'use strict'; /* eslint-disable node-core/prefer-primordials */ // This file subclasses and stores the JS builtins that come from the VM // so that Node.js's builtin modules do not need to later look these up from // the global proxy, which can be mutated by users. // Use of primordials have sometimes a dramatic impact on performance, please // benchmark all changes made in performance-sensitive areas of the codebase. // See: https://github.com/nodejs/node/pull/38248 const { defineProperty: ReflectDefineProperty, getOwnPropertyDescriptor: ReflectGetOwnPropertyDescriptor, ownKeys: ReflectOwnKeys, } = Reflect; // `uncurryThis` is equivalent to `func => Function.prototype.call.bind(func)`. // It is using `bind.bind(call)` to avoid using `Function.prototype.bind` // and `Function.prototype.call` after it may have been mutated by users. const { apply, bind, call } = Function.prototype; const uncurryThis = bind.bind(call); primordials.uncurryThis = uncurryThis; // `applyBind` is equivalent to `func => Function.prototype.apply.bind(func)`. // It is using `bind.bind(apply)` to avoid using `Function.prototype.bind` // and `Function.prototype.apply` after it may have been mutated by users. const applyBind = bind.bind(apply); primordials.applyBind = applyBind; // Methods that accept a variable number of arguments, and thus it's useful to // also create `${prefix}${key}Apply`, which uses `Function.prototype.apply`, // instead of `Function.prototype.call`, and thus doesn't require iterator // destructuring. const varargsMethods = [ // 'ArrayPrototypeConcat' is omitted, because it performs the spread // on its own for arrays and array-likes with a truthy // @@isConcatSpreadable symbol property. 'ArrayOf', 'ArrayPrototypePush', 'ArrayPrototypeUnshift', // 'FunctionPrototypeCall' is omitted, since there's 'ReflectApply' // and 'FunctionPrototypeApply'. 'MathHypot', 'MathMax', 'MathMin', 'StringPrototypeConcat', 'TypedArrayOf', ]; function getNewKey(key) { return typeof key === 'symbol' ? `Symbol${key.description[7].toUpperCase()}${key.description.slice(8)}` : `${key[0].toUpperCase()}${key.slice(1)}`; } function copyAccessor(dest, prefix, key, { enumerable, get, set }) { ReflectDefineProperty(dest, `${prefix}Get${key}`, { value: uncurryThis(get), enumerable }); if (set !== undefined) { ReflectDefineProperty(dest, `${prefix}Set${key}`, { value: uncurryThis(set), enumerable }); } } function copyPropsRenamed(src, dest, prefix) { for (const key of ReflectOwnKeys(src)) { const newKey = getNewKey(key); const desc = ReflectGetOwnPropertyDescriptor(src, key); if ('get' in desc) { copyAccessor(dest, prefix, newKey, desc); } else { const name = `${prefix}${newKey}`; ReflectDefineProperty(dest, name, desc); if (varargsMethods.includes(name)) { ReflectDefineProperty(dest, `${name}Apply`, { // `src` is bound as the `this` so that the static `this` points // to the object it was defined on, // e.g.: `ArrayOfApply` gets a `this` of `Array`: value: applyBind(desc.value, src), }); } } } } function copyPropsRenamedBound(src, dest, prefix) { for (const key of ReflectOwnKeys(src)) { const newKey = getNewKey(key); const desc = ReflectGetOwnPropertyDescriptor(src, key); if ('get' in desc) { copyAccessor(dest, prefix, newKey, desc); } else { const { value } = desc; if (typeof value === 'function') { desc.value = value.bind(src); } const name = `${prefix}${newKey}`; ReflectDefineProperty(dest, name, desc); if (varargsMethods.includes(name)) { ReflectDefineProperty(dest, `${name}Apply`, { value: applyBind(value, src), }); } } } } function copyPrototype(src, dest, prefix) { for (const key of ReflectOwnKeys(src)) { const newKey = getNewKey(key); const desc = ReflectGetOwnPropertyDescriptor(src, key); if ('get' in desc) { copyAccessor(dest, prefix, newKey, desc); } else { const { value } = desc; if (typeof value === 'function') { desc.value = uncurryThis(value); } const name = `${prefix}${newKey}`; ReflectDefineProperty(dest, name, desc); if (varargsMethods.includes(name)) { ReflectDefineProperty(dest, `${name}Apply`, { value: applyBind(value), }); } } } } // Create copies of configurable value properties of the global object [ 'Proxy', 'globalThis', ].forEach((name) => { // eslint-disable-next-line no-restricted-globals primordials[name] = globalThis[name]; }); // Create copies of URI handling functions [ decodeURI, decodeURIComponent, encodeURI, encodeURIComponent, ].forEach((fn) => { primordials[fn.name] = fn; }); // Create copies of the namespace objects [ 'JSON', 'Math', 'Proxy', 'Reflect', ].forEach((name) => { // eslint-disable-next-line no-restricted-globals copyPropsRenamed(global[name], primordials, name); }); // Create copies of intrinsic objects [ 'AggregateError', 'Array', 'ArrayBuffer', 'BigInt', 'BigInt64Array', 'BigUint64Array', 'Boolean', 'DataView', 'Date', 'Error', 'EvalError', 'FinalizationRegistry', 'Float32Array', 'Float64Array', 'Function', 'Int16Array', 'Int32Array', 'Int8Array', 'Map', 'Number', 'Object', 'RangeError', 'ReferenceError', 'RegExp', 'Set', 'String', 'Symbol', 'SyntaxError', 'TypeError', 'URIError', 'Uint16Array', 'Uint32Array', 'Uint8Array', 'Uint8ClampedArray', 'WeakMap', 'WeakRef', 'WeakSet', ].forEach((name) => { // eslint-disable-next-line no-restricted-globals const original = global[name]; primordials[name] = original; copyPropsRenamed(original, primordials, name); copyPrototype(original.prototype, primordials, `${name}Prototype`); }); // Create copies of intrinsic objects that require a valid `this` to call // static methods. // Refs: https://www.ecma-international.org/ecma-262/#sec-promise.all [ 'Promise', ].forEach((name) => { // eslint-disable-next-line no-restricted-globals const original = global[name]; primordials[name] = original; copyPropsRenamedBound(original, primordials, name); copyPrototype(original.prototype, primordials, `${name}Prototype`); }); // Create copies of abstract intrinsic objects that are not directly exposed // on the global object. // Refs: https://tc39.es/ecma262/#sec-%typedarray%-intrinsic-object [ { name: 'TypedArray', original: Reflect.getPrototypeOf(Uint8Array) }, { name: 'ArrayIterator', original: { prototype: Reflect.getPrototypeOf(Array.prototype[Symbol.iterator]()), } }, { name: 'StringIterator', original: { prototype: Reflect.getPrototypeOf(String.prototype[Symbol.iterator]()), } }, ].forEach(({ name, original }) => { primordials[name] = original; // The static %TypedArray% methods require a valid `this`, but can't be bound, // as they need a subclass constructor as the receiver: copyPrototype(original, primordials, name); copyPrototype(original.prototype, primordials, `${name}Prototype`); }); /* eslint-enable node-core/prefer-primordials */ const { ArrayPrototypeForEach, FinalizationRegistry, FunctionPrototypeCall, Map, ObjectFreeze, ObjectSetPrototypeOf, Promise, PromisePrototypeThen, Set, SymbolIterator, WeakMap, WeakRef, WeakSet, } = primordials; // Because these functions are used by `makeSafe`, which is exposed // on the `primordials` object, it's important to use const references // to the primordials that they use: const createSafeIterator = (factory, next) => { class SafeIterator { constructor(iterable) { this._iterator = factory(iterable); } next() { return next(this._iterator); } [SymbolIterator]() { return this; } } ObjectSetPrototypeOf(SafeIterator.prototype, null); ObjectFreeze(SafeIterator.prototype); ObjectFreeze(SafeIterator); return SafeIterator; }; primordials.SafeArrayIterator = createSafeIterator( primordials.ArrayPrototypeSymbolIterator, primordials.ArrayIteratorPrototypeNext ); primordials.SafeStringIterator = createSafeIterator( primordials.StringPrototypeSymbolIterator, primordials.StringIteratorPrototypeNext ); const copyProps = (src, dest) => { ArrayPrototypeForEach(ReflectOwnKeys(src), (key) => { if (!ReflectGetOwnPropertyDescriptor(dest, key)) { ReflectDefineProperty( dest, key, ReflectGetOwnPropertyDescriptor(src, key)); } }); }; /** * @type {typeof primordials.makeSafe} */ const makeSafe = (unsafe, safe) => { if (SymbolIterator in unsafe.prototype) { const dummy = new unsafe(); let next; // We can reuse the same `next` method. ArrayPrototypeForEach(ReflectOwnKeys(unsafe.prototype), (key) => { if (!ReflectGetOwnPropertyDescriptor(safe.prototype, key)) { const desc = ReflectGetOwnPropertyDescriptor(unsafe.prototype, key); if ( typeof desc.value === 'function' && desc.value.length === 0 && SymbolIterator in (FunctionPrototypeCall(desc.value, dummy) ?? {}) ) { const createIterator = uncurryThis(desc.value); next ??= uncurryThis(createIterator(dummy).next); const SafeIterator = createSafeIterator(createIterator, next); desc.value = function() { return new SafeIterator(this); }; } ReflectDefineProperty(safe.prototype, key, desc); } }); } else { copyProps(unsafe.prototype, safe.prototype); } copyProps(unsafe, safe); ObjectSetPrototypeOf(safe.prototype, null); ObjectFreeze(safe.prototype); ObjectFreeze(safe); return safe; }; primordials.makeSafe = makeSafe; // Subclass the constructors because we need to use their prototype // methods later. // Defining the `constructor` is necessary here to avoid the default // constructor which uses the user-mutable `%ArrayIteratorPrototype%.next`. primordials.SafeMap = makeSafe( Map, class SafeMap extends Map { constructor(i) { super(i); } // eslint-disable-line no-useless-constructor } ); primordials.SafeWeakMap = makeSafe( WeakMap, class SafeWeakMap extends WeakMap { constructor(i) { super(i); } // eslint-disable-line no-useless-constructor } ); primordials.SafeSet = makeSafe( Set, class SafeSet extends Set { constructor(i) { super(i); } // eslint-disable-line no-useless-constructor } ); primordials.SafeWeakSet = makeSafe( WeakSet, class SafeWeakSet extends WeakSet { constructor(i) { super(i); } // eslint-disable-line no-useless-constructor } ); primordials.SafeFinalizationRegistry = makeSafe( FinalizationRegistry, class SafeFinalizationRegistry extends FinalizationRegistry { // eslint-disable-next-line no-useless-constructor constructor(cleanupCallback) { super(cleanupCallback); } } ); primordials.SafeWeakRef = makeSafe( WeakRef, class SafeWeakRef extends WeakRef { // eslint-disable-next-line no-useless-constructor constructor(target) { super(target); } } ); const SafePromise = makeSafe( Promise, class SafePromise extends Promise { // eslint-disable-next-line no-useless-constructor constructor(executor) { super(executor); } } ); primordials.PromisePrototypeCatch = (thisPromise, onRejected) => PromisePrototypeThen(thisPromise, undefined, onRejected); /** * Attaches a callback that is invoked when the Promise is settled (fulfilled or * rejected). The resolved value cannot be modified from the callback. * Prefer using async functions when possible. * @param {Promise} thisPromise * @param {() => void) | undefined | null} onFinally The callback to execute * when the Promise is settled (fulfilled or rejected). * @returns A Promise for the completion of the callback. */ primordials.SafePromisePrototypeFinally = (thisPromise, onFinally) => // Wrapping on a new Promise is necessary to not expose the SafePromise // prototype to user-land. new Promise((a, b) => new SafePromise((a, b) => PromisePrototypeThen(thisPromise, a, b)) .finally(onFinally) .then(a, b) ); primordials.AsyncIteratorPrototype = primordials.ReflectGetPrototypeOf( primordials.ReflectGetPrototypeOf( async function* () {}).prototype); ObjectSetPrototypeOf(primordials, null); ObjectFreeze(primordials);