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/*
* Copyright (c) 2022, David Tuin <davidot@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibJS/Runtime/AbstractOperations.h>
#include <LibJS/Runtime/Completion.h>
#include <LibJS/Runtime/GlobalEnvironment.h>
#include <LibJS/Runtime/ModuleEnvironment.h>
#include <LibJS/Runtime/VM.h>
#include <LibJS/SyntheticModule.h>
namespace JS {
// 1.2.1 CreateSyntheticModule ( exportNames, evaluationSteps, realm, hostDefined ), https://tc39.es/proposal-json-modules/#sec-createsyntheticmodule
SyntheticModule::SyntheticModule(Vector<FlyString> export_names, SyntheticModule::EvaluationFunction evaluation_steps, Realm& realm, StringView filename)
: Module(realm, filename)
, m_export_names(move(export_names))
, m_evaluation_steps(move(evaluation_steps))
{
// 1. Return Synthetic Module Record { [[Realm]]: realm, [[Environment]]: undefined, [[Namespace]]: undefined, [[HostDefined]]: hostDefined, [[ExportNames]]: exportNames, [[EvaluationSteps]]: evaluationSteps }.
}
// 1.2.3.1 GetExportedNames( exportStarSet ), https://tc39.es/proposal-json-modules/#sec-smr-getexportednames
ThrowCompletionOr<Vector<FlyString>> SyntheticModule::get_exported_names(VM&, Vector<Module*>)
{
// 1. Return module.[[ExportNames]].
return m_export_names;
}
// 1.2.3.2 ResolveExport( exportName, resolveSet ), https://tc39.es/proposal-json-modules/#sec-smr-resolveexport
ThrowCompletionOr<ResolvedBinding> SyntheticModule::resolve_export(VM&, FlyString const& export_name, Vector<ResolvedBinding>)
{
// 1. If module.[[ExportNames]] does not contain exportName, return null.
if (!m_export_names.contains_slow(export_name))
return ResolvedBinding::null();
// 2. Return ResolvedBinding Record { [[Module]]: module, [[BindingName]]: exportName }.
return ResolvedBinding { ResolvedBinding::BindingName, this, export_name };
}
// 1.2.3.3 Link ( ), https://tc39.es/proposal-json-modules/#sec-smr-instantiate
ThrowCompletionOr<void> SyntheticModule::link(VM& vm)
{
// Note: Has some changes from PR: https://github.com/tc39/proposal-json-modules/pull/13.
// Which includes renaming it from Instantiate ( ) to Link ( ).
// 1. Let realm be module.[[Realm]].
// 2. Assert: realm is not undefined.
// Note: This must be true because we use a reference.
auto& global_object = realm().global_object();
// 3. Let env be NewModuleEnvironment(realm.[[GlobalEnv]]).
auto* environment = vm.heap().allocate_without_global_object<ModuleEnvironment>(&realm().global_environment());
// 4. Set module.[[Environment]] to env.
set_environment(environment);
// 5. For each exportName in module.[[ExportNames]],
for (auto& export_name : m_export_names) {
// a. Perform ! envRec.CreateMutableBinding(exportName, false).
environment->create_mutable_binding(global_object, export_name, false);
// b. Perform ! envRec.InitializeBinding(exportName, undefined).
environment->initialize_binding(global_object, export_name, js_undefined());
}
// 6. Return undefined.
// Note: This return value is never visible to the outside so we use void.
return {};
}
// 1.2.3.4 Evaluate ( ), https://tc39.es/proposal-json-modules/#sec-smr-Evaluate
ThrowCompletionOr<Promise*> SyntheticModule::evaluate(VM& vm)
{
// Note: Has some changes from PR: https://github.com/tc39/proposal-json-modules/pull/13.
// 1. Suspend the currently running execution context.
// FIXME: We don't have suspend yet.
// 2. Let moduleContext be a new ECMAScript code execution context.
ExecutionContext module_context { vm.heap() };
// 3. Set the Function of moduleContext to null.
// Note: This is the default value.
// 4. Set the Realm of moduleContext to module.[[Realm]].
module_context.realm = &realm();
// 5. Set the ScriptOrModule of moduleContext to module.
module_context.script_or_module = this->make_weak_ptr();
// 6. Set the VariableEnvironment of moduleContext to module.[[Environment]].
module_context.variable_environment = environment();
// 7. Set the LexicalEnvironment of moduleContext to module.[[Environment]].
module_context.lexical_environment = environment();
// 8. Push moduleContext on to the execution context stack; moduleContext is now the running execution context.
TRY(vm.push_execution_context(module_context, realm().global_object()));
// 9. Let result be the result of performing module.[[EvaluationSteps]](module).
auto result = m_evaluation_steps(*this);
// 10. Suspend moduleContext and remove it from the execution context stack.
vm.pop_execution_context();
// 11. Resume the context that is now on the top of the execution context stack as the running execution context.
// 12. Return Completion(result).
// Note: Because we expect it to return a promise we convert this here.
auto* promise = Promise::create(realm().global_object());
if (result.is_error()) {
VERIFY(result.throw_completion().value().has_value());
promise->reject(*result.throw_completion().value());
} else {
// Note: This value probably isn't visible to JS code? But undefined is fine anyway.
promise->fulfill(js_undefined());
}
return promise;
}
// 1.2.2 SetSyntheticModuleExport ( module, exportName, exportValue ), https://tc39.es/proposal-json-modules/#sec-setsyntheticmoduleexport
ThrowCompletionOr<void> SyntheticModule::set_synthetic_module_export(FlyString const& export_name, Value export_value)
{
// Note: Has some changes from PR: https://github.com/tc39/proposal-json-modules/pull/13.
// 1. Return ? module.[[Environment]].SetMutableBinding(name, value, true).
return environment()->set_mutable_binding(realm().global_object(), export_name, export_value, true);
}
// 1.3 CreateDefaultExportSyntheticModule ( defaultExport ), https://tc39.es/proposal-json-modules/#sec-create-default-export-synthetic-module
NonnullRefPtr<SyntheticModule> SyntheticModule::create_default_export_synthetic_module(Value default_export, Realm& realm, StringView filename)
{
// Note: Has some changes from PR: https://github.com/tc39/proposal-json-modules/pull/13.
// 1. Let closure be the a Abstract Closure with parameters (module) that captures defaultExport and performs the following steps when called:
auto closure = [default_export = make_handle(default_export)](SyntheticModule& module) -> ThrowCompletionOr<void> {
// a. Return ? module.SetSyntheticExport("default", defaultExport).
return module.set_synthetic_module_export("default", default_export.value());
};
// 2. Return CreateSyntheticModule("default", closure, realm)
return adopt_ref(*new SyntheticModule({ "default" }, move(closure), realm, filename));
}
// 1.4 ParseJSONModule ( source ), https://tc39.es/proposal-json-modules/#sec-parse-json-module
ThrowCompletionOr<NonnullRefPtr<Module>> parse_json_module(StringView source_text, Realm& realm, StringView filename)
{
// 1. Let jsonParse be realm's intrinsic object named "%JSON.parse%".
auto* json_parse = realm.global_object().json_parse_function();
// 2. Let json be ? Call(jsonParse, undefined, « sourceText »).
auto json = TRY(call(realm.global_object(), *json_parse, js_undefined(), js_string(realm.vm(), source_text)));
// 3. Return CreateDefaultExportSyntheticModule(json, realm, hostDefined).
return SyntheticModule::create_default_export_synthetic_module(json, realm, filename);
}
}
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