consolidate skip_if_cannot_represent_filename()

Remove duplicate copies of this utility, move it from a mixin/test-class
method to being a simple function in common_util.py

src/allmydata/test/cli/common.py

@@ -1,10 +1,7 @@
 from cStringIO import StringIO
-from twisted.trial import unittest
 from twisted.internet import threads # CLI tests use deferToThread
 from ...util.assertutil import precondition
-from ...util.encodingutil import (unicode_platform,
-                                  get_filesystem_encoding,
-                                  unicode_to_argv)
+from ...util.encodingutil import unicode_to_argv
 from ...scripts import runner
 from ..common_util import ReallyEqualMixin
 
@@ -36,13 +33,3 @@ class CLITestMixin(ReallyEqualMixin):
             return rc, stdout.getvalue(), stderr.getvalue()
         d.addCallback(_done)
         return d
-
-    def skip_if_cannot_represent_filename(self, u):
-        precondition(isinstance(u, unicode))
-
-        enc = get_filesystem_encoding()
-        if not unicode_platform():
-            try:
-                u.encode(enc)
-            except UnicodeEncodeError:
-                raise unittest.SkipTest("A non-ASCII filename could not be encoded on this platform.")

src/allmydata/test/cli/test_cli.py

@@ -29,7 +29,7 @@ from allmydata.scripts.common import DEFAULT_ALIAS, get_aliases, get_alias, \
      DefaultAliasMarker
 
 from allmydata.scripts import cli, debug, runner
-from ..common_util import ReallyEqualMixin
+from ..common_util import ReallyEqualMixin, skip_if_cannot_represent_filename
 from ..no_network import GridTestMixin
 from .common import CLITestMixin, parse_options
 from twisted.internet import threads # CLI tests use deferToThread
@@ -493,7 +493,7 @@ class CLI(CLITestMixin, unittest.TestCase):
         filenames = [u'L\u00F4zane', u'Bern', u'Gen\u00E8ve']  # must be NFC
 
         for name in filenames:
-            self.skip_if_cannot_represent_filename(name)
+            skip_if_cannot_represent_filename(name)
 
         basedir = "cli/common/listdir_unicode_good"
         fileutil.make_dirs(basedir)

src/allmydata/test/cli/test_cp.py

@@ -10,6 +10,7 @@ from allmydata.util.encodingutil import (quote_output, get_io_encoding,
 from allmydata.util.assertutil import _assert
 from ..no_network import GridTestMixin
 from .common import CLITestMixin
+from ..common_util import skip_if_cannot_represent_filename
 
 timeout = 480 # deep_check takes 360s on Zandr's linksys box, others take > 240s
 
@@ -30,7 +31,7 @@ class Cp(GridTestMixin, CLITestMixin, unittest.TestCase):
         except UnicodeEncodeError:
             raise unittest.SkipTest("A non-ASCII command argument could not be encoded on this platform.")
 
-        self.skip_if_cannot_represent_filename(fn1)
+        skip_if_cannot_represent_filename(fn1)
 
         self.set_up_grid(oneshare=True)
 
@@ -198,7 +199,7 @@ class Cp(GridTestMixin, CLITestMixin, unittest.TestCase):
         except UnicodeEncodeError:
             raise unittest.SkipTest("A non-ASCII command argument could not be encoded on this platform.")
 
-        self.skip_if_cannot_represent_filename(fn1)
+        skip_if_cannot_represent_filename(fn1)
 
         self.set_up_grid(oneshare=True)
 

src/allmydata/test/cli/test_put.py

@@ -6,6 +6,7 @@ from allmydata.util import fileutil
 from allmydata.scripts.common import get_aliases
 from allmydata.scripts import cli
 from ..no_network import GridTestMixin
+from ..common_util import skip_if_cannot_represent_filename
 from allmydata.util.encodingutil import get_io_encoding, unicode_to_argv
 from allmydata.util.fileutil import abspath_expanduser_unicode
 from .common import CLITestMixin
@@ -427,7 +428,7 @@ class Put(GridTestMixin, CLITestMixin, unittest.TestCase):
         except UnicodeEncodeError:
             raise unittest.SkipTest("A non-ASCII command argument could not be encoded on this platform.")
 
-        self.skip_if_cannot_represent_filename(u"\u00E0 trier.txt")
+        skip_if_cannot_represent_filename(u"\u00E0 trier.txt")
 
         self.basedir = "cli/Put/immutable_from_file_unicode"
         self.set_up_grid(oneshare=True)

src/allmydata/test/common_util.py

@@ -3,10 +3,21 @@ from random import randrange
 
 from twisted.internet import reactor, defer
 from twisted.python import failure
+from twisted.trial import unittest
 
 from allmydata.util import fileutil, log
+from ..util.assertutil import precondition
 from allmydata.util.encodingutil import unicode_platform, get_filesystem_encoding
 
+def skip_if_cannot_represent_filename(u):
+    precondition(isinstance(u, unicode))
+
+    enc = get_filesystem_encoding()
+    if not unicode_platform():
+        try:
+            u.encode(enc)
+        except UnicodeEncodeError:
+            raise unittest.SkipTest("A non-ASCII filename could not be encoded on this platform.")
 
 class DevNullDictionary(dict):
     def __setitem__(self, key, value):

src/allmydata/test/test_backupdb.py

@@ -4,9 +4,9 @@ from StringIO import StringIO
 from twisted.trial import unittest
 
 from allmydata.util import fileutil
-from allmydata.util.encodingutil import listdir_unicode, get_filesystem_encoding, unicode_platform
-from allmydata.util.assertutil import precondition
+from allmydata.util.encodingutil import listdir_unicode
 from allmydata.scripts import backupdb
+from .common_util import skip_if_cannot_represent_filename
 
 class BackupDB(unittest.TestCase):
     def create(self, dbfile):
@@ -15,16 +15,6 @@ class BackupDB(unittest.TestCase):
         self.failUnless(bdb, "unable to create backupdb from %r" % (dbfile,))
         return bdb
 
-    def skip_if_cannot_represent_filename(self, u):
-        precondition(isinstance(u, unicode))
-
-        enc = get_filesystem_encoding()
-        if not unicode_platform():
-            try:
-                u.encode(enc)
-            except UnicodeEncodeError:
-                raise unittest.SkipTest("A non-ASCII filename could not be encoded on this platform.")
-
     def test_basic(self):
         self.basedir = basedir = os.path.join("backupdb", "create")
         fileutil.make_dirs(basedir)
@@ -222,8 +212,8 @@ class BackupDB(unittest.TestCase):
         self.failIf(r.was_created())
 
     def test_unicode(self):
-        self.skip_if_cannot_represent_filename(u"f\u00f6\u00f6.txt")
-        self.skip_if_cannot_represent_filename(u"b\u00e5r.txt")
+        skip_if_cannot_represent_filename(u"f\u00f6\u00f6.txt")
+        skip_if_cannot_represent_filename(u"b\u00e5r.txt")
 
         self.basedir = basedir = os.path.join("backupdb", "unicode")
         fileutil.make_dirs(basedir)

src/allmydata/test/test_encodingutil.py

@@ -71,7 +71,7 @@ from allmydata.util.encodingutil import argv_to_unicode, unicode_to_url, \
     get_io_encoding, get_filesystem_encoding, to_str, from_utf8_or_none, _reload, \
     to_filepath, extend_filepath, unicode_from_filepath, unicode_segments_from
 from allmydata.dirnode import normalize
-
+from .common_util import skip_if_cannot_represent_filename
 from twisted.python import usage
 
 
@@ -265,16 +265,8 @@ class StdlibUnicode(unittest.TestCase):
     """This mainly tests that some of the stdlib functions support Unicode paths, but also that
     listdir_unicode works for valid filenames."""
 
-    def skip_if_cannot_represent_filename(self, u):
-        enc = get_filesystem_encoding()
-        if not unicode_platform():
-            try:
-                u.encode(enc)
-            except UnicodeEncodeError:
-                raise unittest.SkipTest("A non-ASCII filename could not be encoded on this platform.")
-
     def test_mkdir_open_exists_abspath_listdir_expanduser(self):
-        self.skip_if_cannot_represent_filename(lumiere_nfc)
+        skip_if_cannot_represent_filename(lumiere_nfc)
 
         try:
             os.mkdir(lumiere_nfc)