def test_normal_case(self):
p = PlayList()
p.load_data(StringIO(INPUT))
p.apply_changes(StringIO(CHANGE))
output = StringIO()
p.gen_output(output)
obj = json.loads(output.getvalue())
self.assertEqual(len(obj['users']), 1)
self.assertEqual(obj['users'][0]['id'], '1')
self.assertEqual(len(obj['playlists']), 2)
self.assertEqual(obj['playlists'][0]['id'], '2')
self.assertEqual(obj['playlists'][0]['song_ids'], ['1', '2'])
self.assertEqual(obj['playlists'][1]['id'], '3')
self.assertEqual(obj['playlists'][1]['song_ids'], ['1', '2'])
def test_not_allow_duplicate_song_in_playlist(self):
change = """
[
{
"type": "add_song_to_playlist",
"playlist_id": "1",
"song_ids" : ["1"]
}
]
"""
p = PlayList()
p.load_data(StringIO(INPUT))
p.apply_changes(StringIO(change))
output = StringIO()
p.gen_output(output)
obj = json.loads(output.getvalue())
self.assertEqual(len(obj['playlists'][0]['song_ids']), 2)
