jasmine BDD example

gistfile1.js

describe("Player", function() {
    var player;
    // hook before each test
    beforeEach(function(){
        player = new Player();
        spyOn(loading,'show'); // intercept and record calls to loading.show
        player.play();
    });

    // actual specifications/tests
    it('shows a loading indicator',function(){
        expect(loading.show).toHaveBeenCalled();
    });
    it('plays',function(){
        expect(player.isPlaying).toBe(true);
    });

    // specs may be nested recursively
    describe('pausing',function(){
        beforeEach(function(){
            player.pause();
        });
        it('pauses',function() {
            expect(player).not.toBePlaying();
        });
    });
});

Note: toBePlaying is implemented as a custom expect hook in another file.

  beforeEach(function() {
    this.addMatchers({
      toBePlaying: function(expectedSong) {
        var player = this.actual;
        return player.currentlyPlayingSong === expectedSong
            && player.isPlaying;
      }
    })
  });