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"""
Ensure objects defined in gitlab.v4.objects have REST* as last item in class
definition
Original notes by John L. Villalovos
An example of an incorrect definition:
class ProjectPipeline(RESTObject, RefreshMixin, ObjectDeleteMixin):
^^^^^^^^^^ This should be at the end.
Correct way would be:
class ProjectPipeline(RefreshMixin, ObjectDeleteMixin, RESTObject):
Correctly at the end ^^^^^^^^^^
Why this is an issue:
When we do type-checking for gitlab/mixins.py we make RESTObject or
RESTManager the base class for the mixins
Here is how our classes look when type-checking:
class RESTObject:
def __init__(self, manager: "RESTManager", attrs: Dict[str, Any]) -> None:
...
class Mixin(RESTObject):
...
# Wrong ordering here
class Wrongv4Object(RESTObject, RefreshMixin):
...
If we actually ran this in Python we would get the following error:
class Wrongv4Object(RESTObject, Mixin):
TypeError: Cannot create a consistent method resolution
order (MRO) for bases RESTObject, Mixin
When we are type-checking it fails to understand the class Wrongv4Object
and thus we can't type check it correctly.
Almost all classes in gitlab/v4/objects/*py were already correct before this
check was added.
"""
import inspect
import pytest
import gitlab.v4.objects
def test_show_issue() -> None:
"""Test case to demonstrate the TypeError that occurs"""
class RESTObject:
def __init__(self, manager: str, attrs: int) -> None:
...
class Mixin(RESTObject):
...
with pytest.raises(TypeError) as exc_info:
# Wrong ordering here
class Wrongv4Object(RESTObject, Mixin): # type: ignore
...
# The error message in the exception should be:
# TypeError: Cannot create a consistent method resolution
# order (MRO) for bases RESTObject, Mixin
# Make sure the exception string contains "MRO"
assert "MRO" in exc_info.exconly()
# Correctly ordered class, no exception
class Correctv4Object(Mixin, RESTObject):
...
def test_mros() -> None:
"""Ensure objects defined in gitlab.v4.objects have REST* as last item in
class definition.
We do this as we need to ensure the MRO (Method Resolution Order) is
correct.
"""
failed_messages = []
for module_name, module_value in inspect.getmembers(gitlab.v4.objects):
if not inspect.ismodule(module_value):
# We only care about the modules
continue
# Iterate through all the classes in our module
for class_name, class_value in inspect.getmembers(module_value):
if not inspect.isclass(class_value):
continue
# Ignore imported classes from gitlab.base
if class_value.__module__ == "gitlab.base":
continue
mro = class_value.mro()
# We only check classes which have a 'gitlab.base' class in their MRO
has_base = False
for count, obj in enumerate(mro, start=1):
if obj.__module__ == "gitlab.base":
has_base = True
base_classname = obj.__name__
if has_base:
filename = inspect.getfile(class_value)
# NOTE(jlvillal): The very last item 'mro[-1]' is always going
# to be 'object'. That is why we are checking 'mro[-2]'.
if mro[-2].__module__ != "gitlab.base":
failed_messages.append(
(
f"class definition for {class_name!r} in file {filename!r} "
f"must have {base_classname!r} as the last class in the "
f"class definition"
)
)
failed_msg = "\n".join(failed_messages)
assert not failed_messages, failed_msg
|
