Question

I’m trying to write some tests with Jasmine, but now have a problem if there are some code is asynchronous in beforeEach.

The sample code looks like:

describe("Jasmine", function() {

    var data ;

    beforeEach(function(){
        console.log('Before each');
        getSomeDataFromRemote(function(res){
            data = res;
        });
    });

    it("test1", function() {
        expect(data).toBe(something);
        console.log('Test finished');
    });

});

You can see, in the beforeEach, I want to get some data from remote, and assign it to the data asynchronously.

But in the test1, when I try to verify:

 expect(data).toBe(something);

The data is undefined, because getSomeDataFromRemote has not finished yet.

How to fix it?

Answer 1

Just like the async stuff within an it you can use the runs and waitsFor in your beforeEach:

define( 'Jasmine' , function () {
    var data ;

    beforeEach(function(){
        runs( function () {
            getSomeDataFromRemote(function(res){
                data = res;
            });
        });

        waitsFor(function () { return !!data; } , 'Timed out', 1000);
    });

    it("test1", function() {
        runs( function () {
              expect(data).toBe(something);
        });
    });
});

Although I’m going to assume that it’s because this was test code I think you should probably have the getSomeDataFromRemote call inside your it as that’s actually what you’re testing 😉

You can see some larger examples in some tests I’ve written for an async API here: https://github.com/aaronpowell/db.js/blob/f8a1c331a20e14e286e3f21ff8cea8c2e3e57be6/tests/public/specs/open-db.js