blob: 1c90e8b8ea4f1a5ef2cb93806dc81c5e760bf249 [file] [log] [blame]
# Copyright 2016 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.
import inspect
from collections import defaultdict
from collections import namedtuple
from functools import reduce
from past.builtins import basestring
from recipe_engine.internal import recipe_deps
from .util import ModuleInjectionSite
from .util import ModuleInjectionError
from .util import static_call
from .util import static_wraps
def combineify(name, dest, a, b, overwrite=False):
"""
Combines dictionary members in two objects into a third one using addition.
Args:
name - the name of the member
dest - the destination object
a - the first source object
b - the second source object
overwrite - if True, for the same key, overwrite value from a with the one
from b; otherwise, use addition to merge them.
"""
dest_dict = getattr(dest, name)
dest_dict.update(getattr(a, name))
for k, v in getattr(b, name).items():
if k in dest_dict:
if not overwrite:
dest_dict[k] += v
else:
dest_dict[k] = v
else:
dest_dict[k] = v
class BaseTestData:
def __init__(self, enabled=True):
super(BaseTestData, self).__init__()
self._enabled = enabled
@property
def enabled(self):
return self._enabled
class PlaceholderTestData(BaseTestData):
def __init__(self, data=None, name=None):
super(PlaceholderTestData, self).__init__()
self.data = data
self.name = name
def __repr__(self):
if self.name is None:
return "PlaceholderTestData(DEFAULT, %r)" % (self.data,)
else:
return "PlaceholderTestData(%r, %r)" % (self.name, self.data,)
class StepTestData(BaseTestData):
"""
Mutable container for per-step test data.
This data is consumed while running the recipe (during
annotated_run.run_steps).
"""
def __init__(self):
super(StepTestData, self).__init__()
# { (module, placeholder, name) -> data }. Data are for output placeholders.
self.placeholder_data = defaultdict(dict)
self.override = False
self._stdout = None
self._stderr = None
self._retcode = None
self._times_out_after = None
self._cancel = False
self._global_shutdown_event = None # None, "before" or "after"
def __add__(self, other):
assert isinstance(other, StepTestData)
if other.override:
return other
ret = StepTestData()
combineify('placeholder_data', ret, self, other, overwrite=True)
# pylint: disable=W0212
ret._stdout = other._stdout or self._stdout
ret._stderr = other._stderr or self._stderr
ret._cancel = other._cancel or self._cancel
ret._global_shutdown_event = (
other._global_shutdown_event or self._global_shutdown_event
)
ret._retcode = self._retcode
if other._retcode is not None:
if ret._retcode is not None and ret._retcode != other._retcode:
raise ValueError('Conflicting retcode values.')
ret._retcode = other._retcode
ret._times_out_after = self._times_out_after
if other._times_out_after is not None:
if ret._times_out_after is not None:
raise ValueError('Conflicting times_out_after values.')
ret._times_out_after = other._times_out_after
return ret
def unwrap_placeholder(self):
# {(module, placeholder, name): data} => data.
if len(self.placeholder_data) != 1:
raise ValueError('Cannot unwrap placeholder_data with length > 1: len=%d'
% len(self.placeholder_data))
return list(self.placeholder_data.values())[0]
def pop_placeholder(self, module_name, placeholder_name, name):
return self.placeholder_data.pop(
(module_name, placeholder_name, name), PlaceholderTestData())
@property
def retcode(self): # pylint: disable=E0202
return self._retcode
@retcode.setter
def retcode(self, value): # pylint: disable=E0202
self._retcode = value
@property
def times_out_after(self): # pylint: disable=E0202
return self._times_out_after or 0
@times_out_after.setter
def times_out_after(self, value): # pylint: disable=E0202
self._times_out_after = value
@property
def global_shutdown_event(self): # pylint: disable=E0202
return self._global_shutdown_event
@global_shutdown_event.setter
def global_shutdown_event(self, value): # pylint: disable=E0202
assert value in ('before', 'after', None), "bad global_shutdown_event"
self._global_shutdown_event = value
@property
def cancel(self): # pylint: disable=E0202
return self._cancel
@cancel.setter
def cancel(self, value): # pylint: disable=E0202
self._cancel = value
@property
def stdout(self):
return self._stdout or PlaceholderTestData(None)
@stdout.setter
def stdout(self, value):
assert isinstance(value, PlaceholderTestData)
self._stdout = value
@property
def stderr(self):
return self._stderr or PlaceholderTestData(None)
@stderr.setter
def stderr(self, value):
assert isinstance(value, PlaceholderTestData)
self._stderr = value
@property
def stdin(self): # pylint: disable=R0201
return PlaceholderTestData(None)
def __repr__(self):
dct = {
'placeholder_data': dict(self.placeholder_data.items()),
'stdout': self._stdout,
'stderr': self._stderr,
'retcode': self._retcode,
'override': self.override,
'cancel': self.cancel,
}
if self.global_shutdown_event:
dct['global_shutdown_event'] = self.global_shutdown_event
if self.times_out_after:
dct['times_out_after'] = self.times_out_after
return "StepTestData(%r)" % dct
class ModuleTestData(BaseTestData, dict):
"""
Mutable container for test data for a specific module.
This test data is consumed at module load time (i.e. when create_recipe_api
runs).
"""
def __add__(self, other):
assert isinstance(other, ModuleTestData)
# BUG(crbug.com/327644647) - this implementation can silently drop data.
ret = ModuleTestData()
ret.update(self)
ret.update(other)
return ret
def __repr__(self):
return "ModuleTestData(%r)" % super(ModuleTestData, self).__repr__()
PostprocessHookContext = namedtuple(
'PostprocessHookContext', 'func args kwargs filename lineno')
"""The context describing where a post-process hook was added."""
PostprocessHook = namedtuple(
'PostprocessHook', 'func args kwargs context')
"""The details of a post-process hook.
func, args and kwargs detail the actual objects to use to invoke the check.
Context describes where the hook was added. Depending on whether post_process
or post_check is used, the context may or may not contain the same func, args
and kwargs.
"""
class TestData(BaseTestData):
def __init__(self, name=None):
super(TestData, self).__init__()
self.name = name
self.properties = {} # key -> val
self.environ = {} # key -> val
self.luci_context = {} # key -> val
self.mod_data = defaultdict(ModuleTestData)
self.step_data = defaultdict(StepTestData)
self.expected_exceptions = []
self.expected_status = None
self.post_process_hooks = [] # list(PostprocessHook)
# Filled in by recipe_deps.Recipe.gen_tests()
self.expect_file = None
def __add__(self, other):
assert isinstance(other, TestData)
ret = TestData(self.name or other.name)
ret.properties.update(self.properties)
ret.properties.update(other.properties)
ret.environ.update(self.environ)
ret.environ.update(other.environ)
# Override each section value instead of merging
combineify('luci_context', ret, self, other, overwrite=True)
combineify('mod_data', ret, self, other)
combineify('step_data', ret, self, other)
ret.post_process_hooks.extend(self.post_process_hooks)
ret.post_process_hooks.extend(other.post_process_hooks)
ret.expected_status = self.expected_status
if other.expected_status is not None:
ret.expected_status = other.expected_status
ret.expected_exceptions = [
*self.expected_exceptions, *other.expected_exceptions
]
return ret
@property
def consumed(self):
return not (self.step_data or self.expected_exception)
def pop_step_test_data(self, step_name, step_test_data_fn):
step_test_data = step_test_data_fn()
if step_name in self.step_data:
try:
step_test_data += self.step_data.pop(step_name)
except ValueError as ve:
raise ValueError('in step %r: %s' % (step_name, ve))
return step_test_data
def get_module_test_data(self, module_name):
return self.mod_data.get(module_name, ModuleTestData())
def expect_exception(self, exception):
if not isinstance(exception, basestring):
raise ValueError('expect_exception expects a string containing the '
'exception class name')
self.expected_exceptions.append(exception)
def post_process(self, func, args, kwargs, context):
self.post_process_hooks.append(PostprocessHook(func, args, kwargs, context))
def __repr__(self):
return "TestData(%r)" % ({
'name': self.name,
'properties': self.properties,
'environ': self.environ,
'luci_context': self.luci_context,
'mod_data': dict(self.mod_data.items()),
'step_data': dict(self.step_data.items()),
'expected_exceptions': self.expected_exceptions,
'expected_status': self.expected_status,
},)
class DisabledTestData(BaseTestData):
def __init__(self):
super(DisabledTestData, self).__init__(False)
def __getattr__(self, name):
return self
def pop_placeholder(self, _module_name, _placeholder_name, _name):
return self
def pop_step_test_data(self, _step_name, _step_test_data_fn):
return self
def get_module_test_data(self, _module_name):
return ModuleTestData(enabled=False)
def mod_test_data(func):
@static_wraps(func)
def inner(self, *args, **kwargs):
assert isinstance(self, RecipeTestApi)
ret = TestData(None)
data = static_call(self, func, *args, **kwargs)
ret.mod_data[self._module.name][inner.__name__] = data
return ret
return inner
def placeholder_step_data(func):
"""Decorates RecipeTestApi member functions to allow those functions to
return just the output placeholder data, instead of the normally required
StepTestData() object.
The wrapped function may return either:
* <placeholder data>, <retcode or None>, <name or None>
* StepTestData containing exactly one PlaceholderTestData and possible a
retcode. This is useful for returning the result of another method which
is wrapped with placeholder_step_data.
In either case, the wrapper function will return a StepTestData object with
the retcode and placeholder datum inserted with a name of:
(<Test module name>, <wrapped function name>, <name>)
Say you had a 'foo_module' with the following RecipeTestApi:
class FooTestApi(RecipeTestApi):
@placeholder_step_data
@staticmethod
def cool_method(data, retcode=None, name=None):
return ("Test data (%s)" % data), retcode, name
@placeholder_step_data
def other_method(self, retcode=None, name=None):
return self.cool_method('hammer time', retcode=retcode, name=name)
Code calling cool_method('hello', name='cool1') would get a StepTestData:
StepTestData(
placeholder_data = {
('foo_module', 'cool_method', 'cool1') :
PlaceholderTestData('Test data (hello)')
},
retcode = None
)
Code calling other_method(retcode=50, name='other1') would get a StepTestData:
StepTestData(
placeholder_data = {
('foo_module', 'other_method', 'other1'):
PlaceholderTestData('Test data (hammer time)')
},
retcode = 50
)
You can also use the alternate form of the decorator to mock a RecipeApi
placeholder method with a different name from the decorated RecipeTestApi
method:
class FooTestApi(RecipeTestApi):
@placeholder_step_data('cool_method')
@staticmethod
def blah_method(data, retcode=None, name=None):
return ("Test data (%s)" % data), retcode, name
Code calling blah_method('hello', name='blah1') would get a StepTestData:
StepTestData(
placeholder_data = {
('foo_module', 'cool_method', 'cool1') :
PlaceholderTestData('Test data (hello)')
},
retcode = None
)
Note that the placeholder name (cool_method) is different from the
RecipeTestApi method name (blah_method). This lets you define many
RecipeTestApi helper methods for mocking a single
"""
if callable(func) or isinstance(func, staticmethod):
# Plain decorator:
# @placeholder_step_data
return _placeholder_step_data(func)
else:
# Decorator with placeholder name argument:
# @placeholder_step_data('placeholder_name')
mocked_func_name = func
assert isinstance(mocked_func_name, basestring), (
'placeholder_step_data used as decorator with non-string argument %r'
% mocked_func_name
)
def decorator(func):
return _placeholder_step_data(func, mocked_func_name)
return decorator
def _placeholder_step_data(func, placeholder_name=None):
@static_wraps(func)
def inner(self, *args, **kwargs):
assert isinstance(self, RecipeTestApi)
data = static_call(self, func, *args, **kwargs)
if isinstance(data, StepTestData):
all_data = list(data.placeholder_data.values())
if len(all_data) != 1:
raise ValueError(
'placeholder_step_data is only expecting a single output placeholder '
'datum. Got: %r' % data
)
placeholder_data, retcode = all_data[0], data._retcode
else:
placeholder_data, retcode, name = data
placeholder_data = PlaceholderTestData(data=placeholder_data, name=name)
ret = StepTestData()
final_placeholder_name = placeholder_name
if placeholder_name is None:
final_placeholder_name = inner.__name__
key = (self._module.name, final_placeholder_name, placeholder_data.name)
ret.placeholder_data[key] = placeholder_data
ret.retcode = retcode
return ret
return inner
class RecipeTestApi:
"""Provides testing interface for GenTest method.
There are two primary components to the test api:
* Test data creation methods (test and step_data)
* test_api's from all the modules in DEPS.
Every test in GenTests(api) takes the form:
yield <instance of TestData>
There are 7 basic pieces to TestData:
name - The name of the test.
status - The expected status of the test. Must be one of the statuses
found in the Common.Status enum. Defaults to SUCCESS.
properties - Dictionary which is used as the properties for this test.
You may use protobuf message objects as part of the
dictionary and they'll be expanded to their JSON dictionary
representation.
environ - Single-level key-value dictionary which is used as the
environment variables for this test.
luci_context - Dictionary (mapping from section key to its proto value
serialized in dict) which is used as the initial
LUCI_CONTEXT value for this test.
mod_data - Module-specific testing data (see the platform module for a
good example). This is testing data which is only used once
at the start of the execution of the recipe. Modules should
provide methods to get their specific test information. See
the platform module's test_api for a good example of this.
step_data - Step-specific data. There are two major components to this.
retcode - The return code of the step
placeholder_data - A mapping from placeholder name to the
PlaceholderTestData object in the step.
stdout, stderr - PlaceholderTestData objects for stdout and stderr.
TestData objects are concatenatable, so it's convenient to phrase test cases
as a series of added TestData objects. For example:
DEPS = ['properties', 'platform', 'json']
def GenTests(api):
yield (
api.test('try_win64') +
api.properties.tryserver(power_level=9001) +
api.context.luci_context(
luciexe=sections_pb2.LUCIExe(cache_dir='/a/b/c'),
resultdb=sections_pb2.ResultDB(current_invocation=...)
) +
api.platform('win', 64) +
api.step_data(
'some_step',
api.json.output("bobface", name="a"),
api.json.output({'key': 'value'}, name="b")
)
)
This example would run a single test (named 'try_win64') with the standard
tryserver properties (plus an extra property 'power_level' whose value was
over 9000). The test would run as if it were being run on a 64-bit windows
installation, and the step named 'some_step' would have the json output of
the placeholder with name "a" be mocked to return '"bobface"', and the json
output of the placeholder with name "b" be mocked to return
'{"key": "value"}'. The test would expect the status at the end to be success.
The properties.tryserver() call is documented in the 'properties' module's
test_api.
The platform() call is documented in the 'platform' module's test_api.
The json.output() call is documented in the 'json' module's test_api.
"""
def __init__(self, module: 'recipe_deps.RecipeModule | None'):
"""Note: Injected dependencies are NOT available in __init__()."""
# If we're the 'root' api, inject directly into 'self'.
# Otherwise inject into 'self.m'
self.m = self if module is None else ModuleInjectionSite()
self._module = module
def __getattr__(self, name):
if self._module is None:
raise ModuleInjectionError(
f"Recipe has no dependency {name!r}. (Add it to DEPS?)")
raise AttributeError(f"'RecipeTestApi' object has no attribute {name!r}")
# TODO(iannucci): Fix this and other kwargs to use direct keyword py3 syntax.
@staticmethod
def test(name, *test_data, **kwargs):
"""Returns a new empty TestData with the name filled in.
Use in GenTests:
def GenTests(api):
yield api.test('basic')
yield api.test(
# All test cases have a name; Recipe test full test names always
# look like '<name of recipe>.<test case name>'. Recipe names
# will look like 'path/under/recipes/directory/to/recipe_file'
# or 'recipe_module_name:tests/recipe_file'.
#
# Note that spaces in test names are allowed, but can be annoying to
# work with when e.g. using the `--filter` CLI argument on
# `recipes.py test train` due to extra quoting requirements.
'moreComplex',
# Properties are semi-structured input (~JSON object) which the
# recipe operates on, and can observe with PROPERTIES declarations
# or (less preferred) via the `properties` recipe module.
api.properties(
foo='foo-value',
bar='bar-value',
),
# Here is an example of how to mock the state of the `platform`
# module using its 'test API'. This adjusts state in the `platform`
# module so that when the recipe queries it during this test, it
# will claim that the recipe is operating in a 32bit windows
# environment. Many modules have ways to mock their state, though
# most mocks will appear in the form of `step_data` which mocks the
# output of running one (or more) steps from that module, providing
# mock outputs such as JSON output, return codes, etc.
api.platform.name('win'),
api.platform.bits(32),
# Most recipes keep and review expectation files, but some teams
# use DropExpectation in addition to other additional assertions
# instead.
#
# If you choose to drop expectations, but don't make any other
# assertions, your test will not be doing much aside from
# ensuring that the code does not crash when executed.
api.post_process(<assertion>),
api.post_process(<other assertion>),
api.post_process(post_process.DropExpectation),
# All recipe tests must state the expected outcome of the overall
# recipe by setting the status. By default, tests which omit this
# status will expect a SUCCESS outcome. If your test uses
# `expect_exception`, the test will expect an INFRA_FAILURE outcome.
# The valid statuses here are:
# * SUCCESS
# * FAILURE (recipe ended by explicitly returning this, or raising
# StepFailure)
# * INFRA_FAILURE (recipe ended by explicitly returning this,
# raising InfraFailure, or by raising some other exception)
# * CANCELED (recipe ended by explicitly returning this,
# raising InfraFailure (canceled), or by mocking external
# cancelation)
#
# This is a shorthand for using `api.expect_status(...)` at the very
# beginning of `test_data`. Adding api.expect_status into test_data,
# or using api.expect_exception will override this.
status='FAILURE',
)
Arguments:
name - The name of the test.
*test_data - Additional TestData objects to combine into the returned
TestData. The returned TestData will have each element added (in the
same order they are passed) to it.
"""
from PB.go.chromium.org.luci.buildbucket.proto.common import Status
base = TestData(name)
if 'status' in kwargs:
base.expected_status = Status.Value(kwargs['status'])
ret = sum(test_data, base)
return ret
@staticmethod
def empty_test_data():
"""Returns a TestData with no information.
This is the identity of the + operator for combining TestData.
"""
return TestData()
@staticmethod
def _step_data(name, *data, **kwargs):
"""Returns a new TestData with the mock data filled in for a single step.
Used by step_data and override_step_data.
Args:
name - The name of the step we're providing data for
data - Zero or more StepTestData objects. These may fill in output
placeholder data for zero or more modules, as well as possibly
setting the retcode for this step.
retcode=(int or None) - Override the retcode for this step, even if it
was set by |data|. This must be set as a keyword arg. In the case
of None, if the step completes successfully (not canceled or timed
out), then the step's retcode will be 0.
stdout - StepTestData object with a single output placeholder datum for a
step's stdout.
stderr - StepTestData object with a single output placeholder datum for a
step's stderr.
override=(bool) - This step data completely replaces any previously
generated step data, instead of adding on to it.
times_out_after=(int) - Causes the step to timeout after the given number
of seconds.
cancel=(bool) - Causes the step to indicate that it was canceled.
global_shutdown_event=(None,'before','after') - Causes a global shutdown
either before or after this step runs.
Use in GenTests:
# Hypothetically, suppose that your recipe has default test data for two
# steps 'init' and 'sync' (probably via recipe_api.inject_test_data()).
# For this example, lets say that the default test data looks like:
# api.step_data('init', api.json.output({'some': ["cool", "json"]}))
# AND
# api.step_data('sync', api.json.output({'src': {'rev': 100}}))
# Then, your GenTests code may augment or replace this data like:
def GenTests(api):
yield (
api.test('more') +
api.step_data( # Adds step data for a step with no default test data
'mystep',
api.json.output({'legend': ['...', 'DARY!']})
) +
api.step_data( # Adds retcode to default step_data for this step
'init',
retcode=1
) +
api.override_step_data( # Removes json output and overrides retcode
'sync',
retcode=100
)
)
"""
assert all(isinstance(d, StepTestData) for d in data)
ret = TestData(None)
if data:
ret.step_data[name] = reduce(lambda x,y: x + y, data)
if 'retcode' in kwargs:
ret.step_data[name].retcode = kwargs['retcode']
if 'times_out_after' in kwargs:
ret.step_data[name].times_out_after = kwargs['times_out_after']
if 'cancel' in kwargs:
ret.step_data[name].cancel = kwargs['cancel']
if 'global_shutdown_event' in kwargs:
ret.step_data[name].global_shutdown_event = (
kwargs['global_shutdown_event'])
if 'override' in kwargs:
ret.step_data[name].override = kwargs['override']
for key in ('stdout', 'stderr'):
if key in kwargs:
stdio_test_data = kwargs[key]
assert isinstance(stdio_test_data, StepTestData)
setattr(ret.step_data[name], key, stdio_test_data.unwrap_placeholder())
return ret
def step_data(self, name, *data, **kwargs):
"""See _step_data()"""
return self._step_data(name, *data, **kwargs)
step_data.__doc__ = _step_data.__doc__
def override_step_data(self, name, *data, **kwargs):
"""See _step_data()"""
kwargs['override'] = True
return self._step_data(name, *data, **kwargs)
override_step_data.__doc__ = _step_data.__doc__
def expect_exception(self, exc_type):
"""Indicate that this test should end by raising an exception from RunSteps
whose exception class name is `exc_type`.
Using this will imply an `expect_status` of INFRA_FAILURE - If you want to
override this, add an explicit expect_status after this expect_exception.
Args:
* exc_type - String value of exception name.
Returns `TestData` which can be added to other TestData prior to yielding
from GenTests, or can be included as `*test_data` to the `test(name, ...)`
function in RecipeTestApi.
"""
from PB.go.chromium.org.luci.buildbucket.proto.common import Status
ret = TestData()
ret.expect_exception(exc_type)
ret.expected_status = Status.INFRA_FAILURE
return ret
def expect_status(self, status):
"""Indicate that this test should have an overall status of `status`.
Args:
* status - String value of Buildbucket Common Status (i.e. SUCCESS,
FAILURE, INFRA_FAILURE, CANCELED)
Returns `TestData` which can be added to other TestData prior to yielding
from GenTests, or can be included as `*test_data` to the `test(name, ...)`
function in RecipeTestApi.
"""
from PB.go.chromium.org.luci.buildbucket.proto.common import Status
ret = TestData()
ret.expected_status = Status.Value(status)
return ret
def post_process(self, func, *args, **kwargs):
"""Calling this adds a post-processing hook for this test's expectations.
`func` should be a callable whose signature is in the form of:
func(check, step_odict, *args, **kwargs) -> (step_odict or None)
Where:
* `step_odict` is an ordered dictionary of `Step` objects (see `Step` in
//recipe_engine/post_process_inputs.py). The final item will have the key
'$result' and will be a dictionary describing the final result of the
recipe rather than a `Step`.
* `check` is a semi-magical function which you can use to test things.
Using `check` will allow you to see all the violated assertions from your
post_process functions simultaneously. Always call `check` directly (i.e.
with parens) to produce helpful check messages. `check` also has a second
form that takes a human hint to print when the `check` fails. Hints should
be written as the ___ in the sentence 'check that ___.'. Essentially,
check has the function signatures:
`def check(<bool expression>) #=> bool`
`def check(hint, <bool expression>) #=> bool`
Check returns True iff the boolean expression was True.
If the hint is omitted, then the boolean expression itself becomes the
hint when the check failure message is printed.
Note that check DOES NOT stop your function. It is not an assert. Your
function will continue to execute after invoking the check function. If
the boolean expression is False, the check will produce a helpful error
message and cause the test case to fail.
* args and kwargs are optional, and completely up to your implementation.
They will be passed straight through to your function, and are provided to
eliminate an extra `lambda` if your function needs to take additional
inputs.
If a KeyError is raised, it will be caught and a check failure will be
emitted with details about the expression that resulted in the KeyError and
post-processing will continue at the next hook. This allows hooks to assume
that a key is present without sacrificing debuggability. If any other
exception is raised, the exception will be printed and the post-processing
chain will be halted.
The function must return either `None`, or it may return a filtered subset
of step_odict (e.g. omitting some steps and/or step fields). This will be
the new value of step_odict for the test. Returning an empty dict or
OrderedDict will remove the expectations from disk altogether. Returning
`None` (Python's implicit default return value) is equivalent to returning
the unmodified step_odict. To use lambdas that simply call `check`, use
`post_check` instead of `post_process`.
Steps can be returned either as a `Step` or as a dictionary obtained by
calling `to_step_dict` on a `Step`. It is fine to mix representations
between different steps. Fields can be removed from a field either by
setting them to their default value or removing the item for the field when
returning a dict. 'name' will always be preserved in every step, even if you
remove it.
Calling post_process multiple times will apply each function in order,
chaining the output of one function to the input of the next function. This
is intended to be use to compose the effects of multiple re-usable
post-processing functions, some of which are pre-defined in
`recipe_engine.post_process` which you can import in your recipe.
Example:
from recipe_engine.post_process import (Filter, DoesNotRun,
DropExpectation)
def GenTests(api):
yield api.test('no post processing')
yield (api.test('only thing_step')
+ api.post_process(Filter('thing_step'))
)
tstepFilt = Filter()
tstepFilt = tstepFilt.include('thing_step', 'cmd')
yield (api.test('only thing_step\'s cmd')
+ api.post_process(tstepFilt)
)
yield (api.test('assert bob_step does not run')
+ api.post_process(DoesNotRun, 'bob_step')
)
yield (api.test('only care one step and the result')
+ api.post_process(Filter('one_step', '$result'))
)
def assertStuff(check, step_odict, to_check):
check(to_check in step_odict['step_name'].cmd)
yield (api.test('assert something and have NO expectation file')
+ api.post_process(assertStuff, 'to_check_arg')
+ api.post_process(DropExpectation)
)
"""
ret = TestData()
_, filename, lineno, _, _, _ = inspect.stack()[1]
context = PostprocessHookContext(func, args, kwargs, filename, lineno)
ret.post_process(func, args, kwargs, context)
return ret
def post_check(self, func, *args, **kwargs):
"""Add a check-only post-processing hook.
See `post_process` for information on the arguments and behavior. The
difference between `post_check` and `post_process` is the return value of
`func` is ignored, so it's not possible for a hook added using `post_check`
to propagate changes in the steps dictionary to later hooks. This enables
the use of lambdas for performing simple checks.
Example:
from recipe_engine.post_process import DoesNotRun, DropExpectation
def GenTests(api):
yield (api.test('lambda-check')
+ api.post_check(lambda check, steps: check('foo' not in steps))
+ api.post_process(DropExpectation)
)
yield (api.test('reuse-existing-hook')
+ api.post_check(DoesNotRun, 'foo')
+ api.post_process(DropExpectation)
)
"""
def post_check(check, steps, f, *args, **kwargs):
f(check, steps, *args, **kwargs)
ret = TestData()
_, filename, lineno, _, _, _ = inspect.stack()[1]
context = PostprocessHookContext(func, args, kwargs, filename, lineno)
ret.post_process(post_check, (func,) + args, kwargs, context)
return ret