Vague error message when the docstring of a member is dynamically assigned.

[austinyu]

Consider this simple example

class A:
    def __init__(self):
        pass

    def method_a(self):
        """This is method_a"""

class B:
    def __init__(self):
        pass

    def method_b(self):
        pass

    method_b.__doc__ = A.method_a.__doc__

When I run pydoclint, I get this long traceback

  File "...\.venv\Lib\site-packages\click\core.py", line 1157, in __call__
    return self.main(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "...\.venv\Lib\site-packages\click\core.py", line 1078, in main
    rv = self.invoke(ctx)
         ^^^^^^^^^^^^^^^^
  File "...\.venv\Lib\site-packages\click\core.py", line 1434, in invoke
    return ctx.invoke(self.callback, **ctx.params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "...\.venv\Lib\site-packages\click\core.py", line 783, in invoke
    return __callback(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "...\.venv\Lib\site-packages\click\decorators.py", line 33, in new_func
    return f(get_current_context(), *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "...\.venv\Lib\site-packages\pydoclint\main.py", line 393, in main
    violationsInAllFiles: Dict[str, List[Violation]] = _checkPaths(
                                                       ^^^^^^^^^^^^
  File "...\.venv\Lib\site-packages\pydoclint\main.py", line 564, in _checkPaths
    violationsInThisFile: List[Violation] = _checkFile(
                                            ^^^^^^^^^^^
  File "...\.venv\Lib\site-packages\pydoclint\main.py", line 645, in _checkFile
    visitor.visit(tree)
  File "...\AppData\Local\Programs\Python\Python312\Lib\ast.py", 
line 407, in visit
    return visitor(node)
           ^^^^^^^^^^^^^
  File "...\AppData\Local\Programs\Python\Python312\Lib\ast.py", 
line 415, in generic_visit
    self.visit(item)
  File "...\AppData\Local\Programs\Python\Python312\Lib\ast.py", 
line 407, in visit
    return visitor(node)
           ^^^^^^^^^^^^^
  File "...\.venv\Lib\site-packages\pydoclint\visitor.py", line 101, in visit_ClassDef
    checkClassAttributesAgainstClassDocstring(
  File "...\.venv\Lib\site-packages\pydoclint\utils\visitor_helper.py", line 44, in checkClassAttributesAgainstClassDocstring
    actualArgs: ArgList = extractClassAttributesFromNode(
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "...\.venv\Lib\site-packages\pydoclint\utils\visitor_helper.py", line 167, in extractClassAttributesFromNode
    atl.extend(ArgList.fromAstAssign(itm).infoList)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "...\.venv\Lib\site-packages\pydoclint\utils\arg.py", line 224, in fromAstAssign
    raise InternalError(
pydoclint.utils.internal_error.InternalError: astAssign.targets[0] is of type <class 'ast.Attribute'>

I have a workaround here.

class A:
    def __init__(self):
        pass

    def method_a(self):
        """This is method_a"""

class B:
    def __init__(self):
        pass

    def method_b(self):
        pass

B.method_b.__doc__ = A.method_a.__doc__

However, I think fixing this error should not be that challenging. As far as I understand, we need another case for Attribute here
pydoclint\utils\arg.py", line 224

    @classmethod
    def fromAstAssign(cls, astAssign: ast.Assign) -> 'ArgList':
        """Construct an ArgList from variable declaration/assignment"""
        infoList: List[Arg] = []
        for i, target in enumerate(astAssign.targets):
            if isinstance(target, ast.Tuple):  # such as `a, b = c, d = 1, 2`
                for j, item in enumerate(target.elts):
                    if not isinstance(item, ast.Name):
                        raise InternalError(
                            f'astAssign.targets[{i}].elts[{j}] is of'
                            f' type {type(item)} instead of ast.Name'
                        )

                    infoList.append(Arg(name=item.id, typeHint=''))
            elif isinstance(target, ast.Name):  # such as `a = 1` or `a = b = 2`
                infoList.append(Arg(name=target.id, typeHint=''))
            else:
                raise InternalError(
                    f'astAssign.targets[{i}] is of type {type(target)}'
                )

        return ArgList(infoList=infoList)
     ```