Special case get_version() to include git revision id if we're running from a git repo

mopidy/__init__.py

@@ -1,9 +1,31 @@
+import os
 import sys
 if not (2, 6) <= sys.version_info < (3,):
     sys.exit(u'Mopidy requires Python >= 2.6, < 3')
 
+VERSION = (0, 4, 0)
+
+def is_in_git_repo():
+    git_dir = os.path.abspath(os.path.join(
+        os.path.dirname(__file__), '../.git'))
+    return os.path.exists(git_dir)
+
+def get_git_version():
+    if not is_in_git_repo():
+        return None
+    git_version = os.popen('git describe').read().strip()
+    if git_version.startswith('v'):
+        git_version = git_version[1:]
+    return git_version
+
+def get_plain_version():
+    return '.'.join(map(str, VERSION))
+
 def get_version():
-    return u'0.4.0'
+    if is_in_git_repo():
+        return get_git_version()
+    else:
+        return get_plain_version()
 
 class MopidyException(Exception):
     def __init__(self, message, *args, **kwargs):

tests/version_test.py

@@ -1,11 +1,11 @@
 from distutils.version import StrictVersion as SV
 import unittest
 
-from mopidy import get_version
+from mopidy import get_plain_version
 
 class VersionTest(unittest.TestCase):
     def test_current_version_is_parsable_as_a_strict_version_number(self):
-        SV(get_version())
+        SV(get_plain_version())
 
     def test_versions_can_be_strictly_ordered(self):
         self.assert_(SV('0.1.0a0') < SV('0.1.0a1'))
@@ -16,5 +16,5 @@ class VersionTest(unittest.TestCase):
         self.assert_(SV('0.1.0') < SV('1.0.0'))
         self.assert_(SV('0.2.0') < SV('0.3.0'))
         self.assert_(SV('0.3.0') < SV('0.3.1'))
-        self.assert_(SV('0.3.1') < SV(get_version()))
-        self.assert_(SV(get_version()) < SV('0.4.1'))
+        self.assert_(SV('0.3.1') < SV(get_plain_version()))
+        self.assert_(SV(get_plain_version()) < SV('0.4.1'))