get_microphone(), get_speaker(): Improved comparison between the call parameter "id" and existing device names

soundcard/coreaudio.py

@@ -3,7 +3,6 @@
 import numpy
 import collections
 import time
-import re
 import math
 import threading
 import warnings

soundcard/mediafoundation.py

@@ -2,7 +2,6 @@
 
 import os
 import cffi
-import re
 import time
 import struct
 import collections

soundcard/pulseaudio.py

@@ -2,7 +2,6 @@
 import atexit
 import collections
 import time
-import re
 import threading
 import warnings
 import numpy

soundcard/utils.py

@@ -1,21 +1,39 @@
+import re
+
 def match_device(id, devices):
     """Find id in a list of devices.
 
-    id can be a platfom-specific id, a substring of the device name, or a
+    id can be a platfom specific id, a substring of the device name, or a
     fuzzy-matched pattern for the microphone name.
-
     """
     devices_by_id = {device.id: device for device in devices}
-    devices_by_name = {device.name: device for device in devices}
+    real_devices_by_name = {
+        device.name: device for device in devices
+        if not getattr(device, 'isloopback', True)}
+    loopback_devices_by_name = {
+        device.name: device for device in devices
+        if getattr(device, 'isloopback', True)}
     if id in devices_by_id:
         return devices_by_id[id]
+    for device_map in real_devices_by_name, loopback_devices_by_name:
+        if id in device_map:
+            return device_map[id]
     # try substring match:
-    for name, device in devices_by_name.items():
-        if id in name:
-            return device
+    for device_map in real_devices_by_name, loopback_devices_by_name:
+        for name, device in device_map.items():
+            if id in name:
+                return device
     # try fuzzy match:
-    pattern = '.*'.join(id)
-    for name, device in devices_by_name.items():
-        if re.match(pattern, name):
-            return device
+    id_parts = list(id)
+    # Escape symbols in the provided id that have a special meaning
+    # in regular expression to prevent syntax errors e.g. for
+    # unbalanced parentheses.
+    for special_re_char in r'.^$*+?{}\[]|()':
+        while special_re_char in id_parts:
+            id_parts[id_parts.index(special_re_char)] = '\\' + special_re_char
+    pattern = '.*'.join(id_parts)
+    for device_map in real_devices_by_name, loopback_devices_by_name:
+        for name, device in device_map.items():
+            if re.search(pattern, name):
+                return device
     raise IndexError('no device with id {}'.format(id))

test_soundcard.py

@@ -3,6 +3,14 @@
 import numpy
 import pytest
 
+
+if sys.platform == 'linux':
+    import soundcard.pulseaudio as platform_lib
+elif sys.platform == 'darwin':
+    import soundcard.coreaudio as platform_lib
+elif sys.platform == 'win32':
+    import soundcard.mediafoundation as platform_lib
+
 skip_if_not_linux = pytest.mark.skipif(sys.platform != 'linux', reason='Only implemented for PulseAudio so far')
 
 ones = numpy.ones(1024)
@@ -157,3 +165,147 @@ def test_loopback_multichannel_channelmap(loopback_speaker, loopback_microphone)
     assert right.mean() < 0
     assert (left > 0.5).sum() == len(signal)
     assert (right < -0.5).sum() == len(signal)
+
+
+class FakeMicrophone:
+    def __init__(self, id, name, isloopback):
+        self.id = id
+        self.name = name
+        self.isloopback = isloopback
+
+
+fake_microphones = [
+    FakeMicrophone(
+        'alsa_output.usb-PCM2702-00.analog-stereo.monitor',
+        'Monitor of PCM2702 16-bit stereo audio DAC Analog Stereo',
+        True),
+    FakeMicrophone(
+        'alsa_output.pci-0000_00_1b.0.analog-stereo.monitor',
+        'Monitor of Build-in Sound Device Analog Stereo',
+        True),
+    FakeMicrophone(
+        'alsa_input.pci-0000_00_1b.0.analog-stereo',
+        'Build-in Sound Device Analog Stereo',
+        False),
+    FakeMicrophone(
+        'alsa_output.pci-0000_00_03.0.hdmi-stereo-extra1.monitor',
+        'Monitor of Build-in Sound Device Digital Stereo (HDMI 2)',
+        True),
+    FakeMicrophone(
+        'alsa_input.bluetooth-stuff.monitor',
+        'Name with regex pitfalls [).',
+        True),
+    FakeMicrophone(
+        'alsa_input.bluetooth-stuff',
+        'Name with regex pitfalls [). Longer than than the lookback name.',
+        False),
+    ]
+
+@pytest.fixture
+def mock_all_microphones(monkeypatch):
+
+    def mocked_all_microphones(include_loopback=False, exclude_monitors=True):
+        return fake_microphones
+
+    monkeypatch.setattr(
+        platform_lib, "all_microphones", mocked_all_microphones)
+
+
+def test_get_microphone(mock_all_microphones):
+    # Internal IDs can be specified.
+    mic = soundcard.get_microphone('alsa_input.pci-0000_00_1b.0.analog-stereo')
+    assert mic == fake_microphones[2]
+    # No fuzzy matching for IDs.
+    with pytest.raises(IndexError) as exc_info:
+        soundcard.get_microphone('alsa_input.pci-0000_00_1b.0')
+    assert (
+        exc_info.exconly() ==
+        'IndexError: no device with id alsa_input.pci-0000_00_1b.0')
+
+    # The name of a microphone can be specified.
+    mic = soundcard.get_microphone('Build-in Sound Device Analog Stereo')
+    assert mic == fake_microphones[2]
+
+    # Complete name matches have precedence over substring matches.
+    mic = soundcard.get_microphone('Name with regex pitfalls [).')
+    assert mic == fake_microphones[4]
+
+    mic = soundcard.get_microphone('Name with regex pitfalls')
+    assert mic == fake_microphones[5]
+
+
+    # A substring of a device name can be specified. If the parameter passed
+    # to get_microphone() is a substring of more than one microphone name,
+    # real microphones are preferably returned.
+    mic = soundcard.get_microphone('Sound Device Analog')
+    assert mic == fake_microphones[2]
+
+    # If none of the lookup methods above matches a device, a "fuzzy match"
+    # is tried.
+    mic = soundcard.get_microphone('Snd Dev Analog')
+    assert mic == fake_microphones[2]
+
+    # "Fuzzy matching" uses a regular expression; symbols with a specail
+    # meaning in regexes are escaped.
+    mic = soundcard.get_microphone('regex pitfall [')
+    assert mic == fake_microphones[5]
+
+
+class FakeSpeaker:
+    def __init__(self, id, name):
+        self.id = id
+        self.name = name
+
+
+fake_speakers = [
+    FakeSpeaker(
+        'alsa_output.usb-PCM2702-00.analog-stereo',
+        'PCM2702 16-bit stereo audio DAC Analog Stereo'),
+    FakeSpeaker(
+        'alsa_output.pci-0000_00_1b.0.analog-stereo',
+        'Build-in Sound Device Analog Stereo'),
+    FakeSpeaker(
+        'alsa_output.pci-0000_00_03.0.hdmi-stereo-extra1',
+        'Build-in Sound Device Digital Stereo (HDMI 2)'),
+    FakeSpeaker(
+        'alsa_output.wire_fire_thingy',
+        r'A nonsensical name \[a-z]{3}'),
+    ]
+
+@pytest.fixture
+def mock_all_speakers(monkeypatch):
+
+    def mocked_all_speakers(include_loopback=False, exclude_monitors=True):
+        return fake_speakers
+
+    monkeypatch.setattr(
+        platform_lib, "all_speakers", mocked_all_speakers)
+
+def test_get_speaker(mock_all_speakers):
+    # Internal IDs can be specified.
+    spk = soundcard.get_speaker('alsa_output.pci-0000_00_1b.0.analog-stereo')
+    assert spk == fake_speakers[1]
+    # No fuzzy matching for IDs.
+    with pytest.raises(IndexError) as exc_info:
+        soundcard.get_speaker('alsa_output.pci-0000_00_1b.0')
+    assert (
+        exc_info.exconly() ==
+        'IndexError: no device with id alsa_output.pci-0000_00_1b.0')
+
+    # The name of a speaker can be specified.
+    spk = soundcard.get_speaker('Build-in Sound Device Analog Stereo')
+    assert spk == fake_speakers[1]
+
+    # Substrings of a device name can be specified.
+    spk = soundcard.get_speaker('Sound Device Analog')
+    assert spk == fake_speakers[1]
+
+    # If none of the lookup methods above matches a device, a "fuzzy match"
+    # is tried.
+    spk = soundcard.get_speaker('Snd Dev Analog')
+    assert spk == fake_speakers[1]
+
+    # "Fuzzy matching" uses a regular expression; symbols with a specail
+    # meaning in regexes are escaped.
+    spk = soundcard.get_speaker('nonsense {3')
+    assert spk == fake_speakers[3]