LibJS: Remove cloneConstructor parameter from CloneArrayBuffer

This is a normative change in the ECMA-262 spec. See:
https://github.com/tc39/ecma262/commit/e7979fd

Note that this implements a FIXME in InitializeTypedArrayFromTypedArray,
now that shared array buffers are no longer a concern there. We already
have test coverage for the now-handled case.

4 files changed, 48 insertions, 51 deletions

diff --git a/Userland/Libraries/LibJS/Runtime/ArrayBuffer.cpp b/Userland/Libraries/LibJS/Runtime/ArrayBuffer.cpp
index 35766ba9c0..a477113dd2 100644
--- a/Userland/Libraries/LibJS/Runtime/ArrayBuffer.cpp
+++ b/Userland/Libraries/LibJS/Runtime/ArrayBuffer.cpp
@@ -7,6 +7,7 @@
 
 #include <LibJS/Runtime/AbstractOperations.h>
 #include <LibJS/Runtime/ArrayBuffer.h>
+#include <LibJS/Runtime/ArrayBufferConstructor.h>
 #include <LibJS/Runtime/GlobalObject.h>
 
 namespace JS {
@@ -121,16 +122,13 @@ ThrowCompletionOr<Value> detach_array_buffer(GlobalObject& global_object, ArrayB
 }
 
 // 25.1.2.4 CloneArrayBuffer ( srcBuffer, srcByteOffset, srcLength, cloneConstructor ), https://tc39.es/ecma262/#sec-clonearraybuffer
-ThrowCompletionOr<ArrayBuffer*> clone_array_buffer(GlobalObject& global_object, ArrayBuffer& source_buffer, size_t source_byte_offset, size_t source_length, FunctionObject& clone_constructor)
+ThrowCompletionOr<ArrayBuffer*> clone_array_buffer(GlobalObject& global_object, ArrayBuffer& source_buffer, size_t source_byte_offset, size_t source_length)
 {
-    auto& vm = global_object.vm();
-
-    // 1. Let targetBuffer be ? AllocateArrayBuffer(cloneConstructor, srcLength).
-    auto* target_buffer = TRY(allocate_array_buffer(global_object, clone_constructor, source_length));
+    // 1. Assert: IsDetachedBuffer(srcBuffer) is false.
+    VERIFY(!source_buffer.is_detached());
 
-    // 2. If IsDetachedBuffer(srcBuffer) is true, throw a TypeError exception.
-    if (source_buffer.is_detached())
-        return vm.throw_completion<TypeError>(global_object, ErrorType::DetachedArrayBuffer);
+    // 2. Let targetBuffer be ? AllocateArrayBuffer(%ArrayBuffer%, srcLength).
+    auto* target_buffer = TRY(allocate_array_buffer(global_object, *global_object.array_buffer_constructor(), source_length));
 
     // 3. Let srcBlock be srcBuffer.[[ArrayBufferData]].
     auto& source_block = source_buffer.buffer();
diff --git a/Userland/Libraries/LibJS/Runtime/ArrayBuffer.h b/Userland/Libraries/LibJS/Runtime/ArrayBuffer.h
index 0dddc1d1ba..f64a25b7ca 100644
--- a/Userland/Libraries/LibJS/Runtime/ArrayBuffer.h
+++ b/Userland/Libraries/LibJS/Runtime/ArrayBuffer.h
@@ -82,7 +82,7 @@ private:
 
 ThrowCompletionOr<ArrayBuffer*> allocate_array_buffer(GlobalObject&, FunctionObject& constructor, size_t byte_length, Optional<size_t> max_byte_length = {});
 ThrowCompletionOr<Value> detach_array_buffer(GlobalObject&, ArrayBuffer& array_buffer, Optional<Value> key = {});
-ThrowCompletionOr<ArrayBuffer*> clone_array_buffer(GlobalObject&, ArrayBuffer& source_buffer, size_t source_byte_offset, size_t source_length, FunctionObject& clone_constructor);
+ThrowCompletionOr<ArrayBuffer*> clone_array_buffer(GlobalObject&, ArrayBuffer& source_buffer, size_t source_byte_offset, size_t source_length);
 
 // 25.1.2.9 RawBytesToNumeric ( type, rawBytes, isLittleEndian ), https://tc39.es/ecma262/#sec-rawbytestonumeric
 template<typename T>
diff --git a/Userland/Libraries/LibJS/Runtime/TypedArray.cpp b/Userland/Libraries/LibJS/Runtime/TypedArray.cpp
index b3f8f3277b..47691a0f12 100644
--- a/Userland/Libraries/LibJS/Runtime/TypedArray.cpp
+++ b/Userland/Libraries/LibJS/Runtime/TypedArray.cpp
@@ -164,63 +164,64 @@ static ThrowCompletionOr<void> initialize_typed_array_from_typed_array(GlobalObj
     if (byte_length.has_overflow())
         return vm.template throw_completion<RangeError>(global_object, ErrorType::InvalidLength, "typed array");
 
-    // FIXME:
-    // 10. If IsSharedArrayBuffer(srcData) is false, then
-    //     a. Let bufferConstructor be ? SpeciesConstructor(srcData, %ArrayBuffer%).
-    // 11. Else,
-    //     a. Let bufferConstructor be %ArrayBuffer%.
-    // 12. If elementType is the same as srcType, then
-    //     a. Let data be ? CloneArrayBuffer(srcData, srcByteOffset, byteLength, bufferConstructor).
-    // 13. Else,
+    ArrayBuffer* data = nullptr;
 
-    // a. Let data be ? AllocateArrayBuffer(bufferConstructor, byteLength).
-    auto* data = TRY(allocate_array_buffer(global_object, *global_object.array_buffer_constructor(), byte_length.value()));
+    // 10. If elementType is the same as srcType, then
+    if (dest_array.element_name() == src_array.element_name()) {
+        // a. Let data be ? CloneArrayBuffer(srcData, srcByteOffset, byteLength).
+        data = TRY(clone_array_buffer(global_object, *src_data, src_byte_offset, byte_length.value()));
+    }
+    // 11. Else,
+    else {
+        // a. Let data be ? AllocateArrayBuffer(bufferConstructor, byteLength).
+        data = TRY(allocate_array_buffer(global_object, *global_object.array_buffer_constructor(), byte_length.value()));
 
-    // b. If IsDetachedBuffer(srcData) is true, throw a TypeError exception.
-    if (src_data->is_detached())
-        return vm.template throw_completion<TypeError>(global_object, ErrorType::DetachedArrayBuffer);
+        // b. If IsDetachedBuffer(srcData) is true, throw a TypeError exception.
+        if (src_data->is_detached())
+            return vm.template throw_completion<TypeError>(global_object, ErrorType::DetachedArrayBuffer);
 
-    // c. If srcArray.[[ContentType]] ≠ O.[[ContentType]], throw a TypeError exception.
-    if (src_array.content_type() != dest_array.content_type())
-        return vm.template throw_completion<TypeError>(global_object, ErrorType::TypedArrayContentTypeMismatch, dest_array.class_name(), src_array.class_name());
+        // c. If srcArray.[[ContentType]] ≠ O.[[ContentType]], throw a TypeError exception.
+        if (src_array.content_type() != dest_array.content_type())
+            return vm.template throw_completion<TypeError>(global_object, ErrorType::TypedArrayContentTypeMismatch, dest_array.class_name(), src_array.class_name());
 
-    // d. Let srcByteIndex be srcByteOffset.
-    u64 src_byte_index = src_byte_offset;
+        // d. Let srcByteIndex be srcByteOffset.
+        u64 src_byte_index = src_byte_offset;
 
-    // e. Let targetByteIndex be 0.
-    u64 target_byte_index = 0;
+        // e. Let targetByteIndex be 0.
+        u64 target_byte_index = 0;
 
-    // f. Let count be elementLength.
-    // g. Repeat, while count > 0,
-    for (u32 i = 0; i < element_length; ++i) {
-        // i. Let value be GetValueFromBuffer(srcData, srcByteIndex, srcType, true, Unordered).
-        auto value = src_array.get_value_from_buffer(src_byte_index, ArrayBuffer::Order::Unordered);
+        // f. Let count be elementLength.
+        // g. Repeat, while count > 0,
+        for (u32 i = 0; i < element_length; ++i) {
+            // i. Let value be GetValueFromBuffer(srcData, srcByteIndex, srcType, true, Unordered).
+            auto value = src_array.get_value_from_buffer(src_byte_index, ArrayBuffer::Order::Unordered);
 
-        // ii. Perform SetValueInBuffer(data, targetByteIndex, elementType, value, true, Unordered).
-        data->template set_value<T>(target_byte_index, value, true, ArrayBuffer::Order::Unordered);
+            // ii. Perform SetValueInBuffer(data, targetByteIndex, elementType, value, true, Unordered).
+            data->template set_value<T>(target_byte_index, value, true, ArrayBuffer::Order::Unordered);
 
-        // iii. Set srcByteIndex to srcByteIndex + srcElementSize.
-        src_byte_index += src_element_size;
+            // iii. Set srcByteIndex to srcByteIndex + srcElementSize.
+            src_byte_index += src_element_size;
 
-        // iv. Set targetByteIndex to targetByteIndex + elementSize.
-        target_byte_index += element_size;
+            // iv. Set targetByteIndex to targetByteIndex + elementSize.
+            target_byte_index += element_size;
 
-        // v. Set count to count - 1.
+            // v. Set count to count - 1.
+        }
     }
 
-    // 14. Set O.[[ViewedArrayBuffer]] to data.
+    // 12. Set O.[[ViewedArrayBuffer]] to data.
     dest_array.set_viewed_array_buffer(data);
 
-    // 15. Set O.[[ByteLength]] to byteLength.
+    // 13. Set O.[[ByteLength]] to byteLength.
     dest_array.set_byte_length(byte_length.value());
 
-    // 16. Set O.[[ByteOffset]] to 0.
+    // 14. Set O.[[ByteOffset]] to 0.
     dest_array.set_byte_offset(0);
 
-    // 17. Set O.[[ArrayLength]] to elementLength.
+    // 15. Set O.[[ArrayLength]] to elementLength.
     dest_array.set_array_length(element_length);
 
-    // 18. Return unused.
+    // 16. Return unused.
     return {};
 }
 
diff --git a/Userland/Libraries/LibJS/Runtime/TypedArrayPrototype.cpp b/Userland/Libraries/LibJS/Runtime/TypedArrayPrototype.cpp
index d2621706fa..fd78a0f7fa 100644
--- a/Userland/Libraries/LibJS/Runtime/TypedArrayPrototype.cpp
+++ b/Userland/Libraries/LibJS/Runtime/TypedArrayPrototype.cpp
@@ -7,7 +7,6 @@
  */
 
 #include <LibJS/Runtime/AbstractOperations.h>
-#include <LibJS/Runtime/ArrayBufferConstructor.h>
 #include <LibJS/Runtime/ArrayIterator.h>
 #include <LibJS/Runtime/GlobalObject.h>
 #include <LibJS/Runtime/TypedArray.h>
@@ -670,11 +669,10 @@ static ThrowCompletionOr<void> set_typed_array_from_typed_array(GlobalObject& gl
         // a. Let srcByteLength be source.[[ByteLength]].
         auto source_byte_length = source.byte_length();
 
-        // b. Set srcBuffer to ? CloneArrayBuffer(srcBuffer, srcByteOffset, srcByteLength, %ArrayBuffer%).
-        source_buffer = TRY(clone_array_buffer(global_object, *source_buffer, source_byte_offset, source_byte_length, *global_object.array_buffer_constructor()));
-        // c. NOTE: %ArrayBuffer% is used to clone srcBuffer because is it known to not have any observable side-effects.
+        // b. Set srcBuffer to ? CloneArrayBuffer(srcBuffer, srcByteOffset, srcByteLength).
+        source_buffer = TRY(clone_array_buffer(global_object, *source_buffer, source_byte_offset, source_byte_length));
 
-        // d. Let srcByteIndex be 0.
+        // c. Let srcByteIndex be 0.
         source_byte_index = 0;
     }
     // 19. Else, let srcByteIndex be srcByteOffset.