LibJS: Add spec comments to AggregateErrorConstructor

Userland/Libraries/LibJS/Runtime/AggregateErrorConstructor.cpp

@@ -30,31 +30,45 @@ void AggregateErrorConstructor::initialize(Realm& realm)
     define_direct_property(vm.names.length, Value(2), Attribute::Configurable);
 }
 
-// 20.5.7.1.1 AggregateError ( errors, message ), https://tc39.es/ecma262/#sec-aggregate-error
+// 20.5.7.1.1 AggregateError ( errors, message [ , options ] ), https://tc39.es/ecma262/#sec-aggregate-error
 ThrowCompletionOr<Value> AggregateErrorConstructor::call()
 {
+    // 1. If NewTarget is undefined, let newTarget be the active function object; else let newTarget be NewTarget.
     return TRY(construct(*this));
 }
 
-// 20.5.7.1.1 AggregateError ( errors, message ), https://tc39.es/ecma262/#sec-aggregate-error
+// 20.5.7.1.1 AggregateError ( errors, message [ , options ] ), https://tc39.es/ecma262/#sec-aggregate-error
 ThrowCompletionOr<Object*> AggregateErrorConstructor::construct(FunctionObject& new_target)
 {
     auto& vm = this->vm();
     auto& realm = *vm.current_realm();
 
+    auto errors = vm.argument(0);
+    auto message = vm.argument(1);
+    auto options = vm.argument(2);
+
+    // 2. Let O be ? OrdinaryCreateFromConstructor(newTarget, "%AggregateError.prototype%", « [[ErrorData]] »).
     auto* aggregate_error = TRY(ordinary_create_from_constructor<AggregateError>(vm, new_target, &Intrinsics::aggregate_error_prototype));
 
-    if (!vm.argument(1).is_undefined()) {
-        auto message = TRY(vm.argument(1).to_string(vm));
-        aggregate_error->create_non_enumerable_data_property_or_throw(vm.names.message, PrimitiveString::create(vm, message));
+    // 3. If message is not undefined, then
+    if (!message.is_undefined()) {
+        // a. Let msg be ? ToString(message).
+        auto msg = TRY(message.to_string(vm));
+
+        // b. Perform CreateNonEnumerableDataPropertyOrThrow(O, "message", msg).
+        aggregate_error->create_non_enumerable_data_property_or_throw(vm.names.message, PrimitiveString::create(vm, msg));
     }
 
-    TRY(aggregate_error->install_error_cause(vm.argument(2)));
+    // 4. Perform ? InstallErrorCause(O, options).
+    TRY(aggregate_error->install_error_cause(options));
 
-    auto errors_list = TRY(iterable_to_list(vm, vm.argument(0)));
+    // 5. Let errorsList be ? IterableToList(errors).
+    auto errors_list = TRY(iterable_to_list(vm, errors));
 
+    // 6. Perform ! DefinePropertyOrThrow(O, "errors", PropertyDescriptor { [[Configurable]]: true, [[Enumerable]]: false, [[Writable]]: true, [[Value]]: CreateArrayFromList(errorsList) }).
     MUST(aggregate_error->define_property_or_throw(vm.names.errors, { .value = Array::create_from(realm, errors_list), .writable = true, .enumerable = false, .configurable = true }));
 
+    // 7. Return O.
     return aggregate_error;
 }