[loader] Make recipe engine support examples/ module subdir

recipe_modules/raw_io/example.py

-# Copyright 2014 The LUCI Authors. All rights reserved.
-# Use of this source code is governed under the Apache License, Version 2.0
-# that can be found in the LICENSE file.
-
-DEPS = [
-  'path',
-  'properties',
-  'python',
-  'raw_io',
-  'step',
-]
-
-
-def RunSteps(api):
-  # Read command's stdout and stderr.
-  step_result = api.step('echo', ['echo', 'Hello World'],
-      stdout=api.raw_io.output(),
-      stderr=api.raw_io.output())
-  assert step_result.stdout == 'Hello World\n'
-  assert step_result.stderr == ''
-
-  # Pass stuff to command's stdin, read it from stdout.
-  step_result = api.step('cat', ['cat'],
-      stdin=api.raw_io.input_text(data='hello'),
-      stdout=api.raw_io.output('out'))
-  assert step_result.stdout == 'hello'
-
-  step_result = api.step('cat', ['cat', api.raw_io.input_text(data='hello')],
-      stdout=api.raw_io.output('out'))
-  assert step_result.stdout == 'hello'
-
-  # \xe2 is not encodable by utf-8 (and has shown up in actual recipe data)
-  # so test that input correctly doesn't try to encode it as utf-8.
-  step_result = api.step('cat', ['cat'],
-      stdin=api.raw_io.input(data='\xe2hello'),
-      stdout=api.raw_io.output())
-  assert step_result.stdout == '\xe2hello'
-
-  # Example of auto-mocking stdout. '\n' appended to mock 'echo' behavior.
-  step_result = api.step('automock', ['echo', 'huh'],
-                 stdout=api.raw_io.output('out'),
-                 step_test_data=(
-                   lambda: api.raw_io.test_api.stream_output('huh\n')))
-  assert step_result.stdout == 'huh\n'
-
-  # Example of auto-mocking stdout + stderr.
-  step_result = api.step(
-    'automock (fail)', ['bash', '-c', 'echo blah && echo fail 1>&2'],
-    stdout=api.raw_io.output('out'),
-    stderr=api.raw_io.output('err'),
-    step_test_data=(
-      lambda: (
-        api.raw_io.test_api.stream_output('blah\n') +
-        api.raw_io.test_api.stream_output('fail\n', 'stderr')
-      ))
-  )
-  assert step_result.stdout == 'blah\n'
-  assert step_result.stderr == 'fail\n'
-
-  # leak_to coverage.
-  step_result = api.step(
-      'leak stdout', ['echo', 'leaking'],
-      stdout=api.raw_io.output(leak_to=api.path['tmp_base'].join('out.txt')),
-      step_test_data=(
-        lambda: api.raw_io.test_api.stream_output('leaking\n')))
-  assert step_result.stdout == 'leaking\n'
-
-  api.step('list temp dir', ['ls', api.raw_io.output_dir()])
-  api.step('leak dir', ['ls', api.raw_io.output_dir(
-      leak_to=api.path['tmp_base'].join('out'))])
-
-  # Example of overriding default mocked output for a single named output.
-  step_result = api.python.inline(
-      'override_default_mock',
-      """
-      import sys
-      with open(sys.argv[1], 'w') as f:
-        f.write(%r)
-      """ % api.properties.get('some_prop', 'good_value'),
-      args=[api.raw_io.output_text(name='test')],
-      step_test_data=(
-          lambda: api.raw_io.test_api.output_text(
-              'second_bad_value', name='test')))
-  assert step_result.raw_io.output_texts['test'] == 'good_value'
-  assert step_result.raw_io.output_text == 'good_value'
-
-
-def GenTests(api):
-  # This test shows that you can override a specific placeholder, even with
-  # default `step_test_data`. However, since this recipe is ACTUALLY run in
-  # the presubmit, we need to do a trick with properties:
-  #   When run for real, "some_prop" will be "good_value" and pass.
-  #   When run for simulation, we override this property to provide a bad value,
-  #     AND the default step_test_data in RunSteps above ALSO provides another
-  #     bad value, the simulation passes ONLY because of the
-  #     'override_default_mock' below.
-  yield (api.test('basic') +
-      api.properties(some_prop='bad_value') +
-      api.step_data('echo',
-          stdout=api.raw_io.output('Hello World\n'),
-          stderr=api.raw_io.output('')) +
-      api.step_data('cat',
-          stdout=api.raw_io.output('hello')) +
-      api.step_data('cat (2)',
-          stdout=api.raw_io.output('hello')) +
-      api.step_data('cat (3)',
-          stdout=api.raw_io.output('\xe2hello')) +
-      api.step_data('override_default_mock',
-          api.raw_io.output_text('good_value', name='test'))
-  )