Add UnixLocalPath*() in presubmit_support.

This adds AffectedFile.UnixLocalPath(), Change.UnixLocalPaths(), and
input_api.UnixLocalPaths() to the presubmit support APIs, so that we can
check paths in a platform-independent manner (i.e., not have to worry
about whether we're running on Windows and might need to handle
backslashes).

Change-Id: I1a424825384cb950ef2d4d3008c9c6e60028cf07
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/6236404
Reviewed-by: Gavin Mak <gavinmak@google.com>
Commit-Queue: Dirk Pranke <dpranke@google.com>

presubmit_support.py

@@ -741,11 +741,26 @@ class InputApi(object):
                 self.change.AffectedFiles(include_deletes, file_filter)))
 
     def LocalPaths(self):
-        """Returns local paths of input_api.AffectedFiles()."""
+        """Returns platform-native local paths of .AffectedFiles().
+
+        E.g. on Windows the paths will contain backslashes. The paths
+        will be relative to the client root, which might be different
+        than the CWD, so use this for platform-appropriate error messages,
+        but not for accessing the files. Use .AbsoluteLocalPaths() when you
+        need to actually access the files."""
         paths = [af.LocalPath() for af in self.AffectedFiles()]
         logging.debug('LocalPaths: %s', paths)
         return paths
 
+    def UnixLocalPaths(self):
+        """Returns unix-style local paths of input_api.AffectedFiles().
+
+        I.e., on Windows the path will contain forward slashes,
+        not backslashes. Other platforms are unchanged.
+
+        Use this when you need to check paths in a platform-independent way."""
+        return [p.replace(os.path.sep, '/') for p in self.LocalPaths()]
+
     def AbsoluteLocalPaths(self):
         """Returns absolute local paths of input_api.AffectedFiles()."""
         return [af.AbsoluteLocalPath() for af in self.AffectedFiles()]
@@ -784,6 +799,9 @@ class InputApi(object):
         '/' path separators should be used in the regular expressions and will work
         on Windows as well as other platforms.
 
+        For backwards-compatibility, '\' path separators will
+        also work correctly on Windows (but not on other platforms).
+
         Note: Copy-paste this function to suit your needs or use a lambda function.
         """
         if files_to_check is None:
@@ -793,13 +811,11 @@ class InputApi(object):
 
         def Find(affected_file, items):
             local_path = affected_file.LocalPath()
+            unix_local_path = affected_file.UnixLocalPath()
             for item in items:
                 if self.re.match(item, local_path):
                     return True
-                # Handle the cases where the files regex only handles /, but the
-                # local path uses \.
-                if self.is_windows and self.re.match(
-                        item, local_path.replace('\\', '/')):
+                if self.re.match(item, unix_local_path):
                     return True
             return False
 
@@ -1035,14 +1051,24 @@ class AffectedFile(object):
     def LocalPath(self):
         """Returns the path of this file on the local disk relative to client root.
 
-        This should be used for error messages but not for accessing files,
+        This should be used for error messages but not for accessing the file,
         because presubmit checks are run with CWD=PresubmitLocalPath() (which is
-        often != client root).
+        often != client root). Use .AbsoluteLocalPath() to access the file.
         """
         return normpath(self._path)
 
+    def UnixLocalPath(self):
+        """Returns LocalPath() normalized to use forward slashes.
+
+        On Windows, this means that any backslashes in the path will be
+        replaced with forward slashes. On other platforms the behavior
+        is unchanged."""
+        return self.LocalPath().replace(os.path.sep, '/')
+
     def AbsoluteLocalPath(self):
-        """Returns the absolute path of this file on the local disk."""
+        """Returns the absolute path of this file on the local disk.
+
+        Use this when you need to actually access the file."""
         return os.path.abspath(os.path.join(self._local_root, self.LocalPath()))
 
     def Action(self):
@@ -1387,9 +1413,24 @@ class Change(object):
         return self.AffectedTestableFiles(include_deletes=include_deletes)
 
     def LocalPaths(self):
-        """Convenience function."""
+        """Returns platform-native local paths of .AffectedFiles().
+
+        E.g.., on Windows the paths will contain backslashes. The paths
+        will be relative to the client root, which might be different
+        than the CWD, so use this for platform-appropriate error messages,
+        but not for accessing the files. Use .AbsoluteLocalPaths() when
+        you need to actually access the files."""
         return [af.LocalPath() for af in self.AffectedFiles()]
 
+    def UnixLocalPaths(self):
+        """Returns unix-style local paths of .AffectedFiles().
+
+        I.e., on Windows the path will contain forward slashes,
+        not backslashes. Other platforms are unchanged.
+
+        Use this when you need to check paths in a platform-independent way."""
+        return [p.replace(os.path.sep, '/') for p in self.LocalPaths()]
+
     def LocalSubmodules(self):
         """Returns local paths for affected submodules."""
         return [af.LocalPath() for af in self.AffectedSubmodules()]

tests/presubmit_support_test.py

@@ -98,6 +98,13 @@ class ProvidedDiffChangeTest(fake_repos.FakeReposTestBase):
         self._test('somewhere/else', ['not a top level file!'],
                    ['still not a top level file!'])
 
+    def test_unix_local_paths(self):
+        if sys.platform == 'win32':
+            self.assertIn(r'somewhere\else', self.change.LocalPaths())
+        else:
+            self.assertIn('somewhere/else', self.change.LocalPaths())
+        self.assertIn('somewhere/else', self.change.UnixLocalPaths())
+
 
 class TestGenerateDiff(fake_repos.FakeReposTestBase):
     """ Tests for --generate_diff.

tests/presubmit_unittest.py

@@ -1353,6 +1353,12 @@ class InputApiUnittest(PresubmitTestsBase):
         self.assertEqual(got_files[3].LocalPath(),
                          presubmit.normpath(files[7][1]))
 
+        self.assertIn('foo/blat.cc', input_api.UnixLocalPaths())
+        if sys.platform == 'win32':
+            self.assertIn(r'foo\blat.cc', input_api.LocalPaths())
+        else:
+            self.assertIn('foo/blat.cc', input_api.LocalPaths())
+
     def testDefaultFilesToCheckFilesToSkipFilters(self):
         def f(x):
             return presubmit.AffectedFile(x, 'M', self.fake_root_dir, None)