feat(promise): promise.timeout method

promise_/timeout.js

@@ -0,0 +1,34 @@
+"use strict";
+
+var customError   = require("es5-ext/error/custom")
+  , isValue       = require("es5-ext/object/is-value")
+  , ensurePromise = require("es5-ext/object/ensure-promise")
+  , nextTick      = require("next-tick")
+  , ensureTimeout = require("../valid-timeout");
+
+module.exports = function (/* timeout */) {
+	ensurePromise(this);
+	var timeout = arguments[0];
+	if (isValue(timeout)) timeout = ensureTimeout(timeout);
+	return new this.constructor(
+		function (resolve, reject) {
+			var isSettled = false;
+			this.then(
+				function (value) {
+					isSettled = true;
+					resolve(value);
+				},
+				function (reason) {
+					isSettled = true;
+					reject(reason);
+				}
+			);
+			var timeoutCallback = function () {
+				if (isSettled) return;
+				reject(customError("Operation timeout", "PROMISE_TIMEOUT"));
+			};
+			if (isValue(timeout)) setTimeout(timeoutCallback, timeout);
+			else nextTick(timeoutCallback);
+		}.bind(this)
+	);
+};

test/promise_/.eslintrc.json

@@ -0,0 +1,3 @@
+{
+	"globals": { "Promise": true }
+}

test/promise_/timeout.js

@@ -0,0 +1,50 @@
+"use strict";
+
+var delay = require("../../delay");
+
+module.exports = function (t, a) {
+	if (typeof Promise !== "function") return null;
+	return {
+		Success: function (d) {
+			var promise = t.call(
+				new Promise(function (resolve) {
+					setTimeout(function () {
+						resolve("foo");
+					}, 20);
+				}),
+				40
+			);
+
+			promise.then(
+				// Delay to escape error swallowing
+				delay(function (result) {
+					a(result, "foo");
+					d();
+				}),
+				delay(d)
+			);
+		},
+		Timeout: function (d) {
+			var promise = t.call(
+				new Promise(function (resolve) {
+					setTimeout(function () {
+						resolve("foo");
+					}, 40);
+				}),
+				20
+			);
+
+			promise.then(
+				// Delay to escape error swallowing
+				delay(function () {
+					a.never();
+					d();
+				}),
+				delay(function (err) {
+					a(err.code, "PROMISE_TIMEOUT");
+					d();
+				})
+			);
+		}
+	};
+};