Cap the maximum number of flaky tests that we record from a step

appengine/chromium_try_flakes/handlers/test/flake_issues_test.py

 # Copyright 2015 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 datetime
 import json
 import mock
 import urllib2
 
 from google.appengine.datastore import datastore_stub_util
@@ skipping 839 matching lines @@
 
     flakes = Flake.query().fetch()
     self.assertEqual(len(flakes), len(EXPECTED_FLAKES))
     expected_flake_names = set([ef[1] for ef in EXPECTED_FLAKES])
     actual_flake_names = set([f.name for f in flakes])
     self.assertEqual(expected_flake_names, actual_flake_names)
 
     for flake in flakes:
       self.assertEqual(flake.occurrences, [flaky_run.key])
 
+  def test_records_step_as_a_flake_when_too_many_tests_fail(self):
+    now = datetime.datetime.utcnow()
+    br_f, br_s = self._create_build_runs(now - datetime.timedelta(hours=1), now)
+    urlfetch_mock = mock.Mock(side_effect = [
+      # Buildbot reply.
+      mock.Mock(status_code=200, content=json.dumps({
+        'steps': [
+          {'results': [2], 'name': 'test-step', 'text': ['']},
+        ]
+      })),
+      # Test-results reply.
+      mock.Mock(status_code=200, content=json.dumps({
+        'tests': {
+          'test%d' % i: {
+            'expected': 'PASS',
+            'actual': 'FAIL',
+          } for i in range(51)
+        }
+      }))
+    ])
+
+    with mock.patch('google.appengine.api.urlfetch.fetch', urlfetch_mock):
+      self.test_app.post('/issues/create_flaky_run',
+                         {'failure_run_key': br_f.urlsafe(),
+                          'success_run_key': br_s.urlsafe()})
+
+    flaky_runs = FlakyRun.query().fetch(100)
+    self.assertEqual(len(flaky_runs), 1)
+    flaky_run = flaky_runs[0]
+    self.assertEqual(len(flaky_run.flakes), 1)
+    self.assertEqual(flaky_run.flakes[0].name, 'test-step')
+    self.assertEqual(flaky_run.flakes[0].failure, 'test-step')
+
   def test_flattens_tests_correctly(self):
     passed, failed, skipped = CreateFlakyRun._flatten_tests(
         json.loads(TEST_TEST_RESULTS_REPLY)['tests'], '/')
     self.assertEqual(set(passed), set(['test1']))
     self.assertEqual(set(failed), set(['test2/a', 'test2/d']))
     self.assertEqual(set(skipped), set(['test2/b']))
 
   def test_stores_and_updates_is_step_property(self):
     now = datetime.datetime.utcnow()
     br_f, br_s = self._create_build_runs(now - datetime.timedelta(hours=1), now)
@@ skipping 51 matching lines @@
     key = Flake(name='foobar', issue_id=issue.id).put()
     self.test_app.get(
         '/override_issue_id?key=%s&issue_id=%d' % (key.urlsafe(), issue.id))
     self.assertEqual(key.get().issue_id, issue.id)
 
   def test_overrides_issue_id_with_0(self):
     key = Flake(name='foobar', issue_id=100000).put()
     self.test_app.get(
         '/override_issue_id?key=%s&issue_id=0' % key.urlsafe())
     self.assertEqual(key.get().issue_id, 0)