Test MIXER_MAX_VOLUME and fix detected bugs

mopidy/mixers/__init__.py

@@ -18,11 +18,13 @@ class BaseMixer(object):
         Integer in range [0, 100]. :class:`None` if unknown. Values below 0 is
         equal to 0. Values above 100 is equal to 100.
         """
-        return self._get_volume() / self.amplification_factor
+        if self._get_volume() is None:
+            return None
+        return int(self._get_volume() / self.amplification_factor)
 
     @volume.setter
     def volume(self, volume):
-        volume = int(volume) * self.amplification_factor
+        volume = int(int(volume) * self.amplification_factor)
         if volume < 0:
             volume = 0
         elif volume > 100:

tests/mixers/base_test.py

@@ -1,18 +1,16 @@
-import unittest
-
-from mopidy.mixers.dummy import DummyMixer
-
-class BaseMixerTest(unittest.TestCase):
+class BaseMixerTest(object):
     MIN = 0
     MAX = 100
-
     ACTUAL_MIN = MIN
     ACTUAL_MAX = MAX
-
     INITIAL = None
 
+    mixer_class = None
+
     def setUp(self):
-        self.mixer = DummyMixer(None)
+        assert self.mixer_class is not None, \
+            "mixer_class must be set in subclass"
+        self.mixer = self.mixer_class(None)
 
     def test_initial_volume(self):
         self.assertEqual(self.mixer.volume, self.INITIAL)

tests/mixers/denon_test.py

@@ -1,3 +1,5 @@
+import unittest
+
 from mopidy.mixers.denon import DenonMixer
 from tests.mixers.base_test import BaseMixerTest
 
@@ -22,11 +24,12 @@ class DenonMixerDeviceMock(object):
     def open(self):
         self._open = True
 
-class DenonMixerTest(BaseMixerTest):
+class DenonMixerTest(BaseMixerTest, unittest.TestCase):
     ACTUAL_MAX = 99
-
     INITIAL = 1
 
+    mixer_class = DenonMixer
+
     def setUp(self):
         self.device = DenonMixerDeviceMock()
         self.mixer = DenonMixer(None, device=self.device)

tests/mixers/dummy_test.py

@@ -0,0 +1,17 @@
+import unittest
+
+from mopidy.mixers.dummy import DummyMixer
+from tests.mixers.base_test import BaseMixerTest
+
+class DenonMixerTest(BaseMixerTest, unittest.TestCase):
+    mixer_class = DummyMixer
+
+    def test_set_volume_is_capped(self):
+        self.mixer.amplification_factor = 0.5
+        self.mixer.volume = 100
+        self.assertEquals(self.mixer._volume, 50)
+
+    def test_get_volume_does_not_show_that_the_volume_is_capped(self):
+        self.mixer.amplification_factor = 0.5
+        self.mixer._volume = 50
+        self.assertEquals(self.mixer.volume, 100)