Excerpt from the BookPlayerPageGenerator tests

ch_pos_test.js

it('updates chapter position property to match audio player position', function () {
    bppg.generatePage({book: BOOK_OBJECT, chapter: chapterObjInstance});
    chapterObjInstance.position = -1 // set the position to a nonzero value
    var dom_ele = $('#audioSource').trigger('timeupdate');
    expect(chapterObjInstance.position).equal(0);
});