test: add case for microphone failure

When the microphone fails, it will raise an IOError during the `read`. This is simulated with a new test.

ref: N25B-119

test/unit/test_audio_sender.py

@@ -55,23 +55,50 @@ def test_sending_audio(mocker):
     mock_choose_mic.return_value = {"name": u"Some mic", "index": 0L}
 
     mock_state = mocker.patch("robot_interface.endpoints.audio_sender.state")
-    mock_state.exit_event.is_set.return_value = False
-
-    mock_audio = mocker.patch("robot_interface.endpoints.audio_sender.pyaudio")
-    mock_audio.PyAudio = mock.Mock()
-    stream = mock.Mock()
-    stream.read = _fake_read
-    mock_audio.PyAudio.open.return_value = stream
+    mock_state.exit_event.is_set.side_effect = [False, True]
 
     mock_zmq_context = mock.Mock()
     send_socket = mock.Mock()
 
+    # If there's something wrong with the microphone, it will raise an IOError when `read`ing.
+    stream = mock.Mock()
+    stream.read = _fake_read
+
     sender = AudioSender(mock_zmq_context)
     sender.socket.send = send_socket
+    sender.audio.open = mock.Mock()
+    sender.audio.open.return_value = stream
 
     sender.start()
-    time.sleep(0.01)
-    mock_state.exit_event.is_set.return_value = True
     sender.wait_until_done()
 
     send_socket.assert_called()
+
+
+def _fake_read_error(num_frames):
+    raise IOError()
+
+
+def test_break_microphone(mocker):
+    mock_choose_mic = mocker.patch("robot_interface.endpoints.audio_sender.choose_mic_default")
+    mock_choose_mic.return_value = {"name": u"Some mic", "index": 0L}
+
+    mock_state = mocker.patch("robot_interface.endpoints.audio_sender.state")
+    mock_state.exit_event.is_set.side_effect = [False, True]
+
+    mock_zmq_context = mock.Mock()
+    send_socket = mock.Mock()
+
+    # If there's something wrong with the microphone, it will raise an IOError when `read`ing.
+    stream = mock.Mock()
+    stream.read = _fake_read_error
+
+    sender = AudioSender(mock_zmq_context)
+    sender.socket.send = send_socket
+    sender.audio.open = mock.Mock()
+    sender.audio.open.return_value = stream
+
+    sender.start()
+    sender.wait_until_done()
+
+    send_socket.assert_not_called()