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

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

Index: third_party/WebKit/Tools/Scripts/webkitpy/w3c/test_exporter_unittest.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/w3c/test_exporter_unittest.py b/third_party/WebKit/Tools/Scripts/webkitpy/w3c/test_exporter_unittest.py
new file mode 100644
index 0000000000000000000000000000000000000000..f8629e1baa68f72d32c18d6732d2361b8a27c439
--- /dev/null
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/w3c/test_exporter_unittest.py
@@ -0,0 +1,71 @@
+# 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.common.system.executive_mock import MockExecutive2
+from webkitpy.w3c.test_exporter import TestExporter
+from webkitpy.w3c.wpt_github_mock import MockWPTGitHub
+
+
+class TestExporterTest(unittest.TestCase):
+
+    def test_stops_if_more_than_one_pr_is_in_flight(self):
+        host = MockHost()
+        wpt_github = MockWPTGitHub(pull_requests=[{'id': 1}, {'id': 2}])
+
+        # TODO: make Exception more specific
+        with self.assertRaises(Exception):
+            TestExporter(host, wpt_github).run()
+
+    def test_if_pr_exists_merges_it(self):
+        host = MockHost()
+        wpt_github = MockWPTGitHub(pull_requests=[{'number': 1, 'title': 'abc'}])
+        TestExporter(host, wpt_github).run()
+
+        self.assertIn('merge_pull_request', wpt_github.calls)
+
+    def test_merge_failure_errors_out(self):
+        host = MockHost()
+        wpt_github = MockWPTGitHub(pull_requests=[{'number': 1, 'title': 'abc'}],
+                                   unsuccessful_merge=True)
+
+        # TODO: make Exception more specific
+        with self.assertRaises(Exception):
+            TestExporter(host, wpt_github).run()
+
+    def test_dry_run_stops_before_creating_pr(self):
+        host = MockHost()
+        host.executive = MockExecutive2(output='beefcafe')
+        wpt_github = MockWPTGitHub(pull_requests=[{'number': 1, 'title': 'abc'}])
+        TestExporter(host, wpt_github, dry_run=True).run()
+
+        self.assertEqual(wpt_github.calls, ['in_flight_pull_requests'])
+
+    def test_creates_pull_request_for_earliest_commit(self):
+        host = MockHost()
+
+        def mock_command(args):
+            git_command = args[1]
+            if git_command == 'rev-list':
+                return 'facebeef\ncafedad5'
+            elif git_command == 'footers':
+                return 'fake-cr-position'
+            elif git_command == 'show':
+                if 'cafedad5' in args:
+                    return 'newer fake text'
+                elif 'facebeef' in args:
+                    return 'older fake text'
+            else:
+                return ''
+
+        host.executive = MockExecutive2(run_command_fn=mock_command)
+        wpt_github = MockWPTGitHub(pull_requests=[])
+
+        TestExporter(host, wpt_github).run()
+
+        self.assertEqual(wpt_github.calls, ['in_flight_pull_requests', 'create_pr'])
+        self.assertEqual(wpt_github.pull_requests_created,
+                         [('chromium-export-try', 'older fake text', 'older fake text')])