From 2300b66c09ac853fbf332ad1bbdd291d6d0c1d87 Mon Sep 17 00:00:00 2001 From: MarkKoz Date: Sun, 16 Aug 2020 12:27:24 -0700 Subject: Tests: optionally prevent autospec helper from passing mocks Not everything that's decorated needs the mocks that are patched. Being required to add the args to the test function anyway is annoying. It's especially bad if trying to decorate an entire test suite, as every test would need the args. Move the definition to a separate module to keep things cleaner. --- tests/_autospec.py | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) create mode 100644 tests/_autospec.py (limited to 'tests/_autospec.py') diff --git a/tests/_autospec.py b/tests/_autospec.py new file mode 100644 index 000000000..ee2fc1973 --- /dev/null +++ b/tests/_autospec.py @@ -0,0 +1,64 @@ +import contextlib +import functools +import unittest.mock +from typing import Callable + + +@functools.wraps(unittest.mock._patch.decoration_helper) +@contextlib.contextmanager +def _decoration_helper(self, patched, args, keywargs): + """Skips adding patchings as args if their `dont_pass` attribute is True.""" + # Don't ask what this does. It's just a copy from stdlib, but with the dont_pass check added. + extra_args = [] + with contextlib.ExitStack() as exit_stack: + for patching in patched.patchings: + arg = exit_stack.enter_context(patching) + if not getattr(patching, "dont_pass", False): + # Only add the patching as an arg if dont_pass is False. + if patching.attribute_name is not None: + keywargs.update(arg) + elif patching.new is unittest.mock.DEFAULT: + extra_args.append(arg) + + args += tuple(extra_args) + yield args, keywargs + + +@functools.wraps(unittest.mock._patch.copy) +def _copy(self): + """Copy the `dont_pass` attribute along with the standard copy operation.""" + patcher_copy = _copy.original(self) + patcher_copy.dont_pass = getattr(self, "dont_pass", False) + return patcher_copy + + +# Monkey-patch the patcher class :) +_copy.original = unittest.mock._patch.copy +unittest.mock._patch.copy = _copy +unittest.mock._patch.decoration_helper = _decoration_helper + + +def autospec(target, *attributes: str, pass_mocks: bool = True, **patch_kwargs) -> Callable: + """ + Patch multiple `attributes` of a `target` with autospecced mocks and `spec_set` as True. + + If `pass_mocks` is True, pass the autospecced mocks as arguments to the decorated object. + """ + # Caller's kwargs should take priority and overwrite the defaults. + kwargs = dict(spec_set=True, autospec=True) + kwargs.update(patch_kwargs) + + # Import the target if it's a string. + # This is to support both object and string targets like patch.multiple. + if type(target) is str: + target = unittest.mock._importer(target) + + def decorator(func): + for attribute in attributes: + patcher = unittest.mock.patch.object(target, attribute, **kwargs) + if not pass_mocks: + # A custom attribute to keep track of which patchings should be skipped. + patcher.dont_pass = True + func = patcher(func) + return func + return decorator -- cgit v1.2.3