Now TypeInfo.get_method also returns Decorator nodes

[sobolevn]

Closes #10409

[JukkaL]

Thanks for the PR! Left a few comments and a question.

[sobolevn]

This commit just addresses the code review: 28d950d

Now, I am going to change how .get_method() is defined. Let's see what will happen!

[sobolevn]

I am running self-check with the only change: def get_method(self) -> Union[FuncBase, Decorator, None]

» python runtests.py self
run self: ['/Users/sobolev/Desktop/mypy/.venv/bin/python', '-m', 'mypy', '--config-file', 'mypy_self_check.ini', '-p', 'mypy']
mypy/subtypes.py:618: error: Item "Decorator" of "Union[FuncBase, Decorator]" has no
attribute "is_property"  [union-attr]
            if method.is_property:
               ^
mypy/subtypes.py:623: error: Argument 1 to "find_node_type" has incompatible type
"Union[FuncBase, Decorator]"; expected "Union[Var, FuncBase]"  [arg-type]
            return find_node_type(method, itype, subtype)
                                  ^
mypy/subtypes.py:644: error: Argument 1 to "find_node_type" has incompatible type
"Union[FuncBase, Decorator]"; expected "Union[Var, FuncBase]"  [arg-type]
    ...         getattr_type = get_proper_type(find_node_type(method, itype, subtyp...
                                                              ^
mypy/subtypes.py:667: error: Item "Decorator" of "Union[FuncBase, Decorator]" has no
attribute "is_property"  [union-attr]
            if method.is_property:
               ^
mypy/checkmember.py:199: error: Item "Decorator" of "Union[FuncBase, Decorator]" has
no attribute "is_property"  [union-attr]
            if method.is_property:
               ^
mypy/checkmember.py:205: error: Argument 1 to "function_type" has incompatible type
"Union[FuncBase, Decorator]"; expected "FuncBase"  [arg-type]
            signature = function_type(method, mx.builtin_type('builtins.function...
                                      ^
mypy/checkmember.py:216: error: Item "Decorator" of "Union[FuncBase, Decorator]" has
no attribute "is_class"  [union-attr]
    ...     signature = check_self_arg(signature, dispatched_type, method.is_class,
                                                                   ^
mypy/checkmember.py:218: error: Item "Decorator" of "Union[FuncBase, Decorator]" has
no attribute "is_class"  [union-attr]
    ...gnature = bind_self(signature, mx.self_type, is_classmethod=method.is_class)
                                                                   ^
mypy/checkmember.py:392: error: Argument 1 to "function_type" has incompatible type
"Union[FuncBase, Decorator]"; expected "FuncBase"  [arg-type]
                        function = function_type(method, mx.builtin_type('builti...
                                                 ^
mypy/checkmember.py:409: error: Argument 1 to "function_type" has incompatible type
"Union[FuncBase, Decorator]"; expected "FuncBase"  [arg-type]
                    setattr_func = function_type(setattr_meth, mx.builtin_type('...
                                                 ^
mypy/checkmember.py:479: error: Argument 1 to "function_type" has incompatible type
"Union[FuncBase, Decorator]"; expected "FuncBase"  [arg-type]
        function = function_type(dunder_get, builtin_type('builtins.function'))
                                 ^
mypy/checker.py:3125: error: Argument 1 to "function_type" has incompatible type
"Union[FuncBase, Decorator]"; expected "FuncBase"  [arg-type]
            function = function_type(dunder_set, self.named_type('builtins.funct...
                                     ^
mypy/checker.py:6042: error: Never apply isinstance() to unexpanded types; use
mypy.types.get_proper_type() first  [misc]
                if isinstance(method.type, Overloaded):
                   ^
mypy/checker.py:6042: note: If you pass on the original type after the check, always use its unexpanded version
Found 13 errors in 3 files (checked 164 source files)

FAILED: self

Looks doable! 👍

[sobolevn]

This is now pretty big:

1. I've changed all parts where .get_method() was used to work with decorators, including

• Protocol checks with find_member
• is_untyped_decorator function in checker
• checkmember

2. I've changed how type was inferenced from decorators, so for example decorating x.__getattr__ actually changes what type is inferred for x.attr
3. I've added new tests for each individual change, improved some existing ones

[sobolevn]

Now plugin hooks are also triggered for non callable types as well.

[sobolevn]

Ok, looks like mypyc also need to be fixed. It is failing right now https://github.com/python/mypy/runs/3673913236

@JukkaL any tips on that? I haven't used mypyc 😞

[sobolevn]

mypyc didn't like this code:

if isinstance(node, (FuncBase, Decorator)):
    return node

But, it accepted this code:

if isinstance(node, FuncBase):
    return node
elif isinstance(node, Decorator):
    return node

Seems like a bug in mypyc to me.

[JukkaL]

I think I found a reproducer for the mypyc issue: mypyc/mypyc#892

[sobolevn]

@JukkaL awesome! Thanks! Is there anything else left to do here?

[sobolevn]

Rebased on master 🚆

[sobolevn]

@JukkaL any chance to get this merged? 🙂

[sobolevn]

@JukkaL rebased once again 🙂

I will also friendly ping @hauntsaninja as well.

[97littleleaf11]

Using MemberContext in analyze_descriptor_access is a good refactoring!

[JukkaL]

Thanks for the PR, this looks solid! I like how this fixes many related issues.

[JukkaL]

Code quite similar to this if/else gets repeated several times. I wonder if it would be possible to abstract it into a helper function, for example? If this sounds like a feasible idea, it could be a nice follow-up PR.

[sobolevn]

@JukkaL thank you! I will think about a helper function 🙂