From ae10d40dc038f4d694fc9d83101fc877971cecfb Mon Sep 17 00:00:00 2001
From: raskad <32105367+raskad@users.noreply.github.com>
Date: Wed, 17 Aug 2022 11:03:38 +0000
Subject: [PATCH] Fix `arguments` object iterator function (#2231)

This Pull Request changes the following:

- Create the `%Array.prototype.values%` function object once and use it in both the `Array` prototype and as the `@@iterator` value of `arguments` objects.

This fixes a test where `arguments[Symbol.iterator]` and `[][Symbol.iterator]` would not be equal.
---
 boa_engine/src/builtins/array/mod.rs          | 19 ++++++++++---------
 boa_engine/src/builtins/function/arguments.rs |  7 ++++---
 boa_engine/src/context/intrinsics.rs          | 15 ++++++++++++++-
 3 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/boa_engine/src/builtins/array/mod.rs b/boa_engine/src/builtins/array/mod.rs
index 549ce87398..54f2280029 100644
--- a/boa_engine/src/builtins/array/mod.rs
+++ b/boa_engine/src/builtins/array/mod.rs
@@ -52,7 +52,7 @@ impl BuiltIn for Array {
             .constructor(false)
             .build();
 
-        let values_function = Self::values_intrinsic(context);
+        let values_function = context.intrinsics().objects().array_prototype_values();
         let unscopables_object = Self::unscopables_intrinsic(context);
 
         ConstructorBuilder::with_standard_constructor(
@@ -2738,6 +2738,15 @@ impl Array {
         ))
     }
 
+    /// Creates an `Array.prototype.values( )` function object.
+    pub(crate) fn create_array_prototype_values(context: &mut Context) -> JsFunction {
+        FunctionBuilder::native(context, Self::values)
+            .name("values")
+            .length(0)
+            .constructor(false)
+            .build()
+    }
+
     /// `Array.prototype.keys( )`
     ///
     /// The keys method returns an iterable that iterates over the indexes in the array.
@@ -2840,14 +2849,6 @@ impl Array {
         }
     }
 
-    pub(crate) fn values_intrinsic(context: &mut Context) -> JsFunction {
-        FunctionBuilder::native(context, Self::values)
-            .name("values")
-            .length(0)
-            .constructor(false)
-            .build()
-    }
-
     /// `Array.prototype [ @@unscopables ]`
     ///
     /// The initial value of the 'unscopables' data property is an ordinary object
diff --git a/boa_engine/src/builtins/function/arguments.rs b/boa_engine/src/builtins/function/arguments.rs
index cc28c657a3..ab1626a87c 100644
--- a/boa_engine/src/builtins/function/arguments.rs
+++ b/boa_engine/src/builtins/function/arguments.rs
@@ -1,5 +1,4 @@
 use crate::{
-    builtins::Array,
     environments::DeclarativeEnvironment,
     object::{JsObject, ObjectData},
     property::PropertyDescriptor,
@@ -111,10 +110,11 @@ impl Arguments {
         // 7. Perform ! DefinePropertyOrThrow(obj, @@iterator, PropertyDescriptor {
         // [[Value]]: %Array.prototype.values%, [[Writable]]: true, [[Enumerable]]: false,
         // [[Configurable]]: true }).
+        let values_function = context.intrinsics().objects().array_prototype_values();
         obj.define_property_or_throw(
             symbol::WellKnownSymbols::iterator(),
             PropertyDescriptor::builder()
-                .value(Array::values_intrinsic(context))
+                .value(values_function)
                 .writable(true)
                 .enumerable(false)
                 .configurable(true),
@@ -263,10 +263,11 @@ impl Arguments {
         // 20. Perform ! DefinePropertyOrThrow(obj, @@iterator, PropertyDescriptor {
         // [[Value]]: %Array.prototype.values%, [[Writable]]: true, [[Enumerable]]: false,
         // [[Configurable]]: true }).
+        let values_function = context.intrinsics().objects().array_prototype_values();
         obj.define_property_or_throw(
             WellKnownSymbols::iterator(),
             PropertyDescriptor::builder()
-                .value(Array::values_intrinsic(context))
+                .value(values_function)
                 .writable(true)
                 .enumerable(false)
                 .configurable(true),
diff --git a/boa_engine/src/context/intrinsics.rs b/boa_engine/src/context/intrinsics.rs
index 719b40939d..e8d7dac720 100644
--- a/boa_engine/src/context/intrinsics.rs
+++ b/boa_engine/src/context/intrinsics.rs
@@ -1,5 +1,7 @@
 use crate::{
-    builtins::{error::r#type::create_throw_type_error, iterable::IteratorPrototypes},
+    builtins::{
+        array::Array, error::r#type::create_throw_type_error, iterable::IteratorPrototypes,
+    },
     object::{JsObject, ObjectData},
     property::PropertyDescriptorBuilder,
     Context,
@@ -407,6 +409,10 @@ impl StandardConstructors {
 pub struct IntrinsicObjects {
     /// %ThrowTypeError% intrinsic object
     throw_type_error: JsObject,
+
+    /// %Array.prototype.values%
+    array_prototype_values: JsObject,
+
     /// Cached iterator prototypes.
     iterator_prototypes: IteratorPrototypes,
 }
@@ -416,6 +422,7 @@ impl IntrinsicObjects {
     pub fn init(context: &mut Context) -> Self {
         Self {
             throw_type_error: create_throw_type_error(context),
+            array_prototype_values: Array::create_array_prototype_values(context).into(),
             iterator_prototypes: IteratorPrototypes::init(context),
         }
     }
@@ -426,6 +433,12 @@ impl IntrinsicObjects {
         self.throw_type_error.clone()
     }
 
+    /// Get the `%Array.prototype.values%` intrinsic object.
+    #[inline]
+    pub fn array_prototype_values(&self) -> JsObject {
+        self.array_prototype_values.clone()
+    }
+
     /// Get the cached iterator prototypes.
     #[inline]
     pub fn iterator_prototypes(&self) -> &IteratorPrototypes {