Module parsing (#2411)

I'm creating this draft PR, since I wanted to have some early feedback, and because I though I would have time to finish it last week, but I got caught up with other stuff. Feel free to contribute :)

The main thing here is that I have divided `eval()`, `parse()` and similar functions so that they can decide if they are parsing scripts or modules. Let me know your thoughts.

Then, I was checking the import & export parsing, and I noticed we are using `TokenKind::Identifier` for `IdentifierName`, so I changed that name. An `Identifier` is an `IdentifierName` that isn't a `ReservedWord`. This means we should probably also adapt all `IdentifierReference`, `BindingIdentifier` and so on parsing. I already created an `Identifier` parser.

Something interesting there is that `await` is not a valid `Identifier` if the goal symbol is `Module`, as you can see in the [spec](https://tc39.es/ecma262/#prod-LabelIdentifier), but currently we don't have that information in the `InputElement` enumeration, we only have `Div`, `RegExp` and `TemplateTail`. How could we approach this?

Co-authored-by: jedel1043 <jedel0124@gmail.com>

boa_ast/src/declaration/export.rs

@@ -0,0 +1,215 @@
+//! Export declaration AST nodes.
+//!
+//! This module contains `export` declaration AST nodes.
+//!
+//! More information:
+//!  - [MDN documentation][mdn]
+//!  - [ECMAScript specification][spec]
+//!
+//! [spec]: https://tc39.es/ecma262/#sec-exports
+//! [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/export
+
+use std::ops::ControlFlow;
+
+use super::{ModuleSpecifier, VarDeclaration};
+use crate::{
+    function::{AsyncFunction, AsyncGenerator, Class, Function, Generator},
+    try_break,
+    visitor::{VisitWith, Visitor, VisitorMut},
+    Declaration, Expression,
+};
+use boa_interner::Sym;
+
+/// The kind of re-export in an [`ExportDeclaration`].
+#[derive(Debug, Clone)]
+pub enum ReExportKind {
+    /// Namespaced Re-export (`export * as name from "module-name"`).
+    Namespaced {
+        /// Reexported name for the imported module.
+        name: Option<Sym>,
+    },
+    /// Re-export list (`export { export1, export2 as alias2 } from "module-name"`).
+    Named {
+        /// List of the required re-exports of the re-exported module.
+        names: Box<[ExportSpecifier]>,
+    },
+}
+
+impl VisitWith for ReExportKind {
+    fn visit_with<'a, V>(&'a self, visitor: &mut V) -> ControlFlow<V::BreakTy>
+    where
+        V: Visitor<'a>,
+    {
+        match self {
+            Self::Namespaced { name: Some(name) } => visitor.visit_sym(name),
+            Self::Namespaced { name: None } => ControlFlow::Continue(()),
+            Self::Named { names } => {
+                for name in &**names {
+                    try_break!(visitor.visit_export_specifier(name));
+                }
+                ControlFlow::Continue(())
+            }
+        }
+    }
+
+    fn visit_with_mut<'a, V>(&'a mut self, visitor: &mut V) -> ControlFlow<V::BreakTy>
+    where
+        V: VisitorMut<'a>,
+    {
+        match self {
+            Self::Namespaced { name: Some(name) } => visitor.visit_sym_mut(name),
+            Self::Namespaced { name: None } => ControlFlow::Continue(()),
+            Self::Named { names } => {
+                for name in &mut **names {
+                    try_break!(visitor.visit_export_specifier_mut(name));
+                }
+                ControlFlow::Continue(())
+            }
+        }
+    }
+}
+
+/// An export declaration AST node.
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-ExportDeclaration
+#[derive(Debug, Clone)]
+pub enum ExportDeclaration {
+    /// Re-export.
+    ReExport {
+        /// The kind of reexport declared.
+        kind: ReExportKind,
+        /// Reexported module specifier.
+        specifier: ModuleSpecifier,
+    },
+    /// List of exports.
+    List(Box<[ExportSpecifier]>),
+    /// Variable statement export.
+    VarStatement(VarDeclaration),
+    /// Declaration export.
+    Declaration(Declaration),
+    /// Default function export.
+    DefaultFunction(Function),
+    /// Default generator export.
+    DefaultGenerator(Generator),
+    /// Default async function export.
+    DefaultAsyncFunction(AsyncFunction),
+    /// Default async generator export.
+    DefaultAsyncGenerator(AsyncGenerator),
+    /// Default class declaration export.
+    DefaultClassDeclaration(Class),
+    /// Default assignment expression export.
+    DefaultAssignmentExpression(Expression),
+}
+
+impl VisitWith for ExportDeclaration {
+    fn visit_with<'a, V>(&'a self, visitor: &mut V) -> ControlFlow<V::BreakTy>
+    where
+        V: Visitor<'a>,
+    {
+        match self {
+            Self::ReExport { specifier, kind } => {
+                try_break!(visitor.visit_module_specifier(specifier));
+                visitor.visit_re_export_kind(kind)
+            }
+            Self::List(list) => {
+                for item in &**list {
+                    try_break!(visitor.visit_export_specifier(item));
+                }
+                ControlFlow::Continue(())
+            }
+            Self::VarStatement(var) => visitor.visit_var_declaration(var),
+            Self::Declaration(decl) => visitor.visit_declaration(decl),
+            Self::DefaultFunction(f) => visitor.visit_function(f),
+            Self::DefaultGenerator(g) => visitor.visit_generator(g),
+            Self::DefaultAsyncFunction(af) => visitor.visit_async_function(af),
+            Self::DefaultAsyncGenerator(ag) => visitor.visit_async_generator(ag),
+            Self::DefaultClassDeclaration(c) => visitor.visit_class(c),
+            Self::DefaultAssignmentExpression(expr) => visitor.visit_expression(expr),
+        }
+    }
+
+    fn visit_with_mut<'a, V>(&'a mut self, visitor: &mut V) -> ControlFlow<V::BreakTy>
+    where
+        V: VisitorMut<'a>,
+    {
+        match self {
+            Self::ReExport { specifier, kind } => {
+                try_break!(visitor.visit_module_specifier_mut(specifier));
+                visitor.visit_re_export_kind_mut(kind)
+            }
+            Self::List(list) => {
+                for item in &mut **list {
+                    try_break!(visitor.visit_export_specifier_mut(item));
+                }
+                ControlFlow::Continue(())
+            }
+            Self::VarStatement(var) => visitor.visit_var_declaration_mut(var),
+            Self::Declaration(decl) => visitor.visit_declaration_mut(decl),
+            Self::DefaultFunction(f) => visitor.visit_function_mut(f),
+            Self::DefaultGenerator(g) => visitor.visit_generator_mut(g),
+            Self::DefaultAsyncFunction(af) => visitor.visit_async_function_mut(af),
+            Self::DefaultAsyncGenerator(ag) => visitor.visit_async_generator_mut(ag),
+            Self::DefaultClassDeclaration(c) => visitor.visit_class_mut(c),
+            Self::DefaultAssignmentExpression(expr) => visitor.visit_expression_mut(expr),
+        }
+    }
+}
+
+/// Export specifier
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-ExportSpecifier
+#[derive(Debug, Clone, Copy)]
+pub struct ExportSpecifier {
+    alias: Sym,
+    private_name: Sym,
+}
+
+impl ExportSpecifier {
+    /// Creates a new [`ExportSpecifier`].
+    #[inline]
+    #[must_use]
+    pub const fn new(alias: Sym, private_name: Sym) -> Self {
+        Self {
+            alias,
+            private_name,
+        }
+    }
+
+    /// Gets the original alias.
+    #[inline]
+    #[must_use]
+    pub const fn alias(self) -> Sym {
+        self.alias
+    }
+
+    /// Gets the private name of the export inside the module.
+    #[inline]
+    #[must_use]
+    pub const fn private_name(self) -> Sym {
+        self.private_name
+    }
+}
+
+impl VisitWith for ExportSpecifier {
+    fn visit_with<'a, V>(&'a self, visitor: &mut V) -> ControlFlow<V::BreakTy>
+    where
+        V: Visitor<'a>,
+    {
+        try_break!(visitor.visit_sym(&self.alias));
+        visitor.visit_sym(&self.private_name)
+    }
+
+    fn visit_with_mut<'a, V>(&'a mut self, visitor: &mut V) -> ControlFlow<V::BreakTy>
+    where
+        V: VisitorMut<'a>,
+    {
+        try_break!(visitor.visit_sym_mut(&mut self.alias));
+        visitor.visit_sym_mut(&mut self.private_name)
+    }
+}

boa_ast/src/declaration/import.rs

@@ -0,0 +1,206 @@
+//! Import declaration AST nodes.
+//!
+//! This module contains `import` declaration AST nodes.
+//!
+//! More information:
+//! - [MDN documentation][mdn]
+//!  - [ECMAScript specification][spec]
+//!
+//! [spec]: https://tc39.es/ecma262/#sec-imports
+//! [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/import
+
+use std::ops::ControlFlow;
+
+use crate::{
+    expression::Identifier,
+    try_break,
+    visitor::{VisitWith, Visitor, VisitorMut},
+};
+use boa_interner::Sym;
+
+use super::ModuleSpecifier;
+
+/// The kind of import in an [`ImportDeclaration`].
+#[derive(Debug, Clone)]
+pub enum ImportKind {
+    /// Default (`import defaultName from "module-name"`) or unnamed (`import "module-name").
+    DefaultOrUnnamed,
+    /// Namespaced import (`import * as name from "module-name"`).
+    Namespaced {
+        /// Binding for the namespace created from the exports of the imported module.
+        binding: Identifier,
+    },
+    /// Import list (`import { export1, export2 as alias2 } from "module-name"`).
+    Named {
+        /// List of the required exports of the imported module.
+        names: Box<[ImportSpecifier]>,
+    },
+}
+
+impl VisitWith for ImportKind {
+    fn visit_with<'a, V>(&'a self, visitor: &mut V) -> ControlFlow<V::BreakTy>
+    where
+        V: Visitor<'a>,
+    {
+        match self {
+            Self::DefaultOrUnnamed => ControlFlow::Continue(()),
+            Self::Namespaced { binding } => visitor.visit_identifier(binding),
+            Self::Named { names } => {
+                for name in &**names {
+                    try_break!(visitor.visit_import_specifier(name));
+                }
+                ControlFlow::Continue(())
+            }
+        }
+    }
+
+    fn visit_with_mut<'a, V>(&'a mut self, visitor: &mut V) -> ControlFlow<V::BreakTy>
+    where
+        V: VisitorMut<'a>,
+    {
+        match self {
+            Self::DefaultOrUnnamed => ControlFlow::Continue(()),
+            Self::Namespaced { binding } => visitor.visit_identifier_mut(binding),
+            Self::Named { names } => {
+                for name in &mut **names {
+                    try_break!(visitor.visit_import_specifier_mut(name));
+                }
+                ControlFlow::Continue(())
+            }
+        }
+    }
+}
+
+/// An import declaration AST node.
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-ImportDeclaration
+#[derive(Debug, Clone)]
+pub struct ImportDeclaration {
+    /// Binding for the default export of `specifier`.
+    default: Option<Identifier>,
+    /// See [`ImportKind`].
+    kind: ImportKind,
+    /// Module specifier.
+    specifier: ModuleSpecifier,
+}
+
+impl ImportDeclaration {
+    /// Creates a new import declaration.
+    #[inline]
+    #[must_use]
+    pub const fn new(
+        default: Option<Identifier>,
+        kind: ImportKind,
+        specifier: ModuleSpecifier,
+    ) -> Self {
+        Self {
+            default,
+            kind,
+            specifier,
+        }
+    }
+
+    /// Gets the binding for the default export of the module.
+    #[inline]
+    #[must_use]
+    pub const fn default(&self) -> Option<Identifier> {
+        self.default
+    }
+
+    /// Gets the module specifier of the import declaration.
+    #[inline]
+    #[must_use]
+    pub const fn specifier(&self) -> ModuleSpecifier {
+        self.specifier
+    }
+
+    /// Gets the import kind of the import declaration
+    #[inline]
+    #[must_use]
+    pub const fn kind(&self) -> &ImportKind {
+        &self.kind
+    }
+}
+
+impl VisitWith for ImportDeclaration {
+    fn visit_with<'a, V>(&'a self, visitor: &mut V) -> ControlFlow<V::BreakTy>
+    where
+        V: Visitor<'a>,
+    {
+        if let Some(default) = &self.default {
+            try_break!(visitor.visit_identifier(default));
+        }
+        try_break!(visitor.visit_import_kind(&self.kind));
+        visitor.visit_module_specifier(&self.specifier)
+    }
+
+    fn visit_with_mut<'a, V>(&'a mut self, visitor: &mut V) -> ControlFlow<V::BreakTy>
+    where
+        V: VisitorMut<'a>,
+    {
+        if let Some(default) = &mut self.default {
+            try_break!(visitor.visit_identifier_mut(default));
+        }
+        try_break!(visitor.visit_import_kind_mut(&mut self.kind));
+        visitor.visit_module_specifier_mut(&mut self.specifier)
+    }
+}
+
+/// Import specifier
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-ImportSpecifier
+#[derive(Debug, Clone, Copy)]
+pub struct ImportSpecifier {
+    binding: Identifier,
+    export_name: Sym,
+}
+
+impl ImportSpecifier {
+    /// Creates a new [`ImportSpecifier`].
+    #[inline]
+    #[must_use]
+    pub const fn new(binding: Identifier, export_name: Sym) -> Self {
+        Self {
+            binding,
+            export_name,
+        }
+    }
+
+    /// Gets the binding of the import specifier.
+    #[inline]
+    #[must_use]
+    pub const fn binding(self) -> Identifier {
+        self.binding
+    }
+
+    /// Gets the optional export name of the import.
+    #[inline]
+    #[must_use]
+    pub const fn export_name(self) -> Sym {
+        self.export_name
+    }
+}
+
+impl VisitWith for ImportSpecifier {
+    fn visit_with<'a, V>(&'a self, visitor: &mut V) -> ControlFlow<V::BreakTy>
+    where
+        V: Visitor<'a>,
+    {
+        try_break!(visitor.visit_identifier(&self.binding));
+        visitor.visit_sym(&self.export_name)
+    }
+
+    fn visit_with_mut<'a, V>(&'a mut self, visitor: &mut V) -> ControlFlow<V::BreakTy>
+    where
+        V: VisitorMut<'a>,
+    {
+        try_break!(visitor.visit_identifier_mut(&mut self.binding));
+        visitor.visit_sym_mut(&mut self.export_name)
+    }
+}

boa_ast/src/declaration/mod.rs

@@ -15,12 +15,16 @@
 //! [diff]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements#difference_between_statements_and_declarations
 
 use super::function::{AsyncFunction, AsyncGenerator, Class, Function, Generator};
-use boa_interner::{Interner, ToIndentedString, ToInternedString};
+use boa_interner::{Interner, Sym, ToIndentedString, ToInternedString};
 use core::ops::ControlFlow;
 
+mod export;
+mod import;
 mod variable;
 
 use crate::visitor::{VisitWith, Visitor, VisitorMut};
+pub use export::*;
+pub use import::*;
 pub use variable::*;
 
 /// The `Declaration` Parse Node.
@@ -95,3 +99,51 @@ impl VisitWith for Declaration {
         }
     }
 }
+
+/// Module specifier.
+///
+/// This is equivalent to the [`ModuleSpecifier`] production.
+///
+/// [`FromClause`]: https://tc39.es/ecma262/#prod-ModuleSpecifier
+#[derive(Debug, Clone, Copy)]
+pub struct ModuleSpecifier {
+    module: Sym,
+}
+
+impl ModuleSpecifier {
+    /// Creates a `ModuleSpecifier` from a `Sym`.
+    #[must_use]
+    pub const fn new(module: Sym) -> Self {
+        Self { module }
+    }
+
+    /// Gets the inner `Sym` of the module specifier.
+    #[inline]
+    #[must_use]
+    pub const fn sym(self) -> Sym {
+        self.module
+    }
+}
+
+impl From<Sym> for ModuleSpecifier {
+    #[inline]
+    fn from(module: Sym) -> Self {
+        Self::new(module)
+    }
+}
+
+impl VisitWith for ModuleSpecifier {
+    fn visit_with<'a, V>(&'a self, visitor: &mut V) -> ControlFlow<V::BreakTy>
+    where
+        V: Visitor<'a>,
+    {
+        visitor.visit_sym(&self.module)
+    }
+
+    fn visit_with_mut<'a, V>(&'a mut self, visitor: &mut V) -> ControlFlow<V::BreakTy>
+    where
+        V: VisitorMut<'a>,
+    {
+        visitor.visit_sym_mut(&mut self.module)
+    }
+}

boa_ast/src/lib.rs

@@ -102,6 +102,7 @@ pub mod declaration;
 pub mod expression;
 pub mod function;
 pub mod keyword;
+pub mod module_item_list;
 pub mod operations;
 pub mod pattern;
 pub mod property;
@@ -114,6 +115,7 @@ pub use self::{
     declaration::Declaration,
     expression::Expression,
     keyword::Keyword,
+    module_item_list::{ModuleItem, ModuleItemList},
     position::{Position, Span},
     punctuator::Punctuator,
     statement::Statement,

boa_ast/src/module_item_list/mod.rs

@@ -0,0 +1,275 @@
+//! Module item list AST nodes.
+//!
+//! More information:
+//!  - [ECMAScript specification][spec]
+//!
+//! [spec]: https://tc39.es/ecma262/#sec-modules
+
+use std::{convert::Infallible, ops::ControlFlow};
+
+use boa_interner::Sym;
+use rustc_hash::FxHashSet;
+
+use crate::{
+    declaration::{ExportDeclaration, ExportSpecifier, ImportDeclaration, ReExportKind},
+    expression::Identifier,
+    operations::BoundNamesVisitor,
+    try_break,
+    visitor::{VisitWith, Visitor, VisitorMut},
+    StatementListItem,
+};
+
+/// Module item list AST node.
+///
+/// It contains a list of
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-ModuleItemList
+#[derive(Debug, Clone)]
+pub struct ModuleItemList {
+    items: Box<[ModuleItem]>,
+}
+
+impl ModuleItemList {
+    /// Gets the list of module items.
+    #[inline]
+    #[must_use]
+    pub const fn items(&self) -> &[ModuleItem] {
+        &self.items
+    }
+
+    /// Abstract operation [`ExportedNames`][spec].
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-static-semantics-exportednames
+    #[inline]
+    #[must_use]
+    pub fn exported_names(&self) -> Vec<Sym> {
+        #[derive(Debug)]
+        struct ExportedItemsVisitor<'vec>(&'vec mut Vec<Sym>);
+
+        impl<'ast> Visitor<'ast> for ExportedItemsVisitor<'_> {
+            type BreakTy = Infallible;
+
+            fn visit_import_declaration(
+                &mut self,
+                _: &'ast ImportDeclaration,
+            ) -> ControlFlow<Self::BreakTy> {
+                ControlFlow::Continue(())
+            }
+            fn visit_statement_list_item(
+                &mut self,
+                _: &'ast StatementListItem,
+            ) -> ControlFlow<Self::BreakTy> {
+                ControlFlow::Continue(())
+            }
+            fn visit_export_specifier(
+                &mut self,
+                node: &'ast ExportSpecifier,
+            ) -> ControlFlow<Self::BreakTy> {
+                self.0.push(node.alias());
+                ControlFlow::Continue(())
+            }
+            fn visit_export_declaration(
+                &mut self,
+                node: &'ast ExportDeclaration,
+            ) -> ControlFlow<Self::BreakTy> {
+                match node {
+                    ExportDeclaration::ReExport { kind, .. } => {
+                        match kind {
+                            ReExportKind::Namespaced { name: Some(name) } => self.0.push(*name),
+                            ReExportKind::Namespaced { name: None } => {}
+                            ReExportKind::Named { names } => {
+                                for specifier in &**names {
+                                    try_break!(self.visit_export_specifier(specifier));
+                                }
+                            }
+                        }
+                        ControlFlow::Continue(())
+                    }
+                    ExportDeclaration::List(list) => {
+                        for specifier in &**list {
+                            try_break!(self.visit_export_specifier(specifier));
+                        }
+                        ControlFlow::Continue(())
+                    }
+                    ExportDeclaration::VarStatement(var) => {
+                        BoundNamesVisitor(self.0).visit_var_declaration(var)
+                    }
+                    ExportDeclaration::Declaration(decl) => {
+                        BoundNamesVisitor(self.0).visit_declaration(decl)
+                    }
+                    ExportDeclaration::DefaultFunction(_)
+                    | ExportDeclaration::DefaultGenerator(_)
+                    | ExportDeclaration::DefaultAsyncFunction(_)
+                    | ExportDeclaration::DefaultAsyncGenerator(_)
+                    | ExportDeclaration::DefaultClassDeclaration(_)
+                    | ExportDeclaration::DefaultAssignmentExpression(_) => {
+                        self.0.push(Sym::DEFAULT);
+                        ControlFlow::Continue(())
+                    }
+                }
+            }
+        }
+
+        let mut names = Vec::new();
+
+        ExportedItemsVisitor(&mut names).visit_module_item_list(self);
+
+        names
+    }
+
+    /// Abstract operation [`ExportedBindings`][spec].
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-static-semantics-exportedbindings
+    #[inline]
+    #[must_use]
+    pub fn exported_bindings(&self) -> FxHashSet<Identifier> {
+        #[derive(Debug)]
+        struct ExportedBindingsVisitor<'vec>(&'vec mut FxHashSet<Identifier>);
+
+        impl<'ast> Visitor<'ast> for ExportedBindingsVisitor<'_> {
+            type BreakTy = Infallible;
+
+            fn visit_import_declaration(
+                &mut self,
+                _: &'ast ImportDeclaration,
+            ) -> ControlFlow<Self::BreakTy> {
+                ControlFlow::Continue(())
+            }
+            fn visit_statement_list_item(
+                &mut self,
+                _: &'ast StatementListItem,
+            ) -> ControlFlow<Self::BreakTy> {
+                ControlFlow::Continue(())
+            }
+            fn visit_export_specifier(
+                &mut self,
+                node: &'ast ExportSpecifier,
+            ) -> ControlFlow<Self::BreakTy> {
+                self.0.insert(Identifier::new(node.private_name()));
+                ControlFlow::Continue(())
+            }
+            fn visit_export_declaration(
+                &mut self,
+                node: &'ast ExportDeclaration,
+            ) -> ControlFlow<Self::BreakTy> {
+                let name = match node {
+                    ExportDeclaration::ReExport { .. } => return ControlFlow::Continue(()),
+                    ExportDeclaration::List(list) => {
+                        for specifier in &**list {
+                            try_break!(self.visit_export_specifier(specifier));
+                        }
+                        return ControlFlow::Continue(());
+                    }
+                    ExportDeclaration::DefaultAssignmentExpression(expr) => {
+                        return BoundNamesVisitor(self.0).visit_expression(expr);
+                    }
+                    ExportDeclaration::VarStatement(var) => {
+                        return BoundNamesVisitor(self.0).visit_var_declaration(var);
+                    }
+                    ExportDeclaration::Declaration(decl) => {
+                        return BoundNamesVisitor(self.0).visit_declaration(decl);
+                    }
+                    ExportDeclaration::DefaultFunction(f) => f.name(),
+                    ExportDeclaration::DefaultGenerator(g) => g.name(),
+                    ExportDeclaration::DefaultAsyncFunction(af) => af.name(),
+                    ExportDeclaration::DefaultAsyncGenerator(ag) => ag.name(),
+                    ExportDeclaration::DefaultClassDeclaration(cl) => cl.name(),
+                };
+
+                self.0
+                    .insert(name.unwrap_or_else(|| Identifier::new(Sym::DEFAULT_EXPORT)));
+
+                ControlFlow::Continue(())
+            }
+        }
+
+        let mut names = FxHashSet::default();
+
+        ExportedBindingsVisitor(&mut names).visit_module_item_list(self);
+
+        names
+    }
+}
+
+impl<T> From<T> for ModuleItemList
+where
+    T: Into<Box<[ModuleItem]>>,
+{
+    #[inline]
+    fn from(items: T) -> Self {
+        Self {
+            items: items.into(),
+        }
+    }
+}
+
+impl VisitWith for ModuleItemList {
+    fn visit_with<'a, V>(&'a self, visitor: &mut V) -> ControlFlow<V::BreakTy>
+    where
+        V: Visitor<'a>,
+    {
+        for item in &*self.items {
+            try_break!(visitor.visit_module_item(item));
+        }
+
+        ControlFlow::Continue(())
+    }
+
+    fn visit_with_mut<'a, V>(&'a mut self, visitor: &mut V) -> ControlFlow<V::BreakTy>
+    where
+        V: VisitorMut<'a>,
+    {
+        for item in &mut *self.items {
+            try_break!(visitor.visit_module_item_mut(item));
+        }
+
+        ControlFlow::Continue(())
+    }
+}
+
+/// Module item AST node.
+///
+/// This is an extension over a [`StatementList`](crate::StatementList), which can also include
+/// multiple [`ImportDeclaration`] and [`ExportDeclaration`] nodes, along with
+/// [`StatementListItem`] nodes.
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-ModuleItem
+#[derive(Debug, Clone)]
+pub enum ModuleItem {
+    /// See [`ImportDeclaration`].
+    ImportDeclaration(ImportDeclaration),
+    /// See [`ExportDeclaration`].
+    ExportDeclaration(ExportDeclaration),
+    /// See [`StatementListItem`].
+    StatementListItem(StatementListItem),
+}
+
+impl VisitWith for ModuleItem {
+    fn visit_with<'a, V>(&'a self, visitor: &mut V) -> ControlFlow<V::BreakTy>
+    where
+        V: Visitor<'a>,
+    {
+        match self {
+            Self::ImportDeclaration(i) => visitor.visit_import_declaration(i),
+            Self::ExportDeclaration(e) => visitor.visit_export_declaration(e),
+            Self::StatementListItem(s) => visitor.visit_statement_list_item(s),
+        }
+    }
+
+    fn visit_with_mut<'a, V>(&'a mut self, visitor: &mut V) -> ControlFlow<V::BreakTy>
+    where
+        V: VisitorMut<'a>,
+    {
+        match self {
+            Self::ImportDeclaration(i) => visitor.visit_import_declaration_mut(i),
+            Self::ExportDeclaration(e) => visitor.visit_export_declaration_mut(e),
+            Self::StatementListItem(s) => visitor.visit_statement_list_item_mut(s),
+        }
+    }
+}

boa_ast/src/operations.rs

@@ -9,7 +9,7 @@ use boa_interner::Sym;
 use rustc_hash::{FxHashMap, FxHashSet};
 
 use crate::{
-    declaration::VarDeclaration,
+    declaration::{ExportDeclaration, ImportDeclaration, VarDeclaration},
     expression::{access::SuperPropertyAccess, Await, Identifier, SuperCall, Yield},
     function::{
         ArrowFunction, AsyncArrowFunction, AsyncFunction, AsyncGenerator, Class, ClassElement,
@@ -299,37 +299,43 @@ pub fn has_direct_super(method: &MethodDefinition) -> bool {
 }
 
 /// A container that [`BoundNamesVisitor`] can use to push the found identifiers.
-trait IdentList {
-    fn add(&mut self, value: Identifier, function: bool);
+pub(crate) trait IdentList {
+    fn add(&mut self, value: Sym, function: bool);
 }
 
-impl IdentList for Vec<Identifier> {
-    fn add(&mut self, value: Identifier, _function: bool) {
+impl IdentList for Vec<Sym> {
+    fn add(&mut self, value: Sym, _function: bool) {
         self.push(value);
     }
 }
 
+impl IdentList for Vec<Identifier> {
+    fn add(&mut self, value: Sym, _function: bool) {
+        self.push(Identifier::new(value));
+    }
+}
+
 impl IdentList for Vec<(Identifier, bool)> {
-    fn add(&mut self, value: Identifier, function: bool) {
-        self.push((value, function));
+    fn add(&mut self, value: Sym, function: bool) {
+        self.push((Identifier::new(value), function));
     }
 }
 
 impl IdentList for FxHashSet<Identifier> {
-    fn add(&mut self, value: Identifier, _function: bool) {
-        self.insert(value);
+    fn add(&mut self, value: Sym, _function: bool) {
+        self.insert(Identifier::new(value));
     }
 }
 
 /// The [`Visitor`] used to obtain the bound names of a node.
 #[derive(Debug)]
-struct BoundNamesVisitor<'a, T: IdentList>(&'a mut T);
+pub(crate) struct BoundNamesVisitor<'a, T: IdentList>(pub(crate) &'a mut T);
 
 impl<'ast, T: IdentList> Visitor<'ast> for BoundNamesVisitor<'_, T> {
     type BreakTy = Infallible;
 
     fn visit_identifier(&mut self, node: &'ast Identifier) -> ControlFlow<Self::BreakTy> {
-        self.0.add(*node, false);
+        self.0.add(node.sym(), false);
         ControlFlow::Continue(())
     }
 
@@ -337,41 +343,82 @@ impl<'ast, T: IdentList> Visitor<'ast> for BoundNamesVisitor<'_, T> {
         ControlFlow::Continue(())
     }
 
-    // TODO: add "*default" for module default functions without name
     fn visit_function(&mut self, node: &'ast Function) -> ControlFlow<Self::BreakTy> {
         if let Some(ident) = node.name() {
-            self.0.add(ident, true);
+            self.0.add(ident.sym(), true);
         }
         ControlFlow::Continue(())
     }
 
     fn visit_generator(&mut self, node: &'ast Generator) -> ControlFlow<Self::BreakTy> {
         if let Some(ident) = node.name() {
-            self.0.add(ident, false);
+            self.0.add(ident.sym(), false);
         }
         ControlFlow::Continue(())
     }
 
     fn visit_async_function(&mut self, node: &'ast AsyncFunction) -> ControlFlow<Self::BreakTy> {
         if let Some(ident) = node.name() {
-            self.0.add(ident, false);
+            self.0.add(ident.sym(), false);
         }
         ControlFlow::Continue(())
     }
 
     fn visit_async_generator(&mut self, node: &'ast AsyncGenerator) -> ControlFlow<Self::BreakTy> {
         if let Some(ident) = node.name() {
-            self.0.add(ident, false);
+            self.0.add(ident.sym(), false);
         }
         ControlFlow::Continue(())
     }
 
     fn visit_class(&mut self, node: &'ast Class) -> ControlFlow<Self::BreakTy> {
         if let Some(ident) = node.name() {
-            self.0.add(ident, false);
+            self.0.add(ident.sym(), false);
         }
         ControlFlow::Continue(())
     }
+
+    fn visit_export_declaration(
+        &mut self,
+        node: &'ast ExportDeclaration,
+    ) -> ControlFlow<Self::BreakTy> {
+        match node {
+            ExportDeclaration::VarStatement(var) => try_break!(self.visit_var_declaration(var)),
+            ExportDeclaration::Declaration(decl) => try_break!(self.visit_declaration(decl)),
+            ExportDeclaration::DefaultFunction(f) => {
+                self.0
+                    .add(f.name().map_or(Sym::DEFAULT_EXPORT, Identifier::sym), true);
+            }
+            ExportDeclaration::DefaultGenerator(g) => {
+                self.0
+                    .add(g.name().map_or(Sym::DEFAULT_EXPORT, Identifier::sym), false);
+            }
+            ExportDeclaration::DefaultAsyncFunction(af) => {
+                self.0.add(
+                    af.name().map_or(Sym::DEFAULT_EXPORT, Identifier::sym),
+                    false,
+                );
+            }
+            ExportDeclaration::DefaultAsyncGenerator(ag) => {
+                self.0.add(
+                    ag.name().map_or(Sym::DEFAULT_EXPORT, Identifier::sym),
+                    false,
+                );
+            }
+            ExportDeclaration::DefaultClassDeclaration(cl) => {
+                self.0.add(
+                    cl.name().map_or(Sym::DEFAULT_EXPORT, Identifier::sym),
+                    false,
+                );
+            }
+            ExportDeclaration::DefaultAssignmentExpression(_) => {
+                self.0.add(Sym::DEFAULT_EXPORT, false);
+            }
+            ExportDeclaration::ReExport { .. } | ExportDeclaration::List(_) => {}
+        }
+
+        ControlFlow::Continue(())
+    }
 }
 
 /// Returns a list with the bound names of an AST node, which may contain duplicates.
@@ -448,6 +495,21 @@ impl<'ast, T: IdentList> Visitor<'ast> for LexicallyDeclaredNamesVisitor<'_, T>
         }
         ControlFlow::Continue(())
     }
+    fn visit_import_declaration(
+        &mut self,
+        node: &'ast ImportDeclaration,
+    ) -> ControlFlow<Self::BreakTy> {
+        BoundNamesVisitor(self.0).visit_import_declaration(node)
+    }
+    fn visit_export_declaration(
+        &mut self,
+        node: &'ast ExportDeclaration,
+    ) -> ControlFlow<Self::BreakTy> {
+        if matches!(node, ExportDeclaration::VarStatement(_)) {
+            return ControlFlow::Continue(());
+        }
+        BoundNamesVisitor(self.0).visit_export_declaration(node)
+    }
 
     // TODO:  ScriptBody : StatementList
     // 1. Return TopLevelLexicallyDeclaredNames of StatementList.
@@ -552,6 +614,25 @@ impl<'ast> Visitor<'ast> for VarDeclaredNamesVisitor<'_> {
         node.visit_with(self)
     }
 
+    fn visit_import_declaration(
+        &mut self,
+        _: &'ast ImportDeclaration,
+    ) -> ControlFlow<Self::BreakTy> {
+        ControlFlow::Continue(())
+    }
+
+    fn visit_export_declaration(
+        &mut self,
+        node: &'ast ExportDeclaration,
+    ) -> ControlFlow<Self::BreakTy> {
+        match node {
+            ExportDeclaration::VarStatement(var) => {
+                BoundNamesVisitor(self.0).visit_var_declaration(var)
+            }
+            _ => ControlFlow::Continue(()),
+        }
+    }
+
     // TODO:  ScriptBody : StatementList
     // 1. Return TopLevelVarDeclaredNames of StatementList.
     // But we don't have that node yet. In the meantime, use `top_level_var_declared_names` directly.

boa_ast/src/visitor.rs

@@ -7,7 +7,9 @@ use std::ops::ControlFlow;
 
 use crate::{
     declaration::{
-        Binding, Declaration, LexicalDeclaration, VarDeclaration, Variable, VariableList,
+        Binding, Declaration, ExportDeclaration, ExportSpecifier, ImportDeclaration, ImportKind,
+        ImportSpecifier, LexicalDeclaration, ModuleSpecifier, ReExportKind, VarDeclaration,
+        Variable, VariableList,
     },
     expression::{
         access::{
@@ -36,7 +38,7 @@ use crate::{
         Block, Case, Catch, Finally, If, Labelled, LabelledItem, Return, Statement, Switch, Throw,
         Try,
     },
-    StatementList, StatementListItem,
+    ModuleItem, ModuleItemList, StatementList, StatementListItem,
 };
 use boa_interner::Sym;
 
@@ -194,6 +196,15 @@ node_ref! {
     ArrayPatternElement,
     PropertyAccessField,
     OptionalOperationKind,
+    ModuleItemList,
+    ModuleItem,
+    ModuleSpecifier,
+    ImportKind,
+    ImportDeclaration,
+    ImportSpecifier,
+    ReExportKind,
+    ExportDeclaration,
+    ExportSpecifier
 }
 
 /// Represents an AST visitor.
@@ -282,6 +293,15 @@ pub trait Visitor<'ast>: Sized {
     define_visit!(visit_array_pattern_element, ArrayPatternElement);
     define_visit!(visit_property_access_field, PropertyAccessField);
     define_visit!(visit_optional_operation_kind, OptionalOperationKind);
+    define_visit!(visit_module_item_list, ModuleItemList);
+    define_visit!(visit_module_item, ModuleItem);
+    define_visit!(visit_module_specifier, ModuleSpecifier);
+    define_visit!(visit_import_kind, ImportKind);
+    define_visit!(visit_import_declaration, ImportDeclaration);
+    define_visit!(visit_import_specifier, ImportSpecifier);
+    define_visit!(visit_re_export_kind, ReExportKind);
+    define_visit!(visit_export_declaration, ExportDeclaration);
+    define_visit!(visit_export_specifier, ExportSpecifier);
 
     /// Generic entry point for a node that is visitable by a `Visitor`.
     ///
@@ -367,6 +387,15 @@ pub trait Visitor<'ast>: Sized {
             NodeRef::ArrayPatternElement(n) => self.visit_array_pattern_element(n),
             NodeRef::PropertyAccessField(n) => self.visit_property_access_field(n),
             NodeRef::OptionalOperationKind(n) => self.visit_optional_operation_kind(n),
+            NodeRef::ModuleItemList(n) => self.visit_module_item_list(n),
+            NodeRef::ModuleItem(n) => self.visit_module_item(n),
+            NodeRef::ModuleSpecifier(n) => self.visit_module_specifier(n),
+            NodeRef::ImportKind(n) => self.visit_import_kind(n),
+            NodeRef::ImportDeclaration(n) => self.visit_import_declaration(n),
+            NodeRef::ImportSpecifier(n) => self.visit_import_specifier(n),
+            NodeRef::ReExportKind(n) => self.visit_re_export_kind(n),
+            NodeRef::ExportDeclaration(n) => self.visit_export_declaration(n),
+            NodeRef::ExportSpecifier(n) => self.visit_export_specifier(n),
         }
     }
 }
@@ -457,6 +486,15 @@ pub trait VisitorMut<'ast>: Sized {
     define_visit_mut!(visit_array_pattern_element_mut, ArrayPatternElement);
     define_visit_mut!(visit_property_access_field_mut, PropertyAccessField);
     define_visit_mut!(visit_optional_operation_kind_mut, OptionalOperationKind);
+    define_visit_mut!(visit_module_item_list_mut, ModuleItemList);
+    define_visit_mut!(visit_module_item_mut, ModuleItem);
+    define_visit_mut!(visit_module_specifier_mut, ModuleSpecifier);
+    define_visit_mut!(visit_import_kind_mut, ImportKind);
+    define_visit_mut!(visit_import_declaration_mut, ImportDeclaration);
+    define_visit_mut!(visit_import_specifier_mut, ImportSpecifier);
+    define_visit_mut!(visit_re_export_kind_mut, ReExportKind);
+    define_visit_mut!(visit_export_declaration_mut, ExportDeclaration);
+    define_visit_mut!(visit_export_specifier_mut, ExportSpecifier);
 
     /// Generic entry point for a node that is visitable by a `VisitorMut`.
     ///
@@ -542,6 +580,15 @@ pub trait VisitorMut<'ast>: Sized {
             NodeRefMut::ArrayPatternElement(n) => self.visit_array_pattern_element_mut(n),
             NodeRefMut::PropertyAccessField(n) => self.visit_property_access_field_mut(n),
             NodeRefMut::OptionalOperationKind(n) => self.visit_optional_operation_kind_mut(n),
+            NodeRefMut::ModuleItemList(n) => self.visit_module_item_list_mut(n),
+            NodeRefMut::ModuleItem(n) => self.visit_module_item_mut(n),
+            NodeRefMut::ModuleSpecifier(n) => self.visit_module_specifier_mut(n),
+            NodeRefMut::ImportKind(n) => self.visit_import_kind_mut(n),
+            NodeRefMut::ImportDeclaration(n) => self.visit_import_declaration_mut(n),
+            NodeRefMut::ImportSpecifier(n) => self.visit_import_specifier_mut(n),
+            NodeRefMut::ReExportKind(n) => self.visit_re_export_kind_mut(n),
+            NodeRefMut::ExportDeclaration(n) => self.visit_export_declaration_mut(n),
+            NodeRefMut::ExportSpecifier(n) => self.visit_export_specifier_mut(n),
         }
     }
 }

boa_cli/src/main.rs

@@ -194,7 +194,7 @@ where
     S: AsRef<[u8]> + ?Sized,
 {
     boa_parser::Parser::new(Source::from_bytes(&src))
-        .parse_all(context.interner_mut())
+        .parse_script(context.interner_mut())
         .map_err(|e| format!("Uncaught SyntaxError: {e}"))
 }
 
@@ -232,8 +232,8 @@ fn generate_flowgraph(
     format: FlowgraphFormat,
     direction: Option<FlowgraphDirection>,
 ) -> JsResult<String> {
-    let ast = context.parse(Source::from_bytes(src))?;
-    let code = context.compile(&ast)?;
+    let ast = context.parse_script(Source::from_bytes(src))?;
+    let code = context.compile_script(&ast)?;
 
     let direction = match direction {
         Some(FlowgraphDirection::TopToBottom) | None => Direction::TopToBottom,
@@ -281,7 +281,7 @@ fn main() -> Result<(), io::Error> {
                 Err(v) => eprintln!("Uncaught {v}"),
             }
         } else {
-            match context.eval(Source::from_bytes(&buffer)) {
+            match context.eval_script(Source::from_bytes(&buffer)) {
                 Ok(v) => println!("{}", v.display()),
                 Err(v) => eprintln!("Uncaught {v}"),
             }
@@ -338,7 +338,7 @@ fn main() -> Result<(), io::Error> {
                             Err(v) => eprintln!("Uncaught {v}"),
                         }
                     } else {
-                        match context.eval(Source::from_bytes(line.trim_end())) {
+                        match context.eval_script(Source::from_bytes(line.trim_end())) {
                             Ok(v) => {
                                 println!("{}", v.display());
                             }

boa_engine/benches/full.rs

@@ -25,7 +25,7 @@ macro_rules! full_benchmarks {
                     static CODE: &str = include_str!(concat!("bench_scripts/", stringify!($name), ".js"));
                     let mut context = Context::default();
                     c.bench_function(concat!($id, " (Parser)"), move |b| {
-                        b.iter(|| context.parse(black_box(Source::from_bytes(CODE))))
+                        b.iter(|| context.parse_script(black_box(Source::from_bytes(CODE))))
                     });
                 }
             )*
@@ -35,10 +35,10 @@ macro_rules! full_benchmarks {
                 {
                     static CODE: &str = include_str!(concat!("bench_scripts/", stringify!($name), ".js"));
                     let mut context = Context::default();
-                    let statement_list = context.parse(Source::from_bytes(CODE)).expect("parsing failed");
+                    let statement_list = context.parse_script(Source::from_bytes(CODE)).expect("parsing failed");
                     c.bench_function(concat!($id, " (Compiler)"), move |b| {
                         b.iter(|| {
-                            context.compile(black_box(&statement_list))
+                            context.compile_script(black_box(&statement_list))
                         })
                     });
                 }
@@ -49,8 +49,8 @@ macro_rules! full_benchmarks {
                 {
                     static CODE: &str = include_str!(concat!("bench_scripts/", stringify!($name), ".js"));
                     let mut context = Context::default();
-                    let statement_list = context.parse(Source::from_bytes(CODE)).expect("parsing failed");
-                    let code_block = context.compile(&statement_list).unwrap();
+                    let statement_list = context.parse_script(Source::from_bytes(CODE)).expect("parsing failed");
+                    let code_block = context.compile_script(&statement_list).unwrap();
                     c.bench_function(concat!($id, " (Execution)"), move |b| {
                         b.iter(|| {
                             context.execute(black_box(code_block.clone())).unwrap()

boa_engine/src/builtins/array/tests.rs

@@ -12,62 +12,64 @@ fn is_array() {
         var new_arr = new Array();
         var many = ["a", "b", "c"];
         "#;
-    context.eval(Source::from_bytes(init)).unwrap();
+    context.eval_script(Source::from_bytes(init)).unwrap();
     assert_eq!(
         context
-            .eval(Source::from_bytes("Array.isArray(empty)"))
+            .eval_script(Source::from_bytes("Array.isArray(empty)"))
             .unwrap(),
         JsValue::new(true)
     );
     assert_eq!(
         context
-            .eval(Source::from_bytes("Array.isArray(new_arr)"))
+            .eval_script(Source::from_bytes("Array.isArray(new_arr)"))
             .unwrap(),
         JsValue::new(true)
     );
     assert_eq!(
         context
-            .eval(Source::from_bytes("Array.isArray(many)"))
+            .eval_script(Source::from_bytes("Array.isArray(many)"))
             .unwrap(),
         JsValue::new(true)
     );
     assert_eq!(
         context
-            .eval(Source::from_bytes("Array.isArray([1, 2, 3])"))
+            .eval_script(Source::from_bytes("Array.isArray([1, 2, 3])"))
             .unwrap(),
         JsValue::new(true)
     );
     assert_eq!(
         context
-            .eval(Source::from_bytes("Array.isArray([])"))
+            .eval_script(Source::from_bytes("Array.isArray([])"))
             .unwrap(),
         JsValue::new(true)
     );
     assert_eq!(
         context
-            .eval(Source::from_bytes("Array.isArray({})"))
+            .eval_script(Source::from_bytes("Array.isArray({})"))
             .unwrap(),
         JsValue::new(false)
     );
     assert_eq!(
         context
-            .eval(Source::from_bytes("Array.isArray(new Array)"))
+            .eval_script(Source::from_bytes("Array.isArray(new Array)"))
             .unwrap(),
         JsValue::new(true)
     );
     assert_eq!(
-        context.eval(Source::from_bytes("Array.isArray()")).unwrap(),
+        context
+            .eval_script(Source::from_bytes("Array.isArray()"))
+            .unwrap(),
         JsValue::new(false)
     );
     assert_eq!(
         context
-            .eval(Source::from_bytes("Array.isArray({ constructor: Array })"))
+            .eval_script(Source::from_bytes("Array.isArray({ constructor: Array })"))
             .unwrap(),
         JsValue::new(false)
     );
     assert_eq!(
         context
-            .eval(Source::from_bytes(
+            .eval_script(Source::from_bytes(
                 "Array.isArray({ push: Array.prototype.push, concat: Array.prototype.concat })"
             ))
             .unwrap(),
@@ -75,13 +77,13 @@ fn is_array() {
     );
     assert_eq!(
         context
-            .eval(Source::from_bytes("Array.isArray(17)"))
+            .eval_script(Source::from_bytes("Array.isArray(17)"))
             .unwrap(),
         JsValue::new(false)
     );
     assert_eq!(
         context
-            .eval(Source::from_bytes(
+            .eval_script(Source::from_bytes(
                 "Array.isArray({ __proto__: Array.prototype })"
             ))
             .unwrap(),
@@ -89,7 +91,7 @@ fn is_array() {
     );
     assert_eq!(
         context
-            .eval(Source::from_bytes("Array.isArray({ length: 0 })"))
+            .eval_script(Source::from_bytes("Array.isArray({ length: 0 })"))
             .unwrap(),
         JsValue::new(false)
     );
@@ -100,66 +102,66 @@ fn of() {
     let mut context = Context::default();
     assert_eq!(
         context
-            .eval(Source::from_bytes("Array.of(1, 2, 3)"))
+            .eval_script(Source::from_bytes("Array.of(1, 2, 3)"))
             .unwrap()
             .to_string(&mut context)
             .unwrap(),
         context
-            .eval(Source::from_bytes("[1, 2, 3]"))
+            .eval_script(Source::from_bytes("[1, 2, 3]"))
             .unwrap()
             .to_string(&mut context)
             .unwrap()
     );
     assert_eq!(
         context
-            .eval(Source::from_bytes("Array.of(1, 'a', [], undefined, null)"))
+            .eval_script(Source::from_bytes("Array.of(1, 'a', [], undefined, null)"))
             .unwrap()
             .to_string(&mut context)
             .unwrap(),
         context
-            .eval(Source::from_bytes("[1, 'a', [], undefined, null]"))
+            .eval_script(Source::from_bytes("[1, 'a', [], undefined, null]"))
             .unwrap()
             .to_string(&mut context)
             .unwrap()
     );
     assert_eq!(
         context
-            .eval(Source::from_bytes("Array.of()"))
+            .eval_script(Source::from_bytes("Array.of()"))
             .unwrap()
             .to_string(&mut context)
             .unwrap(),
         context
-            .eval(Source::from_bytes("[]"))
+            .eval_script(Source::from_bytes("[]"))
             .unwrap()
             .to_string(&mut context)
             .unwrap()
     );
 
     context
-        .eval(Source::from_bytes(
+        .eval_script(Source::from_bytes(
             r#"let a = Array.of.call(Date, "a", undefined, 3);"#,
         ))
         .unwrap();
     assert_eq!(
         context
-            .eval(Source::from_bytes("a instanceof Date"))
+            .eval_script(Source::from_bytes("a instanceof Date"))
             .unwrap(),
         JsValue::new(true)
     );
     assert_eq!(
-        context.eval(Source::from_bytes("a[0]")).unwrap(),
+        context.eval_script(Source::from_bytes("a[0]")).unwrap(),
         JsValue::new("a")
     );
     assert_eq!(
-        context.eval(Source::from_bytes("a[1]")).unwrap(),
+        context.eval_script(Source::from_bytes("a[1]")).unwrap(),
         JsValue::undefined()
     );
     assert_eq!(
-        context.eval(Source::from_bytes("a[2]")).unwrap(),
+        context.eval_script(Source::from_bytes("a[2]")).unwrap(),
         JsValue::new(3)
     );
     assert_eq!(
-        context.eval(Source::from_bytes("a.length")).unwrap(),
+        context.eval_script(Source::from_bytes("a.length")).unwrap(),
         JsValue::new(3)
     );
 }
@@ -171,31 +173,31 @@ fn concat() {
     var empty = [];
     var one = [1];
     "#;
-    context.eval(Source::from_bytes(init)).unwrap();
+    context.eval_script(Source::from_bytes(init)).unwrap();
     // Empty ++ Empty
     let ee = context
-        .eval(Source::from_bytes("empty.concat(empty)"))
+        .eval_script(Source::from_bytes("empty.concat(empty)"))
         .unwrap()
         .display()
         .to_string();
     assert_eq!(ee, "[]");
     // Empty ++ NonEmpty
     let en = context
-        .eval(Source::from_bytes("empty.concat(one)"))
+        .eval_script(Source::from_bytes("empty.concat(one)"))
         .unwrap()
         .display()
         .to_string();
     assert_eq!(en, "[ 1 ]");
     // NonEmpty ++ Empty
     let ne = context
-        .eval(Source::from_bytes("one.concat(empty)"))
+        .eval_script(Source::from_bytes("one.concat(empty)"))
         .unwrap()
         .display()
         .to_string();
     assert_eq!(ne, "[ 1 ]");
     // NonEmpty ++ NonEmpty
     let nn = context
-        .eval(Source::from_bytes("one.concat(one)"))
+        .eval_script(Source::from_bytes("one.concat(one)"))
         .unwrap()
         .display()
         .to_string();

boa_engine/src/builtins/json/mod.rs

@@ -205,7 +205,7 @@ impl Json {
         // 10. Assert: unfiltered is either a String, Number, Boolean, Null, or an Object that is defined by either an ArrayLiteral or an ObjectLiteral.
         let mut parser = Parser::new(Source::from_bytes(&script_string));
         parser.set_json_parse();
-        let statement_list = parser.parse_all(context.interner_mut())?;
+        let statement_list = parser.parse_script(context.interner_mut())?;
         let code_block = context.compile_json_parse(&statement_list)?;
         let unfiltered = context.execute(code_block)?;
 

boa_engine/src/builtins/object/tests.rs

@@ -252,7 +252,7 @@ fn get_own_property_descriptor_1_arg_returns_undefined() {
         Object.getOwnPropertyDescriptor(obj)
     "#;
     assert_eq!(
-        context.eval(Source::from_bytes(code)).unwrap(),
+        context.eval_script(Source::from_bytes(code)).unwrap(),
         JsValue::undefined()
     );
 }
@@ -324,7 +324,7 @@ fn object_is_prototype_of() {
     "#;
 
     assert_eq!(
-        context.eval(Source::from_bytes(init)).unwrap(),
+        context.eval_script(Source::from_bytes(init)).unwrap(),
         JsValue::new(true)
     );
 }

boa_engine/src/builtins/promise/tests.rs

@@ -15,7 +15,7 @@ fn promise() {
         count += 1;
         count;
     "#;
-    let result = context.eval(Source::from_bytes(init)).unwrap();
+    let result = context.eval_script(Source::from_bytes(init)).unwrap();
     assert_eq!(result.as_number(), Some(2_f64));
     context.run_jobs();
     let after_completion = forward(&mut context, "count");

boa_engine/src/builtins/weak/weak_ref.rs

@@ -150,7 +150,7 @@ mod tests {
         let context = &mut Context::default();
 
         assert!(context
-            .eval(Source::from_bytes(
+            .eval_script(Source::from_bytes(
                 r#"
             var ptr;
             {
@@ -167,7 +167,7 @@ mod tests {
 
         assert_eq!(
             context
-                .eval(Source::from_bytes(
+                .eval_script(Source::from_bytes(
                     r#"
             ptr.deref()
         "#

boa_engine/src/bytecompiler/class.rs

@@ -97,7 +97,7 @@ impl ByteCompiler<'_, '_> {
             } else {
                 None
             };
-            compiler.create_decls(expr.body(), false);
+            compiler.create_script_decls(expr.body(), false);
             compiler.compile_statement_list(expr.body(), false, false)?;
             if let Some(env_label) = env_label {
                 let (num_bindings, compile_environment) =
@@ -445,7 +445,7 @@ impl ByteCompiler<'_, '_> {
                         .context
                         .create_immutable_binding(class_name.into(), true);
                     compiler.context.push_compile_time_environment(true);
-                    compiler.create_decls(statement_list, false);
+                    compiler.create_script_decls(statement_list, false);
                     compiler.compile_statement_list(statement_list, false, false)?;
                     let (num_bindings, compile_environment) =
                         compiler.context.pop_compile_time_environment();

boa_engine/src/bytecompiler/function.rs

@@ -199,7 +199,7 @@ impl FunctionCompiler {
             compiler.emit_opcode(Opcode::Yield);
         }
 
-        compiler.create_decls(body, false);
+        compiler.create_script_decls(body, false);
         compiler.compile_statement_list(body, false, false)?;
 
         if let Some(env_label) = env_label {

boa_engine/src/bytecompiler/mod.rs

@@ -5,6 +5,7 @@ mod declaration;
 mod expression;
 mod function;
 mod jump_control;
+mod module;
 mod statement;
 
 use crate::{
@@ -703,7 +704,7 @@ impl<'b, 'host> ByteCompiler<'b, 'host> {
         self.context.push_compile_time_environment(strict);
         let push_env = self.emit_opcode_with_two_operands(Opcode::PushDeclarativeEnvironment);
 
-        self.create_decls(list, true);
+        self.create_script_decls(list, true);
 
         if use_expr {
             let expr_index = list
@@ -1271,7 +1272,12 @@ impl<'b, 'host> ByteCompiler<'b, 'host> {
         self.compile_declaration_pattern_impl(pattern, def)
     }
 
-    pub(crate) fn create_decls(&mut self, stmt_list: &StatementList, configurable_globals: bool) {
+    /// Creates the declarations for a sript.
+    pub(crate) fn create_script_decls(
+        &mut self,
+        stmt_list: &StatementList,
+        configurable_globals: bool,
+    ) {
         for node in stmt_list.statements() {
             self.create_decls_from_stmt_list_item(node, configurable_globals);
         }

boa_engine/src/bytecompiler/module.rs

@@ -0,0 +1,65 @@
+use boa_ast::{ModuleItem, ModuleItemList};
+
+use crate::JsResult;
+
+use super::ByteCompiler;
+
+impl ByteCompiler<'_, '_> {
+    /// Compiles a [`ModuleItemList`].
+    #[inline]
+    pub fn compile_module_item_list(
+        &mut self,
+        list: &ModuleItemList,
+        configurable_globals: bool,
+    ) -> JsResult<()> {
+        for node in list.items() {
+            self.compile_module_item(node, configurable_globals)?;
+        }
+        Ok(())
+    }
+
+    /// Compiles a [`ModuleItem`].
+    #[inline]
+    #[allow(unused_variables, clippy::missing_panics_doc)] // Unimplemented
+    pub fn compile_module_item(
+        &mut self,
+        item: &ModuleItem,
+        configurable_globals: bool,
+    ) -> JsResult<()> {
+        match item {
+            ModuleItem::ImportDeclaration(import) => todo!("import declaration compilation"),
+            ModuleItem::ExportDeclaration(export) => todo!("export declaration compilation"),
+            ModuleItem::StatementListItem(stmt) => {
+                self.compile_stmt_list_item(stmt, false, configurable_globals)
+            }
+        }
+    }
+
+    /// Creates the declarations for a module.
+    pub(crate) fn create_module_decls(
+        &mut self,
+        stmt_list: &ModuleItemList,
+        configurable_globals: bool,
+    ) {
+        for node in stmt_list.items() {
+            self.create_decls_from_module_item(node, configurable_globals);
+        }
+    }
+
+    /// Creates the declarations from a [`ModuleItem`].
+    #[inline]
+    #[allow(unused_variables)] // Unimplemented
+    pub(crate) fn create_decls_from_module_item(
+        &mut self,
+        item: &ModuleItem,
+        configurable_globals: bool,
+    ) -> bool {
+        match item {
+            ModuleItem::ImportDeclaration(import) => todo!("import declaration generation"),
+            ModuleItem::ExportDeclaration(export) => todo!("export declaration generation"),
+            ModuleItem::StatementListItem(stmt) => {
+                self.create_decls_from_stmt_list_item(stmt, configurable_globals)
+            }
+        }
+    }
+}

boa_engine/src/bytecompiler/statement/block.rs

@@ -13,7 +13,7 @@ impl ByteCompiler<'_, '_> {
         self.context.push_compile_time_environment(false);
         let push_env = self.emit_and_track_decl_env();
 
-        self.create_decls(block.statement_list(), configurable_globals);
+        self.create_script_decls(block.statement_list(), configurable_globals);
         self.compile_statement_list(block.statement_list(), use_expr, configurable_globals)?;
 
         let (num_bindings, compile_environment) = self.context.pop_compile_time_environment();

boa_engine/src/bytecompiler/statement/switch.rs

@@ -12,7 +12,7 @@ impl ByteCompiler<'_, '_> {
         self.context.push_compile_time_environment(false);
         let push_env = self.emit_opcode_with_two_operands(Opcode::PushDeclarativeEnvironment);
         for case in switch.cases() {
-            self.create_decls(case.body(), configurable_globals);
+            self.create_script_decls(case.body(), configurable_globals);
         }
         self.emit_opcode(Opcode::LoopStart);
 
@@ -35,7 +35,7 @@ impl ByteCompiler<'_, '_> {
 
         self.patch_jump(exit);
         if let Some(body) = switch.default() {
-            self.create_decls(body, configurable_globals);
+            self.create_script_decls(body, configurable_globals);
             self.compile_statement_list(body, false, configurable_globals)?;
         }
 

boa_engine/src/bytecompiler/statement/try.rs

@@ -19,7 +19,7 @@ impl ByteCompiler<'_, '_> {
         self.context.push_compile_time_environment(false);
         let push_env = self.emit_opcode_with_two_operands(Opcode::PushDeclarativeEnvironment);
 
-        self.create_decls(t.block().statement_list(), configurable_globals);
+        self.create_script_decls(t.block().statement_list(), configurable_globals);
         self.compile_statement_list(t.block().statement_list(), use_expr, configurable_globals)?;
 
         let (num_bindings, compile_environment) = self.context.pop_compile_time_environment();
@@ -58,7 +58,7 @@ impl ByteCompiler<'_, '_> {
                 self.emit_opcode(Opcode::Pop);
             }
 
-            self.create_decls(catch.block().statement_list(), configurable_globals);
+            self.create_script_decls(catch.block().statement_list(), configurable_globals);
             self.compile_statement_list(
                 catch.block().statement_list(),
                 use_expr,
@@ -96,7 +96,7 @@ impl ByteCompiler<'_, '_> {
             self.context.push_compile_time_environment(false);
             let push_env = self.emit_opcode_with_two_operands(Opcode::PushDeclarativeEnvironment);
 
-            self.create_decls(finally.block().statement_list(), configurable_globals);
+            self.create_script_decls(finally.block().statement_list(), configurable_globals);
             self.compile_statement_list(
                 finally.block().statement_list(),
                 false,

boa_engine/src/context/hooks.rs

@@ -32,7 +32,7 @@ use super::intrinsics::Intrinsics;
 /// }
 /// let hooks = Hooks; // Can have additional state.
 /// let context = &mut ContextBuilder::new().host_hooks(&hooks).build();
-/// let result = context.eval(Source::from_bytes(r#"eval("let a = 5")"#));
+/// let result = context.eval_script(Source::from_bytes(r#"eval("let a = 5")"#));
 /// assert_eq!(result.unwrap_err().to_string(), "TypeError: eval calls not available");
 /// ```
 ///

boa_engine/src/context/mod.rs

@@ -28,8 +28,7 @@ use crate::{
     vm::{CallFrame, CodeBlock, Vm},
     JsResult, JsValue, Source,
 };
-
-use boa_ast::StatementList;
+use boa_ast::{ModuleItemList, StatementList};
 use boa_gc::Gc;
 use boa_interner::{Interner, Sym};
 use boa_parser::{Error as ParseError, Parser};
@@ -65,7 +64,7 @@ use boa_profiler::Profiler;
 /// let mut context = Context::default();
 ///
 /// // Populate the script definition to the context.
-/// context.eval(Source::from_bytes(script)).unwrap();
+/// context.eval_script(Source::from_bytes(script)).unwrap();
 ///
 /// // Create an object that can be used in eval calls.
 /// let arg = ObjectInitializer::new(&mut context)
@@ -73,7 +72,7 @@ use boa_profiler::Profiler;
 ///     .build();
 /// context.register_global_property("arg", arg, Attribute::all());
 ///
-/// let value = context.eval(Source::from_bytes("test(arg)")).unwrap();
+/// let value = context.eval_script(Source::from_bytes("test(arg)")).unwrap();
 ///
 /// assert_eq!(value.as_number(), Some(12.0))
 /// ```
@@ -141,7 +140,7 @@ impl Context<'_> {
         ContextBuilder::default()
     }
 
-    /// Evaluates the given script `Source` by compiling down to bytecode, then interpreting the
+    /// Evaluates the given script `src` by compiling down to bytecode, then interpreting the
     /// bytecode into a value.
     ///
     /// # Examples
@@ -150,7 +149,7 @@ impl Context<'_> {
     /// let mut context = Context::default();
     ///
     /// let source = Source::from_bytes("1 + 3");
-    /// let value = context.eval(source).unwrap();
+    /// let value = context.eval_script(source).unwrap();
     ///
     /// assert!(value.is_number());
     /// assert_eq!(value.as_number().unwrap(), 4.0);
@@ -159,11 +158,41 @@ impl Context<'_> {
     /// Note that this won't run any scheduled promise jobs; you need to call [`Context::run_jobs`]
     /// on the context or [`JobQueue::run_jobs`] on the provided queue to run them.
     #[allow(clippy::unit_arg, clippy::drop_copy)]
-    pub fn eval<R: Read>(&mut self, src: Source<'_, R>) -> JsResult<JsValue> {
-        let main_timer = Profiler::global().start_event("Evaluation", "Main");
+    pub fn eval_script<R: Read>(&mut self, src: Source<'_, R>) -> JsResult<JsValue> {
+        let main_timer = Profiler::global().start_event("Script evaluation", "Main");
+
+        let script = self.parse_script(src)?;
+        let code_block = self.compile_script(&script)?;
+        let result = self.execute(code_block);
+
+        // The main_timer needs to be dropped before the Profiler is.
+        drop(main_timer);
+        Profiler::global().drop();
+
+        result
+    }
+
+    /// Evaluates the given module `src` by compiling down to bytecode, then interpreting the
+    /// bytecode into a value.
+    ///
+    /// # Examples
+    /// ```
+    /// # use boa_engine::{Context, Source};
+    /// let mut context = Context::default();
+    ///
+    /// let source = Source::from_bytes("1 + 3");
+    ///
+    /// let value = context.eval_module(source).unwrap();
+    ///
+    /// assert!(value.is_number());
+    /// assert_eq!(value.as_number().unwrap(), 4.0);
+    /// ```
+    #[allow(clippy::unit_arg, clippy::drop_copy)]
+    pub fn eval_module<R: Read>(&mut self, src: Source<'_, R>) -> JsResult<JsValue> {
+        let main_timer = Profiler::global().start_event("Module evaluation", "Main");
 
-        let script = self.parse(src)?;
-        let code_block = self.compile(&script)?;
+        let module_item_list = self.parse_module(src)?;
+        let code_block = self.compile_module(&module_item_list)?;
         let result = self.execute(code_block);
 
         // The main_timer needs to be dropped before the Profiler is.
@@ -174,30 +203,54 @@ impl Context<'_> {
     }
 
     /// Parse the given source script.
-    pub fn parse<R: Read>(&mut self, src: Source<'_, R>) -> Result<StatementList, ParseError> {
-        let _timer = Profiler::global().start_event("Parsing", "Main");
+    pub fn parse_script<R: Read>(
+        &mut self,
+        src: Source<'_, R>,
+    ) -> Result<StatementList, ParseError> {
+        let _timer = Profiler::global().start_event("Script parsing", "Main");
         let mut parser = Parser::new(src);
         if self.strict {
             parser.set_strict();
         }
-        parser.parse_all(&mut self.interner)
+        parser.parse_script(&mut self.interner)
     }
 
-    /// Compile the AST into a `CodeBlock` ready to be executed by the VM.
-    pub fn compile(&mut self, statement_list: &StatementList) -> JsResult<Gc<CodeBlock>> {
-        let _timer = Profiler::global().start_event("Compilation", "Main");
+    /// Parse the given source script.
+    pub fn parse_module<R: Read>(
+        &mut self,
+        src: Source<'_, R>,
+    ) -> Result<ModuleItemList, ParseError> {
+        let _timer = Profiler::global().start_event("Module parsing", "Main");
+        let mut parser = Parser::new(src);
+        parser.parse_module(&mut self.interner)
+    }
+
+    /// Compile the script AST into a `CodeBlock` ready to be executed by the VM.
+    pub fn compile_script(&mut self, statement_list: &StatementList) -> JsResult<Gc<CodeBlock>> {
+        let _timer = Profiler::global().start_event("Script compilation", "Main");
         let mut compiler = ByteCompiler::new(Sym::MAIN, statement_list.strict(), false, self);
-        compiler.create_decls(statement_list, false);
+        compiler.create_script_decls(statement_list, false);
         compiler.compile_statement_list(statement_list, true, false)?;
         Ok(Gc::new(compiler.finish()))
     }
 
+    /// Compile the module AST into a `CodeBlock` ready to be executed by the VM.
+    pub fn compile_module(&mut self, statement_list: &ModuleItemList) -> JsResult<Gc<CodeBlock>> {
+        let _timer = Profiler::global().start_event("Module compilation", "Main");
+
+        let mut compiler = ByteCompiler::new(Sym::MAIN, true, false, self);
+        compiler.create_module_decls(statement_list, false);
+        compiler.compile_module_item_list(statement_list, false)?;
+        Ok(Gc::new(compiler.finish()))
+    }
+
     /// Call the VM with a `CodeBlock` and return the result.
     ///
     /// Since this function receives a `Gc<CodeBlock>`, cloning the code is very cheap, since it's
     /// just a pointer copy. Therefore, if you'd like to execute the same `CodeBlock` multiple
     /// times, there is no need to re-compile it, and you can just call `clone()` on the
-    /// `Gc<CodeBlock>` returned by the [`Self::compile()`] function.
+    /// `Gc<CodeBlock>` returned by the [`Context::compile_script`] or [`Context::compile_module`]
+    /// functions.
     ///
     /// Note that this won't run any scheduled promise jobs; you need to call [`Context::run_jobs`]
     /// on the context or [`JobQueue::run_jobs`] on the provided queue to run them.
@@ -373,7 +426,7 @@ impl Context<'_> {
         self.vm.trace = trace;
     }
 
-    /// Executes all code in strict mode.
+    /// Changes the strictness mode of the context.
     pub fn strict(&mut self, strict: bool) {
         self.strict = strict;
     }
@@ -417,7 +470,7 @@ impl Context<'_> {
     ) -> JsResult<Gc<CodeBlock>> {
         let _timer = Profiler::global().start_event("Compilation", "Main");
         let mut compiler = ByteCompiler::new(Sym::MAIN, statement_list.strict(), true, self);
-        compiler.create_decls(statement_list, false);
+        compiler.create_script_decls(statement_list, false);
         compiler.compile_statement_list(statement_list, true, false)?;
         Ok(Gc::new(compiler.finish()))
     }

boa_engine/src/lib.rs

@@ -189,7 +189,7 @@ where
     S: AsRef<[u8]> + ?Sized,
 {
     context
-        .eval(Source::from_bytes(src))
+        .eval_script(Source::from_bytes(src))
         .map_or_else(|e| format!("Uncaught {e}"), |v| v.display().to_string())
 }
 
@@ -207,7 +207,7 @@ pub(crate) fn forward_val<T: AsRef<[u8]> + ?Sized>(
 
     let main_timer = Profiler::global().start_event("Main", "Main");
 
-    let result = context.eval(Source::from_bytes(src));
+    let result = context.eval_script(Source::from_bytes(src));
 
     // The main_timer needs to be dropped before the Profiler is.
     drop(main_timer);
@@ -219,7 +219,7 @@ pub(crate) fn forward_val<T: AsRef<[u8]> + ?Sized>(
 /// Create a clean Context and execute the code
 #[cfg(test)]
 pub(crate) fn exec<T: AsRef<[u8]> + ?Sized>(src: &T) -> String {
-    match Context::default().eval(Source::from_bytes(src)) {
+    match Context::default().eval_script(Source::from_bytes(src)) {
         Ok(value) => value.display().to_string(),
         Err(error) => error.to_string(),
     }

boa_engine/src/tests.rs

@@ -456,7 +456,9 @@ fn test_invalid_break_target() {
         }
         "#;
 
-    assert!(Context::default().eval(Source::from_bytes(src)).is_err());
+    assert!(Context::default()
+        .eval_script(Source::from_bytes(src))
+        .is_err());
 }
 
 #[test]

boa_engine/src/value/serde_json.rs

@@ -227,7 +227,7 @@ mod tests {
         let mut context = Context::default();
 
         let add = context
-            .eval(Source::from_bytes(
+            .eval_script(Source::from_bytes(
                 r#"
                 1000000 + 500
             "#,
@@ -237,7 +237,7 @@ mod tests {
         assert_eq!(add, 1_000_500);
 
         let sub = context
-            .eval(Source::from_bytes(
+            .eval_script(Source::from_bytes(
                 r#"
                 1000000 - 500
             "#,
@@ -247,7 +247,7 @@ mod tests {
         assert_eq!(sub, 999_500);
 
         let mult = context
-            .eval(Source::from_bytes(
+            .eval_script(Source::from_bytes(
                 r#"
                 1000000 * 500
             "#,
@@ -257,7 +257,7 @@ mod tests {
         assert_eq!(mult, 500_000_000);
 
         let div = context
-            .eval(Source::from_bytes(
+            .eval_script(Source::from_bytes(
                 r#"
                 1000000 / 500
             "#,
@@ -267,7 +267,7 @@ mod tests {
         assert_eq!(div, 2000);
 
         let rem = context
-            .eval(Source::from_bytes(
+            .eval_script(Source::from_bytes(
                 r#"
                 233894 % 500
             "#,
@@ -277,7 +277,7 @@ mod tests {
         assert_eq!(rem, 394);
 
         let pow = context
-            .eval(Source::from_bytes(
+            .eval_script(Source::from_bytes(
                 r#"
                 36 ** 5
             "#,

boa_engine/src/vm/tests.rs

@@ -47,7 +47,7 @@ fn try_catch_finally_from_init() {
 
     assert_eq!(
         Context::default()
-            .eval(Source::from_bytes(source))
+            .eval_script(Source::from_bytes(source))
             .unwrap_err()
             .as_opaque()
             .unwrap(),
@@ -70,7 +70,9 @@ fn multiple_catches() {
     "#;
 
     assert_eq!(
-        Context::default().eval(Source::from_bytes(source)).unwrap(),
+        Context::default()
+            .eval_script(Source::from_bytes(source))
+            .unwrap(),
         JsValue::Undefined
     );
 }
@@ -89,7 +91,9 @@ fn use_last_expr_try_block() {
     "#;
 
     assert_eq!(
-        Context::default().eval(Source::from_bytes(source)).unwrap(),
+        Context::default()
+            .eval_script(Source::from_bytes(source))
+            .unwrap(),
         JsValue::from("Hello!")
     );
 }
@@ -107,7 +111,9 @@ fn use_last_expr_catch_block() {
     "#;
 
     assert_eq!(
-        Context::default().eval(Source::from_bytes(source)).unwrap(),
+        Context::default()
+            .eval_script(Source::from_bytes(source))
+            .unwrap(),
         JsValue::from("Hello!")
     );
 }
@@ -123,7 +129,9 @@ fn no_use_last_expr_finally_block() {
     "#;
 
     assert_eq!(
-        Context::default().eval(Source::from_bytes(source)).unwrap(),
+        Context::default()
+            .eval_script(Source::from_bytes(source))
+            .unwrap(),
         JsValue::undefined()
     );
 }
@@ -142,7 +150,9 @@ fn finally_block_binding_env() {
     "#;
 
     assert_eq!(
-        Context::default().eval(Source::from_bytes(source)).unwrap(),
+        Context::default()
+            .eval_script(Source::from_bytes(source))
+            .unwrap(),
         JsValue::from("Hey hey people")
     );
 }
@@ -161,7 +171,9 @@ fn run_super_method_in_object() {
     "#;
 
     assert_eq!(
-        Context::default().eval(Source::from_bytes(source)).unwrap(),
+        Context::default()
+            .eval_script(Source::from_bytes(source))
+            .unwrap(),
         JsValue::from("super")
     );
 }
@@ -187,7 +199,9 @@ fn get_reference_by_super() {
     "#;
 
     assert_eq!(
-        Context::default().eval(Source::from_bytes(source)).unwrap(),
+        Context::default()
+            .eval_script(Source::from_bytes(source))
+            .unwrap(),
         JsValue::from("ab")
     );
 }

boa_examples/src/bin/classes.rs

@@ -134,7 +134,7 @@ fn main() {
     // Having done all of that, we can execute Javascript code with `eval`,
     // and access the `Person` class defined in Rust!
     context
-        .eval(Source::from_bytes(
+        .eval_script(Source::from_bytes(
             r"
 		let person = new Person('John', 19);
 		person.sayHello();

boa_examples/src/bin/closures.rs

@@ -36,7 +36,10 @@ fn main() -> Result<(), JsError> {
         }),
     );
 
-    assert_eq!(context.eval(Source::from_bytes("closure()"))?, 255.into());
+    assert_eq!(
+        context.eval_script(Source::from_bytes("closure()"))?,
+        255.into()
+    );
 
     // We have created a closure with moved variables and executed that closure
     // inside Javascript!
@@ -117,13 +120,13 @@ fn main() -> Result<(), JsError> {
     );
 
     assert_eq!(
-        context.eval(Source::from_bytes("createMessage()"))?,
+        context.eval_script(Source::from_bytes("createMessage()"))?,
         "message from `Boa dev`: Hello!".into()
     );
 
     // The data mutates between calls
     assert_eq!(
-        context.eval(Source::from_bytes("createMessage(); createMessage();"))?,
+        context.eval_script(Source::from_bytes("createMessage(); createMessage();"))?,
         "message from `Boa dev`: Hello! Hello! Hello!".into()
     );
 
@@ -167,7 +170,7 @@ fn main() -> Result<(), JsError> {
     );
 
     // First call should return the array `[0]`.
-    let result = context.eval(Source::from_bytes("enumerate()"))?;
+    let result = context.eval_script(Source::from_bytes("enumerate()"))?;
     let object = result
         .as_object()
         .cloned()
@@ -178,7 +181,7 @@ fn main() -> Result<(), JsError> {
     assert_eq!(array.get(1, &mut context)?, JsValue::undefined());
 
     // First call should return the array `[0, 1]`.
-    let result = context.eval(Source::from_bytes("enumerate()"))?;
+    let result = context.eval_script(Source::from_bytes("enumerate()"))?;
     let object = result
         .as_object()
         .cloned()

boa_examples/src/bin/commuter_visitor.rs

@@ -69,7 +69,7 @@ fn main() {
         Parser::new(Source::from_filepath(Path::new("boa_examples/scripts/calc.js")).unwrap());
     let mut ctx = Context::default();
 
-    let mut statements = parser.parse_all(ctx.interner_mut()).unwrap();
+    let mut statements = parser.parse_script(ctx.interner_mut()).unwrap();
 
     let mut visitor = CommutorVisitor::default();
 

boa_examples/src/bin/loadfile.rs

@@ -13,7 +13,7 @@ fn main() {
             // Instantiate the execution context
             let mut context = Context::default();
             // Parse the source code
-            match context.eval(src) {
+            match context.eval_script(src) {
                 Ok(res) => {
                     println!(
                         "{}",

boa_examples/src/bin/loadstring.rs

@@ -9,7 +9,7 @@ fn main() {
     let mut context = Context::default();
 
     // Parse the source code
-    match context.eval(Source::from_bytes(js_code)) {
+    match context.eval_script(Source::from_bytes(js_code)) {
         Ok(res) => {
             println!(
                 "{}",

boa_examples/src/bin/modulehandler.rs

@@ -31,7 +31,8 @@ fn main() {
 
     // Instantiating the engine with the execution context
     // Loading, parsing and executing the JS code from the source file
-    ctx.eval(Source::from_bytes(&buffer.unwrap())).unwrap();
+    ctx.eval_script(Source::from_bytes(&buffer.unwrap()))
+        .unwrap();
 }
 
 // Custom implementation that mimics the 'require' module loader
@@ -52,7 +53,8 @@ fn require(_: &JsValue, args: &[JsValue], ctx: &mut Context<'_>) -> JsResult<JsV
         Ok(JsValue::Rational(-1.0))
     } else {
         // Load and parse the module source
-        ctx.eval(Source::from_bytes(&buffer.unwrap())).unwrap();
+        ctx.eval_script(Source::from_bytes(&buffer.unwrap()))
+            .unwrap();
 
         // Access module.exports and return as ResultValue
         let global_obj = ctx.global_object().to_owned();

boa_examples/src/bin/symbol_visitor.rs

@@ -28,7 +28,7 @@ fn main() {
         Parser::new(Source::from_filepath(Path::new("boa_examples/scripts/calc.js")).unwrap());
     let mut ctx = Context::default();
 
-    let statements = parser.parse_all(ctx.interner_mut()).unwrap();
+    let statements = parser.parse_script(ctx.interner_mut()).unwrap();
 
     let mut visitor = SymbolVisitor::default();
 

boa_interner/src/sym.rs

@@ -122,7 +122,7 @@ static_syms! {
     "yield",
     // End strict reserved identifiers
 
-    "",
+    ("", EMPTY_STRING),
     "prototype",
     "constructor",
     "arguments",
@@ -130,13 +130,16 @@ static_syms! {
     "RegExp",
     "get",
     "set",
-    "<main>",
+    ("<main>", MAIN),
     "raw",
     "anonymous",
     "async",
     "of",
     "target",
+    "as",
+    "from",
     "__proto__",
     "name",
     "await",
+    ("*default*", DEFAULT_EXPORT)
 }

boa_macros/src/lib.rs

@@ -59,20 +59,76 @@
 
 use proc_macro::TokenStream;
 use proc_macro2::Ident;
-use quote::quote;
+use quote::{quote, ToTokens};
 use syn::{
     parse::{Parse, ParseStream},
     parse_macro_input,
     punctuated::Punctuated,
-    LitStr, Token,
+    Expr, ExprLit, Lit, LitStr, Token,
 };
 use synstructure::{decl_derive, AddBounds, Structure};
 
-struct Syms(Vec<LitStr>);
+struct Static {
+    literal: LitStr,
+    ident: Ident,
+}
+
+impl Parse for Static {
+    fn parse(input: ParseStream<'_>) -> syn::Result<Self> {
+        let expr = Expr::parse(input)?;
+        match expr {
+            Expr::Tuple(expr) => {
+                let mut elems = expr.elems.iter().cloned();
+                let literal = elems
+                    .next()
+                    .ok_or_else(|| syn::Error::new_spanned(&expr, "invalid empty tuple"))?;
+                let ident = elems.next();
+                if elems.next().is_some() {
+                    return Err(syn::Error::new_spanned(
+                        &expr,
+                        "invalid tuple with more than two elements",
+                    ));
+                }
+                let Expr::Lit(ExprLit {
+                    lit: Lit::Str(literal), ..
+                }) = literal else {
+                    return Err(syn::Error::new_spanned(
+                        literal,
+                        "expected an UTF-8 string literal",
+                    ));
+                };
+
+                let ident = if let Some(ident) = ident {
+                    syn::parse2::<Ident>(ident.into_token_stream())?
+                } else {
+                    Ident::new(&literal.value().to_uppercase(), literal.span())
+                };
+
+                Ok(Self { literal, ident })
+            }
+            Expr::Lit(expr) => match expr.lit {
+                Lit::Str(str) => Ok(Self {
+                    ident: Ident::new(&str.value().to_uppercase(), str.span()),
+                    literal: str,
+                }),
+                _ => Err(syn::Error::new_spanned(
+                    expr,
+                    "expected an UTF-8 string literal",
+                )),
+            },
+            _ => Err(syn::Error::new_spanned(
+                expr,
+                "expected a string literal or a tuple expression",
+            )),
+        }
+    }
+}
+
+struct Syms(Vec<Static>);
 
 impl Parse for Syms {
     fn parse(input: ParseStream<'_>) -> syn::Result<Self> {
-        let parsed = Punctuated::<LitStr, Token![,]>::parse_terminated(input)?;
+        let parsed = Punctuated::<Static, Token![,]>::parse_terminated(input)?;
         let literals = parsed.into_iter().collect();
         Ok(Self(literals))
     }
@@ -84,22 +140,15 @@ pub fn static_syms(input: TokenStream) -> TokenStream {
     let literals = parse_macro_input!(input as Syms).0;
 
     let consts = literals.iter().enumerate().map(|(mut idx, lit)| {
-        let ident = lit.value();
-        let (doc, ident) = match &*ident {
-            "" => (
-                String::from("Symbol for the empty string."),
-                String::from("EMPTY_STRING"),
-            ),
-            "<main>" => (
-                String::from("Symbol for the `<main>` string."),
-                String::from("MAIN"),
-            ),
-            ident => (
-                format!("Symbol for the `{ident}` string.",),
-                ident.to_uppercase(),
-            ),
-        };
-        let ident = Ident::new(&ident, lit.span());
+        let doc = format!(
+            "Symbol for the \"{}\" string.",
+            lit.literal
+                .value()
+                .replace('<', r"\<")
+                .replace('>', r"\>")
+                .replace('*', r"\*")
+        );
+        let ident = &lit.ident;
         idx += 1;
         quote! {
             #[doc = #doc]
@@ -107,6 +156,8 @@ pub fn static_syms(input: TokenStream) -> TokenStream {
         }
     });
 
+    let literals = literals.iter().map(|lit| &lit.literal).collect::<Vec<_>>();
+
     let caches = quote! {
         type Set<T> = ::indexmap::IndexSet<T, ::core::hash::BuildHasherDefault<::rustc_hash::FxHasher>>;
 

boa_parser/src/error.rs

@@ -66,7 +66,7 @@ pub enum Error {
     /// Catch all General Error
     General {
         /// The error message.
-        message: &'static str,
+        message: Box<str>,
 
         /// Position of the source code where the error occurred.
         position: Position,
@@ -115,22 +115,29 @@ impl Error {
     }
 
     /// Creates a "general" parsing error.
-    pub(crate) const fn general(message: &'static str, position: Position) -> Self {
-        Self::General { message, position }
+    pub(crate) fn general<S>(message: S, position: Position) -> Self
+    where
+        S: Into<Box<str>>,
+    {
+        Self::General {
+            message: message.into(),
+            position,
+        }
     }
 
     /// Creates a "general" parsing error with the specific error message for a wrong function declaration in non-strict mode.
-    pub(crate) const fn wrong_function_declaration_non_strict(position: Position) -> Self {
+    pub(crate) fn wrong_function_declaration_non_strict(position: Position) -> Self {
         Self::General {
-            message: "In non-strict mode code, functions can only be declared at top level, inside a block, or as the body of an if statement.",
+            message: "In non-strict mode code, functions can only be declared at top level, inside a block, or as the body of an if statement.".into(),
             position
         }
     }
 
     /// Creates a "general" parsing error with the specific error message for a wrong function declaration with label.
-    pub(crate) const fn wrong_labelled_function_declaration(position: Position) -> Self {
+    pub(crate) fn wrong_labelled_function_declaration(position: Position) -> Self {
         Self::General {
-            message: "Labelled functions can only be declared at top level or inside a block",
+            message: "Labelled functions can only be declared at top level or inside a block"
+                .into(),
             position,
         }
     }

boa_parser/src/lexer/error.rs

@@ -33,6 +33,7 @@ impl From<io::Error> for Error {
 
 impl Error {
     /// Creates a new syntax error.
+    #[inline]
     pub(super) fn syntax<M, P>(err: M, pos: P) -> Self
     where
         M: Into<Box<str>>,

boa_parser/src/lexer/token.rs

@@ -48,6 +48,7 @@ impl Token {
     }
 
     /// Converts the token to a `String`.
+    #[inline]
     pub(crate) fn to_string(&self, interner: &Interner) -> String {
         self.kind.to_string(interner)
     }
@@ -198,6 +199,7 @@ impl TokenKind {
     }
 
     /// Creates a `NumericLiteral` token kind.
+    #[must_use]
     pub fn numeric_literal<L>(lit: L) -> Self
     where
         L: Into<Numeric>,

boa_parser/src/parser/expression/assignment/arrow_function.rs

@@ -161,6 +161,7 @@ where
             &bound_names(&params),
             &top_level_lexically_declared_names(&body),
             params_start_position,
+            interner,
         )?;
 
         Ok(ast::function::ArrowFunction::new(self.name, params, body))

boa_parser/src/parser/expression/assignment/async_arrow_function.rs

@@ -147,6 +147,7 @@ where
             &bound_names(&params),
             &top_level_lexically_declared_names(&body),
             params_start_position,
+            interner,
         )?;
 
         Ok(ast::function::AsyncArrowFunction::new(

boa_parser/src/parser/expression/assignment/mod.rs

@@ -228,6 +228,7 @@ where
                 &bound_names(&parameters),
                 &top_level_lexically_declared_names(&body),
                 position,
+                interner,
             )?;
 
             return Ok(boa_ast::function::ArrowFunction::new(self.name, parameters, body).into());

boa_parser/src/parser/expression/identifiers.rs

@@ -29,6 +29,7 @@ pub(in crate::parser) struct IdentifierReference {
 
 impl IdentifierReference {
     /// Creates a new `IdentifierReference` parser.
+    #[inline]
     pub(in crate::parser) fn new<Y, A>(allow_yield: Y, allow_await: A) -> Self
     where
         Y: Into<AllowYield>,
@@ -82,6 +83,7 @@ pub(in crate::parser) struct BindingIdentifier {
 
 impl BindingIdentifier {
     /// Creates a new `BindingIdentifier` parser.
+    #[inline]
     pub(in crate::parser) fn new<Y, A>(allow_yield: Y, allow_await: A) -> Self
     where
         Y: Into<AllowYield>,

boa_parser/src/parser/expression/left_hand_side/optional/tests.rs

@@ -1,7 +1,5 @@
-use boa_interner::Interner;
-use boa_macros::utf16;
+use crate::parser::tests::{check_invalid_script, check_script_parser};
 
-use crate::parser::tests::{check_invalid, check_script_parser};
 use boa_ast::{
     expression::{
         access::PropertyAccessField, literal::Literal, Identifier, Optional, OptionalOperation,
@@ -9,6 +7,8 @@ use boa_ast::{
     },
     Expression, Statement,
 };
+use boa_interner::Interner;
+use boa_macros::utf16;
 
 #[test]
 fn simple() {
@@ -81,9 +81,9 @@ fn complex_chain() {
 
 #[test]
 fn reject_templates() {
-    check_invalid("console.log?.`Hello`");
-    check_invalid("console?.log`Hello`");
-    check_invalid(
+    check_invalid_script("console.log?.`Hello`");
+    check_invalid_script("console?.log`Hello`");
+    check_invalid_script(
         r#"
 const a = console?.log
 `Hello`"#,

boa_parser/src/parser/expression/mod.rs

@@ -773,14 +773,14 @@ expression!(
 );
 
 /// Returns an error if `arguments` or `eval` are used as identifier in strict mode.
-const fn check_strict_arguments_or_eval(ident: Identifier, position: Position) -> ParseResult<()> {
+fn check_strict_arguments_or_eval(ident: Identifier, position: Position) -> ParseResult<()> {
     match ident.sym() {
         Sym::ARGUMENTS => Err(Error::general(
-            "unexpected identifier 'arguments' in strict mode",
+            "unexpected identifier `arguments` in strict mode",
             position,
         )),
         Sym::EVAL => Err(Error::general(
-            "unexpected identifier 'eval' in strict mode",
+            "unexpected identifier `eval` in strict mode",
             position,
         )),
         _ => Ok(()),

boa_parser/src/parser/expression/primary/async_function_expression/mod.rs

@@ -142,6 +142,7 @@ where
             &bound_names(&params),
             &top_level_lexically_declared_names(&body),
             params_start_position,
+            interner,
         )?;
 
         let function = AsyncFunction::new(name.or(self.name), params, body, name.is_some());

boa_parser/src/parser/expression/primary/async_generator_expression/mod.rs

@@ -179,6 +179,7 @@ where
             &bound_names(&params),
             &top_level_lexically_declared_names(&body),
             params_start_position,
+            interner,
         )?;
 
         let function = AsyncGenerator::new(name.or(self.name), params, body, name.is_some());

boa_parser/src/parser/expression/primary/async_generator_expression/tests.rs

@@ -1,5 +1,3 @@
-use std::convert::TryInto;
-
 use crate::parser::tests::check_script_parser;
 use boa_ast::{
     declaration::{LexicalDeclaration, Variable},

boa_parser/src/parser/expression/primary/function_expression/mod.rs

@@ -137,6 +137,7 @@ where
             &bound_names(&params),
             &top_level_lexically_declared_names(&body),
             params_start_position,
+            interner,
         )?;
 
         let function =

boa_parser/src/parser/expression/primary/generator_expression/mod.rs

@@ -145,6 +145,7 @@ where
             &bound_names(&params),
             &top_level_lexically_declared_names(&body),
             params_start_position,
+            interner,
         )?;
 
         // It is a Syntax Error if FormalParameters Contains YieldExpression is true.

boa_parser/src/parser/expression/primary/object_initializer/mod.rs

@@ -436,6 +436,7 @@ where
                     &bound_names(&parameters),
                     &top_level_lexically_declared_names(&body),
                     params_start_position,
+                    interner,
                 )?;
 
                 let name = property_name.literal().map(|name| {
@@ -511,6 +512,7 @@ where
                     &bound_names(&params),
                     &top_level_lexically_declared_names(&body),
                     params_start_position,
+                    interner,
                 )?;
 
                 let method = MethodDefinition::Ordinary(Function::new(
@@ -592,10 +594,17 @@ where
             }
             TokenKind::NullLiteral => (Sym::NULL).into(),
             TokenKind::BooleanLiteral(bool) => match bool {
-                true => (interner.get_or_intern_static("true", utf16!("true"))).into(),
-                false => (interner.get_or_intern_static("false", utf16!("false"))).into(),
+                true => Sym::TRUE.into(),
+                false => Sym::FALSE.into(),
             },
-            _ => return Err(Error::AbruptEnd),
+            _ => {
+                return Err(Error::expected(
+                    vec!["property name".to_owned()],
+                    token.to_string(interner),
+                    token.span(),
+                    "property name",
+                ))
+            }
         };
         cursor.advance(interner);
         Ok(name)
@@ -786,6 +795,7 @@ where
             &bound_names(&params),
             &top_level_lexically_declared_names(&body),
             params_start_position,
+            interner,
         )?;
 
         let method = MethodDefinition::Generator(Generator::new(
@@ -901,6 +911,7 @@ where
             &bound_names(&params),
             &top_level_lexically_declared_names(&body),
             params_start_position,
+            interner,
         )?;
 
         let method = MethodDefinition::AsyncGenerator(AsyncGenerator::new(
@@ -993,6 +1004,7 @@ where
             &bound_names(&params),
             &top_level_lexically_declared_names(&body),
             params_start_position,
+            interner,
         )?;
 
         let method = MethodDefinition::Async(AsyncFunction::new(

boa_parser/src/parser/expression/primary/object_initializer/tests.rs

@@ -1,4 +1,4 @@
-use crate::parser::tests::{check_invalid, check_script_parser};
+use crate::parser::tests::{check_invalid_script, check_script_parser};
 use boa_ast::{
     declaration::{LexicalDeclaration, Variable},
     expression::{
@@ -12,7 +12,7 @@ use boa_ast::{
     property::{MethodDefinition, PropertyDefinition, PropertyName},
     Declaration, StatementList,
 };
-use boa_interner::Interner;
+use boa_interner::{Interner, Sym};
 use boa_macros::utf16;
 
 /// Checks object literal parsing.
@@ -239,7 +239,7 @@ fn check_object_short_function_get() {
     let interner = &mut Interner::default();
 
     let object_properties = vec![PropertyDefinition::MethodDefinition(
-        interner.get_or_intern_static("get", utf16!("get")).into(),
+        Sym::GET.into(),
         MethodDefinition::Ordinary(Function::new(
             Some(interner.get_or_intern_static("get", utf16!("get")).into()),
             FormalParameterList::default(),
@@ -270,7 +270,7 @@ fn check_object_short_function_set() {
     let interner = &mut Interner::default();
 
     let object_properties = vec![PropertyDefinition::MethodDefinition(
-        interner.get_or_intern_static("set", utf16!("set")).into(),
+        Sym::SET.into(),
         MethodDefinition::Ordinary(Function::new(
             Some(interner.get_or_intern_static("set", utf16!("set")).into()),
             FormalParameterList::default(),
@@ -485,7 +485,7 @@ fn check_async_generator_method() {
 
 #[test]
 fn check_async_method_lineterminator() {
-    check_invalid(
+    check_invalid_script(
         "const x = {
             async
             dive(){}
@@ -496,7 +496,7 @@ fn check_async_method_lineterminator() {
 
 #[test]
 fn check_async_gen_method_lineterminator() {
-    check_invalid(
+    check_invalid_script(
         "const x = {
             async
             * vroom() {}

boa_parser/src/parser/expression/tests.rs

@@ -1,4 +1,4 @@
-use crate::parser::tests::{check_invalid, check_script_parser};
+use crate::parser::tests::{check_invalid_script, check_script_parser};
 use boa_ast::{
     declaration::{LexicalDeclaration, Variable},
     expression::{
@@ -684,10 +684,10 @@ fn check_logical_expressions() {
         interner,
     );
 
-    check_invalid("a ?? b && c");
-    check_invalid("a && b ?? c");
-    check_invalid("a ?? b || c");
-    check_invalid("a || b ?? c");
+    check_invalid_script("a ?? b && c");
+    check_invalid_script("a && b ?? c");
+    check_invalid_script("a ?? b || c");
+    check_invalid_script("a || b ?? c");
 }
 
 macro_rules! check_non_reserved_identifier {

boa_parser/src/parser/function/tests.rs

@@ -1,4 +1,4 @@
-use crate::parser::tests::{check_invalid, check_script_parser};
+use crate::parser::tests::{check_invalid_script, check_script_parser};
 use boa_ast::{
     declaration::{LexicalDeclaration, Variable},
     expression::{
@@ -81,7 +81,7 @@ fn check_duplicates_strict_off() {
 /// Checks if duplicate parameter names are an error with strict mode on.
 #[test]
 fn check_duplicates_strict_on() {
-    check_invalid("'use strict'; function foo(a, a) {}");
+    check_invalid_script("'use strict'; function foo(a, a) {}");
 }
 
 /// Checks basic function declaration parsing with automatic semicolon insertion.

boa_parser/src/parser/mod.rs

@@ -21,9 +21,10 @@ use boa_ast::{
     expression::Identifier,
     function::FormalParameterList,
     operations::{
-        contains, top_level_lexically_declared_names, top_level_var_declared_names, ContainsSymbol,
+        contains, lexically_declared_names, top_level_lexically_declared_names,
+        top_level_var_declared_names, var_declared_names, ContainsSymbol,
     },
-    Position, StatementList,
+    ModuleItemList, Position, StatementList,
 };
 use boa_interner::Interner;
 use rustc_hash::FxHashSet;
@@ -130,10 +131,25 @@ impl<'a, R: Read> Parser<'a, R> {
     /// Will return `Err` on any parsing error, including invalid reads of the bytes being parsed.
     ///
     /// [spec]: https://tc39.es/ecma262/#prod-Script
-    pub fn parse_all(&mut self, interner: &mut Interner) -> ParseResult<StatementList> {
+    pub fn parse_script(&mut self, interner: &mut Interner) -> ParseResult<StatementList> {
         Script::new(false).parse(&mut self.cursor, interner)
     }
 
+    /// Parse the full input as an [ECMAScript Module][spec] into the boa AST representation.
+    /// The resulting `ModuleItemList` can be compiled into boa bytecode and executed in the boa vm.
+    ///
+    /// # Errors
+    ///
+    /// Will return `Err` on any parsing error, including invalid reads of the bytes being parsed.
+    ///
+    /// [spec]: https://tc39.es/ecma262/#prod-Module
+    pub fn parse_module(&mut self, interner: &mut Interner) -> ParseResult<ModuleItemList>
+    where
+        R: Read,
+    {
+        Module.parse(&mut self.cursor, interner)
+    }
+
     /// [`19.2.1.1 PerformEval ( x, strictCaller, direct )`][spec]
     ///
     /// Parses the source text input of an `eval` call.
@@ -232,7 +248,6 @@ where
             .parse(cursor, interner)?;
 
         // 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 lexical_names = FxHashSet::default();
         for name in top_level_lexically_declared_names(&statement_list) {
             if !lexical_names.insert(name) {
@@ -243,6 +258,7 @@ where
             }
         }
 
+        // It is a Syntax Error if any element of the LexicallyDeclaredNames of ScriptBody also occurs in the VarDeclaredNames of ScriptBody.
         for name in top_level_var_declared_names(&statement_list) {
             if lexical_names.contains(&name) {
                 return Err(Error::general(
@@ -314,6 +330,13 @@ where
                     Position::new(1, 1),
                 ));
             }
+
+            // TODO:
+            // It is a Syntax Error if ContainsDuplicateLabels of StatementList with argument « » is true.
+            // It is a Syntax Error if ContainsUndefinedBreakTarget of StatementList with argument « » is true.
+            // It is a Syntax Error if ContainsUndefinedContinueTarget of StatementList with arguments « » and « » is true.
+            // It is a Syntax Error if AllPrivateIdentifiersValid of StatementList with argument « » is false unless the
+            // source text containing ScriptBody is eval code that is being processed by a direct eval.
         }
 
         Ok(body)
@@ -325,13 +348,17 @@ fn name_in_lexically_declared_names(
     bound_names: &[Identifier],
     lexical_names: &[Identifier],
     position: Position,
+    interner: &Interner,
 ) -> ParseResult<()> {
     for name in bound_names {
         if lexical_names.contains(name) {
-            return Err(Error::General {
-                message: "formal parameter declared in lexically declared names",
+            return Err(Error::general(
+                format!(
+                    "formal parameter `{}` declared in lexically declared names",
+                    interner.resolve_expect(name.sym())
+                ),
                 position,
-            });
+            ));
         }
     }
     Ok(())
@@ -348,3 +375,111 @@ impl<T> OrAbrupt<T> for ParseResult<Option<T>> {
         self?.ok_or(Error::AbruptEnd)
     }
 }
+
+/// Parses a full module.
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-Module
+#[derive(Debug, Clone, Copy)]
+struct Module;
+
+impl<R> TokenParser<R> for Module
+where
+    R: Read,
+{
+    type Output = ModuleItemList;
+
+    fn parse(self, cursor: &mut Cursor<R>, interner: &mut Interner) -> ParseResult<Self::Output> {
+        cursor.set_module_mode();
+
+        let items = if cursor.peek(0, interner)?.is_some() {
+            self::statement::ModuleItemList.parse(cursor, interner)?
+        } else {
+            return Ok(Vec::new().into());
+        };
+
+        // It is a Syntax Error if the LexicallyDeclaredNames of ModuleItemList contains any duplicate entries.
+        let mut bindings = FxHashSet::default();
+        for name in lexically_declared_names(&items) {
+            if !bindings.insert(name) {
+                return Err(Error::general(
+                    format!(
+                        "lexical name `{}` declared multiple times",
+                        interner.resolve_expect(name.sym())
+                    ),
+                    Position::new(1, 1),
+                ));
+            }
+        }
+
+        // It is a Syntax Error if any element of the LexicallyDeclaredNames of ModuleItemList also occurs in the
+        // VarDeclaredNames of ModuleItemList.
+        for name in var_declared_names(&items) {
+            if !bindings.insert(name) {
+                return Err(Error::general(
+                    format!(
+                        "lexical name `{}` declared multiple times",
+                        interner.resolve_expect(name.sym())
+                    ),
+                    Position::new(1, 1),
+                ));
+            }
+        }
+
+        // It is a Syntax Error if the ExportedNames of ModuleItemList contains any duplicate entries.
+        {
+            let mut exported_names = FxHashSet::default();
+            for name in items.exported_names() {
+                if !exported_names.insert(name) {
+                    return Err(Error::general(
+                        format!(
+                            "exported name `{}` declared multiple times",
+                            interner.resolve_expect(name)
+                        ),
+                        Position::new(1, 1),
+                    ));
+                }
+            }
+        }
+
+        // It is a Syntax Error if any element of the ExportedBindings of ModuleItemList does not also occur in either
+        // the VarDeclaredNames of ModuleItemList, or the LexicallyDeclaredNames of ModuleItemList.
+        for name in items.exported_bindings() {
+            if !bindings.contains(&name) {
+                return Err(Error::general(
+                    format!(
+                        "could not find the exported binding `{}` in the declared names of the module",
+                        interner.resolve_expect(name.sym())
+                    ),
+                    Position::new(1, 1),
+                ));
+            }
+        }
+
+        // It is a Syntax Error if ModuleItemList Contains super.
+        if contains(&items, ContainsSymbol::Super) {
+            return Err(Error::general(
+                "module cannot contain `super` on the top-level",
+                Position::new(1, 1),
+            ));
+        }
+
+        // It is a Syntax Error if ModuleItemList Contains NewTarget.
+        if contains(&items, ContainsSymbol::NewTarget) {
+            return Err(Error::general(
+                "module cannot contain `new.target` on the top-level",
+                Position::new(1, 1),
+            ));
+        }
+
+        // TODO:
+        // It is a Syntax Error if ContainsDuplicateLabels of ModuleItemList with argument « » is true.
+        // It is a Syntax Error if ContainsUndefinedBreakTarget of ModuleItemList with argument « » is true.
+        // It is a Syntax Error if ContainsUndefinedContinueTarget of ModuleItemList with arguments « » and « » is true.
+        // It is a Syntax Error if AllPrivateIdentifiersValid of ModuleItemList with argument « » is false.
+
+        Ok(items)
+    }
+}

boa_parser/src/parser/statement/block/tests.rs

@@ -1,7 +1,5 @@
 //! Block statement parsing tests.
 
-use std::convert::TryInto;
-
 use crate::parser::tests::check_script_parser;
 use boa_ast::{
     declaration::{VarDeclaration, Variable},

boa_parser/src/parser/statement/break_stm/tests.rs

@@ -4,7 +4,7 @@ use boa_ast::{
     statement::{Block, Break, WhileLoop},
     Statement, StatementListItem,
 };
-use boa_interner::Interner;
+use boa_interner::{Interner, Sym};
 use boa_macros::utf16;
 
 #[test]
@@ -114,9 +114,7 @@ fn reserved_label() {
         vec![Statement::WhileLoop(WhileLoop::new(
             Literal::from(true).into(),
             Block::from(vec![StatementListItem::Statement(Statement::Break(
-                Break::new(Some(
-                    interner.get_or_intern_static("await", utf16!("await")),
-                )),
+                Break::new(Some(Sym::AWAIT)),
             ))])
             .into(),
         ))
@@ -132,9 +130,7 @@ fn reserved_label() {
         vec![Statement::WhileLoop(WhileLoop::new(
             Literal::from(true).into(),
             Block::from(vec![StatementListItem::Statement(Statement::Break(
-                Break::new(Some(
-                    interner.get_or_intern_static("yield", utf16!("yield")),
-                )),
+                Break::new(Some(Sym::YIELD)),
             ))])
             .into(),
         ))

boa_parser/src/parser/statement/continue_stm/tests.rs

@@ -4,7 +4,7 @@ use boa_ast::{
     statement::{Block, Continue, WhileLoop},
     Statement, StatementListItem,
 };
-use boa_interner::Interner;
+use boa_interner::{Interner, Sym};
 use boa_macros::utf16;
 
 #[test]
@@ -114,9 +114,7 @@ fn reserved_label() {
         vec![Statement::WhileLoop(WhileLoop::new(
             Literal::from(true).into(),
             Block::from(vec![StatementListItem::Statement(Statement::Continue(
-                Continue::new(Some(
-                    interner.get_or_intern_static("await", utf16!("await")),
-                )),
+                Continue::new(Some(Sym::AWAIT)),
             ))])
             .into(),
         ))
@@ -132,9 +130,7 @@ fn reserved_label() {
         vec![Statement::WhileLoop(WhileLoop::new(
             Literal::from(true).into(),
             Block::from(vec![StatementListItem::Statement(Statement::Continue(
-                Continue::new(Some(
-                    interner.get_or_intern_static("yield", utf16!("yield")),
-                )),
+                Continue::new(Some(Sym::YIELD)),
             ))])
             .into(),
         ))

boa_parser/src/parser/statement/declaration/export.rs

@@ -0,0 +1,316 @@
+//! Export declaration parsing
+//!
+//! This parses `export` declarations.
+//!
+//! More information:
+//! - [MDN documentation][mdn]
+//!  - [ECMAScript specification][spec]
+//!
+//! [spec]: https://tc39.es/ecma262/#sec-exports
+//! [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/export
+
+use crate::{
+    lexer::{token::ContainsEscapeSequence, TokenKind},
+    parser::{
+        cursor::Cursor,
+        expression::AssignmentExpression,
+        statement::{declaration::ClassDeclaration, variable::VariableStatement},
+        Error, OrAbrupt, ParseResult, TokenParser,
+    },
+};
+use boa_ast::{
+    declaration::{ExportDeclaration as AstExportDeclaration, ReExportKind},
+    Keyword, Punctuator,
+};
+use boa_interner::{Interner, Sym};
+use boa_profiler::Profiler;
+use std::io::Read;
+
+use super::{
+    hoistable::{AsyncFunctionDeclaration, AsyncGeneratorDeclaration, GeneratorDeclaration},
+    Declaration, FromClause, FunctionDeclaration,
+};
+
+/// Parses an export declaration.
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-ExportDeclaration
+#[derive(Debug, Clone, Copy)]
+pub(in crate::parser) struct ExportDeclaration;
+
+impl<R> TokenParser<R> for ExportDeclaration
+where
+    R: Read,
+{
+    type Output = AstExportDeclaration;
+
+    fn parse(self, cursor: &mut Cursor<R>, interner: &mut Interner) -> ParseResult<Self::Output> {
+        let _timer = Profiler::global().start_event("ExportDeclaration", "Parsing");
+
+        cursor.expect((Keyword::Export, false), "export declaration", interner)?;
+
+        let tok = cursor.peek(0, interner).or_abrupt()?;
+
+        let export_clause: Self::Output = match tok.kind() {
+            TokenKind::Punctuator(Punctuator::Mul) => {
+                cursor.advance(interner);
+
+                let next = cursor.peek(0, interner).or_abrupt()?;
+
+                match next.kind() {
+                    TokenKind::IdentifierName((Sym::AS, _)) => {
+                        cursor.advance(interner);
+                        let tok = cursor.next(interner).or_abrupt()?;
+
+                        let alias = match tok.kind() {
+                            TokenKind::StringLiteral((export_name, _))
+                            | TokenKind::IdentifierName((export_name, _)) => *export_name,
+                            _ => {
+                                return Err(Error::expected(
+                                    ["identifier".to_owned(), "string literal".to_owned()],
+                                    tok.to_string(interner),
+                                    tok.span(),
+                                    "export declaration",
+                                ))
+                            }
+                        };
+
+                        let specifier =
+                            FromClause::new("export declaration").parse(cursor, interner)?;
+
+                        AstExportDeclaration::ReExport {
+                            kind: ReExportKind::Namespaced { name: Some(alias) },
+                            specifier,
+                        }
+                    }
+                    TokenKind::IdentifierName((Sym::FROM, _)) => {
+                        let specifier =
+                            FromClause::new("export declaration").parse(cursor, interner)?;
+
+                        AstExportDeclaration::ReExport {
+                            kind: ReExportKind::Namespaced { name: None },
+                            specifier,
+                        }
+                    }
+                    _ => {
+                        return Err(Error::expected(
+                            ["as".to_owned(), "from".to_owned()],
+                            next.to_string(interner),
+                            next.span(),
+                            "export declaration",
+                        ))
+                    }
+                }
+            }
+            TokenKind::Punctuator(Punctuator::OpenBlock) => {
+                let names = NamedExports.parse(cursor, interner)?;
+
+                let next = cursor.peek(0, interner).or_abrupt()?;
+
+                if matches!(
+                    next.kind(),
+                    TokenKind::IdentifierName((Sym::FROM, ContainsEscapeSequence(false)))
+                ) {
+                    let specifier =
+                        FromClause::new("export declaration").parse(cursor, interner)?;
+                    AstExportDeclaration::ReExport {
+                        kind: ReExportKind::Named { names },
+                        specifier,
+                    }
+                } else {
+                    AstExportDeclaration::List(names)
+                }
+            }
+            TokenKind::Keyword((Keyword::Var, false)) => VariableStatement::new(false, true)
+                .parse(cursor, interner)
+                .map(AstExportDeclaration::VarStatement)?,
+            TokenKind::Keyword((Keyword::Default, _)) => {
+                cursor.advance(interner);
+
+                let tok = cursor.peek(0, interner).or_abrupt()?;
+
+                match tok.kind() {
+                    TokenKind::Keyword((Keyword::Function, false)) => {
+                        let next_token = cursor.peek(1, interner).or_abrupt()?;
+                        if next_token.kind() == &TokenKind::Punctuator(Punctuator::Mul) {
+                            AstExportDeclaration::DefaultGenerator(
+                                GeneratorDeclaration::new(false, true, true)
+                                    .parse(cursor, interner)?,
+                            )
+                        } else {
+                            AstExportDeclaration::DefaultFunction(
+                                FunctionDeclaration::new(false, true, true)
+                                    .parse(cursor, interner)?,
+                            )
+                        }
+                    }
+                    TokenKind::Keyword((Keyword::Async, false)) => {
+                        let next_token = cursor.peek(2, interner).or_abrupt()?;
+                        if next_token.kind() == &TokenKind::Punctuator(Punctuator::Mul) {
+                            AstExportDeclaration::DefaultAsyncGenerator(
+                                AsyncGeneratorDeclaration::new(false, true, true)
+                                    .parse(cursor, interner)?,
+                            )
+                        } else {
+                            AstExportDeclaration::DefaultAsyncFunction(
+                                AsyncFunctionDeclaration::new(false, true, true)
+                                    .parse(cursor, interner)?,
+                            )
+                        }
+                    }
+                    TokenKind::Keyword((Keyword::Class, false)) => {
+                        AstExportDeclaration::DefaultClassDeclaration(
+                            ClassDeclaration::new(false, true, true).parse(cursor, interner)?,
+                        )
+                    }
+                    _ => AstExportDeclaration::DefaultAssignmentExpression(
+                        AssignmentExpression::new(None, true, false, true)
+                            .parse(cursor, interner)?,
+                    ),
+                }
+            }
+            _ => AstExportDeclaration::Declaration(
+                Declaration::new(false, true).parse(cursor, interner)?,
+            ),
+        };
+
+        Ok(export_clause)
+    }
+}
+
+/// Parses a named export list.
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-NamedExports
+#[derive(Debug, Clone, Copy)]
+struct NamedExports;
+
+impl<R> TokenParser<R> for NamedExports
+where
+    R: Read,
+{
+    type Output = Box<[boa_ast::declaration::ExportSpecifier]>;
+
+    fn parse(self, cursor: &mut Cursor<R>, interner: &mut Interner) -> ParseResult<Self::Output> {
+        cursor.expect(Punctuator::OpenBlock, "export declaration", interner)?;
+
+        let mut list = Vec::new();
+
+        loop {
+            let tok = cursor.next(interner).or_abrupt()?;
+            match tok.kind() {
+                TokenKind::Punctuator(Punctuator::CloseBlock) => {
+                    break;
+                }
+                TokenKind::Punctuator(Punctuator::Comma) => {
+                    if list.is_empty() {
+                        return Err(Error::expected(
+                            [
+                                Punctuator::CloseBlock.to_string(),
+                                "string literal".to_owned(),
+                                "identifier".to_owned(),
+                            ],
+                            tok.to_string(interner),
+                            tok.span(),
+                            "export declaration",
+                        ));
+                    }
+                }
+                TokenKind::StringLiteral(_) | TokenKind::IdentifierName(_) => {
+                    list.push(ExportSpecifier.parse(cursor, interner)?);
+                }
+                _ => {
+                    return Err(Error::expected(
+                        [
+                            Punctuator::CloseBlock.to_string(),
+                            Punctuator::Comma.to_string(),
+                        ],
+                        tok.to_string(interner),
+                        tok.span(),
+                        "export declaration",
+                    ));
+                }
+            }
+        }
+
+        Ok(list.into_boxed_slice())
+    }
+}
+
+/// Parses a module export name.
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-ModuleExportName
+#[derive(Debug, Clone, Copy)]
+pub(super) struct ModuleExportName;
+
+impl<R> TokenParser<R> for ModuleExportName
+where
+    R: Read,
+{
+    type Output = Sym;
+
+    fn parse(self, cursor: &mut Cursor<R>, interner: &mut Interner) -> ParseResult<Self::Output> {
+        let tok = cursor.next(interner).or_abrupt()?;
+
+        match tok.kind() {
+            TokenKind::StringLiteral((ident, _)) => {
+                if interner.resolve_expect(*ident).utf8().is_none() {
+                    return Err(Error::general(
+                        "import specifiers don't allow unpaired surrogates",
+                        tok.span().end(),
+                    ));
+                }
+                Ok(*ident)
+            }
+            TokenKind::IdentifierName((ident, _)) => Ok(*ident),
+            _ => Err(Error::expected(
+                ["identifier".to_owned(), "string literal".to_owned()],
+                tok.to_string(interner),
+                tok.span(),
+                "export specifier parsing",
+            )),
+        }
+    }
+}
+
+/// Parses an export specifier.
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-ExportSpecifier
+#[derive(Debug, Clone, Copy)]
+struct ExportSpecifier;
+
+impl<R> TokenParser<R> for ExportSpecifier
+where
+    R: Read,
+{
+    type Output = boa_ast::declaration::ExportSpecifier;
+
+    fn parse(self, cursor: &mut Cursor<R>, interner: &mut Interner) -> ParseResult<Self::Output> {
+        let inner_name = ModuleExportName.parse(cursor, interner)?;
+
+        if cursor
+            .next_if(TokenKind::identifier(Sym::AS), interner)?
+            .is_some()
+        {
+            let export_name = ModuleExportName.parse(cursor, interner)?;
+            Ok(boa_ast::declaration::ExportSpecifier::new(
+                export_name,
+                inner_name,
+            ))
+        } else {
+            Ok(boa_ast::declaration::ExportSpecifier::new(
+                inner_name, inner_name,
+            ))
+        }
+    }
+}

boa_parser/src/parser/statement/declaration/hoistable/async_function_decl/mod.rs

@@ -18,7 +18,7 @@ use std::io::Read;
 /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/async_function
 /// [spec]: https://tc39.es/ecma262/#prod-AsyncFunctionDeclaration
 #[derive(Debug, Clone, Copy)]
-pub(super) struct AsyncFunctionDeclaration {
+pub(in crate::parser) struct AsyncFunctionDeclaration {
     allow_yield: AllowYield,
     allow_await: AllowAwait,
     is_default: AllowDefault,
@@ -26,7 +26,7 @@ pub(super) struct AsyncFunctionDeclaration {
 
 impl AsyncFunctionDeclaration {
     /// Creates a new `FunctionDeclaration` parser.
-    pub(super) fn new<Y, A, D>(allow_yield: Y, allow_await: A, is_default: D) -> Self
+    pub(in crate::parser) fn new<Y, A, D>(allow_yield: Y, allow_await: A, is_default: D) -> Self
     where
         Y: Into<AllowYield>,
         A: Into<AllowAwait>,

boa_parser/src/parser/statement/declaration/hoistable/async_function_decl/tests.rs

@@ -3,7 +3,7 @@ use boa_ast::{
     function::{AsyncFunction, FormalParameterList},
     Declaration, StatementList,
 };
-use boa_interner::Interner;
+use boa_interner::{Interner, Sym};
 use boa_macros::utf16;
 
 /// Async function declaration parsing.
@@ -34,11 +34,7 @@ fn async_function_declaration_keywords() {
     check_script_parser(
         "async function yield() {}",
         vec![Declaration::AsyncFunction(AsyncFunction::new(
-            Some(
-                interner
-                    .get_or_intern_static("yield", utf16!("yield"))
-                    .into(),
-            ),
+            Some(Sym::YIELD.into()),
             FormalParameterList::default(),
             StatementList::default(),
             false,
@@ -51,11 +47,7 @@ fn async_function_declaration_keywords() {
     check_script_parser(
         "async function await() {}",
         vec![Declaration::AsyncFunction(AsyncFunction::new(
-            Some(
-                interner
-                    .get_or_intern_static("await", utf16!("await"))
-                    .into(),
-            ),
+            Some(Sym::AWAIT.into()),
             FormalParameterList::default(),
             StatementList::default(),
             false,

boa_parser/src/parser/statement/declaration/hoistable/async_generator_decl/mod.rs

@@ -21,7 +21,7 @@ use std::io::Read;
 ///
 /// [spec]: https://tc39.es/ecma262/#prod-AsyncGeneratorDeclaration
 #[derive(Debug, Clone, Copy)]
-pub(super) struct AsyncGeneratorDeclaration {
+pub(in crate::parser) struct AsyncGeneratorDeclaration {
     allow_yield: AllowYield,
     allow_await: AllowAwait,
     is_default: AllowDefault,
@@ -29,7 +29,7 @@ pub(super) struct AsyncGeneratorDeclaration {
 
 impl AsyncGeneratorDeclaration {
     /// Creates a new `AsyncGeneratorDeclaration` parser.
-    pub(super) fn new<Y, A, D>(allow_yield: Y, allow_await: A, is_default: D) -> Self
+    pub(in crate::parser) fn new<Y, A, D>(allow_yield: Y, allow_await: A, is_default: D) -> Self
     where
         Y: Into<AllowYield>,
         A: Into<AllowAwait>,

boa_parser/src/parser/statement/declaration/hoistable/class_decl/mod.rs

@@ -24,7 +24,7 @@ use boa_ast::{
     function::{self, Class, FormalParameterList, Function},
     operations::{contains, contains_arguments, has_direct_super, ContainsSymbol},
     property::{ClassElementName, MethodDefinition},
-    Declaration, Expression, Keyword, Punctuator,
+    Expression, Keyword, Punctuator,
 };
 use boa_interner::{Interner, Sym};
 use boa_macros::utf16;
@@ -40,7 +40,7 @@ use std::io::Read;
 /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/class
 /// [spec]: https://tc39.es/ecma262/#prod-ClassDeclaration
 #[derive(Debug, Clone, Copy)]
-pub(super) struct ClassDeclaration {
+pub(in crate::parser) struct ClassDeclaration {
     allow_yield: AllowYield,
     allow_await: AllowAwait,
     is_default: AllowDefault,
@@ -48,7 +48,7 @@ pub(super) struct ClassDeclaration {
 
 impl ClassDeclaration {
     /// Creates a new `ClassDeclaration` parser.
-    pub(super) fn new<Y, A, D>(allow_yield: Y, allow_await: A, is_default: D) -> Self
+    pub(in crate::parser) fn new<Y, A, D>(allow_yield: Y, allow_await: A, is_default: D) -> Self
     where
         Y: Into<AllowYield>,
         A: Into<AllowAwait>,
@@ -66,7 +66,7 @@ impl<R> TokenParser<R> for ClassDeclaration
 where
     R: Read,
 {
-    type Output = Declaration;
+    type Output = Class;
 
     fn parse(self, cursor: &mut Cursor<R>, interner: &mut Interner) -> ParseResult<Self::Output> {
         cursor.expect((Keyword::Class, false), "class declaration", interner)?;
@@ -93,15 +93,13 @@ where
         };
         cursor.set_strict_mode(strict);
 
-        Ok(Declaration::Class(
-            ClassTail::new(
-                name,
-                has_binding_identifier,
-                self.allow_yield,
-                self.allow_await,
-            )
-            .parse(cursor, interner)?,
-        ))
+        ClassTail::new(
+            name,
+            has_binding_identifier,
+            self.allow_yield,
+            self.allow_await,
+        )
+        .parse(cursor, interner)
     }
 }
 

boa_parser/src/parser/statement/declaration/hoistable/generator_decl/mod.rs

@@ -18,7 +18,7 @@ use std::io::Read;
 /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function*
 /// [spec]: https://tc39.es/ecma262/#prod-GeneratorDeclaration
 #[derive(Debug, Clone, Copy)]
-pub(super) struct GeneratorDeclaration {
+pub(in crate::parser) struct GeneratorDeclaration {
     allow_yield: AllowYield,
     allow_await: AllowAwait,
     is_default: AllowDefault,
@@ -26,7 +26,7 @@ pub(super) struct GeneratorDeclaration {
 
 impl GeneratorDeclaration {
     /// Creates a new `GeneratorDeclaration` parser.
-    pub(super) fn new<Y, A, D>(allow_yield: Y, allow_await: A, is_default: D) -> Self
+    pub(in crate::parser) fn new<Y, A, D>(allow_yield: Y, allow_await: A, is_default: D) -> Self
     where
         Y: Into<AllowYield>,
         A: Into<AllowAwait>,

boa_parser/src/parser/statement/declaration/hoistable/mod.rs

@@ -15,10 +15,6 @@ mod generator_decl;
 
 pub(crate) mod class_decl;
 
-use self::{
-    async_function_decl::AsyncFunctionDeclaration, async_generator_decl::AsyncGeneratorDeclaration,
-    class_decl::ClassDeclaration, generator_decl::GeneratorDeclaration,
-};
 use crate::{
     lexer::TokenKind,
     parser::{
@@ -40,7 +36,11 @@ use boa_interner::{Interner, Sym};
 use boa_profiler::Profiler;
 use std::io::Read;
 
-pub(in crate::parser) use function_decl::FunctionDeclaration;
+pub(in crate::parser) use self::{
+    async_function_decl::AsyncFunctionDeclaration, async_generator_decl::AsyncGeneratorDeclaration,
+    class_decl::ClassDeclaration, function_decl::FunctionDeclaration,
+    generator_decl::GeneratorDeclaration,
+};
 
 /// Hoistable declaration parsing.
 ///
@@ -49,7 +49,7 @@ pub(in crate::parser) use function_decl::FunctionDeclaration;
 ///
 /// [spec]: https://tc39.es/ecma262/#prod-FunctionDeclaration
 #[derive(Debug, Clone, Copy)]
-pub(super) struct HoistableDeclaration {
+pub(in crate::parser) struct HoistableDeclaration {
     allow_yield: AllowYield,
     allow_await: AllowAwait,
     is_default: AllowDefault,
@@ -57,7 +57,7 @@ pub(super) struct HoistableDeclaration {
 
 impl HoistableDeclaration {
     /// Creates a new `HoistableDeclaration` parser.
-    pub(super) fn new<Y, A, D>(allow_yield: Y, allow_await: A, is_default: D) -> Self
+    pub(in crate::parser) fn new<Y, A, D>(allow_yield: Y, allow_await: A, is_default: D) -> Self
     where
         Y: Into<AllowYield>,
         A: Into<AllowAwait>,
@@ -225,6 +225,7 @@ fn parse_callable_declaration<R: Read, C: CallableDeclaration>(
         &bound_names(&params),
         &top_level_lexically_declared_names(&body),
         params_start_position,
+        interner,
     )?;
 
     // It is a Syntax Error if FormalParameters Contains SuperProperty is true.

boa_parser/src/parser/statement/declaration/import.rs

@@ -0,0 +1,327 @@
+//! Import declaration parsing
+//!
+//! This parses `import` declarations.
+//!
+//! More information:
+//! - [MDN documentation][mdn]
+//!  - [ECMAScript specification][spec]
+//!
+//! [spec]: https://tc39.es/ecma262/#sec-imports
+//! [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/import
+
+use crate::{
+    lexer::TokenKind,
+    parser::{
+        cursor::Cursor,
+        statement::{declaration::FromClause, BindingIdentifier},
+        Error, OrAbrupt, ParseResult, TokenParser,
+    },
+};
+use boa_ast::{
+    declaration::{
+        ImportDeclaration as AstImportDeclaration, ImportKind,
+        ImportSpecifier as AstImportSpecifier, ModuleSpecifier,
+    },
+    expression::Identifier,
+    Keyword, Punctuator,
+};
+use boa_interner::{Interner, Sym};
+use boa_profiler::Profiler;
+use std::io::Read;
+
+/// Parses an import declaration.
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-ImportDeclaration
+#[derive(Debug, Clone, Copy)]
+pub(in crate::parser) struct ImportDeclaration;
+
+impl<R> TokenParser<R> for ImportDeclaration
+where
+    R: Read,
+{
+    type Output = AstImportDeclaration;
+
+    fn parse(self, cursor: &mut Cursor<R>, interner: &mut Interner) -> ParseResult<Self::Output> {
+        let _timer = Profiler::global().start_event("ImportDeclaration", "Parsing");
+
+        cursor.expect((Keyword::Import, false), "import declaration", interner)?;
+
+        let tok = cursor.peek(0, interner).or_abrupt()?;
+
+        let import_clause = match tok.kind() {
+            TokenKind::StringLiteral((module_identifier, _)) => {
+                let module_identifier = *module_identifier;
+
+                cursor.advance(interner);
+                cursor.expect_semicolon("import declaration", interner)?;
+
+                return Ok(AstImportDeclaration::new(
+                    None,
+                    ImportKind::DefaultOrUnnamed,
+                    ModuleSpecifier::new(module_identifier),
+                ));
+            }
+            TokenKind::Punctuator(Punctuator::OpenBlock) => {
+                let list = NamedImports.parse(cursor, interner)?;
+                ImportClause::ImportList(None, list)
+            }
+            TokenKind::Punctuator(Punctuator::Mul) => {
+                let alias = NameSpaceImport.parse(cursor, interner)?;
+                ImportClause::Namespace(None, alias)
+            }
+            TokenKind::IdentifierName(_)
+            | TokenKind::Keyword((Keyword::Await | Keyword::Yield, _)) => {
+                let imported_binding = ImportedBinding.parse(cursor, interner)?;
+
+                let tok = cursor.peek(0, interner).or_abrupt()?;
+
+                match tok.kind() {
+                    TokenKind::Punctuator(Punctuator::Comma) => {
+                        cursor.advance(interner);
+                        let tok = cursor.peek(0, interner).or_abrupt()?;
+
+                        match tok.kind() {
+                            TokenKind::Punctuator(Punctuator::OpenBlock) => {
+                                let list = NamedImports.parse(cursor, interner)?;
+                                ImportClause::ImportList(Some(imported_binding), list)
+                            }
+                            TokenKind::Punctuator(Punctuator::Mul) => {
+                                let alias = NameSpaceImport.parse(cursor, interner)?;
+                                ImportClause::Namespace(Some(imported_binding), alias)
+                            }
+                            _ => {
+                                return Err(Error::expected(
+                                    [
+                                        Punctuator::OpenBlock.to_string(),
+                                        Punctuator::Mul.to_string(),
+                                    ],
+                                    tok.to_string(interner),
+                                    tok.span(),
+                                    "import declaration",
+                                ))
+                            }
+                        }
+                    }
+                    _ => ImportClause::ImportList(Some(imported_binding), Box::default()),
+                }
+            }
+            _ => {
+                return Err(Error::expected(
+                    [
+                        Punctuator::OpenBlock.to_string(),
+                        Punctuator::Mul.to_string(),
+                        "identifier".to_owned(),
+                        "string literal".to_owned(),
+                    ],
+                    tok.to_string(interner),
+                    tok.span(),
+                    "import declaration",
+                ))
+            }
+        };
+
+        let module_identifier = FromClause::new("import declaration").parse(cursor, interner)?;
+
+        Ok(import_clause.with_specifier(module_identifier))
+    }
+}
+
+/// Parses an imported binding
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-ImportedBinding
+#[derive(Debug, Clone, Copy)]
+struct ImportedBinding;
+
+impl<R> TokenParser<R> for ImportedBinding
+where
+    R: Read,
+{
+    type Output = Identifier;
+
+    #[inline]
+    fn parse(self, cursor: &mut Cursor<R>, interner: &mut Interner) -> ParseResult<Self::Output> {
+        BindingIdentifier::new(false, true).parse(cursor, interner)
+    }
+}
+
+/// Parses a named import list.
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-NamedImports
+#[derive(Debug, Clone, Copy)]
+struct NamedImports;
+
+impl<R> TokenParser<R> for NamedImports
+where
+    R: Read,
+{
+    type Output = Box<[AstImportSpecifier]>;
+
+    fn parse(self, cursor: &mut Cursor<R>, interner: &mut Interner) -> ParseResult<Self::Output> {
+        cursor.expect(Punctuator::OpenBlock, "import declaration", interner)?;
+
+        let mut list = Vec::new();
+
+        loop {
+            let tok = cursor.next(interner).or_abrupt()?;
+            match tok.kind() {
+                TokenKind::Punctuator(Punctuator::CloseBlock) => {
+                    break;
+                }
+                TokenKind::Punctuator(Punctuator::Comma) => {
+                    if list.is_empty() {
+                        return Err(Error::expected(
+                            [
+                                Punctuator::CloseBlock.to_string(),
+                                "string literal".to_owned(),
+                                "identifier".to_owned(),
+                            ],
+                            tok.to_string(interner),
+                            tok.span(),
+                            "import declaration",
+                        ));
+                    }
+                }
+                TokenKind::StringLiteral(_) | TokenKind::IdentifierName(_) => {
+                    list.push(ImportSpecifier.parse(cursor, interner)?);
+                }
+                _ => {
+                    return Err(Error::expected(
+                        [
+                            Punctuator::CloseBlock.to_string(),
+                            Punctuator::Comma.to_string(),
+                        ],
+                        tok.to_string(interner),
+                        tok.span(),
+                        "import declaration",
+                    ));
+                }
+            }
+        }
+
+        Ok(list.into_boxed_slice())
+    }
+}
+
+/// Parses an import clause.
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-ImportClause
+#[derive(Debug, Clone)]
+enum ImportClause {
+    Namespace(Option<Identifier>, Identifier),
+    ImportList(Option<Identifier>, Box<[AstImportSpecifier]>),
+}
+
+impl ImportClause {
+    #[inline]
+    #[allow(clippy::missing_const_for_fn)]
+    fn with_specifier(self, specifier: ModuleSpecifier) -> AstImportDeclaration {
+        match self {
+            Self::Namespace(default, binding) => {
+                AstImportDeclaration::new(default, ImportKind::Namespaced { binding }, specifier)
+            }
+            Self::ImportList(default, names) => {
+                if names.is_empty() {
+                    AstImportDeclaration::new(default, ImportKind::DefaultOrUnnamed, specifier)
+                } else {
+                    AstImportDeclaration::new(default, ImportKind::Named { names }, specifier)
+                }
+            }
+        }
+    }
+}
+
+/// Parses an import specifier.
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-ImportSpecifier
+#[derive(Debug, Clone, Copy)]
+struct ImportSpecifier;
+
+impl<R> TokenParser<R> for ImportSpecifier
+where
+    R: Read,
+{
+    type Output = AstImportSpecifier;
+
+    fn parse(self, cursor: &mut Cursor<R>, interner: &mut Interner) -> ParseResult<Self::Output> {
+        let tok = cursor.next(interner).or_abrupt()?;
+
+        match tok.kind() {
+            TokenKind::StringLiteral((name, _)) => {
+                if interner.resolve_expect(*name).utf8().is_none() {
+                    return Err(Error::general(
+                        "import specifiers don't allow unpaired surrogates",
+                        tok.span().end(),
+                    ));
+                }
+                cursor.expect(
+                    TokenKind::identifier(Sym::AS),
+                    "import declaration",
+                    interner,
+                )?;
+
+                let binding = ImportedBinding.parse(cursor, interner)?;
+
+                Ok(AstImportSpecifier::new(binding, *name))
+            }
+            TokenKind::IdentifierName((name, _)) => {
+                if cursor
+                    .next_if(TokenKind::identifier(Sym::AS), interner)?
+                    .is_some()
+                {
+                    let binding = ImportedBinding.parse(cursor, interner)?;
+                    Ok(AstImportSpecifier::new(binding, *name))
+                } else {
+                    Ok(AstImportSpecifier::new(Identifier::new(*name), *name))
+                }
+            }
+            _ => Err(Error::expected(
+                ["string literal".to_owned(), "identifier".to_owned()],
+                tok.to_string(interner),
+                tok.span(),
+                "import declaration",
+            )),
+        }
+    }
+}
+
+/// Parses a namespace import
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-NameSpaceImport
+#[derive(Debug, Clone, Copy)]
+struct NameSpaceImport;
+
+impl<R> TokenParser<R> for NameSpaceImport
+where
+    R: Read,
+{
+    type Output = Identifier;
+
+    fn parse(self, cursor: &mut Cursor<R>, interner: &mut Interner) -> ParseResult<Self::Output> {
+        cursor.expect(Punctuator::Mul, "import declaration", interner)?;
+        cursor.expect(
+            TokenKind::identifier(Sym::AS),
+            "import declaration",
+            interner,
+        )?;
+
+        ImportedBinding.parse(cursor, interner)
+    }
+}

boa_parser/src/parser/statement/declaration/lexical.rs

@@ -21,7 +21,7 @@ use ast::operations::bound_names;
 use boa_ast::{self as ast, declaration::Variable, pattern::Pattern, Keyword, Punctuator};
 use boa_interner::{Interner, Sym};
 use boa_profiler::Profiler;
-use std::{convert::TryInto, io::Read};
+use std::io::Read;
 
 /// Parses a lexical declaration.
 ///

boa_parser/src/parser/statement/declaration/mod.rs

@@ -7,22 +7,28 @@
 //! [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements#Declarations
 //! [spec]:https://tc39.es/ecma262/#sec-declarations-and-the-variable-statement
 
+mod export;
 mod hoistable;
+mod import;
 mod lexical;
 #[cfg(test)]
 mod tests;
 
-pub(in crate::parser) use hoistable::class_decl::ClassTail;
-pub(in crate::parser) use hoistable::FunctionDeclaration;
-use hoistable::HoistableDeclaration;
-pub(in crate::parser) use lexical::LexicalDeclaration;
-
+pub(in crate::parser) use self::{
+    export::ExportDeclaration,
+    hoistable::{
+        class_decl::ClassTail, ClassDeclaration, FunctionDeclaration, HoistableDeclaration,
+    },
+    import::ImportDeclaration,
+    lexical::LexicalDeclaration,
+};
 use crate::{
     lexer::TokenKind,
     parser::{AllowAwait, AllowYield, Cursor, OrAbrupt, ParseResult, TokenParser},
+    Error,
 };
 use boa_ast::{self as ast, Keyword};
-use boa_interner::Interner;
+use boa_interner::{Interner, Sym};
 use boa_profiler::Profiler;
 use std::io::Read;
 
@@ -39,6 +45,8 @@ pub(super) struct Declaration {
 }
 
 impl Declaration {
+    /// Creates a new declaration parser.
+    #[inline]
     pub(super) fn new<Y, A>(allow_yield: Y, allow_await: A) -> Self
     where
         Y: Into<AllowYield>,
@@ -75,3 +83,48 @@ where
         }
     }
 }
+
+/// Parses a `from` clause.
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-FromClause
+#[derive(Debug, Clone, Copy)]
+struct FromClause {
+    context: &'static str,
+}
+
+impl FromClause {
+    /// Creates a new `from` clause parser
+    #[inline]
+    const fn new(context: &'static str) -> Self {
+        Self { context }
+    }
+}
+
+impl<R> TokenParser<R> for FromClause
+where
+    R: Read,
+{
+    type Output = ast::declaration::ModuleSpecifier;
+
+    fn parse(self, cursor: &mut Cursor<R>, interner: &mut Interner) -> ParseResult<Self::Output> {
+        let _timer = Profiler::global().start_event("FromClause", "Parsing");
+
+        cursor.expect(TokenKind::identifier(Sym::FROM), self.context, interner)?;
+
+        let tok = cursor.next(interner).or_abrupt()?;
+
+        let TokenKind::StringLiteral((from, _)) = tok.kind() else {
+            return Err(Error::expected(
+                ["string literal".to_owned()],
+                tok.to_string(interner),
+                tok.span(),
+                self.context,
+            ))
+        };
+
+        Ok((*from).into())
+    }
+}

boa_parser/src/parser/statement/declaration/tests.rs

@@ -1,12 +1,10 @@
-use std::convert::TryInto;
-
-use crate::parser::tests::{check_invalid, check_script_parser};
+use crate::parser::tests::{check_invalid_script, check_script_parser};
 use boa_ast::{
     declaration::{LexicalDeclaration, VarDeclaration, Variable},
     expression::literal::Literal,
     Declaration, Statement,
 };
-use boa_interner::Interner;
+use boa_interner::{Interner, Sym};
 use boa_macros::utf16;
 
 /// Checks `var` declaration parsing.
@@ -36,9 +34,7 @@ fn var_declaration_keywords() {
         "var yield = 5;",
         vec![Statement::Var(VarDeclaration(
             vec![Variable::from_identifier(
-                interner
-                    .get_or_intern_static("yield", utf16!("yield"))
-                    .into(),
+                Sym::YIELD.into(),
                 Some(Literal::from(5).into()),
             )]
             .try_into()
@@ -53,9 +49,7 @@ fn var_declaration_keywords() {
         "var await = 5;",
         vec![Statement::Var(VarDeclaration(
             vec![Variable::from_identifier(
-                interner
-                    .get_or_intern_static("await", utf16!("await"))
-                    .into(),
+                Sym::AWAIT.into(),
                 Some(Literal::from(5).into()),
             )]
             .try_into()
@@ -160,9 +154,7 @@ fn let_declaration_keywords() {
         "let yield = 5;",
         vec![Declaration::Lexical(LexicalDeclaration::Let(
             vec![Variable::from_identifier(
-                interner
-                    .get_or_intern_static("yield", utf16!("yield"))
-                    .into(),
+                Sym::YIELD.into(),
                 Some(Literal::from(5).into()),
             )]
             .try_into()
@@ -177,9 +169,7 @@ fn let_declaration_keywords() {
         "let await = 5;",
         vec![Declaration::Lexical(LexicalDeclaration::Let(
             vec![Variable::from_identifier(
-                interner
-                    .get_or_intern_static("await", utf16!("await"))
-                    .into(),
+                Sym::AWAIT.into(),
                 Some(Literal::from(5).into()),
             )]
             .try_into()
@@ -284,9 +274,7 @@ fn const_declaration_keywords() {
         "const yield = 5;",
         vec![Declaration::Lexical(LexicalDeclaration::Const(
             vec![Variable::from_identifier(
-                interner
-                    .get_or_intern_static("yield", utf16!("yield"))
-                    .into(),
+                Sym::YIELD.into(),
                 Some(Literal::from(5).into()),
             )]
             .try_into()
@@ -301,9 +289,7 @@ fn const_declaration_keywords() {
         "const await = 5;",
         vec![Declaration::Lexical(LexicalDeclaration::Const(
             vec![Variable::from_identifier(
-                interner
-                    .get_or_intern_static("await", utf16!("await"))
-                    .into(),
+                Sym::AWAIT.into(),
                 Some(Literal::from(5).into()),
             )]
             .try_into()
@@ -336,7 +322,7 @@ fn const_declaration_no_spaces() {
 /// Checks empty `const` declaration parsing.
 #[test]
 fn empty_const_declaration() {
-    check_invalid("const a;");
+    check_invalid_script("const a;");
 }
 
 /// Checks multiple `const` declarations.

boa_parser/src/parser/statement/iteration/for_statement.rs

@@ -303,16 +303,20 @@ fn initializer_to_iterable_loop_initializer(
             ast::Expression::Identifier(ident) => Ok(IterableLoopInitializer::Identifier(ident)),
             ast::Expression::ArrayLiteral(array) => array
                 .to_pattern(strict)
-                .ok_or(Error::General {
-                    message: "invalid array destructuring pattern in iterable loop initializer",
-                    position,
+                .ok_or_else(|| {
+                    Error::general(
+                        "invalid array destructuring pattern in iterable loop initializer",
+                        position,
+                    )
                 })
                 .map(|arr| IterableLoopInitializer::Pattern(arr.into())),
             ast::Expression::ObjectLiteral(object) => object
                 .to_pattern(strict)
-                .ok_or(Error::General {
-                    message: "invalid object destructuring pattern in iterable loop initializer",
-                    position,
+                .ok_or_else(|| {
+                    Error::general(
+                        "invalid object destructuring pattern in iterable loop initializer",
+                        position,
+                    )
                 })
                 .map(|obj| IterableLoopInitializer::Pattern(obj.into())),
             ast::Expression::PropertyAccess(access) => Ok(IterableLoopInitializer::Access(access)),

boa_parser/src/parser/statement/iteration/tests.rs

@@ -1,4 +1,4 @@
-use crate::parser::tests::{check_invalid, check_script_parser};
+use crate::parser::tests::{check_invalid_script, check_script_parser};
 use boa_ast::{
     declaration::{VarDeclaration, Variable},
     expression::{
@@ -251,11 +251,11 @@ fn do_while_spaces() {
 /// Checks rejection of const bindings without init in for loops
 #[test]
 fn reject_const_no_init_for_loop() {
-    check_invalid("for (const h;;);");
+    check_invalid_script("for (const h;;);");
 }
 
 /// Checks rejection of for await .. in loops
 #[test]
 fn reject_for_await_in_loop() {
-    check_invalid("for await (x in [1,2,3]);");
+    check_invalid_script("for await (x in [1,2,3]);");
 }

boa_parser/src/parser/statement/mod.rs

@@ -25,7 +25,7 @@ use self::{
     block::BlockStatement,
     break_stm::BreakStatement,
     continue_stm::ContinueStatement,
-    declaration::Declaration,
+    declaration::{Declaration, ExportDeclaration, ImportDeclaration},
     expression::ExpressionStatement,
     if_stm::IfStatement,
     iteration::{DoWhileStatement, ForStatement, WhileStatement},
@@ -37,7 +37,10 @@ use self::{
     variable::VariableStatement,
 };
 use crate::{
-    lexer::{token::EscapeSequence, Error as LexError, InputElement, Token, TokenKind},
+    lexer::{
+        token::{ContainsEscapeSequence, EscapeSequence},
+        Error as LexError, InputElement, Token, TokenKind,
+    },
     parser::{
         expression::{BindingIdentifier, Initializer, PropertyName},
         AllowAwait, AllowReturn, AllowYield, Cursor, OrAbrupt, ParseResult, TokenParser,
@@ -49,7 +52,7 @@ use boa_ast::{
     pattern::{ArrayPattern, ArrayPatternElement, ObjectPatternElement},
     Keyword, Punctuator,
 };
-use boa_interner::Interner;
+use boa_interner::{Interner, Sym};
 use boa_macros::utf16;
 use boa_profiler::Profiler;
 use std::io::Read;
@@ -868,3 +871,67 @@ where
         }
     }
 }
+
+/// Parses a module body
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-ModuleBody
+#[derive(Debug, Clone, Copy)]
+pub(super) struct ModuleItemList;
+
+impl<R> TokenParser<R> for ModuleItemList
+where
+    R: Read,
+{
+    type Output = boa_ast::ModuleItemList;
+
+    fn parse(self, cursor: &mut Cursor<R>, interner: &mut Interner) -> ParseResult<Self::Output> {
+        let mut list = Vec::new();
+        while cursor.peek(0, interner)?.is_some() {
+            list.push(ModuleItem.parse(cursor, interner)?);
+        }
+
+        Ok(list.into())
+    }
+}
+
+/// Parses a module item.
+///
+/// More information:
+///  - [ECMAScript specification][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-ModuleItem
+struct ModuleItem;
+
+impl<R> TokenParser<R> for ModuleItem
+where
+    R: Read,
+{
+    type Output = boa_ast::ModuleItem;
+
+    fn parse(self, cursor: &mut Cursor<R>, interner: &mut Interner) -> ParseResult<Self::Output> {
+        let tok = cursor.peek(0, interner).or_abrupt()?;
+
+        match tok.kind() {
+            TokenKind::IdentifierName((ident, ContainsEscapeSequence(false)))
+                if *ident == Sym::IMPORT =>
+            {
+                ImportDeclaration
+                    .parse(cursor, interner)
+                    .map(Self::Output::ImportDeclaration)
+            }
+            TokenKind::IdentifierName((ident, ContainsEscapeSequence(false)))
+                if *ident == Sym::EXPORT =>
+            {
+                ExportDeclaration
+                    .parse(cursor, interner)
+                    .map(Self::Output::ExportDeclaration)
+            }
+            _ => StatementListItem::new(false, true, false)
+                .parse(cursor, interner)
+                .map(Self::Output::StatementListItem),
+        }
+    }
+}

boa_parser/src/parser/statement/switch/tests.rs

@@ -1,4 +1,4 @@
-use crate::parser::tests::{check_invalid, check_script_parser};
+use crate::parser::tests::{check_invalid_script, check_script_parser};
 use boa_ast::{
     declaration::{LexicalDeclaration, Variable},
     expression::{access::SimplePropertyAccess, literal::Literal, Call, Identifier},
@@ -11,7 +11,7 @@ use boa_macros::utf16;
 /// Checks parsing malformed switch with no closeblock.
 #[test]
 fn check_switch_no_closeblock() {
-    check_invalid(
+    check_invalid_script(
         r#"
         let a = 10;
         switch (a) {
@@ -26,7 +26,7 @@ fn check_switch_no_closeblock() {
 /// Checks parsing malformed switch in which a case is started but not finished.
 #[test]
 fn check_switch_case_unclosed() {
-    check_invalid(
+    check_invalid_script(
         r#"
         let a = 10;
         switch (a) {
@@ -40,7 +40,7 @@ fn check_switch_case_unclosed() {
 /// Checks parsing malformed switch with 2 defaults.
 #[test]
 fn check_switch_two_default() {
-    check_invalid(
+    check_invalid_script(
         r#"
         let a = 10;
         switch (a) {
@@ -58,7 +58,7 @@ fn check_switch_two_default() {
 /// Checks parsing malformed switch with no expression.
 #[test]
 fn check_switch_no_expr() {
-    check_invalid(
+    check_invalid_script(
         r#"
         let a = 10;
         switch {
@@ -73,7 +73,7 @@ fn check_switch_no_expr() {
 /// Checks parsing malformed switch with an unknown label.
 #[test]
 fn check_switch_unknown_label() {
-    check_invalid(
+    check_invalid_script(
         r#"
         let a = 10;
         switch (a) {
@@ -88,7 +88,7 @@ fn check_switch_unknown_label() {
 /// Checks parsing malformed switch with two defaults that are seperated by cases.
 #[test]
 fn check_switch_seperated_defaults() {
-    check_invalid(
+    check_invalid_script(
         r#"
         let a = 10;
         switch (a) {

boa_parser/src/parser/statement/try_stm/tests.rs

@@ -1,6 +1,4 @@
-use std::convert::TryInto;
-
-use crate::parser::tests::{check_invalid, check_script_parser};
+use crate::parser::tests::{check_invalid_script, check_script_parser};
 use boa_ast::{
     declaration::{VarDeclaration, Variable},
     expression::{literal::Literal, Identifier},
@@ -265,35 +263,35 @@ fn check_catch_with_var_redeclaration() {
 
 #[test]
 fn check_inline_invalid_catch() {
-    check_invalid("try {} catch");
+    check_invalid_script("try {} catch");
 }
 
 #[test]
 fn check_inline_invalid_catch_without_closing_paren() {
-    check_invalid("try {} catch(e {}");
+    check_invalid_script("try {} catch(e {}");
 }
 
 #[test]
 fn check_inline_invalid_catch_parameter() {
-    check_invalid("try {} catch(1) {}");
+    check_invalid_script("try {} catch(1) {}");
 }
 
 #[test]
 fn check_invalid_try_no_catch_finally() {
-    check_invalid("try {} let a = 10;");
+    check_invalid_script("try {} let a = 10;");
 }
 
 #[test]
 fn check_invalid_catch_with_empty_paren() {
-    check_invalid("try {} catch() {}");
+    check_invalid_script("try {} catch() {}");
 }
 
 #[test]
 fn check_invalid_catch_with_duplicate_params() {
-    check_invalid("try {} catch({ a, b: a }) {}");
+    check_invalid_script("try {} catch({ a, b: a }) {}");
 }
 
 #[test]
 fn check_invalid_catch_with_lexical_redeclaration() {
-    check_invalid("try {} catch(e) { let e = 'oh' }");
+    check_invalid_script("try {} catch(e) { let e = 'oh' }");
 }

boa_parser/src/parser/statement/variable/mod.rs

@@ -11,7 +11,7 @@ use crate::{
 };
 use boa_ast::{
     declaration::{VarDeclaration, Variable},
-    Keyword, Punctuator, Statement,
+    Keyword, Punctuator,
 };
 use boa_interner::Interner;
 use boa_profiler::Profiler;
@@ -51,7 +51,7 @@ impl<R> TokenParser<R> for VariableStatement
 where
     R: Read,
 {
-    type Output = Statement;
+    type Output = VarDeclaration;
 
     fn parse(self, cursor: &mut Cursor<R>, interner: &mut Interner) -> ParseResult<Self::Output> {
         let _timer = Profiler::global().start_event("VariableStatement", "Parsing");
@@ -62,7 +62,7 @@ where
 
         cursor.expect_semicolon("variable statement", interner)?;
 
-        Ok(decl_list.into())
+        Ok(decl_list)
     }
 }
 

boa_parser/src/parser/tests/format/mod.rs

@@ -33,7 +33,7 @@ fn test_formatting(source: &'static str) {
     let source = Source::from_bytes(source);
     let interner = &mut Interner::default();
     let result = Parser::new(source)
-        .parse_all(interner)
+        .parse_script(interner)
         .expect("parsing failed")
         .to_interned_string(interner);
     if scenario != result {

boa_parser/src/parser/tests/mod.rs

@@ -37,7 +37,7 @@ where
 {
     assert_eq!(
         Parser::new(Source::from_bytes(js))
-            .parse_all(interner)
+            .parse_script(interner)
             .expect("failed to parse"),
         StatementList::from(expr.into())
     );
@@ -45,9 +45,9 @@ where
 
 /// Checks that the given javascript string creates a parse error.
 #[track_caller]
-pub(super) fn check_invalid(js: &str) {
+pub(super) fn check_invalid_script(js: &str) {
     assert!(Parser::new(Source::from_bytes(js))
-        .parse_all(&mut Interner::default())
+        .parse_script(&mut Interner::default())
         .is_err());
 }
 

boa_tester/src/exec/js262.rs

@@ -90,7 +90,8 @@ fn detach_array_buffer(_: &JsValue, args: &[JsValue], _: &mut Context<'_>) -> Js
 fn eval_script(_this: &JsValue, args: &[JsValue], context: &mut Context<'_>) -> JsResult<JsValue> {
     args.get(0).and_then(JsValue::as_string).map_or_else(
         || Ok(JsValue::undefined()),
-        |source_text| match context.parse(Source::from_bytes(&source_text.to_std_string_escaped()))
+        |source_text| match context
+            .parse_script(Source::from_bytes(&source_text.to_std_string_escaped()))
         {
             // TODO: check strict
             Err(e) => Err(JsNativeError::typ()
@@ -98,7 +99,7 @@ fn eval_script(_this: &JsValue, args: &[JsValue], context: &mut Context<'_>) ->
                 .into()),
             // Calling eval here parses the code a second time.
             // TODO: We can fix this after we have have defined the public api for the vm executer.
-            Ok(_) => context.eval(Source::from_bytes(&source_text.to_std_string_escaped())),
+            Ok(_) => context.eval_script(Source::from_bytes(&source_text.to_std_string_escaped())),
         },
     )
 }

boa_tester/src/exec/mod.rs

@@ -2,10 +2,10 @@
 
 mod js262;
 
-use super::{
-    Harness, Outcome, Phase, SuiteResult, Test, TestFlags, TestOutcomeResult, TestResult, TestSuite,
+use crate::{
+    read::ErrorType, Harness, Outcome, Phase, SuiteResult, Test, TestFlags, TestOutcomeResult,
+    TestResult, TestSuite,
 };
-use crate::read::ErrorType;
 use boa_engine::{
     context::ContextBuilder, job::SimpleJobQueue, native_function::NativeFunction,
     object::FunctionObjectBuilder, property::Attribute, Context, JsArgs, JsNativeErrorKind,
@@ -187,7 +187,11 @@ impl Test {
                 context.strict(strict);
 
                 // TODO: timeout
-                let value = match context.eval(source) {
+                let value = match if self.is_module() {
+                    context.eval_module(source)
+                } else {
+                    context.eval_script(source)
+                } {
                     Ok(v) => v,
                     Err(e) => return (false, format!("Uncaught {e}")),
                 };
@@ -213,12 +217,22 @@ impl Test {
 
                 let context = &mut Context::default();
                 context.strict(strict);
-                match context.parse(source) {
-                    Ok(statement_list) => match context.compile(&statement_list) {
-                        Ok(_) => (false, "StatementList compilation should fail".to_owned()),
-                        Err(e) => (true, format!("Uncaught {e:?}")),
-                    },
-                    Err(e) => (true, format!("Uncaught {e}")),
+                if self.is_module() {
+                    match context.parse_module(source) {
+                        Ok(module_item_list) => match context.compile_module(&module_item_list) {
+                            Ok(_) => (false, "ModuleItemList compilation should fail".to_owned()),
+                            Err(e) => (true, format!("Uncaught {e:?}")),
+                        },
+                        Err(e) => (true, format!("Uncaught {e}")),
+                    }
+                } else {
+                    match context.parse_script(source) {
+                        Ok(statement_list) => match context.compile_script(&statement_list) {
+                            Ok(_) => (false, "StatementList compilation should fail".to_owned()),
+                            Err(e) => (true, format!("Uncaught {e:?}")),
+                        },
+                        Err(e) => (true, format!("Uncaught {e}")),
+                    }
                 }
             }
             Outcome::Negative {
@@ -230,17 +244,28 @@ impl Test {
                 error_type,
             } => {
                 let context = &mut Context::default();
+                context.strict(strict);
                 if let Err(e) = self.set_up_env(harness, context, AsyncResult::default()) {
                     return (false, e);
                 }
-                context.strict(strict);
-                let code = match context
-                    .parse(source)
-                    .map_err(Into::into)
-                    .and_then(|stmts| context.compile(&stmts))
-                {
-                    Ok(code) => code,
-                    Err(e) => return (false, format!("Uncaught {e}")),
+                let code = if self.is_module() {
+                    match context
+                        .parse_module(source)
+                        .map_err(Into::into)
+                        .and_then(|stmts| context.compile_module(&stmts))
+                    {
+                        Ok(code) => code,
+                        Err(e) => return (false, format!("Uncaught {e}")),
+                    }
+                } else {
+                    match context
+                        .parse_script(source)
+                        .map_err(Into::into)
+                        .and_then(|stmts| context.compile_script(&stmts))
+                    {
+                        Ok(code) => code,
+                        Err(e) => return (false, format!("Uncaught {e}")),
+                    }
                 };
 
                 let e = match context.execute(code) {
@@ -355,10 +380,10 @@ impl Test {
         let sta = Source::from_reader(harness.sta.content.as_bytes(), Some(&harness.sta.path));
 
         context
-            .eval(assert)
+            .eval_script(assert)
             .map_err(|e| format!("could not run assert.js:\n{e}"))?;
         context
-            .eval(sta)
+            .eval_script(sta)
             .map_err(|e| format!("could not run sta.js:\n{e}"))?;
 
         if self.flags.contains(TestFlags::ASYNC) {
@@ -367,7 +392,7 @@ impl Test {
                 Some(&harness.doneprint_handle.path),
             );
             context
-                .eval(dph)
+                .eval_script(dph)
                 .map_err(|e| format!("could not run doneprintHandle.js:\n{e}"))?;
         }
 
@@ -377,7 +402,7 @@ impl Test {
                 .get(include_name)
                 .ok_or_else(|| format!("could not find the {include_name} include file."))?;
             let source = Source::from_reader(include.content.as_bytes(), Some(&include.path));
-            context.eval(source).map_err(|e| {
+            context.eval_script(source).map_err(|e| {
                 format!("could not run the harness `{include_name}`:\nUncaught {e}",)
             })?;
         }
@@ -422,6 +447,7 @@ struct AsyncResult {
 }
 
 impl Default for AsyncResult {
+    #[inline]
     fn default() -> Self {
         Self {
             inner: Rc::new(RefCell::new(Ok(()))),

boa_tester/src/main.rs

@@ -407,9 +407,17 @@ impl Test {
         }
     }
 
+    /// Sets the test as ignored.
+    #[inline]
     fn set_ignored(&mut self) {
         self.ignored = true;
     }
+
+    /// Checks if this is a module test.
+    #[inline]
+    const fn is_module(&self) -> bool {
+        self.flags.contains(TestFlags::MODULE)
+    }
 }
 
 /// An outcome for a test.

boa_wasm/src/lib.rs

@@ -66,7 +66,7 @@ use wasm_bindgen::prelude::*;
 pub fn evaluate(src: &str) -> Result<String, JsValue> {
     // Setup executor
     Context::default()
-        .eval(Source::from_bytes(src))
+        .eval_script(Source::from_bytes(src))
         .map_err(|e| JsValue::from(format!("Uncaught {e}")))
         .map(|v| v.display().to_string())
 }

fuzz/fuzz_targets/bytecompiler-implied.rs

@@ -14,7 +14,7 @@ fn do_fuzz(original: FuzzSource) -> Corpus {
         .instructions_remaining(0)
         .build();
     let mut parser = Parser::new(Cursor::new(&original.source));
-    if let Ok(parsed) = parser.parse_all(ctx.interner_mut()) {
+    if let Ok(parsed) = parser.parse_script(ctx.interner_mut()) {
         let _ = ctx.compile(&parsed);
         Corpus::Keep
     } else {

fuzz/fuzz_targets/parser-idempotency.rs

@@ -21,7 +21,7 @@ fn do_fuzz(mut data: FuzzData) -> Result<(), Box<dyn Error>> {
     let before = data.interner.len();
     // For a variety of reasons, we may not actually produce valid code here (e.g., nameless function).
     // Fail fast and only make the next checks if we were valid.
-    if let Ok(first) = parser.parse_all(&mut data.interner) {
+    if let Ok(first) = parser.parse_script(&mut data.interner) {
         let after_first = data.interner.len();
         let first_interned = first.to_interned_string(&data.interner);
 
@@ -38,7 +38,7 @@ fn do_fuzz(mut data: FuzzData) -> Result<(), Box<dyn Error>> {
 
         // Now, we most assuredly should produce valid code. It has already gone through a first pass.
         let second = parser
-            .parse_all(&mut data.interner)
+            .parse_script(&mut data.interner)
             .expect("Could not parse the first-pass interned copy.");
         let second_interned = second.to_interned_string(&data.interner);
         let after_second = data.interner.len();

test_ignore.toml

@@ -1,5 +1,5 @@
 # Not implemented yet:
-flags = ["module"]
+flags = []
 
 features = [
     # Non-implemented features: