LibJS: Introduce the CanonicalizeKeyedCollectionKey AO

This is an editorial change in the ECMA-262 spec. See:
https://github.com/tc39/ecma262/commit/30257dd

Userland/Libraries/LibJS/CMakeLists.txt

@@ -148,6 +148,7 @@ set(SOURCES
     Runtime/IteratorPrototype.cpp
     Runtime/JSONObject.cpp
     Runtime/JobCallback.cpp
+    Runtime/KeyedCollections.cpp
     Runtime/Map.cpp
     Runtime/MapConstructor.cpp
     Runtime/MapIterator.cpp

Userland/Libraries/LibJS/Runtime/AbstractOperations.h

@@ -15,6 +15,7 @@
 #include <LibJS/Runtime/FunctionObject.h>
 #include <LibJS/Runtime/GlobalObject.h>
 #include <LibJS/Runtime/Iterator.h>
+#include <LibJS/Runtime/KeyedCollections.h>
 #include <LibJS/Runtime/PrivateEnvironment.h>
 #include <LibJS/Runtime/Value.h>
 
@@ -276,9 +277,8 @@ ThrowCompletionOr<GroupsType> group_by(VM& vm, Value items, Value callback_funct
             // i. Assert: keyCoercion is zero.
             static_assert(IsSame<KeyType, void>);
 
-            // ii. If key is -0𝔽, set key to +0𝔽.
-            if (key.value().is_negative_zero())
-                key = Value(0);
+            // ii. Set key to CanonicalizeKeyedCollectionKey(key).
+            key = canonicalize_keyed_collection_key(key.value());
 
             add_value_to_keyed_group(vm, groups, make_handle(key.release_value()), value);
         }

Userland/Libraries/LibJS/Runtime/KeyedCollections.cpp

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2024, Tim Flynn <trflynn89@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibJS/Runtime/KeyedCollections.h>
+
+namespace JS {
+
+// 24.5.1 CanonicalizeKeyedCollectionKey ( key ), https://tc39.es/ecma262/#sec-canonicalizekeyedcollectionkey
+Value canonicalize_keyed_collection_key(Value key)
+{
+    // 1. If key is -0𝔽, return +0𝔽.
+    if (key.is_negative_zero())
+        return Value { 0.0 };
+
+    // 2. Return key.
+    return key;
+}
+
+}

Userland/Libraries/LibJS/Runtime/KeyedCollections.h

@@ -0,0 +1,15 @@
+/*
+ * Copyright (c) 2024, Tim Flynn <trflynn89@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibJS/Runtime/Value.h>
+
+namespace JS {
+
+Value canonicalize_keyed_collection_key(Value);
+
+}

Userland/Libraries/LibJS/Runtime/MapPrototype.cpp

@@ -7,6 +7,7 @@
 #include <AK/HashMap.h>
 #include <AK/TypeCasts.h>
 #include <LibJS/Runtime/AbstractOperations.h>
+#include <LibJS/Runtime/KeyedCollections.h>
 #include <LibJS/Runtime/MapIterator.h>
 #include <LibJS/Runtime/MapPrototype.h>
 
@@ -66,11 +67,14 @@ JS_DEFINE_NATIVE_FUNCTION(MapPrototype::delete_)
     // 2. Perform ? RequireInternalSlot(M, [[MapData]]).
     auto map = TRY(typed_this_object(vm));
 
+    // 3. Set key to CanonicalizeKeyedCollectionKey(key).
+    key = canonicalize_keyed_collection_key(key);
+
     // 3. For each Record { [[Key]], [[Value]] } p of M.[[MapData]], do
-    //    a. If p.[[Key]] is not empty and SameValueZero(p.[[Key]], key) is true, then
-    //        i. Set p.[[Key]] to empty.
-    //        ii. Set p.[[Value]] to empty.
-    //        iii. Return true.
+    //     a. If p.[[Key]] is not empty and SameValue(p.[[Key]], key) is true, then
+    //         i. Set p.[[Key]] to empty.
+    //         ii. Set p.[[Value]] to empty.
+    //         iii. Return true.
     // 4. Return false.
     return Value(map->map_remove(key));
 }
@@ -131,11 +135,13 @@ JS_DEFINE_NATIVE_FUNCTION(MapPrototype::get)
     // 2. Perform ? RequireInternalSlot(M, [[MapData]]).
     auto map = TRY(typed_this_object(vm));
 
+    // 3. Set key to CanonicalizeKeyedCollectionKey(key).
+    key = canonicalize_keyed_collection_key(key);
+
     // 3. For each Record { [[Key]], [[Value]] } p of M.[[MapData]], do
-    //    a. If p.[[Key]] is not empty and SameValueZero(p.[[Key]], key) is true, return p.[[Value]].
-    auto result = map->map_get(key);
-    if (result.has_value())
-        return result.value();
+    //    a. If p.[[Key]] is not empty and SameValue(p.[[Key]], key) is true, return p.[[Value]].
+    if (auto result = map->map_get(key); result.has_value())
+        return result.release_value();
 
     // 4. Return undefined.
     return js_undefined();
@@ -150,8 +156,11 @@ JS_DEFINE_NATIVE_FUNCTION(MapPrototype::has)
     // 2. Perform ? RequireInternalSlot(M, [[MapData]]).
     auto map = TRY(typed_this_object(vm));
 
+    // 3. Set key to CanonicalizeKeyedCollectionKey(key).
+    key = canonicalize_keyed_collection_key(key);
+
     // 3. For each Record { [[Key]], [[Value]] } p of M.[[MapData]], do
-    //    a. If p.[[Key]] is not empty and SameValueZero(p.[[Key]], key) is true, return true.
+    //    a. If p.[[Key]] is not empty and SameValue(p.[[Key]], key) is true, return true.
     // 4. Return false.
     return map->map_has(key);
 }
@@ -178,14 +187,13 @@ JS_DEFINE_NATIVE_FUNCTION(MapPrototype::set)
     // 2. Perform ? RequireInternalSlot(M, [[MapData]]).
     auto map = TRY(typed_this_object(vm));
 
-    // 4. If key is -0𝔽, set key to +0𝔽.
-    if (key.is_negative_zero())
-        key = Value(0);
+    // 3. Set key to CanonicalizeKeyedCollectionKey(key).
+    key = canonicalize_keyed_collection_key(key);
 
-    // 3. For each Record { [[Key]], [[Value]] } p of M.[[MapData]], do
-    //    a. If p.[[Key]] is not empty and SameValueZero(p.[[Key]], key) is true, then
-    //        i. Set p.[[Value]] to value.
-    //        ii. Return M.
+    // 4. For each Record { [[Key]], [[Value]] } p of M.[[MapData]], do
+    //     a. If p.[[Key]] is not empty and SameValue(p.[[Key]], key) is true, then
+    //         i. Set p.[[Value]] to value.
+    //         ii. Return M.
     // 5. Let p be the Record { [[Key]]: key, [[Value]]: value }.
     // 6. Append p to M.[[MapData]].
     map->map_set(key, value);

Userland/Libraries/LibJS/Runtime/SetPrototype.cpp

@@ -9,6 +9,7 @@
 #include <LibJS/Runtime/AbstractOperations.h>
 #include <LibJS/Runtime/FunctionObject.h>
 #include <LibJS/Runtime/Iterator.h>
+#include <LibJS/Runtime/KeyedCollections.h>
 #include <LibJS/Runtime/SetIterator.h>
 #include <LibJS/Runtime/SetPrototype.h>
 #include <LibJS/Runtime/ValueInlines.h>
@@ -62,12 +63,11 @@ JS_DEFINE_NATIVE_FUNCTION(SetPrototype::add)
     // 2. Perform ? RequireInternalSlot(S, [[SetData]]).
     auto set = TRY(typed_this_object(vm));
 
-    // 4. If value is -0𝔽, set value to +0𝔽.
-    if (value.is_negative_zero())
-        value = Value(0);
+    // 3. Set value to CanonicalizeKeyedCollectionKey(value).
+    value = canonicalize_keyed_collection_key(value);
 
-    // 3. For each element e of S.[[SetData]], do
-    //     a. If e is not empty and SameValueZero(e, value) is true, then
+    // 4. For each element e of S.[[SetData]], do
+    //     a. If e is not empty and SameValue(e, value) is true, then
     //         i. Return S.
     // 5. Append value to S.[[SetData]].
     set->set_add(value);
@@ -100,11 +100,14 @@ JS_DEFINE_NATIVE_FUNCTION(SetPrototype::delete_)
     // 2. Perform ? RequireInternalSlot(S, [[SetData]]).
     auto set = TRY(typed_this_object(vm));
 
-    // 3. For each element e of S.[[SetData]], do
-    //     a. If e is not empty and SameValueZero(e, value) is true, then
+    // 3. Set value to CanonicalizeKeyedCollectionKey(value).
+    value = canonicalize_keyed_collection_key(value);
+
+    // 4. For each element e of S.[[SetData]], do
+    //     a. If e is not empty and SameValue(e, value) is true, then
     //         i. Replace the element of S.[[SetData]] whose value is e with an element whose value is empty.
     //         ii. Return true.
-    // 4. Return false.
+    // 5. Return false.
     return Value(set->set_remove(value));
 }
 
@@ -165,9 +168,12 @@ JS_DEFINE_NATIVE_FUNCTION(SetPrototype::has)
     // 2. Perform ? RequireInternalSlot(S, [[SetData]]).
     auto set = TRY(typed_this_object(vm));
 
-    // 3. For each element e of S.[[SetData]], do
-    //     a. If e is not empty and SameValueZero(e, value) is true, return true.
-    // 4. Return false.
+    // 3. Set value to CanonicalizeKeyedCollectionKey(value).
+    value = canonicalize_keyed_collection_key(value);
+
+    // 4. For each element e of S.[[SetData]], do
+    //     a. If e is not empty and SameValue(e, value) is true, return true.
+    // 5. Return false.
     return Value(set->set_has(value));
 }
 

Userland/Libraries/LibJS/Runtime/ValueTraits.h

@@ -25,21 +25,20 @@ struct ValueTraits : public Traits<Value> {
         if (value.is_bigint())
             return value.as_bigint().big_integer().hash();
 
-        if (value.is_negative_zero())
-            value = Value(0);
         // In the IEEE 754 standard a NaN value is encoded as any value from 0x7ff0000000000001 to 0x7fffffffffffffff,
         // with the least significant bits (referred to as the 'payload') carrying some kind of diagnostic information
         // indicating the source of the NaN. Since ECMA262 does not differentiate between different kinds of NaN values,
         // Sets and Maps must not differentiate between them either.
         // This is achieved by replacing any NaN value by a canonical qNaN.
-        else if (value.is_nan())
+        if (value.is_nan())
             value = js_nan();
 
         return u64_hash(value.encoded()); // FIXME: Is this the best way to hash pointers, doubles & ints?
     }
+
     static bool equals(Value const a, Value const b)
     {
-        return same_value_zero(a, b);
+        return same_value(a, b);
     }
 };