Skip commits that don't generate a patch + fixes to get export working

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

Index: third_party/WebKit/Tools/Scripts/webkitpy/w3c/test_exporter.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/w3c/test_exporter.py b/third_party/WebKit/Tools/Scripts/webkitpy/w3c/test_exporter.py
index d23f73b21972aa8b4ff4f8355fe30e1b5a497901..f4bf8b718562732393e4f53267b5cf5b24f3ff1c 100644
--- a/third_party/WebKit/Tools/Scripts/webkitpy/w3c/test_exporter.py
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/w3c/test_exporter.py
@@ -4,21 +4,23 @@
 
 import logging
 from webkitpy.w3c.local_wpt import LocalWPT
-from webkitpy.w3c.chromium_wpt import ChromiumWPT
 from webkitpy.w3c.chromium_commit import ChromiumCommit
 
+CHROMIUM_WPT_DIR = 'third_party/WebKit/LayoutTests/imported/wpt/'
 _log = logging.getLogger(__name__)
 
+# TODO(jeffcarp): integrate chromium_wpt_unittests into this module's tests
+# TODO(jeffcarp): have the script running this fetch Chromium origin/master
 
 class TestExporter(object):
 
     def __init__(self, host, wpt_github, dry_run=False):
         self.host = host
         self.wpt_github = wpt_github
+        self.local_wpt = LocalWPT(self.host)
         self.dry_run = dry_run
 
     def run(self):
-        # First, poll for an in-flight pull request and merge if exists
         pull_requests = self.wpt_github.in_flight_pull_requests()
 
         if len(pull_requests) == 1:
@@ -35,35 +37,50 @@ class TestExporter(object):
                 _log.info('Merging...')
                 self.wpt_github.merge_pull_request(pull_request['number'])
                 _log.info('PR merged!')
+                # TODO(jeffcarp): Delete remote branch after merging
+
+            # The script needs to stop here since the Chromium
+            # WPT mirror lags behind a little bit. Also, it's probably safer
+            # to not be merging and creating a PR in the same run.
+            return
         elif len(pull_requests) > 1:
             _log.error(pull_requests)
             # TODO(jeffcarp): Print links to PRs
             raise Exception('More than two in-flight PRs!')
+        else:
+            self.create_export_pull_request()
 
-        # Second, look for exportable commits in Chromium
-        # At this point, no in-flight PRs should exist
-        # If there was an issue merging, it should have errored out
-        local_wpt = LocalWPT(self.host, use_github=False)
-        chromium_wpt = ChromiumWPT(self.host)
+    def merge_pull_request(self, pull_request):
+        """Attempts to merge an in-flight PR.
 
-        # TODO(jeffcarp): have the script running this fetch Chromium origin/master
-        # TODO(jeffcarp): move WPT fetch out of its constructor to match planned ChromiumWPT pattern
+        Args:
+            pull_request: a dict representing the pull request.
+        """
+        _log.info('In-flight PR found: #%d', pull_request['number'])
+        _log.info(pull_request['title'])
 
-        wpt_commit, chromium_commit = local_wpt.most_recent_chromium_commit()
-        assert chromium_commit, 'No Chromium commit found, this is impossible'
+        # TODO(jeffcarp): Check the PR status here
 
-        wpt_behind_master = local_wpt.commits_behind_master(wpt_commit)
+        if self.dry_run:
+            _log.info('[dry run] Would attempt to merge PR.')
+        else:
+            _log.info('Merging...')
+            self.wpt_github.merge_pull_request(pull_request['number'])
+            _log.info('PR merged!')
+            # TODO(jeffcarp): Delete remote branch after merging
 
-        _log.info('\nLast Chromium export commit in web-platform-tests:')
-        _log.info('web-platform-tests@%s', wpt_commit)
-        _log.info('(%d behind web-platform-tests@origin/master)', wpt_behind_master)
+    def create_export_pull_request(self):
+        """Creates a PR for the earliest exportable commit in Chromium if there is one.
 
-        _log.info('\nThe above WPT commit points to the following Chromium commit:')
-        _log.info('chromium@%s', chromium_commit.sha)
-        _log.info('(%d behind chromium@origin/master)', chromium_commit.num_behind_master())
+        This will create a branch on w3c/web-platform-tests and make a request
+        to the GitHub API to create a pull request.
+
+        At this point, no in-flight PRs should exist.
 
-        # TODO(jeffcarp): Have this function return ChromiumCommits
-        exportable_commits = chromium_wpt.exportable_commits_since(chromium_commit.sha)
+        Returns:
+            None
+        """
+        exportable_commits = self.exportable_commits()
 
         if not exportable_commits:
             _log.info('No exportable commits found in Chromium, stopping.')
@@ -71,17 +88,15 @@ class TestExporter(object):
 
         _log.info('Found %d exportable commits in Chromium:', len(exportable_commits))
         for commit in exportable_commits:
-            _log.info('- %s %s', commit, chromium_wpt.subject(commit))
+            _log.info('- %s %s', commit, commit.subject())
 
-        outbound_commit = ChromiumCommit(self.host, sha=exportable_commits[0])
         _log.info('Picking the earliest commit and creating a PR')
+        outbound_commit = exportable_commits[0]
         _log.info('- %s %s', outbound_commit.sha, outbound_commit.subject())
 
         patch = outbound_commit.format_patch()
         message = outbound_commit.message()
 
-        # TODO: now do a test comparison of patch against local WPT
-
         if self.dry_run:
             _log.info('[dry_run] Stopping before creating PR')
             _log.info('\n\n[dry_run] message:')
@@ -90,11 +105,60 @@ class TestExporter(object):
             _log.info(patch)
             return
 
-        local_branch_name = local_wpt.create_branch_with_patch(message, patch)
+        remote_branch_name = self.local_wpt.create_branch_with_patch(message, patch)
 
         response_data = self.wpt_github.create_pr(
-            local_branch_name=local_branch_name,
+            remote_branch_name=remote_branch_name,
             desc_title=outbound_commit.subject(),
             body=outbound_commit.body())
 
         _log.info('Create PR response: %s', response_data)
+
+        if response_data:
+            data, status_code = self.wpt_github.add_label(response_data['number'])
+            _log.info('Add label response (status %s): %s', status_code, data)
+
+        # TODO(jeffcarp): Create a comment on the PR to CC foolip and qyearsley
+        #   also explain that this is an automated export and will be auto-merged if green
+
+    def exportable_commits(self):
+        """Returns all exportable Chromium commits, earliest first.
+

[qyearsley, 2016/12/15 20:59:14]

Possible extra comment: this looks at commits in Chromium after the last
exported commit. To find the last exported commits, it looks in the git log for
web-platform-tests.

+        Returns:
+            A list of ChromiumCommits

[qyearsley, 2016/12/15 20:59:14]

Nit: period

+        """
+        wpt_commit, chromium_commit = self.local_wpt.most_recent_chromium_commit()
+        assert chromium_commit, 'No Chromium commit found, this is impossible.'
+
+        _log.info('\nLast Chromium export commit in web-platform-tests:')
+        _log.info('web-platform-tests@%s', wpt_commit)
+        _log.info('(%d behind web-platform-tests@origin/master)',
+                  self.local_wpt.commits_behind_master(wpt_commit))
+
+        _log.info('\nThe above WPT commit points to the following Chromium commit:')
+        _log.info('chromium@%s', chromium_commit.sha)
+        _log.info('(%d behind chromium@origin/master)', chromium_commit.num_behind_master())

[qyearsley, 2016/12/15 20:59:14]

This could potentially be changed to debug-level rather than info-level.

+
+        chromium_commits = [ChromiumCommit(self.host, sha=sha)
+                            for sha in self.commits_with_changes_in_wpt_since(chromium_commit.sha)]
+
+        def is_exportable(commit):
+            patch = commit.format_patch()
+            return (
+                patch
+                and self.local_wpt.test_patch(patch)
+                and 'NOEXPORT=true' not in commit.message()
+                and not commit.message().startswith('Import ')
+            )
+
+        return [c for c in chromium_commits if is_exportable(c)]
+
+    def commits_with_changes_in_wpt_since(self, sha):
+        toplevel = self.host.executive.run_command([
+            'git', 'rev-parse', '--show-toplevel'
+        ]).strip()
+
+        return self.host.executive.run_command([
+            'git', 'rev-list', '{}..HEAD'.format(sha), '--reverse',
+            '--', toplevel + '/' + CHROMIUM_WPT_DIR
+        ]).splitlines()