Refactor WPT Export to ensure only one PR in flight at a time

third_party/WebKit/Tools/Scripts/webkitpy/w3c/test_exporter_unittest.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.
+
+import unittest
+
+from webkitpy.common.host_mock import MockHost
+from webkitpy.w3c.test_exporter import TestExporter
+from webkitpy.w3c.github import MockWPTGitHub
+
+
+class TestExporterTest(unittest.TestCase):
+
+    def test_stops_if_more_than_one_PR_is_in_flight(self):

[qyearsley, 2016/11/22 22:08:20]

The linter might complain about capitals in the name here.

+        host = MockHost()
+        mock_pull_requests = [{'id': 1}, {'id': 2}]
+        wpt_github = MockWPTGitHub(pull_requests=mock_pull_requests)

[qyearsley, 2016/11/22 22:08:20]

You could also pass the literal list of mock pull requests directly, e.g.

        wpt_github = MockWPTGitHub(pull_requests=[{'id': 1}, {'id': 2}])

+
+        self.assertRaises(Exception, TestExporter(host, wpt_github))

[qyearsley, 2016/11/22 22:08:20]

An alternate way of expressing this that I've seen is:

with self.assertRaises(Exception):
    TestExporter(host, wpt_github)

[jeffcarp, 2016/11/22 22:30:15]

Hell yes that looks much nicer

+
+    def test_if_PR_exists_merges_it(self):
+        host = MockHost()
+        mock_pull_requests = [{'number': 1, 'title': 'abc'}]
+        wpt_github = MockWPTGitHub(pull_requests=mock_pull_requests)
+        TestExporter(host, wpt_github).run()
+
+        self.assertEqual(len(wpt_github.calls), 2)
+        self.assertEqual(wpt_github.calls[1], 'merge_pull_request')
+
+    def test_merge_failure_errors_out(self):
+        host = MockHost()
+        mock_pull_requests = [{'number': 1, 'title': 'abc'}]
+        wpt_github = MockWPTGitHub(pull_requests=mock_pull_requests, unsuccessful_merge=True)
+
+        self.assertRaises(Exception, TestExporter(host, wpt_github).run)