From bb2b6f638cba59269694d44424d16c9a5ede6a81 Mon Sep 17 00:00:00 2001
From: HalidOdat <halidodat@gmail.com>
Date: Tue, 2 Jun 2020 16:52:28 +0200
Subject: [PATCH] Added `TypeError` implementation (#442)

---
 boa/src/builtins/array/mod.rs    |  3 +-
 boa/src/builtins/bigint/mod.rs   | 19 +++-----
 boa/src/builtins/error/mod.rs    |  5 +-
 boa/src/builtins/error/range.rs  | 22 +--------
 boa/src/builtins/error/type.rs   | 83 ++++++++++++++++++++++++++++++++
 boa/src/builtins/function/mod.rs |  2 +-
 boa/src/builtins/json/tests.rs   |  2 +-
 boa/src/builtins/mod.rs          |  3 +-
 boa/src/builtins/number/mod.rs   | 15 +++---
 boa/src/builtins/string/mod.rs   |  4 +-
 boa/src/exec/exception.rs        | 36 ++++++++++++++
 boa/src/exec/mod.rs              | 11 +++--
 boa/src/exec/operator/mod.rs     |  5 +-
 boa/src/exec/tests.rs            | 25 +++++++---
 14 files changed, 172 insertions(+), 63 deletions(-)
 create mode 100644 boa/src/builtins/error/type.rs
 create mode 100644 boa/src/exec/exception.rs

diff --git a/boa/src/builtins/array/mod.rs b/boa/src/builtins/array/mod.rs
index 44c23e5345..7dd3461116 100644
--- a/boa/src/builtins/array/mod.rs
+++ b/boa/src/builtins/array/mod.rs
@@ -15,7 +15,6 @@ mod tests;
 use super::function::{make_builtin_fn, make_constructor_fn};
 use crate::{
     builtins::{
-        error::RangeError,
         object::{ObjectKind, INSTANCE_PROTOTYPE, PROTOTYPE},
         property::Property,
         value::{same_value_zero, ResultValue, Value, ValueData},
@@ -130,7 +129,7 @@ impl Array {
                 }
             }
             1 if args[0].is_double() => {
-                return Err(RangeError::run_new("invalid array length", ctx)?);
+                return ctx.throw_range_error("invalid array length");
             }
             _ => {
                 for (n, value) in args.iter().enumerate() {
diff --git a/boa/src/builtins/bigint/mod.rs b/boa/src/builtins/bigint/mod.rs
index 5b38583396..fabb2be33f 100644
--- a/boa/src/builtins/bigint/mod.rs
+++ b/boa/src/builtins/bigint/mod.rs
@@ -16,7 +16,6 @@ use crate::{
     builtins::{
         function::{make_builtin_fn, make_constructor_fn},
         value::{ResultValue, Value},
-        RangeError,
     },
     exec::Interpreter,
     syntax::ast::bigint::BigInt as AstBigInt,
@@ -50,13 +49,11 @@ impl BigInt {
                 if let Some(bigint) = value.to_bigint() {
                     Value::from(bigint)
                 } else {
-                    return Err(RangeError::run_new(
-                        format!(
-                            "{} can't be converted to BigInt because it isn't an integer",
-                            ctx.to_string(value)?
-                        ),
-                        ctx,
-                    )?);
+                    let message = format!(
+                        "{} can't be converted to BigInt because it isn't an integer",
+                        ctx.to_string(value)?
+                    );
+                    return ctx.throw_range_error(message);
                 }
             }
             None => Value::from(AstBigInt::from(0)),
@@ -98,10 +95,8 @@ impl BigInt {
             10
         };
         if radix < 2 && radix > 36 {
-            return Err(RangeError::run_new(
-                "radix must be an integer at least 2 and no greater than 36",
-                ctx,
-            )?);
+            return ctx
+                .throw_range_error("radix must be an integer at least 2 and no greater than 36");
         }
         Ok(Value::from(Self::to_native_string_radix(
             &this.to_bigint().unwrap(),
diff --git a/boa/src/builtins/error/mod.rs b/boa/src/builtins/error/mod.rs
index 328edc50bf..d142994c7d 100644
--- a/boa/src/builtins/error/mod.rs
+++ b/boa/src/builtins/error/mod.rs
@@ -23,9 +23,10 @@ use crate::{
 pub(crate) mod range;
 // mod reference;
 // mod syntax;
-// mod type_err;
+pub(crate) mod r#type;
 // mod uri;
 
+pub(crate) use self::r#type::TypeError;
 pub(crate) use self::range::RangeError;
 
 /// Built-in `Error` object.
@@ -48,7 +49,7 @@ impl Error {
         // This value is used by console.log and other routines to match Object type
         // to its Javascript Identifier (global constructor method name)
         this.set_kind(ObjectKind::Error);
-        Ok(Value::undefined())
+        Err(this.clone())
     }
 
     /// `Error.prototype.toString()`
diff --git a/boa/src/builtins/error/range.rs b/boa/src/builtins/error/range.rs
index 34e4c88ff7..afd85021ee 100644
--- a/boa/src/builtins/error/range.rs
+++ b/boa/src/builtins/error/range.rs
@@ -39,7 +39,7 @@ impl RangeError {
         // This value is used by console.log and other routines to match Object type
         // to its Javascript Identifier (global constructor method name)
         this.set_kind(ObjectKind::Error);
-        Ok(Value::undefined())
+        Err(this.clone())
     }
 
     /// `Error.prototype.toString()`
@@ -69,26 +69,6 @@ impl RangeError {
         make_constructor_fn("RangeError", 1, Self::make_error, global, prototype, true)
     }
 
-    /// Runs a `new RangeError(message)`.
-    pub(crate) fn run_new<M>(message: M, interpreter: &mut Interpreter) -> ResultValue
-    where
-        M: Into<String>,
-    {
-        use crate::{
-            exec::Executable,
-            syntax::ast::{
-                node::{Call, Identifier, New},
-                Const,
-            },
-        };
-
-        New::from(Call::new(
-            Identifier::from("RangeError"),
-            vec![Const::from(message.into()).into()],
-        ))
-        .run(interpreter)
-    }
-
     /// Initialise the global object with the `RangeError` object.
     pub(crate) fn init(global: &Value) {
         global.set_field("RangeError", Self::create(global));
diff --git a/boa/src/builtins/error/type.rs b/boa/src/builtins/error/type.rs
new file mode 100644
index 0000000000..f15c39cd7f
--- /dev/null
+++ b/boa/src/builtins/error/type.rs
@@ -0,0 +1,83 @@
+//! This module implements the global `TypeError` object.
+//!
+//! The `TypeError` object represents an error when an operation could not be performed,
+//! typically (but not exclusively) when a value is not of the expected type.
+//!
+//! A `TypeError` may be thrown when:
+//!  - an operand or argument passed to a function is incompatible with the type expected by that operator or function.
+//!  - when attempting to modify a value that cannot be changed.
+//!  - when attempting to use a value in an inappropriate way.
+//!
+//! More information:
+//!  - [MDN documentation][mdn]
+//!  - [ECMAScript reference][spec]
+//!
+//! [spec]: https://tc39.es/ecma262/#sec-native-error-types-used-in-this-standard-typeerror
+//! [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypeError
+
+use crate::{
+    builtins::{
+        function::make_builtin_fn,
+        function::make_constructor_fn,
+        object::ObjectKind,
+        value::{ResultValue, Value},
+    },
+    exec::Interpreter,
+};
+
+/// JavaScript `TypeError` implementation.
+#[derive(Debug, Clone, Copy)]
+pub(crate) struct TypeError;
+
+impl TypeError {
+    /// Create a new error object.
+    pub(crate) fn make_error(this: &mut Value, args: &[Value], _: &mut Interpreter) -> ResultValue {
+        if !args.is_empty() {
+            this.set_field(
+                "message",
+                Value::from(
+                    args.get(0)
+                        .expect("failed getting error message")
+                        .to_string(),
+                ),
+            );
+        }
+
+        // This value is used by console.log and other routines to match Object type
+        // to its Javascript Identifier (global constructor method name)
+        this.set_kind(ObjectKind::Error);
+        Err(this.clone())
+    }
+
+    /// `Error.prototype.toString()`
+    ///
+    /// The toString() method returns a string representing the specified Error object.
+    ///
+    /// More information:
+    ///  - [MDN documentation][mdn]
+    ///  - [ECMAScript reference][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-error.prototype.tostring
+    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error/toString
+    #[allow(clippy::wrong_self_convention)]
+    pub(crate) fn to_string(this: &mut Value, _: &[Value], _: &mut Interpreter) -> ResultValue {
+        let name = this.get_field("name");
+        let message = this.get_field("message");
+        Ok(Value::from(format!("{}: {}", name, message)))
+    }
+
+    /// Create a new `RangeError` object.
+    pub(crate) fn create(global: &Value) -> Value {
+        let prototype = Value::new_object(Some(global));
+        prototype.set_field("message", Value::from(""));
+
+        make_builtin_fn(Self::to_string, "toString", &prototype, 0);
+
+        make_constructor_fn("TypeError", 1, Self::make_error, global, prototype, true)
+    }
+
+    /// Initialise the global object with the `RangeError` object.
+    pub(crate) fn init(global: &Value) {
+        global.set_field("TypeError", Self::create(global));
+    }
+}
diff --git a/boa/src/builtins/function/mod.rs b/boa/src/builtins/function/mod.rs
index 2886b97051..bea69bbbf8 100644
--- a/boa/src/builtins/function/mod.rs
+++ b/boa/src/builtins/function/mod.rs
@@ -224,7 +224,7 @@ impl Function {
         if self.constructable {
             match self.body {
                 FunctionBody::BuiltIn(func) => {
-                    func(this_obj, args_list, interpreter).unwrap();
+                    func(this_obj, args_list, interpreter)?;
                     Ok(this_obj.clone())
                 }
                 FunctionBody::Ordinary(ref body) => {
diff --git a/boa/src/builtins/json/tests.rs b/boa/src/builtins/json/tests.rs
index 90ceb1dd2f..2358f11b1b 100644
--- a/boa/src/builtins/json/tests.rs
+++ b/boa/src/builtins/json/tests.rs
@@ -170,7 +170,7 @@ fn json_stringify_function_replacer_propogate_error() {
         thrown
         "#,
     );
-    let expected = forward(&mut engine, r#"1"#);
+    let expected = forward(&mut engine, "1");
 
     assert_eq!(actual, expected);
 }
diff --git a/boa/src/builtins/mod.rs b/boa/src/builtins/mod.rs
index 60a93cc9eb..2d7ecdcc1a 100644
--- a/boa/src/builtins/mod.rs
+++ b/boa/src/builtins/mod.rs
@@ -20,7 +20,7 @@ pub(crate) use self::{
     array::Array,
     bigint::BigInt,
     boolean::Boolean,
-    error::{Error, RangeError},
+    error::{Error, RangeError, TypeError},
     number::Number,
     regexp::RegExp,
     string::String,
@@ -44,4 +44,5 @@ pub fn init(global: &Value) {
     console::init(global);
     Error::init(global);
     RangeError::init(global);
+    TypeError::init(global);
 }
diff --git a/boa/src/builtins/number/mod.rs b/boa/src/builtins/number/mod.rs
index 4683a192b3..d51ac0f996 100644
--- a/boa/src/builtins/number/mod.rs
+++ b/boa/src/builtins/number/mod.rs
@@ -24,12 +24,11 @@ use crate::{
     builtins::{
         object::internal_methods_trait::ObjectInternalMethods,
         value::{ResultValue, Value, ValueData},
-        RangeError,
     },
     exec::Interpreter,
 };
 use num_traits::float::FloatCore;
-use std::{borrow::Borrow, f64, ops::Deref};
+use std::{borrow::Borrow, ops::Deref};
 
 const BUF_SIZE: usize = 2200;
 
@@ -354,10 +353,8 @@ impl Number {
 
         // 4. If radixNumber < 2 or radixNumber > 36, throw a RangeError exception.
         if radix < 2 || radix > 36 {
-            return Err(RangeError::run_new(
-                "radix must be an integer at least 2 and no greater than 36",
-                ctx,
-            )?);
+            return ctx
+                .throw_range_error("radix must be an integer at least 2 and no greater than 36");
         }
 
         if x == -0. {
@@ -423,11 +420,11 @@ impl Number {
 
         // Constants from:
         // https://tc39.es/ecma262/#sec-properties-of-the-number-constructor
-        number.set_field("EPSILON", Value::from(std::f64::EPSILON));
+        number.set_field("EPSILON", Value::from(f64::EPSILON));
         number.set_field("MAX_SAFE_INTEGER", Value::from(9_007_199_254_740_991_f64));
         number.set_field("MIN_SAFE_INTEGER", Value::from(-9_007_199_254_740_991_f64));
-        number.set_field("MAX_VALUE", Value::from(std::f64::MAX));
-        number.set_field("MIN_VALUE", Value::from(std::f64::MIN));
+        number.set_field("MAX_VALUE", Value::from(f64::MAX));
+        number.set_field("MIN_VALUE", Value::from(f64::MIN));
         number.set_field("NEGATIVE_INFINITY", Value::from(f64::NEG_INFINITY));
         number.set_field("POSITIVE_INFINITY", Value::from(f64::INFINITY));
         number.set_field("NaN", Value::from(f64::NAN));
diff --git a/boa/src/builtins/string/mod.rs b/boa/src/builtins/string/mod.rs
index fb4efc76b2..73833263f6 100644
--- a/boa/src/builtins/string/mod.rs
+++ b/boa/src/builtins/string/mod.rs
@@ -68,12 +68,12 @@ impl String {
 
     /// Get the string value to a primitive string
     #[allow(clippy::wrong_self_convention)]
-    pub(crate) fn to_string(this: &mut Value, _: &[Value], _: &mut Interpreter) -> ResultValue {
+    pub(crate) fn to_string(this: &mut Value, _: &[Value], ctx: &mut Interpreter) -> ResultValue {
         // Get String from String Object and send it back as a new value
         match this.get_internal_slot("StringData").data() {
             ValueData::String(ref string) => Ok(Value::from(string.clone())),
             // Throw expection here:
-            _ => panic!("TypeError: this is not a string"),
+            _ => ctx.throw_type_error("'this' is not a string"),
         }
     }
 
diff --git a/boa/src/exec/exception.rs b/boa/src/exec/exception.rs
new file mode 100644
index 0000000000..ddef2e82ee
--- /dev/null
+++ b/boa/src/exec/exception.rs
@@ -0,0 +1,36 @@
+use super::*;
+use crate::{
+    exec::Executable,
+    syntax::ast::{
+        node::{Call, Identifier, New},
+        Const,
+    },
+};
+
+impl Interpreter {
+    /// Throws a `RangeError` with the specified message.
+    pub fn throw_range_error<M>(&mut self, message: M) -> ResultValue
+    where
+        M: Into<String>,
+    {
+        // Runs a `new RangeError(message)`.
+        New::from(Call::new(
+            Identifier::from("RangeError"),
+            vec![Const::from(message.into()).into()],
+        ))
+        .run(self)
+    }
+
+    /// Throws a `TypeError` with the specified message.
+    pub fn throw_type_error<M>(&mut self, message: M) -> ResultValue
+    where
+        M: Into<String>,
+    {
+        // Runs a `new TypeError(message)`.
+        New::from(Call::new(
+            Identifier::from("TypeError"),
+            vec![Const::from(message.into()).into()],
+        ))
+        .run(self)
+    }
+}
diff --git a/boa/src/exec/mod.rs b/boa/src/exec/mod.rs
index 12e43fefc4..e08ce8b701 100644
--- a/boa/src/exec/mod.rs
+++ b/boa/src/exec/mod.rs
@@ -3,13 +3,15 @@
 mod array;
 mod block;
 mod declaration;
+mod exception;
 mod expression;
 mod iteration;
 mod operator;
 mod statement_list;
+mod try_node;
+
 #[cfg(test)]
 mod tests;
-mod try_node;
 
 use crate::{
     builtins::{
@@ -140,7 +142,10 @@ impl Interpreter {
             ValueData::Rational(rational) => Ok(Number::to_native_string(*rational)),
             ValueData::Integer(integer) => Ok(integer.to_string()),
             ValueData::String(string) => Ok(string.clone()),
-            ValueData::Symbol(_) => panic!("TypeError exception."),
+            ValueData::Symbol(_) => {
+                self.throw_type_error("can't convert symbol to string")?;
+                unreachable!();
+            }
             ValueData::BigInt(ref bigint) => Ok(BigInt::to_native_string(bigint)),
             ValueData::Object(_) => {
                 let primitive = self.to_primitive(&mut value.clone(), Some("string"));
@@ -261,7 +266,7 @@ impl Interpreter {
     /// https://tc39.es/ecma262/#sec-toobject
     #[allow(clippy::wrong_self_convention)]
     pub(crate) fn to_object(&mut self, value: &Value) -> ResultValue {
-        match *value.deref().borrow() {
+        match value.data() {
             ValueData::Undefined | ValueData::Integer(_) | ValueData::Null => {
                 Err(Value::undefined())
             }
diff --git a/boa/src/exec/operator/mod.rs b/boa/src/exec/operator/mod.rs
index 325142dddd..83bad26f0a 100644
--- a/boa/src/exec/operator/mod.rs
+++ b/boa/src/exec/operator/mod.rs
@@ -87,7 +87,10 @@ impl Executable for BinOp {
                     CompOp::LessThanOrEqual => v_a.to_number() <= v_b.to_number(),
                     CompOp::In => {
                         if !v_b.is_object() {
-                            panic!("TypeError: {} is not an Object.", v_b);
+                            return interpreter.throw_type_error(format!(
+                                "right-hand side of 'in' should be an object, got {}",
+                                v_b.get_type()
+                            ));
                         }
                         let key = interpreter.to_property_key(&mut v_a)?;
                         interpreter.has_property(&mut v_b, &key)
diff --git a/boa/src/exec/tests.rs b/boa/src/exec/tests.rs
index 105e34b7f2..a09c98904c 100644
--- a/boa/src/exec/tests.rs
+++ b/boa/src/exec/tests.rs
@@ -609,12 +609,21 @@ mod in_operator {
     }
 
     #[test]
-    #[should_panic(expected = "TypeError: undefined is not an Object.")]
     fn should_type_error_when_rhs_not_object() {
+        let realm = Realm::create();
+        let mut engine = Interpreter::new(realm);
+
         let scenario = r#"
-            'fail' in undefined
+            var x = false;
+            try {
+                'fail' in undefined
+            } catch(e) {
+                x = true;
+            }
         "#;
-        exec(scenario);
+
+        forward(&mut engine, scenario);
+        assert_eq!(forward(&mut engine, "x"), "true");
     }
 
     #[test]
@@ -627,7 +636,7 @@ mod in_operator {
             this.a = "a";
             this.b = "b";
           }
-          
+
           var bar = new Foo();
         "#;
         forward(&mut engine, scenario);
@@ -642,7 +651,7 @@ mod in_operator {
         let mut engine = Interpreter::new(realm);
 
         let scenario = r#"
-            function Foo() {}            
+            function Foo() {}
             var bar = new Foo();
         "#;
         forward(&mut engine, scenario);
@@ -655,7 +664,7 @@ mod in_operator {
 fn var_decl_hoisting() {
     let scenario = r#"
         x = 5;
-        
+
         var x;
         x;
     "#;
@@ -729,7 +738,7 @@ fn function_decl_hoisting() {
 
         function a() {return 5}
         function b() {return a()}
-        
+
         x;
     "#;
     assert_eq!(&exec(scenario), "5");
@@ -739,7 +748,7 @@ fn function_decl_hoisting() {
 
         function b() {return a()}
         function a() {return 5}
-        
+
         x;
     "#;
     assert_eq!(&exec(scenario), "5");