Extract check for thrird party programs in tests

Author: Thomas Scholtes

test/helper.py

@@ -16,6 +16,7 @@
 import os
 import os.path
 import shutil
+import subprocess
 from tempfile import mkdtemp, mkstemp
 from glob import glob
 from contextlib import contextmanager
@@ -67,6 +68,19 @@ def capture_stdout():
         sys.stdout = org
 
 
+def has_program(cmd, args=['--version']):
+    """Returns `True` if `cmd` can be executed.
+    """
+    try:
+        with open(os.devnull, 'wb') as devnull:
+            subprocess.check_call([cmd] + args, stderr=devnull,
+                                  stdout=devnull, stdin=devnull)
+    except OSError:
+        return False
+    else:
+        return True
+
+
 class TestHelper(object):
     """Helper mixin for high-level cli and plugin tests.
 

test/test_replaygain.py

@@ -16,11 +16,10 @@
 import os
 import shutil
 from glob import glob
-import subprocess
 
 import _common
 from _common import unittest
-from helper import TestHelper
+from helper import TestHelper, has_program
 
 from beets.library import Item, Album
 from beets.mediafile import MediaFile
@@ -32,6 +31,11 @@
 except ImportError, ValueError:
     GST_AVAILABLE = False
 
+if any(has_program(cmd, ['-v']) for cmd in ['mp3gain', 'aacgain']):
+    GAIN_PROG_AVAILABLE = True
+else:
+    GAIN_PROG_AVAILABLE = False
+
 
 class ReplayGainCliTestBase(TestHelper):
 
@@ -131,26 +135,10 @@ class ReplayGainGstCliTest(ReplayGainCliTestBase, unittest.TestCase):
     backend = u'gstreamer'
 
 
+@unittest.skipIf(not GAIN_PROG_AVAILABLE, 'no *gain command found')
 class ReplayGainCmdCliTest(ReplayGainCliTestBase, unittest.TestCase):
     backend = u'command'
 
-    def setUp(self):
-        # Check for the backend command.
-        for command in ['mp3gain', 'aacgain']:
-            try:
-                with open(os.devnull, 'wb') as devnull:
-                    subprocess.check_call(
-                        [command, '-v'], stderr=devnull
-                    )
-            except OSError:
-                pass
-            else:
-                break
-        else:
-            self.skipTest('no *gain command found')
-
-        super(ReplayGainCmdCliTest, self).setUp()
-
 
 def suite():
     return unittest.TestLoader().loadTestsFromName(__name__)

test/test_ui.py

@@ -21,7 +21,7 @@
 
 import _common
 from _common import unittest
-from helper import capture_stdout
+from helper import capture_stdout, has_program
 
 from beets import library
 from beets import ui
@@ -931,14 +931,10 @@ def test_completion(self):
             'BASH_COMPLETION_SCRIPT', '/etc/bash_completion'))
 
         # Tests run in bash
-        shell = os.environ.get('BEETS_TEST_SHELL', '/bin/bash --norc')
-        try:
-            with open(os.devnull, 'wb') as devnull:
-                subprocess.check_call(shell.split() + ['--version'],
-                                      stdout=devnull)
-        except OSError:
+        cmd = os.environ.get('BEETS_TEST_SHELL', '/bin/bash --norc').split()
+        if not has_program(cmd[0]):
             self.skipTest('bash not available')
-        tester = subprocess.Popen(shell.split(' '), stdin=subprocess.PIPE,
+        tester = subprocess.Popen(cmd, stdin=subprocess.PIPE,
                                   stdout=subprocess.PIPE)
 
         # Load bash_completion
@@ -954,9 +950,6 @@ def test_completion(self):
         completion_script = self.io.getoutput()
         self.io.restore()
         tester.stdin.writelines(completion_script)
-        # from beets import plugins
-        # for cmd in plugins.commands():
-        #     print(cmd.name)
 
         # Load testsuite
         with open(test_script, 'r') as test_script: