Change ChromiumCommit.format_patch to use a filtered list of files

third_party/WebKit/Tools/Scripts/webkitpy/w3c/chromium_commit.py

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 from webkitpy.common.memoized import memoized
 from webkitpy.common.webkit_finder import WebKitFinder
+from webkitpy.w3c.deps_updater import DepsUpdater
+
+CHROMIUM_WPT_DIR = 'third_party/WebKit/LayoutTests/imported/wpt/'
 
 
 class ChromiumCommit(object):
 
     def __init__(self, host, sha=None, position=None):
         """
         Args:
             host: A Host object
             sha: A Chromium commit SHA
             position: A string of the form:
@@ skipping 37 matching lines @@
         return self.host.executive.run_command([
             'git', 'show', '--format=%b', '--no-patch', self.sha
         ])
 
     def message(self):
         """Returns a string with a commit's subject and body."""
         return self.host.executive.run_command([
             'git', 'show', '--format=%B', '--no-patch', self.sha
         ])
 
+    def filtered_changed_files(self):
+        """Makes a patch with just changes in files in the WPT for a given commit."""

[qyearsley, 2016/12/19 17:50:08]

"in the WPT" -> "in the WPT dir"

+        changed_files = self.host.executive.run_command([
+            'git', 'diff-tree', '--name-only', '--no-commit-id', '-r', self.sha,
+            '--', self.absolute_chromium_wpt_dir()
+        ]).splitlines()
+
+        blacklist = ['MANIFEST.json', 'resources/testharnessreport.js']

[qyearsley, 2016/12/19 17:50:08]

Just in case backslashes might be used on Windows in some cases, this could also
be:

blacklist = [
    'MANIFEST.json',
    self.host.filesystem.join('resources', 'testharnessreport.js'),
]

+        qualified_blacklist = [CHROMIUM_WPT_DIR + f for f in blacklist]

[qyearsley, 2016/12/19 17:50:08]

I'm wondering if there's a better word to use here besides "qualified"...

[jeffcarp, 2016/12/19 21:19:20]

I can't think of anything more fitting but open to any suggestions. I was
thinking of "fully qualified domain name"

[qyearsley, 2016/12/21 00:24:46]

Yep, sometimes there's no clear proper name for something. In this case, at
least, it's clear that what's meant is that it's a file path that's relative to
the Chromium checkout root.

One possible but longer name would be chromium_relative_blacklist, but it's fine
as-is too.

+        return [f for f in changed_files if f not in qualified_blacklist and not DepsUpdater.is_baseline(f)]
+
     def format_patch(self):
-        """Makes a patch with just changes in files in the WPT for a given commit."""
-        # TODO(jeffcarp): exclude expectations files
-        # TODO(jeffcarp): exclude manifest files
+        """Makes a patch with only exportable changes.
+        """

[qyearsley, 2016/12/19 17:50:08]

Nit: the closing quote can go on the previous line.

+        filtered_files = self.filtered_changed_files()
+
+        if not filtered_files:
+            return ''
+
         return self.host.executive.run_command([
             'git', 'format-patch', '-1', '--stdout',
-            self.sha, self.absolute_chromium_wpt_dir()
-        ])
+            self.sha, '--'] + filtered_files, cwd=self.absolute_chromium_dir())
 
     @memoized
     def absolute_chromium_wpt_dir(self):
         finder = WebKitFinder(self.host.filesystem)
         return finder.path_from_webkit_base('LayoutTests', 'imported', 'wpt')
+
+    @memoized
+    def absolute_chromium_dir(self):
+        finder = WebKitFinder(self.host.filesystem)
+        return finder.chromium_base()