Adds Promise.withResolvers

polyfills/Promise/withResolvers/config.toml

@@ -0,0 +1,27 @@
+aliases = [ "es2024" ]
+dependencies = [
+	"_ESAbstract.CreateDataPropertyOrThrow",
+	"_ESAbstract.CreateMethodProperty",
+	"_ESAbstract.IsConstructor",
+	"Promise",
+]
+license = "MIT"
+spec = "https://tc39.es/ecma262/#sec-promise.withResolvers"
+docs = "https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/withResolvers"
+
+[browsers]
+android = "*"
+bb = "*"
+chrome = "<119"
+edge = "*"
+edge_mob = "*"
+firefox = "<121"
+firefox_mob = "<121"
+ie = "*"
+ie_mob = "*"
+opera = "<105"
+op_mob = "<79"
+op_mini = "*"
+safari = "<17.4"
+ios_saf = "<17.4"
+samsung_mob = "*"

polyfills/Promise/withResolvers/detect.js

@@ -0,0 +1 @@
+"Promise" in self && "withResolvers" in self.Promise;

polyfills/Promise/withResolvers/polyfill.js

@@ -0,0 +1,27 @@
+/* global CreateDataPropertyOrThrow, CreateMethodProperty, IsConstructor, Promise */
+(function () {
+	// 27.2.4.8 Promise.withResolvers ( )
+	CreateMethodProperty(Promise, "withResolvers", function withResolvers() {
+		// 1. Let C be the this value.
+		var C = this;
+		// 2. Let promiseCapability be ? NewPromiseCapability(C).
+		if (IsConstructor(C) === false) {
+			throw new TypeError("The `this` value must be a constructor");
+		}
+		var promiseCapability = {};
+		promiseCapability["[[Promise]]"] = new C(function (resolve, reject) {
+			promiseCapability["[[Resolve]]"] = resolve;
+			promiseCapability["[[Reject]]"] = reject;
+		});
+		// 3. Let obj be OrdinaryObjectCreate(%Object.prototype%).
+		var obj = {};
+		// 4. Perform ! CreateDataPropertyOrThrow(obj, "promise", promiseCapability.[[Promise]]).
+		CreateDataPropertyOrThrow(obj, "promise", promiseCapability["[[Promise]]"]);
+		// 5. Perform ! CreateDataPropertyOrThrow(obj, "resolve", promiseCapability.[[Resolve]]).
+		CreateDataPropertyOrThrow(obj, "resolve", promiseCapability["[[Resolve]]"]);
+		// 6. Perform ! CreateDataPropertyOrThrow(obj, "reject", promiseCapability.[[Reject]]).
+		CreateDataPropertyOrThrow(obj, "reject", promiseCapability["[[Reject]]"]);
+		// 7. Return obj.
+		return obj;
+	});
+})();

polyfills/Promise/withResolvers/tests.js

@@ -0,0 +1,66 @@
+/* globals proclaim, Promise */
+
+it("is a function", function () {
+	proclaim.isFunction(Promise.withResolvers);
+});
+
+it("has correct arity", function () {
+	proclaim.arity(Promise.withResolvers, 0);
+});
+
+it("is not enumerable", function () {
+	proclaim.isNotEnumerable(Promise, "withResolvers");
+});
+
+describe("withResolvers", function () {
+	it("returns an object with `promise`, `resolve`, and `reject`", function () {
+		var promiseWithResolvers = Promise.withResolvers();
+		var promise = promiseWithResolvers.promise;
+		var resolve = promiseWithResolvers.resolve;
+		var reject = promiseWithResolvers.reject;
+		proclaim.ok(promise instanceof Promise);
+		proclaim.ok(resolve instanceof Function);
+		proclaim.ok(reject instanceof Function);
+	});
+
+	it("resolves the Promise when `resolve` is called", function () {
+		var promiseWithResolvers = Promise.withResolvers();
+		var promise = promiseWithResolvers.promise;
+		var resolve = promiseWithResolvers.resolve;
+
+		resolve("ok");
+
+		return promise.then(function (value) {
+			proclaim.equal(value, "ok");
+		});
+	});
+
+	it("rejects the Promise when `reject` is called", function () {
+		var promiseWithResolvers = Promise.withResolvers();
+		var promise = promiseWithResolvers.promise;
+		var reject = promiseWithResolvers.reject;
+
+		reject("not ok");
+
+		return promise.catch(function (error) {
+			proclaim.equal(error, "not ok");
+		});
+	});
+
+	it("throws a TypeError for non-constructor `this`", function () {
+		proclaim.throws(function () {
+			Promise.withResolvers.call({});
+		}, TypeError);
+	});
+
+	it("supports `this` as a Promise subclass", function () {
+		function _Promise(executor) {
+			return new Promise(executor);
+		}
+		_Promise.prototype = Promise.prototype;
+
+		var _promise = Promise.withResolvers.call(_Promise).promise;
+
+		proclaim.ok(_promise instanceof _Promise);
+	});
+});