Removing default values in MIDI constructor for midi_in and midi_out based on @tannewt advice.

Updating all the examples to explicitly set midi_in or midi_out to the USB ports.
Adding test case as constructor now raises an error if midi_in and midi_out are both omitted.
This will make sphinx-build work but that appears to be a separate bug. adafruit#13

Author: Kevin J Walters

README.rst

@@ -58,14 +58,14 @@ Usage Example
 
     import time
     import random
+    import usb_midi
     import adafruit_midi
 
-    midi = adafruit_midi.MIDI(out_channel=0)
+    midi = adafruit_midi.MIDI(midi_out=usb_midi.ports[1], out_channel=0)
 
     print("Midi test")
 
-    print("Default output channel:", midi.out_channel)
-    print("Listening on input channel:", midi.in_channel)
+    print("Default output MIDI channel:", midi.out_channel + 1)
 
     while True:
         midi.note_on(44, 120)

adafruit_midi/__init__.py

@@ -42,21 +42,19 @@
 
 """
 
-import usb_midi
-
 from .midi_message import MIDIMessage, ALL_CHANNELS
 
 __version__ = "0.0.0-auto.0"
 __repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_MIDI.git"
 
 
 class MIDI:
-    """MIDI helper class.
+    """MIDI helper class. ``midi_in`` or ``midi_out`` *must* be set or both together.
 
     :param midi_in: an object which implements ``read(length)``,
-        defaults to ``usb_midi.ports[0]``.
+        set to ``usb_midi.ports[0]`` for USB MIDI, default None.
     :param midi_out: an object which implements ``write(buffer, length)``,
-        defaults to ``usb_midi.ports[1]``.
+        set to ``usb_midi.ports[1]`` for USB MIDI, default None.
     :param in_channel: The input channel(s).
         This is used by ``receive`` to filter data.
         This can either be an ``int`` for the wire protocol channel number (0-15)
@@ -65,7 +63,7 @@ class MIDI:
     :param int out_channel: The wire protocol output channel number (0-15)
         used by ``send`` if no channel is specified,
         defaults to 0 (MIDI Channel 1).
-    :param int in_buf_size: Size of input buffer in bytes, default 30.
+    :param int in_buf_size: Maximum size of input buffer in bytes, default 30.
     :param bool debug: Debug mode, default False.
 
     """
@@ -75,8 +73,10 @@ class MIDI:
     PITCH_BEND = 0xE0
     CONTROL_CHANGE = 0xB0
 
-    def __init__(self, midi_in=usb_midi.ports[0], midi_out=usb_midi.ports[1], *,
+    def __init__(self, midi_in=None, midi_out=None, *,
                  in_channel=None, out_channel=0, in_buf_size=30, debug=False):
+        if midi_in is None and midi_out is None:
+            raise ValueError("No midi_in or midi_out provided")
         self._midi_in = midi_in
         self._midi_out = midi_out
         self._in_channel = in_channel  # dealing with pylint inadequacy

docs/conf.py

@@ -20,7 +20,7 @@
 # Uncomment the below if you use native CircuitPython modules such as
 # digitalio, micropython and busio. List the modules you use. Without it, the
 # autodoc module docs will fail to generate with a warning.
-autodoc_mock_imports = ["usb_midi"]
+autodoc_mock_imports = []
 
 
 intersphinx_mapping = {'python': ('https://docs.python.org/3.4', None),'CircuitPython': ('https://circuitpython.readthedocs.io/en/latest/', None)}

examples/midi_inoutdemo.py

@@ -1,5 +1,6 @@
 # midi_inoutdemo - demonstrates receiving and sending MIDI events
 
+import usb_midi
 import adafruit_midi
 
 # TimingClock is worth importing first if present as it
@@ -21,7 +22,9 @@
 
 from adafruit_midi.midi_message import MIDIUnknownEvent
 
-midi = adafruit_midi.MIDI(in_channel=(1, 2, 3), out_channel=0)
+midi = adafruit_midi.MIDI(midi_in=usb_midi.ports[0],
+                          midi_out=usb_midi.ports[1],
+                          in_channel=(1, 2, 3), out_channel=0)
 
 print("Midi Demo in and out")
 

examples/midi_intest1.py

@@ -1,8 +1,9 @@
 import time
+import usb_midi
 import adafruit_midi
 
 ### 0 is MIDI channel 1
-midi = adafruit_midi.MIDI(in_channel=0)
+midi = adafruit_midi.MIDI(midi_in=usb_midi.ports[0], in_channel=0)
 
 print("Midi test II")
 

examples/midi_simpletest.py

@@ -1,8 +1,9 @@
 import time
 import random
+import usb_midi
 import adafruit_midi
 
-midi = adafruit_midi.MIDI(out_channel=0)
+midi = adafruit_midi.MIDI(midi_out=usb_midi.ports[1], out_channel=0)
 
 print("Midi test")
 

examples/midi_simpletest2.py

@@ -1,13 +1,14 @@
 # simple_test demonstrating both interfaces
 import time
 import random
+import usb_midi
 import adafruit_midi
-from adafruit_midi.control_change          import ControlChange
-from adafruit_midi.note_off                import NoteOff
-from adafruit_midi.note_on                 import NoteOn
+from adafruit_midi.control_change   import ControlChange
+from adafruit_midi.note_off         import NoteOff
+from adafruit_midi.note_on          import NoteOn
 from adafruit_midi.pitch_bend       import PitchBend
 
-midi = adafruit_midi.MIDI(out_channel=0)
+midi = adafruit_midi.MIDI(midi_out=usb_midi.ports[1], out_channel=0)
 
 print("Midi test")
 
@@ -25,6 +26,7 @@
     midi.note_off(44, 120)
     midi.control_change(3, 44)
     time.sleep(0.5)
+
     # send message(s) interface
     midi.send(NoteOn(44, 120))
     time.sleep(0.25)

tests/test_MIDIMessage_unittests.py

@@ -27,9 +27,9 @@
 import os
 verbose = int(os.getenv('TESTVERBOSE', '2'))
 
-# adafruit_midi has an import usb_midi
+# adafruit_midi had an import usb_midi
 import sys
-sys.modules['usb_midi'] = MagicMock()
+#sys.modules['usb_midi'] = MagicMock()
 
 # Borrowing the dhalbert/tannewt technique from adafruit/Adafruit_CircuitPython_Motor
 sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))

tests/test_MIDI_unittests.py

@@ -27,9 +27,9 @@
 import os
 verbose = int(os.getenv('TESTVERBOSE', '2'))
 
-# adafruit_midi has an import usb_midi
+# adafruit_midi had an import usb_midi
 import sys
-sys.modules['usb_midi'] = MagicMock()
+#sys.modules['usb_midi'] = MagicMock()
 
 # Borrowing the dhalbert/tannewt technique from adafruit/Adafruit_CircuitPython_Motor
 sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))
@@ -99,6 +99,12 @@ def read(length):
                            out_channel=in_c, in_channel=in_c)
     return m
 
+    
+class Test_MIDI_constructor(unittest.TestCase):
+    def test_no_inout(self):
+        # constructor likes a bit of in out
+        with self.assertRaises(ValueError):
+            adafruit_midi.MIDI()
 
 class Test_MIDI(unittest.TestCase):
     # pylint: disable=too-many-branches

tests/test_note_parser.py

@@ -27,9 +27,9 @@
 import os
 verbose = int(os.getenv('TESTVERBOSE', '2'))
 
-# adafruit_midi has an import usb_midi
+# adafruit_midi had an import usb_midi
 import sys
-sys.modules['usb_midi'] = MagicMock()
+#sys.modules['usb_midi'] = MagicMock()
 
 # Borrowing the dhalbert/tannewt technique from adafruit/Adafruit_CircuitPython_Motor
 sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')))