ladybird/Userland/Libraries/LibJS/Runtime/PromiseResolvingElementFunctions.cpp
Linus Groh 01c2570678 LibJS: Annotate Promise implementation with spec comments
I wanted to do this for a long time. The guts of Promise are pretty
complex, and it's easier to understand with the spec right next to it.
Also found a couple of issues along the way :^)
2021-11-14 15:27:46 +00:00

201 lines
8.6 KiB
C++

/*
* Copyright (c) 2021, Tim Flynn <trflynn89@pm.me>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibJS/Runtime/AbstractOperations.h>
#include <LibJS/Runtime/AggregateError.h>
#include <LibJS/Runtime/Array.h>
#include <LibJS/Runtime/GlobalObject.h>
#include <LibJS/Runtime/PromiseReaction.h>
#include <LibJS/Runtime/PromiseResolvingElementFunctions.h>
namespace JS {
PromiseResolvingElementFunction::PromiseResolvingElementFunction(size_t index, PromiseValueList& values, PromiseCapability capability, RemainingElements& remaining_elements, Object& prototype)
: NativeFunction(prototype)
, m_index(index)
, m_values(values)
, m_capability(move(capability))
, m_remaining_elements(remaining_elements)
{
}
void PromiseResolvingElementFunction::initialize(GlobalObject& global_object)
{
Base::initialize(global_object);
define_direct_property(vm().names.length, Value(1), Attribute::Configurable);
}
ThrowCompletionOr<Value> PromiseResolvingElementFunction::call()
{
if (m_already_called)
return js_undefined();
m_already_called = true;
return resolve_element();
}
void PromiseResolvingElementFunction::visit_edges(Cell::Visitor& visitor)
{
Base::visit_edges(visitor);
visitor.visit(&m_values);
visitor.visit(m_capability.promise);
visitor.visit(m_capability.resolve);
visitor.visit(m_capability.reject);
visitor.visit(&m_remaining_elements);
}
PromiseAllResolveElementFunction* PromiseAllResolveElementFunction::create(GlobalObject& global_object, size_t index, PromiseValueList& values, PromiseCapability capability, RemainingElements& remaining_elements)
{
return global_object.heap().allocate<PromiseAllResolveElementFunction>(global_object, index, values, capability, remaining_elements, *global_object.function_prototype());
}
PromiseAllResolveElementFunction::PromiseAllResolveElementFunction(size_t index, PromiseValueList& values, PromiseCapability capability, RemainingElements& remaining_elements, Object& prototype)
: PromiseResolvingElementFunction(index, values, move(capability), remaining_elements, prototype)
{
}
Value PromiseAllResolveElementFunction::resolve_element()
{
auto& vm = this->vm();
auto& global_object = this->global_object();
// 8. Set values[index] to x.
m_values.values()[m_index] = vm.argument(0);
// 9. Set remainingElementsCount.[[Value]] to remainingElementsCount.[[Value]] - 1.
// 10. If remainingElementsCount.[[Value]] is 0, then
if (--m_remaining_elements.value == 0) {
// a. Let valuesArray be ! CreateArrayFromList(values).
auto* values_array = Array::create_from(global_object, m_values.values());
// b. Return ? Call(promiseCapability.[[Resolve]], undefined, « valuesArray »).
return TRY_OR_DISCARD(vm.call(*m_capability.resolve, js_undefined(), values_array));
}
// 11. Return undefined.
return js_undefined();
}
PromiseAllSettledResolveElementFunction* PromiseAllSettledResolveElementFunction::create(GlobalObject& global_object, size_t index, PromiseValueList& values, PromiseCapability capability, RemainingElements& remaining_elements)
{
return global_object.heap().allocate<PromiseAllSettledResolveElementFunction>(global_object, index, values, capability, remaining_elements, *global_object.function_prototype());
}
PromiseAllSettledResolveElementFunction::PromiseAllSettledResolveElementFunction(size_t index, PromiseValueList& values, PromiseCapability capability, RemainingElements& remaining_elements, Object& prototype)
: PromiseResolvingElementFunction(index, values, move(capability), remaining_elements, prototype)
{
}
Value PromiseAllSettledResolveElementFunction::resolve_element()
{
auto& vm = this->vm();
auto& global_object = this->global_object();
// 9. Let obj be ! OrdinaryObjectCreate(%Object.prototype%).
auto* object = Object::create(global_object, global_object.object_prototype());
// 10. Perform ! CreateDataPropertyOrThrow(obj, "status", "fulfilled").
MUST(object->create_data_property_or_throw(vm.names.status, js_string(vm, "fulfilled"sv)));
// 11. Perform ! CreateDataPropertyOrThrow(obj, "value", x).
MUST(object->create_data_property_or_throw(vm.names.value, vm.argument(0)));
// 12. Set values[index] to obj.
m_values.values()[m_index] = object;
// 13. Set remainingElementsCount.[[Value]] to remainingElementsCount.[[Value]] - 1.
// 14. If remainingElementsCount.[[Value]] is 0, then
if (--m_remaining_elements.value == 0) {
// a. Let valuesArray be ! CreateArrayFromList(values).
auto* values_array = Array::create_from(global_object, m_values.values());
// b. Return ? Call(promiseCapability.[[Resolve]], undefined, « valuesArray »).
return TRY_OR_DISCARD(vm.call(*m_capability.resolve, js_undefined(), values_array));
}
// 15. Return undefined.
return js_undefined();
}
PromiseAllSettledRejectElementFunction* PromiseAllSettledRejectElementFunction::create(GlobalObject& global_object, size_t index, PromiseValueList& values, PromiseCapability capability, RemainingElements& remaining_elements)
{
return global_object.heap().allocate<PromiseAllSettledRejectElementFunction>(global_object, index, values, capability, remaining_elements, *global_object.function_prototype());
}
PromiseAllSettledRejectElementFunction::PromiseAllSettledRejectElementFunction(size_t index, PromiseValueList& values, PromiseCapability capability, RemainingElements& remaining_elements, Object& prototype)
: PromiseResolvingElementFunction(index, values, move(capability), remaining_elements, prototype)
{
}
Value PromiseAllSettledRejectElementFunction::resolve_element()
{
auto& vm = this->vm();
auto& global_object = this->global_object();
// 9. Let obj be ! OrdinaryObjectCreate(%Object.prototype%).
auto* object = Object::create(global_object, global_object.object_prototype());
// 10. Perform ! CreateDataPropertyOrThrow(obj, "status", "rejected").
MUST(object->create_data_property_or_throw(vm.names.status, js_string(vm, "rejected"sv)));
// 11. Perform ! CreateDataPropertyOrThrow(obj, "reason", x).
MUST(object->create_data_property_or_throw(vm.names.reason, vm.argument(0)));
// 12. Set values[index] to obj.
m_values.values()[m_index] = object;
// 13. Set remainingElementsCount.[[Value]] to remainingElementsCount.[[Value]] - 1.
// 14. If remainingElementsCount.[[Value]] is 0, then
if (--m_remaining_elements.value == 0) {
// a. Let valuesArray be ! CreateArrayFromList(values).
auto values_array = Array::create_from(global_object, m_values.values());
// b. Return ? Call(promiseCapability.[[Resolve]], undefined, « valuesArray »).
return TRY_OR_DISCARD(vm.call(*m_capability.resolve, js_undefined(), values_array));
}
// 15. Return undefined.
return js_undefined();
}
PromiseAnyRejectElementFunction* PromiseAnyRejectElementFunction::create(GlobalObject& global_object, size_t index, PromiseValueList& errors, PromiseCapability capability, RemainingElements& remaining_elements)
{
return global_object.heap().allocate<PromiseAnyRejectElementFunction>(global_object, index, errors, capability, remaining_elements, *global_object.function_prototype());
}
PromiseAnyRejectElementFunction::PromiseAnyRejectElementFunction(size_t index, PromiseValueList& errors, PromiseCapability capability, RemainingElements& remaining_elements, Object& prototype)
: PromiseResolvingElementFunction(index, errors, move(capability), remaining_elements, prototype)
{
}
Value PromiseAnyRejectElementFunction::resolve_element()
{
auto& vm = this->vm();
auto& global_object = this->global_object();
// 8. Set errors[index] to x.
m_values.values()[m_index] = vm.argument(0);
// 9. Set remainingElementsCount.[[Value]] to remainingElementsCount.[[Value]] - 1.
// 10. If remainingElementsCount.[[Value]] is 0, then
if (--m_remaining_elements.value == 0) {
// a. Let error be a newly created AggregateError object.
auto* error = AggregateError::create(global_object);
// b. Perform ! DefinePropertyOrThrow(error, "errors", PropertyDescriptor { [[Configurable]]: true, [[Enumerable]]: false, [[Writable]]: true, [[Value]]: ! CreateArrayFromList(errors) }).
auto errors_array = Array::create_from(global_object, m_values.values());
MUST(error->define_property_or_throw(vm.names.errors, { .value = errors_array, .writable = true, .enumerable = false, .configurable = true }));
// c. Return ? Call(promiseCapability.[[Reject]], undefined, « error »).
return TRY_OR_DISCARD(vm.call(*m_capability.reject, js_undefined(), error));
}
return js_undefined();
}
}