Add --list-deps command with Pykka adapter

mopidy/core.py

@@ -22,6 +22,7 @@ from mopidy import (get_version, settings, OptionalDependencyError,
     SettingsError, DATA_PATH, SETTINGS_PATH, SETTINGS_FILE)
 from mopidy.gstreamer import GStreamer
 from mopidy.utils import get_class
+from mopidy.utils.deps import list_deps_optparse_callback
 from mopidy.utils.log import setup_logging
 from mopidy.utils.path import get_or_create_folder, get_or_create_file
 from mopidy.utils.process import (exit_handler, stop_remaining_actors,
@@ -77,6 +78,9 @@ def parse_options():
     parser.add_option('--list-settings',
         action='callback', callback=list_settings_optparse_callback,
         help='list current settings')
+    parser.add_option('--list-deps',
+        action='callback', callback=list_deps_optparse_callback,
+        help='list dependencies and their versions')
     return parser.parse_args(args=mopidy_args)[0]
 
 def check_old_folders():

mopidy/utils/deps.py

@@ -0,0 +1,43 @@
+import sys
+
+import pykka
+
+
+def list_deps_optparse_callback(*args):
+    """
+    Prints a list of all dependencies.
+
+    Called by optparse when Mopidy is run with the :option:`--list-deps`
+    option.
+    """
+    print format_dependency_list()
+    sys.exit(0)
+
+
+def format_dependency_list(adapters=None):
+    if adapters is None:
+        adapters = [
+            pykka_info,
+        ]
+
+    lines = []
+    for adapter in adapters:
+        dep_info = adapter()
+        lines.append('%(name)s: %(version)s' % dep_info)
+        if 'path' in dep_info:
+            lines.append('  Imported from: %(path)s' % dep_info)
+    return '\n'.join(lines)
+
+
+def pykka_info():
+    if hasattr(pykka, '__version__'):
+        # Pykka >= 0.14
+        version = pykka.__version__
+    else:
+        # Pykka < 0.14
+        version = pykka.get_version()
+    return {
+        'name': 'Pykka',
+        'version': version,
+        'path': pykka.__file__,
+    }

tests/utils/deps_test.py

@@ -0,0 +1,27 @@
+import pykka
+
+from mopidy.utils import deps
+
+from tests import unittest
+
+
+class DepsTest(unittest.TestCase):
+    def test_format_dependency_list(self):
+        adapters = [
+            lambda: dict(name='Python', version='FooPython 2.7.3'),
+            lambda: dict(name='Platform', version='Loonix 4.0.1'),
+            lambda: dict(name='Pykka', version='0.1337', path='/foo/bar/baz')
+        ]
+
+        result = deps.format_dependency_list(adapters)
+
+        self.assertIn('Python: FooPython 2.7.3', result)
+        self.assertIn('Platform: Loonix 4.0.1', result)
+        self.assertIn('Imported from: /foo/bar/baz', result)
+
+    def test_pykka_info(self):
+        result = deps.pykka_info()
+
+        self.assertEquals('Pykka', result['name'])
+        self.assertEquals(pykka.__version__, result['version'])
+        self.assertIn('pykka', result['path'])