De-duplicate steps between chromium and chromium_trybot recipes

scripts/slave/recipe_modules/test_utils/api.py

 # Copyright 2013 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 slave import recipe_api
 
 class TestUtilsApi(recipe_api.RecipeApi):
   @staticmethod
   def format_step_text(data):
     """
@@ skipping 17 matching lines @@
         # Only displaying the section (even the header) when it's non-empty
         # simplifies caller code.
         if section[1]:
           step_text.append('<br/>%s<br/>' % section[0])
           step_text.extend(('%s<br/>' % line for line in section[1]))
       else:  # pragma: no cover
         raise ValueError(
             'Expected a one or two-element list, got %r instead.' % section)
     return ''.join(step_text)
 
-  class Test(object):
-    """
-    Base class for tests that can be retried after deapplying a previously
-    applied patch.
-    """
-
-    @property
-    def name(self):  # pragma: no cover
-      """Name of the test."""
-      raise NotImplementedError()
-
-    def pre_run(self, suffix):  # pragma: no cover
-      """Steps to execute before running the test."""
-      return []
-
-    def run(self, suffix):  # pragma: no cover
-      """Run the test. suffix is 'with patch' or 'without patch'."""
-      raise NotImplementedError()
-
-    def post_run(self, suffix):  # pragma: no cover
-      """Steps to execute after running the test."""
-      return []
-
-    def has_valid_results(self, suffix):  # pragma: no cover
-      """
-      Returns True if results (failures) are valid.
-
-      This makes it possible to distinguish between the case of no failures
-      and the test failing to even report its results in machine-readable
-      format.
-      """
-      raise NotImplementedError()
-
-    def failures(self, suffix):  # pragma: no cover
-      """Return list of failures (list of strings)."""
-      raise NotImplementedError()
-
-    def _step_name(self, suffix):
-      """Helper to uniformly combine tests's name with a suffix."""
-      return '%s (%s)' % (self.name, suffix)
-
-  def determine_new_failures(self, tests, deapply_patch_fn):
+  def determine_new_failures(self, api, tests, deapply_patch_fn):
     """
     Utility function for running steps with a patch applied, and retrying
     failing steps without the patch. Failures from the run without the patch are
     ignored.
 
     Args:
+      api - recipe API

[agable, 2014/06/28 00:05:13]

Please call this parent_api (caller_api?) or something like that, to distinguish
it from the api that is present at self.m. Also, would be really good to have a
comment right here explaining why it is necessary to pass the caller's api
through to the Test classes.

[Paweł Hajdan Jr., 2014/06/28 00:19:01]

Done.

       tests - iterable of objects implementing the Test interface above
       deapply_patch_fn - function that takes a list of failing tests
                          and undoes any effect of the previously applied patch
     """
     # Convert iterable to list, since it is enumerated multiple times.
     tests = list(tests)
 
     if self.m.step_history.failed:
       yield self.m.python.inline(
         'Aborting due to failed build state',
         "import sys; sys.exit(1)",
         always_run=True, abort_on_failure=True)
       return  # won't actually hit this, but be explicit
 
     def run(prefix, tests):
-      yield (t.pre_run(prefix) for t in tests)
-      yield (t.run(prefix) for t in tests)
-      yield (t.post_run(prefix) for t in tests)
+      yield (t.pre_run(api, prefix) for t in tests)
+      yield (t.run(api, prefix) for t in tests)
+      yield (t.post_run(api, prefix) for t in tests)
 
     yield run('with patch', tests)
 
     failing_tests = []
     for t in tests:
-      if not t.has_valid_results('with patch'):
+      if not t.has_valid_results(api, 'with patch'):
         yield self.m.python.inline(
           t.name,
           r"""
           import sys
           print 'TEST RESULTS WERE INVALID'
           sys.exit(1)
           """,
           always_run=True)
-      elif t.failures('with patch'):
+      elif t.failures(api, 'with patch'):
         failing_tests.append(t)
     if not failing_tests:
       return
 
     yield deapply_patch_fn(failing_tests)
 
     yield run('without patch', failing_tests)
-    yield (self._summarize_retried_test(t) for t in failing_tests)
+    yield (self._summarize_retried_test(api, t) for t in failing_tests)
 
-  def _summarize_retried_test(self, test):
-    if not test.has_valid_results('without patch'):
+  def _summarize_retried_test(self, api, test):
+    if not test.has_valid_results(api, 'without patch'):
       return self.m.python.inline(
         test.name,
         r"""
         import sys
         print 'TEST RESULTS WERE INVALID'
         sys.exit(1)
         """,
         always_run=True)
 
-    ignored_failures = set(test.failures('without patch'))
-    new_failures = set(test.failures('with patch')) - ignored_failures
+    ignored_failures = set(test.failures(api, 'without patch'))
+    new_failures = set(test.failures(api, 'with patch')) - ignored_failures
 
     def followup_fn(step_result):
       p = step_result.presentation
 
       p.step_text += self.format_step_text([
           ['failures:', new_failures],
           ['ignored:', ignored_failures]
       ])
 
       if new_failures:
@@ skipping 24 matching lines @@
       """,
       args=[
         self.m.json.input({
           'new': list(new_failures),
           'ignored': list(ignored_failures),
         })
       ],
       followup_fn=followup_fn,
       always_run=True,
     )