "invalid super usage",
+                        params_start_position,
+                    ));
+                }
+
                 Ok(object::PropertyDefinition::method_definition(
                     MethodDefinition::Ordinary(FunctionExpr::new(None, params, body)),
                     property_name,
@@ -655,6 +702,13 @@ where
             body_start,
         )?;
 
+        if function_contains_super(&body, &params) {
+            return Err(ParseError::lex(LexError::Syntax(
+                "invalid super usage".into(),
+                body_start,
+            )));
+        }
+
         Ok((
             class_element_name,
             MethodDefinition::Generator(GeneratorExpr::new(None, params, body)),
@@ -742,6 +796,13 @@ where
             body_start,
         )?;
 
+        if function_contains_super(&body, &params) {
+            return Err(ParseError::lex(LexError::Syntax(
+                "invalid super usage".into(),
+                body_start,
+            )));
+        }
+
         Ok((
             property_name,
             MethodDefinition::AsyncGenerator(AsyncGeneratorExpr::new(None, params, body)),
@@ -824,6 +885,13 @@ where
             body_start,
         )?;
 
+        if function_contains_super(&body, &params) {
+            return Err(ParseError::lex(LexError::Syntax(
+                "invalid super usage".into(),
+                body_start,
+            )));
+        }
+
         Ok((
             property_name,
             MethodDefinition::Async(AsyncFunctionExpr::new(None, params, body)),

boa_engine/src/syntax/parser/mod.rs

@@ -14,7 +14,7 @@ mod tests;
 use crate::{
     syntax::{
         ast::{
-            node::{FormalParameterList, StatementList},
+            node::{ContainsSymbol, FormalParameterList, StatementList},
             Position,
         },
         lexer::TokenKind,
@@ -135,65 +135,65 @@ impl<R> Parser<R> {
     where
         R: Read,
     {
-        let statement_list = Script.parse(&mut self.cursor, context.interner_mut())?;
+        Script::new(false).parse(&mut self.cursor, context)
-
-        // It is a Syntax Error if the LexicallyDeclaredNames of ScriptBody contains any duplicate entries.
-        // It is a Syntax Error if any element of the LexicallyDeclaredNames of ScriptBody also occurs in the VarDeclaredNames of ScriptBody.
-        let mut var_declared_names = FxHashSet::default();
-        statement_list.var_declared_names_new(&mut var_declared_names);
-        let lexically_declared_names = statement_list.lexically_declared_names();
-        let mut lexically_declared_names_map: FxHashMap<Sym, bool> = FxHashMap::default();
-        for (name, is_function_declaration) in &lexically_declared_names {
-            if let Some(existing_is_function_declaration) = lexically_declared_names_map.get(name) {
-                if !(*is_function_declaration && *existing_is_function_declaration) {
-                    return Err(ParseError::general(
-                        "lexical name declared multiple times",
-                        Position::new(1, 1),
-                    ));
     }
+
+    pub(crate) fn parse_eval(
+        &mut self,
+        direct: bool,
+        context: &mut Context,
+    ) -> Result<StatementList, ParseError>
+    where
+        R: Read,
+    {
+        let (in_method, in_derived_constructor) = if let Some(function_env) = context
+            .realm
+            .environments
+            .get_this_environment()
+            .as_function_slots()
+        {
+            let function_env_borrow = function_env.borrow();
+            let has_super_binding = function_env_borrow.has_super_binding();
+            let function_object = function_env_borrow.function_object().borrow();
+            (
+                has_super_binding,
+                function_object
+                    .as_function()
+                    .expect("must be function object")
+                    .is_derived_constructor(),
+            )
+        } else {
+            (false, false)
+        };
+
+        let statement_list = Script::new(direct).parse(&mut self.cursor, context)?;
+
+        let mut contains_super_property = false;
+        let mut contains_super_call = false;
+        if direct {
+            for node in statement_list.items() {
+                if !contains_super_property && node.contains(ContainsSymbol::SuperProperty) {
+                    contains_super_property = true;
                 }
-            lexically_declared_names_map.insert(*name, *is_function_declaration);
 
-            if !is_function_declaration && var_declared_names.contains(name) {
+                if !contains_super_call && node.contains(ContainsSymbol::SuperCall) {
-                return Err(ParseError::general(
+                    contains_super_call = true;
-                    "lexical name declared in var names",
-                    Position::new(1, 1),
-                ));
                 }
-            if context.has_binding(*name) {
-                return Err(ParseError::general(
-                    "lexical name declared multiple times",
-                    Position::new(1, 1),
-                ));
             }
-            if !is_function_declaration {
+        }
-                let name_str = context.interner().resolve_expect(*name);
+
-                let desc = context
+        if !in_method && contains_super_property {
-                    .realm
-                    .global_property_map
-                    .string_property_map()
-                    .get(name_str);
-                let non_configurable_binding_exists = match desc {
-                    Some(desc) => !matches!(desc.configurable(), Some(true)),
-                    None => false,
-                };
-                if non_configurable_binding_exists {
             return Err(ParseError::general(
-                        "lexical name declared in var names",
+                "invalid super usage",
                 Position::new(1, 1),
             ));
         }
-            }
+        if !in_derived_constructor && contains_super_call {
-        }
-        for name in var_declared_names {
-            if context.has_binding(name) {
             return Err(ParseError::general(
-                    "lexical name declared in var names",
+                "invalid super usage",
                 Position::new(1, 1),
             ));
         }
-        }
-
         Ok(statement_list)
     }
 
@@ -235,34 +235,97 @@ impl<R> Parser<R> {
 ///
 /// [spec]: https://tc39.es/ecma262/#prod-Script
 #[derive(Debug, Clone, Copy)]
-pub struct Script;
+pub struct Script {
+    direct_eval: bool,
+}
 
-impl<R> TokenParser<R> for Script
+impl Script {
-where
+    /// Create a new `Script` parser.
-    R: Read,
+    fn new(direct_eval: bool) -> Self {
-{
+        Self { direct_eval }
-    type Output = StatementList;
+    }
 
-    fn parse(
+    fn parse<R: Read>(
         self,
         cursor: &mut Cursor<R>,
-        interner: &mut Interner,
+        context: &mut Context,
-    ) -> Result<Self::Output, ParseError> {
+    ) -> Result<StatementList, ParseError> {
         let mut strict = cursor.strict_mode();
-        match cursor.peek(0, interner)? {
+        match cursor.peek(0, context.interner_mut())? {
             Some(tok) => {
                 match tok.kind() {
                     // Set the strict mode
                     TokenKind::StringLiteral(string)
-                        if interner.resolve_expect(*string) == "use strict" =>
+                        if context.interner_mut().resolve_expect(*string) == "use strict" =>
                     {
                         cursor.set_strict_mode(true);
                         strict = true;
                     }
                     _ => {}
                 }
-                let mut statement_list = ScriptBody.parse(cursor, interner)?;
+                let mut statement_list =
+                    ScriptBody::new(self.direct_eval).parse(cursor, context.interner_mut())?;
                 statement_list.set_strict(strict);
+
+                // It is a Syntax Error if the LexicallyDeclaredNames of ScriptBody contains any duplicate entries.
+                // It is a Syntax Error if any element of the LexicallyDeclaredNames of ScriptBody also occurs in the VarDeclaredNames of ScriptBody.
+                let mut var_declared_names = FxHashSet::default();
+                statement_list.var_declared_names_new(&mut var_declared_names);
+                let lexically_declared_names = statement_list.lexically_declared_names();
+                let mut lexically_declared_names_map: FxHashMap<Sym, bool> = FxHashMap::default();
+                for (name, is_function_declaration) in &lexically_declared_names {
+                    if let Some(existing_is_function_declaration) =
+                        lexically_declared_names_map.get(name)
+                    {
+                        if !(*is_function_declaration && *existing_is_function_declaration) {
+                            return Err(ParseError::general(
+                                "lexical name declared multiple times",
+                                Position::new(1, 1),
+                            ));
+                        }
+                    }
+                    lexically_declared_names_map.insert(*name, *is_function_declaration);
+
+                    if !is_function_declaration && var_declared_names.contains(name) {
+                        return Err(ParseError::general(
+                            "lexical name declared in var names",
+                            Position::new(1, 1),
+                        ));
+                    }
+                    if context.has_binding(*name) {
+                        return Err(ParseError::general(
+                            "lexical name declared multiple times",
+                            Position::new(1, 1),
+                        ));
+                    }
+                    if !is_function_declaration {
+                        let name_str = context.interner().resolve_expect(*name);
+                        let desc = context
+                            .realm
+                            .global_property_map
+                            .string_property_map()
+                            .get(name_str);
+                        let non_configurable_binding_exists = match desc {
+                            Some(desc) => !matches!(desc.configurable(), Some(true)),
+                            None => false,
+                        };
+                        if non_configurable_binding_exists {
+                            return Err(ParseError::general(
+                                "lexical name declared in var names",
+                                Position::new(1, 1),
+                            ));
+                        }
+                    }
+                }
+                for name in var_declared_names {
+                    if context.has_binding(name) {
+                        return Err(ParseError::general(
+                            "lexical name declared in var names",
+                            Position::new(1, 1),
+                        ));
+                    }
+                }
+
                 Ok(statement_list)
             }
             None => Ok(StatementList::from(Vec::new())),
@@ -277,7 +340,16 @@ where
 ///
 /// [spec]: https://tc39.es/ecma262/#prod-ScriptBody
 #[derive(Debug, Clone, Copy)]
-pub struct ScriptBody;
+pub struct ScriptBody {
+    direct_eval: bool,
+}
+
+impl ScriptBody {
+    /// Create a new `ScriptBody` parser.
+    fn new(direct_eval: bool) -> Self {
+        Self { direct_eval }
+    }
+}
 
 impl<R> TokenParser<R> for ScriptBody
 where
@@ -290,6 +362,24 @@ where
         cursor: &mut Cursor<R>,
         interner: &mut Interner,
     ) -> Result<Self::Output, ParseError> {
-        self::statement::StatementList::new(false, false, false, &[]).parse(cursor, interner)
+        let body = self::statement::StatementList::new(false, false, false, &[])
+            .parse(cursor, interner)?;
+
+        // It is a Syntax Error if StatementList Contains super unless the source text containing super is eval code that is being processed by a direct eval.
+        // Additional early error rules for super within direct eval are defined in 19.2.1.1.
+        if !self.direct_eval {
+            for node in body.items() {
+                if node.contains(ContainsSymbol::SuperCall)
+                    || node.contains(ContainsSymbol::SuperProperty)
+                {
+                    return Err(ParseError::general(
+                        "invalid super usage",
+                        Position::new(1, 1),
+                    ));
+                }
+            }
+        }
+
+        Ok(body)
     }
 }

boa_engine/src/syntax/parser/statement/declaration/hoistable/class_decl/mod.rs

@@ -3,8 +3,9 @@ use crate::syntax::{
         node::{
             self,
             declaration::class_decl::ClassElement as ClassElementNode,
+            function_contains_super, has_direct_super,
             object::{MethodDefinition, PropertyName::Literal},
-            Class, FormalParameterList, FunctionExpr,
+            Class, ContainsSymbol, FormalParameterList, FunctionExpr,
         },
         Keyword, Punctuator,
     },
@@ -165,10 +166,27 @@ where
             cursor.next(interner).expect("token disappeared");
             Ok(Class::new(self.name, super_ref, None, vec![]))
         } else {
+            let body_start = cursor
+                .peek(0, interner)?
+                .ok_or(ParseError::AbruptEnd)?
+                .span()
+                .start();
             let (constructor, elements) =
                 ClassBody::new(self.name, self.allow_yield, self.allow_await)
                     .parse(cursor, interner)?;
             cursor.expect(Punctuator::CloseBlock, "class tail", interner)?;
+
+            if super_ref.is_none() {
+                if let Some(constructor) = &constructor {
+                    if function_contains_super(constructor.body(), constructor.parameters()) {
+                        return Err(ParseError::lex(LexError::Syntax(
+                            "invalid super usage".into(),
+                            body_start,
+                        )));
+                    }
+                }
+            }
+
             Ok(Class::new(self.name, super_ref, constructor, elements))
         }
     }
@@ -295,8 +313,15 @@ where
                     }
                     (None, Some(element)) => {
                         match &element {
-                            ClassElementNode::PrivateMethodDefinition(name, method) => match method
+                            ClassElementNode::PrivateMethodDefinition(name, method) => {
-                            {
+                                // It is a Syntax Error if PropName of MethodDefinition is not "constructor" and HasDirectSuper of MethodDefinition is true.
+                                if has_direct_super(method.body(), method.parameters()) {
+                                    return Err(ParseError::lex(LexError::Syntax(
+                                        "invalid super usage".into(),
+                                        position,
+                                    )));
+                                }
+                                match method {
                                     MethodDefinition::Get(_) => {
                                         match private_elements_names.get(name) {
                                             Some(PrivateElement::Setter) => {
@@ -344,8 +369,16 @@ where
                                             ));
                                         }
                                     }
-                            },
+                                }
+                            }
                             ClassElementNode::PrivateStaticMethodDefinition(name, method) => {
+                                // It is a Syntax Error if HasDirectSuper of MethodDefinition is true.
+                                if has_direct_super(method.body(), method.parameters()) {
+                                    return Err(ParseError::lex(LexError::Syntax(
+                                        "invalid super usage".into(),
+                                        position,
+                                    )));
+                                }
                                 match method {
                                     MethodDefinition::Get(_) => {
                                         match private_elements_names.get(name) {
@@ -396,7 +429,15 @@ where
                                     }
                                 }
                             }
-                            ClassElementNode::PrivateFieldDefinition(name, _) => {
+                            ClassElementNode::PrivateFieldDefinition(name, init) => {
+                                if let Some(node) = init {
+                                    if node.contains(node::ContainsSymbol::SuperCall) {
+                                        return Err(ParseError::lex(LexError::Syntax(
+                                            "invalid super usage".into(),
+                                            position,
+                                        )));
+                                    }
+                                }
                                 if private_elements_names
                                     .insert(*name, PrivateElement::Value)
                                     .is_some()
@@ -407,7 +448,15 @@ where
                                     ));
                                 }
                             }
-                            ClassElementNode::PrivateStaticFieldDefinition(name, _) => {
+                            ClassElementNode::PrivateStaticFieldDefinition(name, init) => {
+                                if let Some(node) = init {
+                                    if node.contains(node::ContainsSymbol::SuperCall) {
+                                        return Err(ParseError::lex(LexError::Syntax(
+                                            "invalid super usage".into(),
+                                            position,
+                                        )));
+                                    }
+                                }
                                 if private_elements_names
                                     .insert(*name, PrivateElement::StaticValue)
                                     .is_some()
@@ -418,6 +467,28 @@ where
                                     ));
                                 }
                             }
+                            ClassElementNode::MethodDefinition(_, method)
+                            | ClassElementNode::StaticMethodDefinition(_, method) => {
+                                // ClassElement : MethodDefinition:
+                                //  It is a Syntax Error if PropName of MethodDefinition is not "constructor" and HasDirectSuper of MethodDefinition is true.
+                                // ClassElement : static MethodDefinition:
+                                //  It is a Syntax Error if HasDirectSuper of MethodDefinition is true.
+                                if has_direct_super(method.body(), method.parameters()) {
+                                    return Err(ParseError::lex(LexError::Syntax(
+                                        "invalid super usage".into(),
+                                        position,
+                                    )));
+                                }
+                            }
+                            ClassElementNode::FieldDefinition(_, Some(node))
+                            | ClassElementNode::StaticFieldDefinition(_, Some(node)) => {
+                                if node.contains(node::ContainsSymbol::SuperCall) {
+                                    return Err(ParseError::lex(LexError::Syntax(
+                                        "invalid super usage".into(),
+                                        position,
+                                    )));
+                                }
+                            }
                             _ => {}
                         }
                         elements.push(element);
@@ -1276,6 +1347,7 @@ where
             }
             // ClassStaticBlockBody : ClassStaticBlockStatementList
             // It is a Syntax Error if ContainsArguments of ClassStaticBlockStatementList is true.
+            // It is a Syntax Error if ClassStaticBlockStatementList Contains SuperCall is true.
             ClassElementNode::StaticBlock(block) => {
                 for node in block.items() {
                     if node.contains_arguments() {
@@ -1284,6 +1356,9 @@ where
                             position,
                         ));
                     }
+                    if node.contains(ContainsSymbol::SuperCall) {
+                        return Err(ParseError::general("invalid super usage", position));
+                    }
                 }
             }
             _ => {}

boa_engine/src/syntax/parser/statement/declaration/hoistable/mod.rs

@@ -21,7 +21,7 @@ use self::{
 };
 use crate::syntax::{
     ast::node::{FormalParameterList, StatementList},
-    ast::{Keyword, Node, Position, Punctuator},
+    ast::{node::function_contains_super, Keyword, Node, Position, Punctuator},
     lexer::TokenKind,
     parser::{
         expression::BindingIdentifier,
@@ -213,5 +213,12 @@ fn parse_callable_declaration<R: Read, C: CallableDeclaration>(
         params_start_position,
     )?;
 
+    if function_contains_super(&body, &params) {
+        return Err(ParseError::lex(LexError::Syntax(
+            "invalid super usage".into(),
+            params_start_position,
+        )));
+    }
+
     Ok((name, params, body))
 }

boa_engine/src/vm/call_frame.rs

@@ -2,8 +2,7 @@
 //!
 //! This module will provides everything needed to implement the `CallFrame`
 
-use super::CodeBlock;
+use crate::vm::CodeBlock;
-use crate::JsValue;
 use boa_gc::{Finalize, Gc, Trace};
 
 #[derive(Clone, Debug, Finalize, Trace)]
@@ -11,7 +10,6 @@ pub struct CallFrame {
     pub(crate) prev: Option<Box<Self>>,
     pub(crate) code: Gc<CodeBlock>,
     pub(crate) pc: usize,
-    pub(crate) this: JsValue,
     #[unsafe_ignore_trace]
     pub(crate) catch: Vec<CatchAddresses>,
     #[unsafe_ignore_trace]

boa_engine/src/vm/code_block.rs

@@ -5,15 +5,16 @@
 use crate::{
     builtins::{
         function::{
-            arguments::Arguments, Captures, ClosureFunctionSignature, ConstructorKind, Function,
+            arguments::Arguments, ClassFieldDefinition, ConstructorKind, Function, ThisMode,
-            NativeFunctionSignature, ThisMode,
         },
         generator::{Generator, GeneratorContext, GeneratorState},
     },
     context::intrinsics::StandardConstructors,
-    environments::{BindingLocator, CompileTimeEnvironment, DeclarativeEnvironmentStack},
+    environments::{BindingLocator, CompileTimeEnvironment},
-    object::{internal_methods::get_prototype_from_constructor, JsObject, ObjectData},
+    object::{
-    property::{PropertyDescriptor, PropertyKey},
+        internal_methods::get_prototype_from_constructor, JsObject, ObjectData, PrivateElement,
+    },
+    property::PropertyDescriptor,
     syntax::ast::node::FormalParameterList,
     vm::call_frame::GeneratorResumeKind,
     vm::{call_frame::FinallyReturn, CallFrame, Opcode},
@@ -62,10 +63,6 @@ pub struct CodeBlock {
     /// Is this function in strict mode.
     pub(crate) strict: bool,
 
-    /// Constructor type of this function, or `None` if the function is not constructable.
-    #[unsafe_ignore_trace]
-    pub(crate) constructor: Option<ConstructorKind>,
-
     /// \[\[ThisMode\]\]
     pub(crate) this_mode: ThisMode,
 
@@ -90,26 +87,22 @@ pub struct CodeBlock {
     pub(crate) num_bindings: usize,
 
     /// Functions inside this function
-    pub(crate) functions: Vec<Gc<CodeBlock>>,
+    pub(crate) functions: Vec<Gc<Self>>,
-
-    /// Indicates if the codeblock contains a lexical name `arguments`
-    pub(crate) lexical_name_argument: bool,
 
     /// The `arguments` binding location of the function, if set.
     #[unsafe_ignore_trace]
     pub(crate) arguments_binding: Option<BindingLocator>,
 
-    /// Similar to the `[[ClassFieldInitializerName]]` slot in the spec.
-    /// Holds class field names that are computed at class declaration time.
-    pub(crate) computed_field_names: Option<Cell<Vec<PropertyKey>>>,
-
     /// Compile time environments in this function.
     pub(crate) compile_environments: Vec<Gc<Cell<CompileTimeEnvironment>>>,
+
+    /// The `[[IsClassConstructor]]` internal slot.
+    pub(crate) is_class_constructor: bool,
 }
 
 impl CodeBlock {
     /// Constructs a new `CodeBlock`.
-    pub fn new(name: Sym, length: u32, strict: bool, constructor: Option<ConstructorKind>) -> Self {
+    pub fn new(name: Sym, length: u32, strict: bool) -> Self {
         Self {
             code: Vec::new(),
             literals: Vec::new(),
@@ -120,13 +113,11 @@ impl CodeBlock {
             name,
             length,
             strict,
-            constructor,
             this_mode: ThisMode::Global,
             params: FormalParameterList::default(),
-            lexical_name_argument: false,
             arguments_binding: None,
-            computed_field_names: None,
             compile_environments: Vec::new(),
+            is_class_constructor: false,
         }
     }
 
@@ -202,6 +193,8 @@ impl CodeBlock {
             | Opcode::CallWithRest
             | Opcode::New
             | Opcode::NewWithRest
+            | Opcode::SuperCall
+            | Opcode::SuperCallWithRest
             | Opcode::ForInLoopInitIterator
             | Opcode::ForInLoopNext
             | Opcode::ConcatToString
@@ -254,11 +247,17 @@ impl CodeBlock {
             | Opcode::DefineClassGetterByName
             | Opcode::SetPropertySetterByName
             | Opcode::DefineClassSetterByName
-            | Opcode::SetPrivateValue
+            | Opcode::AssignPrivateField
+            | Opcode::SetPrivateField
+            | Opcode::SetPrivateMethod
             | Opcode::SetPrivateSetter
             | Opcode::SetPrivateGetter
             | Opcode::GetPrivateField
-            | Opcode::DeletePropertyByName => {
+            | Opcode::DeletePropertyByName
+            | Opcode::PushClassFieldPrivate
+            | Opcode::PushClassPrivateGetter
+            | Opcode::PushClassPrivateSetter
+            | Opcode::PushClassPrivateMethod => {
                 let operand = self.read::<u32>(*pc);
                 *pc += size_of::<u32>();
                 format!(
@@ -281,6 +280,8 @@ impl CodeBlock {
             | Opcode::PushUndefined
             | Opcode::PushEmptyObject
             | Opcode::PushClassPrototype
+            | Opcode::SetClassPrototype
+            | Opcode::SetHomeObject
             | Opcode::Add
             | Opcode::Sub
             | Opcode::Div
@@ -331,6 +332,7 @@ impl CodeBlock {
             | Opcode::FinallyStart
             | Opcode::FinallyEnd
             | Opcode::This
+            | Opcode::Super
             | Opcode::Return
             | Opcode::PopEnvironment
             | Opcode::LoopStart
@@ -352,7 +354,8 @@ impl CodeBlock {
             | Opcode::PopOnReturnSub
             | Opcode::Yield
             | Opcode::GeneratorNext
-            | Opcode::PushClassComputedFieldName
+            | Opcode::PushClassField
+            | Opcode::SuperCallDerived
             | Opcode::Nop => String::new(),
         }
     }
@@ -453,6 +456,10 @@ pub(crate) fn create_function_object(code: Gc<CodeBlock>, context: &mut Context)
     let function = Function::Ordinary {
         code,
         environments: context.realm.environments.clone(),
+        constructor_kind: ConstructorKind::Base,
+        home_object: None,
+        fields: Vec::new(),
+        private_methods: Vec::new(),
     };
 
     let constructor =
@@ -547,24 +554,6 @@ pub(crate) fn create_generator_function_object(
     constructor
 }
 
-pub(crate) enum FunctionBody {
-    Ordinary {
-        code: Gc<CodeBlock>,
-        environments: DeclarativeEnvironmentStack,
-    },
-    Native {
-        function: NativeFunctionSignature,
-    },
-    Closure {
-        function: Box<dyn ClosureFunctionSignature>,
-        captures: Captures,
-    },
-    Generator {
-        code: Gc<CodeBlock>,
-        environments: DeclarativeEnvironmentStack,
-    },
-}
-
 impl JsObject {
     pub(crate) fn call_internal(
         &self,
@@ -578,85 +567,80 @@ impl JsObject {
             return context.throw_type_error("not a callable function");
         }
 
-        let mut construct = false;
-
-        let body = {
         let object = self.borrow();
-            let function = object.as_function().expect("not a function");
+        let function_object = object.as_function().expect("not a function");
 
-            match function {
+        match function_object {
             Function::Native {
                 function,
                 constructor,
             } => {
-                    if constructor.is_some() {
+                let function = *function;
-                        construct = true;
+                let constructor = *constructor;
-                    }
+                drop(object);
 
-                    FunctionBody::Native {
+                if constructor.is_some() {
-                        function: *function,
+                    function(&JsValue::undefined(), args, context)
+                } else {
+                    function(this, args, context)
                 }
             }
             Function::Closure {
                 function, captures, ..
-                } => FunctionBody::Closure {
+            } => {
-                    function: function.clone(),
+                let function = function.clone();
-                    captures: captures.clone(),
+                let captures = captures.clone();
-                },
+                drop(object);
-                Function::Ordinary { code, environments } => FunctionBody::Ordinary {
-                    code: code.clone(),
-                    environments: environments.clone(),
-                },
-                Function::Generator { code, environments } => FunctionBody::Generator {
-                    code: code.clone(),
-                    environments: environments.clone(),
-                },
-            }
-        };
 
-        match body {
-            FunctionBody::Native { function } if construct => {
-                function(&JsValue::undefined(), args, context)
-            }
-            FunctionBody::Native { function } => function(this, args, context),
-            FunctionBody::Closure { function, captures } => {
                 (function)(this, args, captures, context)
             }
-            FunctionBody::Ordinary {
+            Function::Ordinary {
-                code,
+                code, environments, ..
-                mut environments,
             } => {
+                let code = code.clone();
+                let mut environments = environments.clone();
+                drop(object);
+
+                if code.is_class_constructor {
+                    return context
+                        .throw_type_error("Class constructor cannot be invoked without 'new'");
+                }
+
                 std::mem::swap(&mut environments, &mut context.realm.environments);
 
                 let lexical_this_mode = code.this_mode == ThisMode::Lexical;
 
                 let this = if lexical_this_mode {
-                    if let Some(this) = context.realm.environments.get_last_this() {
+                    None
-                        this
-                    } else {
-                        context.global_object().clone().into()
-                    }
                 } else if code.strict {
-                    this.clone()
+                    Some(this.clone())
                 } else if this.is_null_or_undefined() {
-                    context.global_object().clone().into()
+                    Some(context.global_object().clone().into())
                 } else {
+                    Some(
                         this.to_object(context)
                             .expect("conversion cannot fail")
-                        .into()
+                            .into(),
+                    )
                 };
 
                 if code.params.has_expressions() {
                     context.realm.environments.push_function(
                         code.num_bindings,
                         code.compile_environments[1].clone(),
-                        this.clone(),
+                        this,
+                        self.clone(),
+                        None,
+                        lexical_this_mode,
                     );
                 } else {
                     context.realm.environments.push_function(
                         code.num_bindings,
                         code.compile_environments[0].clone(),
-                        this.clone(),
+                        this,
+                        self.clone(),
+                        None,
+                        lexical_this_mode,
                     );
                 }
 
@@ -704,17 +688,16 @@ impl JsObject {
                 context.vm.push_frame(CallFrame {
                     prev: None,
                     code,
-                    this,
                     pc: 0,
                     catch: Vec::new(),
                     finally_return: FinallyReturn::None,
                     finally_jump: Vec::new(),
                     pop_on_return: 0,
-                    loop_env_stack: vec![0],
+                    loop_env_stack: Vec::from([0]),
-                    try_env_stack: vec![crate::vm::TryStackEntry {
+                    try_env_stack: Vec::from([crate::vm::TryStackEntry {
                         num_env: 0,
                         num_loop_stack_entries: 0,
-                    }],
+                    }]),
                     param_count,
                     arg_count,
                     generator_resume_kind: GeneratorResumeKind::Normal,
@@ -734,37 +717,46 @@ impl JsObject {
                 let (result, _) = result?;
                 Ok(result)
             }
-            FunctionBody::Generator {
+            Function::Generator { code, environments } => {
-                code,
+                let code = code.clone();
-                mut environments,
+                let mut environments = environments.clone();
-            } => {
+                drop(object);
+
                 std::mem::swap(&mut environments, &mut context.realm.environments);
 
                 let lexical_this_mode = code.this_mode == ThisMode::Lexical;
 
                 let this = if lexical_this_mode {
-                    if let Some(this) = context.realm.environments.get_last_this() {
+                    None
-                        this
+                } else if code.strict {
-                    } else {
+                    Some(this.clone())
-                        context.global_object().clone().into()
+                } else if this.is_null_or_undefined() {
-                    }
+                    Some(context.global_object().clone().into())
-                } else if !code.strict && this.is_null_or_undefined() {
-                    context.global_object().clone().into()
                 } else {
-                    this.clone()
+                    Some(
+                        this.to_object(context)
+                            .expect("conversion cannot fail")
+                            .into(),
+                    )
                 };
 
                 if code.params.has_expressions() {
                     context.realm.environments.push_function(
                         code.num_bindings,
                         code.compile_environments[1].clone(),
-                        this.clone(),
+                        this,
+                        self.clone(),
+                        None,
+                        lexical_this_mode,
                     );
                 } else {
                     context.realm.environments.push_function(
                         code.num_bindings,
                         code.compile_environments[0].clone(),
-                        this.clone(),
+                        this,
+                        self.clone(),
+                        None,
+                        lexical_this_mode,
                     );
                 }
 
@@ -808,17 +800,16 @@ impl JsObject {
                 let call_frame = CallFrame {
                     prev: None,
                     code,
-                    this,
                     pc: 0,
                     catch: Vec::new(),
                     finally_return: FinallyReturn::None,
                     finally_jump: Vec::new(),
                     pop_on_return: 0,
-                    loop_env_stack: vec![0],
+                    loop_env_stack: Vec::from([0]),
-                    try_env_stack: vec![crate::vm::TryStackEntry {
+                    try_env_stack: Vec::from([crate::vm::TryStackEntry {
                         num_env: 0,
                         num_loop_stack_entries: 0,
-                    }],
+                    }]),
                     param_count,
                     arg_count,
                     generator_resume_kind: GeneratorResumeKind::Normal,
@@ -871,7 +862,6 @@ impl JsObject {
         context: &mut Context,
     ) -> JsResult<JsObject> {
         let this_function_object = self.clone();
-        // let mut has_parameter_expressions = false;
 
         let create_this = |context| {
             let prototype =
@@ -883,40 +873,23 @@ impl JsObject {
             return context.throw_type_error("not a constructor function");
         }
 
-        let constructor;
-
-        let body = {
         let object = self.borrow();
-            let function = object.as_function().expect("not a function");
+        let function_object = object.as_function().expect("not a function");
-            constructor = function
+
-                .constructor()
+        match function_object {
-                .expect("Already checked that the function was a constructor");
+            Function::Native {
-
+                function,
-            match function {
+                constructor,
-                Function::Native { function, .. } => FunctionBody::Native {
+                ..
-                    function: *function,
+            } => {
-                },
+                let function = *function;
-                Function::Closure {
+                let constructor = *constructor;
-                    function, captures, ..
+                drop(object);
-                } => FunctionBody::Closure {
-                    function: function.clone(),
-                    captures: captures.clone(),
-                },
-                Function::Ordinary { code, environments } => FunctionBody::Ordinary {
-                    code: code.clone(),
-                    environments: environments.clone(),
-                },
-                Function::Generator { .. } => {
-                    unreachable!("generator function cannot be a constructor")
-                }
-            }
-        };
 
-        match body {
+                match function(this_target, args, context)? {
-            FunctionBody::Native { function, .. } => match function(this_target, args, context)? {
                     JsValue::Object(ref o) => Ok(o.clone()),
                     val => {
-                    if constructor.is_base() || val.is_undefined() {
+                        if constructor.expect("hmm").is_base() || val.is_undefined() {
                             create_this(context)
                         } else {
                             context.throw_type_error(
@@ -924,12 +897,23 @@ impl JsObject {
                             )
                         }
                     }
-            },
+                }
-            FunctionBody::Closure { function, captures } => {
+            }
+            Function::Closure {
+                function,
+                captures,
+                constructor,
+                ..
+            } => {
+                let function = function.clone();
+                let captures = captures.clone();
+                let constructor = *constructor;
+                drop(object);
+
                 match (function)(this_target, args, captures, context)? {
                     JsValue::Object(ref o) => Ok(o.clone()),
                     val => {
-                        if constructor.is_base() || val.is_undefined() {
+                        if constructor.expect("hmma").is_base() || val.is_undefined() {
                             create_this(context)
                         } else {
                             context.throw_type_error(
@@ -939,32 +923,57 @@ impl JsObject {
                     }
                 }
             }
-            FunctionBody::Ordinary {
+            Function::Ordinary {
                 code,
-                mut environments,
+                environments,
+                constructor_kind,
+                ..
             } => {
+                let code = code.clone();
+                let mut environments = environments.clone();
+                let constructor_kind = *constructor_kind;
+                drop(object);
+
                 std::mem::swap(&mut environments, &mut context.realm.environments);
 
-                let this = create_this(context)?;
+                let this = if constructor_kind.is_base() {
+                    // If the prototype of the constructor is not an object, then use the default object
+                    // prototype as prototype for the new object
+                    // see <https://tc39.es/ecma262/#sec-ordinarycreatefromconstructor>
+                    // see <https://tc39.es/ecma262/#sec-getprototypefromconstructor>
+                    let prototype = get_prototype_from_constructor(
+                        this_target,
+                        StandardConstructors::object,
+                        context,
+                    )?;
+                    let this = Self::from_proto_and_data(prototype, ObjectData::ordinary());
 
-                // Set computed class field names if they exist.
+                    initialize_instance_elements(&this, self, context)?;
-                if let Some(fields) = &code.computed_field_names {
+
-                    for key in fields.borrow().iter().rev() {
+                    Some(this)
-                        context.vm.push(key);
+                } else {
-                    }
+                    None
-                }
+                };
+
+                let new_target = this_target.as_object().expect("must be object");
 
                 if code.params.has_expressions() {
                     context.realm.environments.push_function(
                         code.num_bindings,
                         code.compile_environments[1].clone(),
-                        this.clone().into(),
+                        this.clone().map(Into::into),
+                        self.clone(),
+                        Some(new_target.clone()),
+                        false,
                     );
                 } else {
                     context.realm.environments.push_function(
                         code.num_bindings,
                         code.compile_environments[0].clone(),
-                        this.clone().into(),
+                        this.clone().map(Into::into),
+                        self.clone(),
+                        Some(new_target.clone()),
+                        false,
                     );
                 }
 
@@ -1025,17 +1034,16 @@ impl JsObject {
                 context.vm.push_frame(CallFrame {
                     prev: None,
                     code,
-                    this: this.into(),
                     pc: 0,
                     catch: Vec::new(),
                     finally_return: FinallyReturn::None,
                     finally_jump: Vec::new(),
                     pop_on_return: 0,
-                    loop_env_stack: vec![0],
+                    loop_env_stack: Vec::from([0]),
-                    try_env_stack: vec![crate::vm::TryStackEntry {
+                    try_env_stack: Vec::from([crate::vm::TryStackEntry {
                         num_env: 0,
                         num_loop_stack_entries: 0,
-                    }],
+                    }]),
                     param_count,
                     arg_count,
                     generator_resume_kind: GeneratorResumeKind::Normal,
@@ -1044,37 +1052,111 @@ impl JsObject {
 
                 let result = context.run();
 
-                let frame = context.vm.pop_frame().expect("must have frame");
+                context.vm.pop_frame();
 
-                context.realm.environments.pop();
+                let mut environment = context.realm.environments.pop();
                 if has_parameter_expressions {
-                    context.realm.environments.pop();
+                    environment = context.realm.environments.pop();
                 }
 
                 std::mem::swap(&mut environments, &mut context.realm.environments);
 
                 let (result, _) = result?;
 
-                match result {
+                if let Some(result) = result.as_object() {
-                    JsValue::Object(ref obj) => Ok(obj.clone()),
+                    Ok(result.clone())
-                    val => {
+                } else if let Some(this) = this {
-                        if constructor.is_base() || val.is_undefined() {
+                    Ok(this)
-                            Ok(frame
+                } else if !result.is_undefined() {
-                                .this
+                    context.throw_type_error("Function constructor must not return non-object")
+                } else {
+                    let function_env = environment
+                        .slots()
+                        .expect("must be function environment")
+                        .as_function_slots()
+                        .expect("must be function environment");
+                    if let Some(this_binding) = function_env.borrow().get_this_binding() {
+                        Ok(this_binding
                             .as_object()
-                                .cloned()
+                            .expect("this binding must be object")
-                                .expect("13. Assert: Type(thisBinding) is Object."))
+                            .clone())
                     } else {
-                            context.throw_type_error(
+                        //context.throw_type_error("Function constructor must not return non-object")
-                                "Derived constructor can only return an Object or undefined",
+                        context.throw_reference_error("Must call super constructor in derived class before accessing 'this' or returning from derived constructor")
-                            )
                     }
                 }
             }
-            }
+            Function::Generator { .. } => {
-            FunctionBody::Generator { .. } => {
                 unreachable!("generator function cannot be a constructor")
             }
         }
     }
 }
+
+/// `InitializeInstanceElements ( O, constructor )`
+///
+/// Add private methods and fields from a class constructor to an object.
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#sec-initializeinstanceelements
+pub(crate) fn initialize_instance_elements(
+    target: &JsObject,
+    constructor: &JsObject,
+    context: &mut Context,
+) -> JsResult<()> {
+    let constructor_borrow = constructor.borrow();
+    let constructor_function = constructor_borrow
+        .as_function()
+        .expect("class constructor must be function object");
+
+    for (name, private_method) in constructor_function.get_private_methods() {
+        match private_method {
+            PrivateElement::Method(_) => {
+                target
+                    .borrow_mut()
+                    .set_private_element(*name, private_method.clone());
+            }
+            PrivateElement::Accessor { getter, setter } => {
+                if let Some(getter) = getter {
+                    target
+                        .borrow_mut()
+                        .set_private_element_getter(*name, getter.clone());
+                }
+                if let Some(setter) = setter {
+                    target
+                        .borrow_mut()
+                        .set_private_element_setter(*name, setter.clone());
+                }
+            }
+            PrivateElement::Field(_) => unreachable!(),
+        }
+    }
+
+    for field in constructor_function.get_fields() {
+        match field {
+            ClassFieldDefinition::Public(name, function) => {
+                let value = function.call(&target.clone().into(), &[], context)?;
+                target.__define_own_property__(
+                    name.clone(),
+                    PropertyDescriptor::builder()
+                        .value(value)
+                        .writable(true)
+                        .enumerable(true)
+                        .configurable(true)
+                        .build(),
+                    context,
+                )?;
+            }
+            ClassFieldDefinition::Private(name, function) => {
+                let value = function.call(&target.clone().into(), &[], context)?;
+                target
+                    .borrow_mut()
+                    .set_private_element(*name, PrivateElement::Field(value));
+            }
+        }
+    }
+
+    Ok(())
+}

boa_engine/src/vm/mod.rs

@@ -3,13 +3,18 @@
 //! plus an interpreter to execute those instructions
 
 use crate::{
-    builtins::{function::Function, iterable::IteratorRecord, Array, ForInIterator, Number},
+    builtins::{
-    object::PrivateElement,
+        function::{ConstructorKind, Function},
-    property::{DescriptorKind, PropertyDescriptor, PropertyKey},
+        iterable::IteratorRecord,
+        Array, ForInIterator, Number,
+    },
+    environments::EnvironmentSlots,
+    object::{JsFunction, JsObject, ObjectData, PrivateElement},
+    property::{DescriptorKind, PropertyDescriptor, PropertyDescriptorBuilder, PropertyKey},
     value::Numeric,
     vm::{
         call_frame::CatchAddresses,
-        code_block::{create_generator_function_object, Readable},
+        code_block::{create_generator_function_object, initialize_instance_elements, Readable},
     },
     Context, JsBigInt, JsResult, JsString, JsValue,
 };
@@ -198,20 +203,103 @@ impl Context {
             Opcode::PushEmptyObject => self.vm.push(self.construct_object()),
             Opcode::PushClassPrototype => {
                 let superclass = self.vm.pop();
-                if superclass.is_null() {
+
-                    self.vm.push(JsValue::Null);
-                }
                 if let Some(superclass) = superclass.as_constructor() {
                     let proto = superclass.get("prototype", self)?;
                     if !proto.is_object() && !proto.is_null() {
                         return self
                             .throw_type_error("superclass prototype must be an object or null");
                     }
+
+                    let class = self.vm.pop();
+                    {
+                        let class_object = class.as_object().expect("class must be object");
+                        class_object.set_prototype(Some(superclass.clone()));
+
+                        let mut class_object_mut = class_object.borrow_mut();
+                        let class_function = class_object_mut
+                            .as_function_mut()
+                            .expect("class must be function object");
+                        if let Function::Ordinary {
+                            constructor_kind, ..
+                        } = class_function
+                        {
+                            *constructor_kind = ConstructorKind::Derived;
+                        }
+                    }
+
+                    self.vm.push(class);
                     self.vm.push(proto);
+                } else if superclass.is_null() {
+                    self.vm.push(JsValue::Null);
                 } else {
                     return self.throw_type_error("superclass must be a constructor");
                 }
             }
+            Opcode::SetClassPrototype => {
+                let prototype_value = self.vm.pop();
+                let prototype = match &prototype_value {
+                    JsValue::Object(proto) => Some(proto.clone()),
+                    JsValue::Null => None,
+                    JsValue::Undefined => {
+                        Some(self.intrinsics().constructors().object().prototype.clone())
+                    }
+                    _ => unreachable!(),
+                };
+
+                let proto = JsObject::from_proto_and_data(prototype, ObjectData::ordinary());
+                let class = self.vm.pop();
+
+                {
+                    let class_object = class.as_object().expect("class must be object");
+                    class_object
+                        .define_property_or_throw(
+                            "prototype",
+                            PropertyDescriptorBuilder::new()
+                                .value(proto.clone())
+                                .writable(false)
+                                .enumerable(false)
+                                .configurable(false),
+                            self,
+                        )
+                        .expect("cannot fail per spec");
+                    let mut class_object_mut = class_object.borrow_mut();
+                    let class_function = class_object_mut
+                        .as_function_mut()
+                        .expect("class must be function object");
+                    class_function.set_home_object(proto.clone());
+                }
+
+                proto
+                    .__define_own_property__(
+                        "constructor".into(),
+                        PropertyDescriptorBuilder::new()
+                            .value(class)
+                            .writable(true)
+                            .enumerable(false)
+                            .configurable(true)
+                            .build(),
+                        self,
+                    )
+                    .expect("cannot fail per spec");
+
+                self.vm.push(proto);
+            }
+            Opcode::SetHomeObject => {
+                let function = self.vm.pop();
+                let function_object = function.as_object().expect("must be object");
+                let home = self.vm.pop();
+                let home_object = home.as_object().expect("must be object");
+
+                function_object
+                    .borrow_mut()
+                    .as_function_mut()
+                    .expect("must be function object")
+                    .set_home_object(home_object.clone());
+
+                self.vm.push(home);
+                self.vm.push(function);
+            }
             Opcode::PushNewArray => {
                 let array = Array::array_create(0, None, self)
                     .expect("Array creation with 0 length should never fail");
@@ -721,6 +809,13 @@ impl Context {
                 } else {
                     object.to_object(self)?
                 };
+                value
+                    .as_object()
+                    .expect("method must be function object")
+                    .borrow_mut()
+                    .as_function_mut()
+                    .expect("method must be function object")
+                    .set_home_object(object.clone());
                 let name = self.vm.frame().code.names[index as usize];
                 let name = self.interner().resolve_expect(name);
                 object.__define_own_property__(
@@ -777,6 +872,13 @@ impl Context {
                 } else {
                     object.to_object(self)?
                 };
+                value
+                    .as_object()
+                    .expect("method must be function object")
+                    .borrow_mut()
+                    .as_function_mut()
+                    .expect("method must be function object")
+                    .set_home_object(object.clone());
                 let key = key.to_property_key(self)?;
                 object.__define_own_property__(
                     key,
@@ -817,6 +919,13 @@ impl Context {
                 let object = self.vm.pop();
                 let value = self.vm.pop();
                 let object = object.to_object(self)?;
+                value
+                    .as_object()
+                    .expect("method must be function object")
+                    .borrow_mut()
+                    .as_function_mut()
+                    .expect("method must be function object")
+                    .set_home_object(object.clone());
                 let name = self.vm.frame().code.names[index as usize];
                 let name = self.interner().resolve_expect(name).into();
                 let set = object
@@ -862,6 +971,13 @@ impl Context {
                 let key = self.vm.pop();
                 let object = self.vm.pop();
                 let object = object.to_object(self)?;
+                value
+                    .as_object()
+                    .expect("method must be function object")
+                    .borrow_mut()
+                    .as_function_mut()
+                    .expect("method must be function object")
+                    .set_home_object(object.clone());
                 let name = key.to_property_key(self)?;
                 let set = object
                     .__get_own_property__(&name, self)?
@@ -907,6 +1023,13 @@ impl Context {
                 let object = self.vm.pop();
                 let value = self.vm.pop();
                 let object = object.to_object(self)?;
+                value
+                    .as_object()
+                    .expect("method must be function object")
+                    .borrow_mut()
+                    .as_function_mut()
+                    .expect("method must be function object")
+                    .set_home_object(object.clone());
                 let name = self.vm.frame().code.names[index as usize];
                 let name = self.interner().resolve_expect(name).into();
                 let get = object
@@ -952,6 +1075,13 @@ impl Context {
                 let key = self.vm.pop();
                 let object = self.vm.pop();
                 let object = object.to_object(self)?;
+                value
+                    .as_object()
+                    .expect("method must be function object")
+                    .borrow_mut()
+                    .as_function_mut()
+                    .expect("method must be function object")
+                    .set_home_object(object.clone());
                 let name = key.to_property_key(self)?;
                 let get = object
                     .__get_own_property__(&name, self)?
@@ -969,7 +1099,41 @@ impl Context {
                     self,
                 )?;
             }
-            Opcode::SetPrivateValue => {
+            Opcode::AssignPrivateField => {
+                let index = self.vm.read::<u32>();
+                let name = self.vm.frame().code.names[index as usize];
+                let value = self.vm.pop();
+                let object = self.vm.pop();
+                if let Some(object) = object.as_object() {
+                    let mut object_borrow_mut = object.borrow_mut();
+                    match object_borrow_mut.get_private_element(name) {
+                        Some(PrivateElement::Field(_)) => {
+                            object_borrow_mut
+                                .set_private_element(name, PrivateElement::Field(value));
+                        }
+                        Some(PrivateElement::Method(_)) => {
+                            return self.throw_type_error("private method is not writable");
+                        }
+                        Some(PrivateElement::Accessor {
+                            setter: Some(setter),
+                            ..
+                        }) => {
+                            let setter = setter.clone();
+                            drop(object_borrow_mut);
+                            setter.call(&object.clone().into(), &[value], self)?;
+                        }
+                        None => {
+                            return self.throw_type_error("private field not defined");
+                        }
+                        _ => {
+                            return self.throw_type_error("private field defined without a setter");
+                        }
+                    }
+                } else {
+                    return self.throw_type_error("cannot set private property on non-object");
+                }
+            }
+            Opcode::SetPrivateField => {
                 let index = self.vm.read::<u32>();
                 let name = self.vm.frame().code.names[index as usize];
                 let value = self.vm.pop();
@@ -985,12 +1149,26 @@ impl Context {
                         drop(object_borrow_mut);
                         setter.call(&object.clone().into(), &[value], self)?;
                     } else {
-                        object_borrow_mut.set_private_element(name, PrivateElement::Value(value));
+                        object_borrow_mut.set_private_element(name, PrivateElement::Field(value));
                     }
                 } else {
                     return self.throw_type_error("cannot set private property on non-object");
                 }
             }
+            Opcode::SetPrivateMethod => {
+                let index = self.vm.read::<u32>();
+                let name = self.vm.frame().code.names[index as usize];
+                let value = self.vm.pop();
+                let value = value.as_callable().expect("method must be callable");
+                let object = self.vm.pop();
+                if let Some(object) = object.as_object() {
+                    let mut object_borrow_mut = object.borrow_mut();
+                    object_borrow_mut
+                        .set_private_element(name, PrivateElement::Method(value.clone()));
+                } else {
+                    return self.throw_type_error("cannot set private setter on non-object");
+                }
+            }
             Opcode::SetPrivateSetter => {
                 let index = self.vm.read::<u32>();
                 let name = self.vm.frame().code.names[index as usize];
@@ -1025,7 +1203,8 @@ impl Context {
                     let object_borrow_mut = object.borrow();
                     if let Some(element) = object_borrow_mut.get_private_element(name) {
                         match element {
-                            PrivateElement::Value(value) => self.vm.push(value),
+                            PrivateElement::Field(value) => self.vm.push(value),
+                            PrivateElement::Method(method) => self.vm.push(method.clone()),
                             PrivateElement::Accessor {
                                 getter: Some(getter),
                                 setter: _,
@@ -1046,25 +1225,111 @@ impl Context {
                     return self.throw_type_error("cannot read private property from non-object");
                 }
             }
-            Opcode::PushClassComputedFieldName => {
+            Opcode::PushClassField => {
-                let object = self.vm.pop();
+                let field_function_value = self.vm.pop();
-                let value = self.vm.pop();
+                let field_name_value = self.vm.pop();
-                let value = value.to_property_key(self)?;
+                let class_value = self.vm.pop();
-                let object_obj = object
+
+                let field_name_key = field_name_value.to_property_key(self)?;
+                let field_function_object = field_function_value
                     .as_object()
-                    .expect("can only add field to function object");
+                    .expect("field value must be function object");
-                let object = object_obj.borrow();
+                let mut field_function_object_borrow = field_function_object.borrow_mut();
-                let function = object
+                let field_function = field_function_object_borrow
-                    .as_function()
+                    .as_function_mut()
-                    .expect("can only add field to function object");
+                    .expect("field value must be function object");
-                if let Function::Ordinary { code, .. } = function {
+                let class_object = class_value
-                    let code_b = code
+                    .as_object()
-                        .computed_field_names
+                    .expect("class must be function object");
-                        .as_ref()
+                field_function.set_home_object(class_object.clone());
-                        .expect("class constructor must have fields");
+                class_object
-                    let mut fields_mut = code_b.borrow_mut();
+                    .borrow_mut()
-                    fields_mut.push(value);
+                    .as_function_mut()
+                    .expect("class must be function object")
+                    .push_field(
+                        field_name_key,
+                        JsFunction::from_object_unchecked(field_function_object.clone()),
+                    );
             }
+            Opcode::PushClassFieldPrivate => {
+                let index = self.vm.read::<u32>();
+                let name = self.vm.frame().code.names[index as usize];
+                let field_function_value = self.vm.pop();
+                let class_value = self.vm.pop();
+
+                let field_function_object = field_function_value
+                    .as_object()
+                    .expect("field value must be function object");
+                let mut field_function_object_borrow = field_function_object.borrow_mut();
+                let field_function = field_function_object_borrow
+                    .as_function_mut()
+                    .expect("field value must be function object");
+                let class_object = class_value
+                    .as_object()
+                    .expect("class must be function object");
+                field_function.set_home_object(class_object.clone());
+                class_object
+                    .borrow_mut()
+                    .as_function_mut()
+                    .expect("class must be function object")
+                    .push_field_private(
+                        name,
+                        JsFunction::from_object_unchecked(field_function_object.clone()),
+                    );
+            }
+            Opcode::PushClassPrivateGetter => {
+                let index = self.vm.read::<u32>();
+                let name = self.vm.frame().code.names[index as usize];
+                let getter = self.vm.pop();
+                let getter_object = getter.as_callable().expect("getter must be callable");
+                let class = self.vm.pop();
+                class
+                    .as_object()
+                    .expect("class must be function object")
+                    .borrow_mut()
+                    .as_function_mut()
+                    .expect("class must be function object")
+                    .push_private_method(
+                        name,
+                        PrivateElement::Accessor {
+                            getter: Some(getter_object.clone()),
+                            setter: None,
+                        },
+                    );
+            }
+            Opcode::PushClassPrivateSetter => {
+                let index = self.vm.read::<u32>();
+                let name = self.vm.frame().code.names[index as usize];
+                let setter = self.vm.pop();
+                let setter_object = setter.as_callable().expect("getter must be callable");
+                let class = self.vm.pop();
+                class
+                    .as_object()
+                    .expect("class must be function object")
+                    .borrow_mut()
+                    .as_function_mut()
+                    .expect("class must be function object")
+                    .push_private_method(
+                        name,
+                        PrivateElement::Accessor {
+                            getter: None,
+                            setter: Some(setter_object.clone()),
+                        },
+                    );
+            }
+            Opcode::PushClassPrivateMethod => {
+                let index = self.vm.read::<u32>();
+                let name = self.vm.frame().code.names[index as usize];
+                let method = self.vm.pop();
+                let method_object = method.as_callable().expect("method must be callable");
+                let class = self.vm.pop();
+                class
+                    .as_object()
+                    .expect("class must be function object")
+                    .borrow_mut()
+                    .as_function_mut()
+                    .expect("class must be function object")
+                    .push_private_method(name, PrivateElement::Method(method_object.clone()));
             }
             Opcode::DeletePropertyByName => {
                 let index = self.vm.read::<u32>();
@@ -1204,8 +1469,203 @@ impl Context {
                     .expect("finally jump must exist here") = Some(address);
             }
             Opcode::This => {
-                let this = self.vm.frame().this.clone();
+                let env = self.realm.environments.get_this_environment();
+                match env {
+                    EnvironmentSlots::Function(env) => {
+                        let env_b = env.borrow();
+                        if let Some(this) = env_b.get_this_binding() {
                             self.vm.push(this);
+                        } else {
+                            drop(env_b);
+                            return self.throw_reference_error("Must call super constructor in derived class before accessing 'this' or returning from derived constructor");
+                        }
+                    }
+                    EnvironmentSlots::Global => {
+                        let this = self.realm.global_object();
+                        self.vm.push(this.clone());
+                    }
+                }
+            }
+            Opcode::Super => {
+                let env = self
+                    .realm
+                    .environments
+                    .get_this_environment()
+                    .as_function_slots()
+                    .expect("super access must be in a function environment");
+
+                let home = if env.borrow().get_this_binding().is_some() {
+                    let env = env.borrow();
+                    let function_object = env.function_object().borrow();
+                    let function = function_object
+                        .as_function()
+                        .expect("must be function object");
+                    function.get_home_object().cloned()
+                } else {
+                    return self.throw_range_error("Must call super constructor in derived class before accessing 'this' or returning from derived constructor");
+                };
+
+                if let Some(home) = home {
+                    if let Some(proto) = home.__get_prototype_of__(self)? {
+                        self.vm.push(JsValue::from(proto));
+                    } else {
+                        self.vm.push(JsValue::Null);
+                    }
+                } else {
+                    self.vm.push(JsValue::Null);
+                };
+            }
+            Opcode::SuperCall => {
+                let argument_count = self.vm.read::<u32>();
+                let mut arguments = Vec::with_capacity(argument_count as usize);
+                for _ in 0..argument_count {
+                    arguments.push(self.vm.pop());
+                }
+                arguments.reverse();
+
+                let (new_target, active_function) = {
+                    let this_env = self
+                        .realm
+                        .environments
+                        .get_this_environment()
+                        .as_function_slots()
+                        .expect("super call must be in function environment");
+                    let this_env_borrow = this_env.borrow();
+                    let new_target = this_env_borrow
+                        .new_target()
+                        .expect("must have new target")
+                        .clone();
+                    let active_function = this_env.borrow().function_object().clone();
+                    (new_target, active_function)
+                };
+                let super_constructor = active_function
+                    .__get_prototype_of__(self)
+                    .expect("function object must have prototype")
+                    .expect("function object must have prototype");
+
+                if !super_constructor.is_constructor() {
+                    return self.throw_type_error("super constructor object must be constructor");
+                }
+
+                let result = super_constructor.__construct__(&arguments, &new_target, self)?;
+
+                initialize_instance_elements(&result, &active_function, self)?;
+
+                let this_env = self
+                    .realm
+                    .environments
+                    .get_this_environment()
+                    .as_function_slots()
+                    .expect("super call must be in function environment");
+
+                if !this_env.borrow_mut().bind_this_value(&result) {
+                    return self.throw_reference_error("this already initialized");
+                }
+                self.vm.push(result);
+            }
+            Opcode::SuperCallWithRest => {
+                let argument_count = self.vm.read::<u32>();
+                let rest_argument = self.vm.pop();
+                let mut arguments = Vec::with_capacity(argument_count as usize);
+                for _ in 0..(argument_count - 1) {
+                    arguments.push(self.vm.pop());
+                }
+                arguments.reverse();
+
+                let iterator_record = rest_argument.get_iterator(self, None, None)?;
+                let mut rest_arguments = Vec::new();
+                while let Some(next) = iterator_record.step(self)? {
+                    rest_arguments.push(next.value(self)?);
+                }
+                arguments.append(&mut rest_arguments);
+
+                let (new_target, active_function) = {
+                    let this_env = self
+                        .realm
+                        .environments
+                        .get_this_environment()
+                        .as_function_slots()
+                        .expect("super call must be in function environment");
+                    let this_env_borrow = this_env.borrow();
+                    let new_target = this_env_borrow
+                        .new_target()
+                        .expect("must have new target")
+                        .clone();
+                    let active_function = this_env.borrow().function_object().clone();
+                    (new_target, active_function)
+                };
+                let super_constructor = active_function
+                    .__get_prototype_of__(self)
+                    .expect("function object must have prototype")
+                    .expect("function object must have prototype");
+
+                if !super_constructor.is_constructor() {
+                    return self.throw_type_error("super constructor object must be constructor");
+                }
+
+                let result = super_constructor.__construct__(&arguments, &new_target, self)?;
+
+                initialize_instance_elements(&result, &active_function, self)?;
+
+                let this_env = self
+                    .realm
+                    .environments
+                    .get_this_environment()
+                    .as_function_slots()
+                    .expect("super call must be in function environment");
+
+                if !this_env.borrow_mut().bind_this_value(&result) {
+                    return self.throw_reference_error("this already initialized");
+                }
+                self.vm.push(result);
+            }
+            Opcode::SuperCallDerived => {
+                let argument_count = self.vm.frame().arg_count;
+                let mut arguments = Vec::with_capacity(argument_count);
+                for _ in 0..argument_count {
+                    arguments.push(self.vm.pop());
+                }
+                arguments.reverse();
+
+                let (new_target, active_function) = {
+                    let this_env = self
+                        .realm
+                        .environments
+                        .get_this_environment()
+                        .as_function_slots()
+                        .expect("super call must be in function environment");
+                    let this_env_borrow = this_env.borrow();
+                    let new_target = this_env_borrow
+                        .new_target()
+                        .expect("must have new target")
+                        .clone();
+                    let active_function = this_env.borrow().function_object().clone();
+                    (new_target, active_function)
+                };
+                let super_constructor = active_function
+                    .__get_prototype_of__(self)
+                    .expect("function object must have prototype")
+                    .expect("function object must have prototype");
+
+                if !super_constructor.is_constructor() {
+                    return self.throw_type_error("super constructor object must be constructor");
+                }
+
+                let result = super_constructor.__construct__(&arguments, &new_target, self)?;
+
+                initialize_instance_elements(&result, &active_function, self)?;
+
+                let this_env = self
+                    .realm
+                    .environments
+                    .get_this_environment()
+                    .as_function_slots()
+                    .expect("super call must be in function environment");
+                if !this_env.borrow_mut().bind_this_value(&result) {
+                    return self.throw_reference_error("this already initialized");
+                }
+
+                self.vm.push(result);
             }
             Opcode::Case => {
                 let address = self.vm.read::<u32>();
@@ -1480,20 +1940,9 @@ impl Context {
                 let compile_environment = self.vm.frame().code.compile_environments
                     [compile_environments_index as usize]
                     .clone();
-
+                self.realm
-                let constructor = self.vm.frame().code.constructor;
+                    .environments
-                let is_lexical = self.vm.frame().code.this_mode.is_lexical();
+                    .push_function_inherit(num_bindings as usize, compile_environment);
-                let this = if constructor.is_some() || !is_lexical {
-                    self.vm.frame().this.clone()
-                } else {
-                    JsValue::undefined()
-                };
-
-                self.realm.environments.push_function(
-                    num_bindings as usize,
-                    compile_environment,
-                    this,
-                );
             }
             Opcode::PopEnvironment => {
                 self.realm.environments.pop();

boa_engine/src/vm/opcode.rs

@@ -142,9 +142,23 @@ pub enum Opcode {
     ///
     /// Operands:
     ///
-    /// Stack: superclass **=>** superclass.prototype
+    /// Stack: class, superclass **=>** class, superclass.prototype
     PushClassPrototype,
 
+    /// Set the prototype of a class object.
+    ///
+    /// Operands:
+    ///
+    /// Stack: class, prototype **=>** class.prototype
+    SetClassPrototype,
+
+    /// Set home object internal slot of a function object.
+    ///
+    /// Operands:
+    ///
+    /// Stack: home, function **=>** home, function
+    SetHomeObject,
+
     /// Push an empty array value on the stack.
     ///
     /// Operands:
@@ -624,16 +638,34 @@ pub enum Opcode {
     /// Stack: object, key, value **=>**
     DefineClassSetterByValue,
 
-    /// Set a private property by name from an object.
+    /// Assign the value of a private property of an object by it's name.
+    ///
+    /// Like `obj.#name = value`
+    ///
+    /// Operands: name_index: `u32`
+    ///
+    /// Stack: object, value **=>**
+    AssignPrivateField,
+
+    /// Set a private property of a class constructor by it's name.
     ///
     /// Like `#name = value`
     ///
     /// Operands: name_index: `u32`
     ///
     /// Stack: object, value **=>**
-    SetPrivateValue,
+    SetPrivateField,
 
-    /// Set a private setter property by name from an object.
+    /// Set a private method of a class constructor by it's name.
+    ///
+    /// Like `#name() {}`
+    ///
+    /// Operands: name_index: `u32`
+    ///
+    /// Stack: object, value **=>**
+    SetPrivateMethod,
+
+    /// Set a private setter property of a class constructor by it's name.
     ///
     /// Like `set #name() {}`
     ///
@@ -642,7 +674,7 @@ pub enum Opcode {
     /// Stack: object, value **=>**
     SetPrivateSetter,
 
-    /// Set a private getter property by name from an object.
+    /// Set a private getter property of a class constructor by it's name.
     ///
     /// Like `get #name() {}`
     ///
@@ -660,12 +692,40 @@ pub enum Opcode {
     /// Stack: object **=>** value
     GetPrivateField,
 
-    /// Push a computed class field name to a class constructor object.
+    /// Push a field to a class.
     ///
     /// Operands:
     ///
-    /// Stack: value, object **=>**
+    /// Stack: class, field_name, field_function **=>**
-    PushClassComputedFieldName,
+    PushClassField,
+
+    /// Push a private field to the class.
+    ///
+    /// Operands: name_index: `u32`
+    ///
+    /// Stack: class, field_function **=>**
+    PushClassFieldPrivate,
+
+    /// Push a private getter to the class.
+    ///
+    /// Operands: name_index: `u32`
+    ///
+    /// Stack: class, getter **=>**
+    PushClassPrivateGetter,
+
+    /// Push a private setter to the class.
+    ///
+    /// Operands: name_index: `u32`
+    ///
+    /// Stack: class, setter **=>**
+    PushClassPrivateSetter,
+
+    /// Push a private method to the class.
+    ///
+    /// Operands: name_index: `u32`
+    ///
+    /// Stack: class, method **=>**
+    PushClassPrivateMethod,
 
     /// Deletes a property by name of an object.
     ///
@@ -803,6 +863,34 @@ pub enum Opcode {
     /// Stack: **=>** this
     This,
 
+    /// Pushes the current `super` value to the stack.
+    ///
+    /// Operands:
+    ///
+    /// Stack: **=>** super
+    Super,
+
+    /// Execute the `super()` method.
+    ///
+    /// Operands: argument_count: `u32`
+    ///
+    /// Stack: argument_1, ... argument_n **=>**
+    SuperCall,
+
+    /// Execute the `super()` method where the last argument is a rest parameter.
+    ///
+    /// Operands: argument_count: `u32`
+    ///
+    /// Stack: argument_1, ... argument_n **=>**
+    SuperCallWithRest,
+
+    /// Execute the `super()` method when no constructor of the class is defined.
+    ///
+    /// Operands:
+    ///
+    /// Stack: argument_1, ... argument_n **=>**
+    SuperCallDerived,
+
     /// Pop the two values of the stack, strict equal compares the two values,
     /// if true jumps to address, otherwise push the second pop'ed value.
     ///
@@ -1079,6 +1167,8 @@ impl Opcode {
             Self::PushLiteral => "PushLiteral",
             Self::PushEmptyObject => "PushEmptyObject",
             Self::PushClassPrototype => "PushClassPrototype",
+            Self::SetClassPrototype => "SetClassPrototype",
+            Self::SetHomeObject => "SetHomeObject",
             Self::PushNewArray => "PushNewArray",
             Self::PushValueToArray => "PushValueToArray",
             Self::PushElisionToArray => "PushElisionToArray",
@@ -1143,11 +1233,17 @@ impl Opcode {
             Self::DefineClassSetterByName => "DefineClassSetterByName",
             Self::SetPropertySetterByValue => "SetPropertySetterByValue",
             Self::DefineClassSetterByValue => "DefineClassSetterByValue",
-            Self::SetPrivateValue => "SetPrivateValue",
+            Self::AssignPrivateField => "AssignPrivateField",
+            Self::SetPrivateField => "SetPrivateValue",
+            Self::SetPrivateMethod => "SetPrivateMethod",
             Self::SetPrivateSetter => "SetPrivateSetter",
             Self::SetPrivateGetter => "SetPrivateGetter",
-            Self::GetPrivateField => "GetPrivateByName",
+            Self::GetPrivateField => "GetPrivateField",
-            Self::PushClassComputedFieldName => "PushClassComputedFieldName",
+            Self::PushClassField => "PushClassField",
+            Self::PushClassFieldPrivate => "PushClassFieldPrivate",
+            Self::PushClassPrivateGetter => "PushClassPrivateGetter",
+            Self::PushClassPrivateSetter => "PushClassPrivateSetter",
+            Self::PushClassPrivateMethod => "PushClassPrivateMethod",
             Self::DeletePropertyByName => "DeletePropertyByName",
             Self::DeletePropertyByValue => "DeletePropertyByValue",
             Self::CopyDataProperties => "CopyDataProperties",
@@ -1166,6 +1262,10 @@ impl Opcode {
             Self::FinallySetJump => "FinallySetJump",
             Self::ToBoolean => "ToBoolean",
             Self::This => "This",
+            Self::Super => "Super",
+            Self::SuperCall => "SuperCall",
+            Self::SuperCallWithRest => "SuperCallWithRest",
+            Self::SuperCallDerived => "SuperCallDerived",
             Self::Case => "Case",
             Self::Default => "Default",
             Self::GetFunction => "GetFunction",
@@ -1300,6 +1400,10 @@ impl Opcode {
             Self::FinallySetJump => "INST - FinallySetJump",
             Self::ToBoolean => "INST - ToBoolean",
             Self::This => "INST - This",
+            Self::Super => "INST - Super",
+            Self::SuperCall => "INST - SuperCall",
+            Self::SuperCallWithRest => "INST - SuperCallWithRest",
+            Self::SuperCallDerived => "INST - SuperCallDerived",
             Self::Case => "INST - Case",
             Self::Default => "INST - Default",
             Self::GetFunction => "INST - GetFunction",
@@ -1335,17 +1439,25 @@ impl Opcode {
             Self::GeneratorNextDelegate => "INST - GeneratorNextDelegate",
             Self::Nop => "INST - Nop",
             Self::PushClassPrototype => "INST - PushClassPrototype",
+            Self::SetClassPrototype => "INST - SetClassPrototype",
+            Self::SetHomeObject => "INST - SetHomeObject",
             Self::DefineClassMethodByName => "INST - DefineClassMethodByName",
             Self::DefineClassMethodByValue => "INST - DefineClassMethodByValue",
             Self::DefineClassGetterByName => "INST - DefineClassGetterByName",
             Self::DefineClassGetterByValue => "INST - DefineClassGetterByValue",
             Self::DefineClassSetterByName => "INST - DefineClassSetterByName",
             Self::DefineClassSetterByValue => "INST - DefineClassSetterByValue",
-            Self::SetPrivateValue => "INST - SetPrivateValue",
+            Self::AssignPrivateField => "INST - AssignPrivateField",
+            Self::SetPrivateField => "INST - SetPrivateValue",
+            Self::SetPrivateMethod => "INST - SetPrivateMethod",
             Self::SetPrivateSetter => "INST - SetPrivateSetter",
             Self::SetPrivateGetter => "INST - SetPrivateGetter",
             Self::GetPrivateField => "INST - GetPrivateField",
-            Self::PushClassComputedFieldName => "INST - PushClassComputedFieldName",
+            Self::PushClassField => "INST - PushClassField",
+            Self::PushClassFieldPrivate => "INST - PushClassFieldPrivate",
+            Self::PushClassPrivateGetter => "INST - PushClassPrivateGetter",
+            Self::PushClassPrivateSetter => "INST - PushClassPrivateSetter",
+            Self::PushClassPrivateMethod => "INST - PushClassPrivateMethod",
             Self::ToPropertyKey => "INST - ToPropertyKey",
         }
     }