edx-platform/xmodule/js/spec/video/async_process_spec.js

(function(require) {
    require(
        ['video/00_async_process.js'],
        function(AsyncProcess) {
            var getArrayNthLength = function(n, multiplier) {
                    var result = [],
                        mul = multiplier || 1;

                    for (var i = 0; i < n; i++) {
                        result[i] = i * mul;
                    }

                    return result;
                },
                items = getArrayNthLength(1000);

            describe('AsyncProcess', function() {
                it('Array is processed successfully', function(done) {
                    var processedArray,
                        expectedArray = getArrayNthLength(1000, 2),
                        process = function(item) {
                            return 2 * item;
                        };

                    AsyncProcess.array(items, process).done(function(result) {
                        processedArray = result;
                    });

                    jasmine.waitUntil(function() {
                        return processedArray;
                    }).then(function() {
                        expect(processedArray).toEqual(expectedArray);
                    }).always(done);
                });

                it('If non-array is passed, error callback is called', function(done) {
                    var isError,
                        process = function() {};

                    AsyncProcess.array('string', process).fail(function() {
                        isError = true;
                    });

                    jasmine.waitUntil(function() {
                        return isError;
                    }).then(function() {
                        expect(isError).toBeTruthy();
                    }).always(done);
                });

                it('If an empty array is passed, returns initial array', function(done) {
                    var processedArray,
                        process = function() {};

                    AsyncProcess.array([], process).done(function(result) {
                        processedArray = result;
                    });

                    jasmine.waitUntil(function() {
                        return processedArray;
                    }).then(function() {
                        expect(processedArray).toEqual([]);
                    }).always(done);
                });

                it('If no process function passed, returns initial array', function(done) {
                    var processedArray;

                    AsyncProcess.array(items).done(function(result) {
                        processedArray = result;
                    });

                    jasmine.waitUntil(function() {
                        return processedArray;
                    }).then(function() {
                        expect(processedArray).toEqual(items);
                    }).always(done);
                });
            });
        });
}(require));