node-bluebird/test/mocha/2.2.7.js

"use strict";

var assert = require("assert");
var testFulfilled = require("./helpers/testThreeCases").testFulfilled;
var testRejected = require("./helpers/testThreeCases").testRejected;
var reasons = require("./helpers/reasons");

var adapter = global.adapter;
var pending = adapter.pending;

var dummy = { dummy: "dummy" }; // we fulfill or reject with this when we don't intend to test against it
var sentinel = { sentinel: "sentinel" }; // a sentinel fulfillment value to test for with strict equality
var other = { other: "other" }; // a value we don't want to be strict equal to

describe("2.2.7: `then` must return a promise: `promise2 = promise1.then(onFulfilled, onRejected)`", function () {
    specify("is a promise", function () {
        var promise1 = pending().promise;
        var promise2 = promise1.then();

        assert(typeof promise2 === "object" || typeof promise2 === "function");
        assert.notStrictEqual(promise2, null);
        assert.strictEqual(typeof promise2.then, "function");
    });

    describe("2.2.7.1: If either `onFulfilled` or `onRejected` returns a value `x`, run the Promise Resolution " +
             "Procedure `[[Resolve]](promise2, x)`", function () {
        specify("see separate 3.3 tests", function () { });
    });

    describe("2.2.7.2: If either `onFulfilled` or `onRejected` throws an exception `e`, `promise2` must be rejected " +
             "with `e` as the reason.", function () {
        function testReason(expectedReason, stringRepresentation) {
            describe("The reason is " + stringRepresentation, function () {
                testFulfilled(dummy, function (promise1, done) {
                    var promise2 = promise1.then(function onFulfilled() {
                        throw expectedReason;
                    });

                    promise2.then(null, function onPromise2Rejected(actualReason) {
                        assert.strictEqual(actualReason, expectedReason);
                        done();
                    });
                });
                testRejected(dummy, function (promise1, done) {
                    var promise2 = promise1.then(null, function onRejected() {
                        throw expectedReason;
                    });

                    promise2.then(null, function onPromise2Rejected(actualReason) {
                        assert.strictEqual(actualReason, expectedReason);
                        done();
                    });
                });
            });
        }

        Object.keys(reasons).forEach(function (stringRepresentation) {
            testReason(reasons[stringRepresentation], stringRepresentation);
        });
    });

    describe("2.2.7.3: If `onFulfilled` is not a function and `promise1` is fulfilled, `promise2` must be fulfilled " +
             "with the same value.", function () {

        function testNonFunction(nonFunction, stringRepresentation) {
            describe("`onFulfilled` is " + stringRepresentation, function () {
                testFulfilled(sentinel, function (promise1, done) {
                    var promise2 = promise1.then(nonFunction);

                    promise2.then(function onPromise2Fulfilled(value) {
                        assert.strictEqual(value, sentinel);
                        done();
                    });
                });
            });
        }

        testNonFunction(undefined, "`undefined`");
        testNonFunction(null, "`null`");
        testNonFunction(false, "`false`");
        testNonFunction(5, "`5`");
        testNonFunction({}, "an object");
        testNonFunction([function () { return other; }], "an array containing a function");
    });

    describe("2.2.7.4: If `onRejected` is not a function and `promise1` is rejected, `promise2` must be rejected " +
             "with the same reason.", function () {

        function testNonFunction(nonFunction, stringRepresentation) {
            describe("`onRejected` is " + stringRepresentation, function () {
                testRejected(sentinel, function (promise1, done) {
                    var promise2 = promise1.then(null, nonFunction);

                    promise2.then(null, function onPromise2Rejected(reason) {
                        assert.strictEqual(reason, sentinel);
                        done();
                    });
                });
            });
        }

        testNonFunction(undefined, "`undefined`");
        testNonFunction(null, "`null`");
        testNonFunction(false, "`false`");
        testNonFunction(5, "`5`");
        testNonFunction({}, "an object");
        testNonFunction([function () { return other; }], "an array containing a function");
    });
});