|
| 1 | +""" |
| 2 | +Ensure objects defined in gitlab.v4.objects have REST* as last item in class |
| 3 | +definition |
| 4 | +
|
| 5 | +Original notes by John L. Villalovos |
| 6 | +
|
| 7 | +An example of an incorrect definition: |
| 8 | + class ProjectPipeline(RESTObject, RefreshMixin, ObjectDeleteMixin): |
| 9 | + ^^^^^^^^^^ This should be at the end. |
| 10 | +
|
| 11 | +Correct way would be: |
| 12 | + class ProjectPipeline(RefreshMixin, ObjectDeleteMixin, RESTObject): |
| 13 | + Correctly at the end ^^^^^^^^^^ |
| 14 | +
|
| 15 | +
|
| 16 | +Why this is an issue: |
| 17 | +
|
| 18 | + When we do type-checking for gitlab/mixins.py we make RESTObject or |
| 19 | + RESTManager the base class for the mixins |
| 20 | +
|
| 21 | + Here is how our classes look when type-checking: |
| 22 | +
|
| 23 | + class RESTObject(object): |
| 24 | + def __init__(self, manager: "RESTManager", attrs: Dict[str, Any]) -> None: |
| 25 | + ... |
| 26 | +
|
| 27 | + class Mixin(RESTObject): |
| 28 | + ... |
| 29 | +
|
| 30 | + # Wrong ordering here |
| 31 | + class Wrongv4Object(RESTObject, RefreshMixin): |
| 32 | + ... |
| 33 | +
|
| 34 | + If we actually ran this in Python we would get the following error: |
| 35 | + class Wrongv4Object(RESTObject, Mixin): |
| 36 | + TypeError: Cannot create a consistent method resolution |
| 37 | + order (MRO) for bases RESTObject, Mixin |
| 38 | +
|
| 39 | + When we are type-checking it fails to understand the class Wrongv4Object |
| 40 | + and thus we can't type check it correctly. |
| 41 | +
|
| 42 | +Almost all classes in gitlab/v4/objects/*py were already correct before this |
| 43 | +check was added. |
| 44 | +""" |
| 45 | +import inspect |
| 46 | + |
| 47 | +import pytest |
| 48 | + |
| 49 | +import gitlab.v4.objects |
| 50 | + |
| 51 | + |
| 52 | +def test_show_issue(): |
| 53 | + """Test case to demonstrate the TypeError that occurs""" |
| 54 | + |
| 55 | + class RESTObject(object): |
| 56 | + def __init__(self, manager: str, attrs: int) -> None: |
| 57 | + ... |
| 58 | + |
| 59 | + class Mixin(RESTObject): |
| 60 | + ... |
| 61 | + |
| 62 | + with pytest.raises(TypeError) as exc_info: |
| 63 | + # Wrong ordering here |
| 64 | + class Wrongv4Object(RESTObject, Mixin): |
| 65 | + ... |
| 66 | + |
| 67 | + # The error message in the exception should be: |
| 68 | + # TypeError: Cannot create a consistent method resolution |
| 69 | + # order (MRO) for bases RESTObject, Mixin |
| 70 | + |
| 71 | + # Make sure the exception string contains "MRO" |
| 72 | + assert "MRO" in exc_info.exconly() |
| 73 | + |
| 74 | + # Correctly ordered class, no exception |
| 75 | + class Correctv4Object(Mixin, RESTObject): |
| 76 | + ... |
| 77 | + |
| 78 | + |
| 79 | +def test_mros(): |
| 80 | + """Ensure objects defined in gitlab.v4.objects have REST* as last item in |
| 81 | + class definition. |
| 82 | +
|
| 83 | + We do this as we need to ensure the MRO (Method Resolution Order) is |
| 84 | + correct. |
| 85 | + """ |
| 86 | + |
| 87 | + failed_messages = [] |
| 88 | + for module_name, module_value in inspect.getmembers(gitlab.v4.objects): |
| 89 | + if not inspect.ismodule(module_value): |
| 90 | + # We only care about the modules |
| 91 | + continue |
| 92 | + # Iterate through all the classes in our module |
| 93 | + for class_name, class_value in inspect.getmembers(module_value): |
| 94 | + if not inspect.isclass(class_value): |
| 95 | + continue |
| 96 | + |
| 97 | + # Ignore imported classes from gitlab.base |
| 98 | + if class_value.__module__ == "gitlab.base": |
| 99 | + continue |
| 100 | + |
| 101 | + mro = class_value.mro() |
| 102 | + |
| 103 | + # We only check classes which have a 'gitlab.base' class in their MRO |
| 104 | + has_base = False |
| 105 | + for count, obj in enumerate(mro, start=1): |
| 106 | + if obj.__module__ == "gitlab.base": |
| 107 | + has_base = True |
| 108 | + base_classname = obj.__name__ |
| 109 | + if has_base: |
| 110 | + filename = inspect.getfile(class_value) |
| 111 | + # NOTE(jlvillal): The very last item 'mro[-1]' is always going |
| 112 | + # to be 'object'. That is why we are checking 'mro[-2]'. |
| 113 | + if mro[-2].__module__ != "gitlab.base": |
| 114 | + failed_messages.append( |
| 115 | + ( |
| 116 | + f"class definition for {class_name!r} in file {filename!r} " |
| 117 | + f"must have {base_classname!r} as the last class in the " |
| 118 | + f"class definition" |
| 119 | + ) |
| 120 | + ) |
| 121 | + failed_msg = "\n".join(failed_messages) |
| 122 | + assert not failed_messages, failed_msg |
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