Recipe package system.

recipe_modules/step/example.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.
 
 DEPS = [
-  'properties',
-  'step',
+  'recipe_engine/properties',
+  'recipe_engine/step',
 ]
 
 from recipe_engine import recipe_api
 
 def RunSteps(api):
   # TODO(martinis) change this
   # The api.step object is directly callable.
   api.step('hello', ['echo', 'Hello World'])
   api.step('hello', ['echo', 'Why hello, there.'])
 
@@ skipping 10 matching lines @@
   # We can manipulate the step presentation arbitrarily until we run
   # the next step.
   step_result = api.step('hello', ['echo', 'hello'])
   step_result.presentation.status = api.step.EXCEPTION
   step_result.presentation.logs['the reason'] = ['The reason\nit failed']
 
   try:
     api.step('goodbye', ['echo', 'goodbye'])
     # Modifying step_result now would raise an AssertionError.
   except api.step.StepFailure:
-    # Raising anything besides StepFailure causes the build to go purple.
+    # Raising anything besides StepFailure or StepWarning causes the build to go 
+    # purple.
     raise ValueError('goodbye must exit 0!')
 
+  try:
+    api.step('warning', ['echo', 'warning'])
+  except api.step.StepFailure as e:
+    e.result.presentation.status = api.step.WARNING
+    raise api.step.StepWarning(e.message)
+
+
   # Aggregate failures from tests!
   try:
     with recipe_api.defer_results():
       api.step('testa', ['echo', 'testa'])
       api.step('testb', ['echo', 'testb'])
   except recipe_api.AggregatedStepFailure as f:
     raise api.step.StepFailure("You can catch step failures.")
 
   # Some steps are needed from an infrastructure point of view. If these
   # steps fail, the build stops, but doesn't get turned red because it's
   # not the developers' fault.
   try:
     api.step('cleanup', ['echo', 'cleaning', 'up', 'build'], infra_step=True)
   except api.step.InfraFailure as f:
     assert f.result.presentation.status == api.step.EXCEPTION
 
   # Run a step through a made-up wrapper program.
   api.step('application', ['echo', 'main', 'application'],
-           wrapper=['python', 'test-wrapper.py', '-v', '--'])
+           wrapper=['python', '-c', 'import sys; print sys.argv'])
 
   if api.properties.get('access_invalid_data'):
     result = api.step('no-op', ['echo', 'I', 'do', 'nothing'])
     # Trying to access non-existent attributes on the result should raise.
     _ = result.json.output
 
-  # You can also raise a warning, which will act like a step failure, but
-  # will turn the build yellow, and stop the build.
-  raise api.step.StepWarning("Warning, robots approaching!")
-
 
 def GenTests(api):
   yield (
       api.test('basic') +
       api.step_data('anything is cool', retcode=3)
     )
 
   # If you don't have the expect_exception in this test, you will get something
   # like this output.
   # ======================================================================
   # ERROR: step:example.exceptional (..../exceptional.json)
   # ----------------------------------------------------------------------
   # Traceback (most recent call last):
   #   <full stack trace ommitted>
   #   File "annotated_run.py", line 537, in run
   #     retcode = steps_function(api)
   #   File "recipe_modules/step/example.py", line 39, in RunSteps
   #     raise ValueError('goodbye must exit 0!')
   # ValueError: goodbye must exit 0!
 
   yield (
       api.test('exceptional') +
       api.step_data('goodbye (2)', retcode=1) +
       api.expect_exception('ValueError')
     )
 
   yield (
+      api.test('warning') +
+      api.step_data('warning', retcode=1) +
+      api.expect_exception('StepWarning')
+    )
+
+  yield (
       api.test('defer_results') +
       api.step_data('testa', retcode=1)
     )
 
   yield (
       api.test('invalid_access') +
       api.properties(access_invalid_data=True) +
       api.expect_exception('StepDataAttributeError')
     )
 
   yield (
       api.test('infra_failure') +
       api.properties(raise_infra_failure=True) +
       api.step_data('cleanup', retcode=1)
     )