Async test doesn't error on fail

问题

I'm having some trouble with getting a simple async test working. The following piece of code doesn't throw any errors in the console, even though it should, because the data passed to the function does not equal 0:

define([
    'intern!bdd',
    'intern/chai!expect'
], function (bdd, expect) {
    with (bdd) {
        describe('Test', function () {
            it('async test', function(){
                var dfd = this.async(2000);
                var wait = function(ms) {
                    setTimeout(function(){
                        dfd.resolve('test');
                    }, ms);

                    return dfd.promise;
                };

                wait(1500).then(dfd.callback(function (data) {
                    // data === 'test', so this should fail.
                    expect(data).to.equal(0);
                }), dfd.reject.bind(dfd));
            });
        });
    }
});

I'm pretty sure I messed up somewhere because I never worked with promises until now, but I can't figure out where. Any ideas would help a lot. Thanks!

回答1:

You’re using the same Deferred object for two different asynchronous operations and resolving it (= successful test) the first time. You need to create your own separate Deferred object for the wait function:

define([
    'intern!bdd',
    'intern/chai!expect',
    'intern/node_modules/dojo/Deferred'
], function (bdd, expect, Deferred) {
    with (bdd) {
        describe('Test', function () {
            it('async test', function(){
                var dfd = this.async(2000);
                var wait = function(ms) {
                    var waitDfd = new Deferred();
                    setTimeout(function(){
                        waitDfd.resolve('test');
                    }, ms);

                    return waitDfd.promise;
                };

                wait(1500).then(dfd.callback(function (data) {
                    // data === 'test', so this should fail.
                    expect(data).to.equal(0);
                }), dfd.reject.bind(dfd));
            });
        });
    }
});

来源：https://stackoverflow.com/questions/17423749/async-test-doesnt-error-on-fail

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intern