Fix issues with attr code. (#4628)

More meesages, no unbound types, better tests.

In response to comments in #4607

Author: euresti

mypy/plugins/attrs.py

@@ -64,11 +64,13 @@ def argument(self, ctx: 'mypy.plugin.ClassDefContext') -> Argument:
                     and converter.type
                     and isinstance(converter.type, CallableType)
                     and converter.type.arg_types):
-                init_type = converter.type.arg_types[0]
+                init_type = ctx.api.anal_type(converter.type.arg_types[0])
             else:
+                ctx.api.fail("Cannot determine type of converter function", self.context)
                 init_type = AnyType(TypeOfAny.from_error)
         elif self.converter_name == '':
             # This means we had a converter but it's not of a type we can infer.
+            # Error was shown in _get_converter_name
             init_type = AnyType(TypeOfAny.from_error)
 
         if init_type is None:
@@ -317,12 +319,13 @@ def _attribute_from_attrib_maker(ctx: 'mypy.plugin.ClassDefContext',
     elif convert:
         ctx.api.fail("convert is deprecated, use converter", rvalue)
         converter = convert
-    converter_name = _get_converter_name(converter)
+    converter_name = _get_converter_name(ctx, converter)
 
     return Attribute(lhs.name, ctx.cls.info, attr_has_default, init, converter_name, stmt)
 
 
-def _get_converter_name(converter: Optional[Expression]) -> Optional[str]:
+def _get_converter_name(ctx: 'mypy.plugin.ClassDefContext',
+                        converter: Optional[Expression]) -> Optional[str]:
     """Return the full name of the converter if it exists and is a simple function."""
     # TODO: Support complex converters, e.g. lambdas, calls, etc.
     if converter:
@@ -334,6 +337,10 @@ def _get_converter_name(converter: Optional[Expression]) -> Optional[str]:
                 and converter.node.type.arg_types):
             return converter.node.fullname()
         # Signal that we have an unsupported converter.
+        ctx.api.fail(
+            "Unsupported converter function, only named functions are currently supported",
+            converter
+        )
         return ''
     return None
 

test-data/unit/check-attr.test

@@ -542,9 +542,9 @@ def factory(default: int):
    ...
 @attr.s
 class C:
-    x: str = attr.ib(converter=thing.do_it)
-    y: str = attr.ib(converter=lambda x: x)
-    z: str = attr.ib(converter=factory(8))
+    x: str = attr.ib(converter=thing.do_it)  # E: Unsupported converter function, only named functions are currently supported
+    y: str = attr.ib(converter=lambda x: x)  # E: Unsupported converter function, only named functions are currently supported
+    z: str = attr.ib(converter=factory(8))  # E: Unsupported converter function, only named functions are currently supported
 reveal_type(C)  # E: Revealed type is 'def (x: Any, y: Any, z: Any) -> __main__.C'
 [builtins fixtures/list.pyi]
 

test-data/unit/check-incremental.test

@@ -3766,19 +3766,53 @@ main:2: error: Revealed type is 'def (x: Union[builtins.int, builtins.None]) ->
 main:2: error: Revealed type is 'def (x: Union[builtins.int, builtins.None]) -> a.a.A'
 
 [case testAttrsIncrementalConverterManyStyles]
+import a
+[file a.py]
 from base import Base
-reveal_type(Base)
+Base(1, 'str', True)
+Base(None, None, None)
+
 from subclass import A, B
-reveal_type(A)
-reveal_type(B)
+A(1, 'str', True)
+A(None, None, None)
+B(1, 'str', True, 1, 'str', True)
+B(None, None, None, None, None, None)
+
+from submodule.base import SubBase
+SubBase(1, 'str', True)
+SubBase(None, None, None)
+
+from submodule.subclass import AA, BB
+AA(1, 'str', True)
+AA(None, None, None)
+BB(1, 'str', True, 1, 'str', True)
+BB(None, None, None, None, None, None)
+
+from submodule.subsubclass import SubAA, SubBB
+SubAA(1, 'str', True)
+SubAA(None, None, None)
+SubBB(1, 'str', True, 1, 'str', True)
+SubBB(None, None, None, None, None, None)
+
+[file a.py.2]
+# Now with errors.
+from base import Base
+Base(1, 1, True)
+
+from subclass import A, B
+A(1, 1, True)
+B(1, 'str', True, 1, 1, True)
+
 from submodule.base import SubBase
-reveal_type(SubBase)
+SubBase(1, 1, True)
+
 from submodule.subclass import AA, BB
-reveal_type(AA)
-reveal_type(BB)
+AA(1, 1, True)
+BB(1, 'str', True, 1, 1, True)
+
 from submodule.subsubclass import SubAA, SubBB
-reveal_type(SubAA)
-reveal_type(SubBB)
+SubAA(1, 1, True)
+SubBB(1, 'str', True, 1, 1, True)
 
 [file foo.py]
 from typing import Optional
@@ -3866,23 +3900,15 @@ class SubBB(SubBase):
     zz: bool = attr.ib(converter=bar.maybe_bool)
 [builtins fixtures/list.pyi]
 [out1]
-main:2: error: Revealed type is 'def (x: Union[builtins.int, builtins.None], y: Union[builtins.str, builtins.None], z: Union[builtins.bool, builtins.None]) -> base.Base'
-main:4: error: Revealed type is 'def (x: Union[builtins.int, builtins.None], y: Union[builtins.str, builtins.None], z: Union[builtins.bool, builtins.None]) -> subclass.A'
-main:5: error: Revealed type is 'def (x: Union[builtins.int, builtins.None], y: Union[builtins.str, builtins.None], z: Union[builtins.bool, builtins.None], xx: Union[builtins.int, builtins.None], yy: Union[builtins.str, builtins.None], zz: Union[builtins.bool, builtins.None]) -> subclass.B'
-main:7: error: Revealed type is 'def (x: Union[builtins.int, builtins.None], y: Union[builtins.str, builtins.None], z: Union[builtins.bool, builtins.None]) -> submodule.base.SubBase'
-main:9: error: Revealed type is 'def (x: Union[builtins.int, builtins.None], y: Union[builtins.str, builtins.None], z: Union[builtins.bool, builtins.None]) -> submodule.subclass.AA'
-main:10: error: Revealed type is 'def (x: Union[builtins.int, builtins.None], y: Union[builtins.str, builtins.None], z: Union[builtins.bool, builtins.None], xx: Union[builtins.int, builtins.None], yy: Union[builtins.str, builtins.None], zz: Union[builtins.bool, builtins.None]) -> submodule.subclass.BB'
-main:12: error: Revealed type is 'def (x: Union[builtins.int, builtins.None], y: Union[builtins.str, builtins.None], z: Union[builtins.bool, builtins.None]) -> submodule.subsubclass.SubAA'
-main:13: error: Revealed type is 'def (x: Union[builtins.int, builtins.None], y: Union[builtins.str, builtins.None], z: Union[builtins.bool, builtins.None], xx: Union[builtins.int, builtins.None], yy: Union[builtins.str, builtins.None], zz: Union[builtins.bool, builtins.None]) -> submodule.subsubclass.SubBB'
-[out2]
-main:2: error: Revealed type is 'def (x: Union[builtins.int, builtins.None], y: Union[builtins.str, builtins.None], z: Union[builtins.bool, builtins.None]) -> base.Base'
-main:4: error: Revealed type is 'def (x: Union[builtins.int, builtins.None], y: Union[builtins.str, builtins.None], z: Union[builtins.bool, builtins.None]) -> subclass.A'
-main:5: error: Revealed type is 'def (x: Union[builtins.int, builtins.None], y: Union[builtins.str, builtins.None], z: Union[builtins.bool, builtins.None], xx: Union[builtins.int, builtins.None], yy: Union[builtins.str, builtins.None], zz: Union[builtins.bool, builtins.None]) -> subclass.B'
-main:7: error: Revealed type is 'def (x: Union[builtins.int, builtins.None], y: Union[builtins.str, builtins.None], z: Union[builtins.bool, builtins.None]) -> submodule.base.SubBase'
-main:9: error: Revealed type is 'def (x: Union[builtins.int, builtins.None], y: Union[builtins.str, builtins.None], z: Union[builtins.bool, builtins.None]) -> submodule.subclass.AA'
-main:10: error: Revealed type is 'def (x: Union[builtins.int, builtins.None], y: Union[builtins.str, builtins.None], z: Union[builtins.bool, builtins.None], xx: Union[builtins.int, builtins.None], yy: Union[builtins.str, builtins.None], zz: Union[builtins.bool, builtins.None]) -> submodule.subclass.BB'
-main:12: error: Revealed type is 'def (x: Union[builtins.int, builtins.None], y: Union[builtins.str, builtins.None], z: Union[builtins.bool, builtins.None]) -> submodule.subsubclass.SubAA'
-main:13: error: Revealed type is 'def (x: Union[builtins.int, builtins.None], y: Union[builtins.str, builtins.None], z: Union[builtins.bool, builtins.None], xx: Union[builtins.int, builtins.None], yy: Union[builtins.str, builtins.None], zz: Union[builtins.bool, builtins.None]) -> submodule.subsubclass.SubBB'
+[out2]
+tmp/a.py:3: error: Argument 2 to "Base" has incompatible type "int"; expected "Optional[str]"
+tmp/a.py:6: error: Argument 2 to "A" has incompatible type "int"; expected "Optional[str]"
+tmp/a.py:7: error: Argument 5 to "B" has incompatible type "int"; expected "Optional[str]"
+tmp/a.py:10: error: Argument 2 to "SubBase" has incompatible type "int"; expected "Optional[str]"
+tmp/a.py:13: error: Argument 2 to "AA" has incompatible type "int"; expected "Optional[str]"
+tmp/a.py:14: error: Argument 5 to "BB" has incompatible type "int"; expected "Optional[str]"
+tmp/a.py:17: error: Argument 2 to "SubAA" has incompatible type "int"; expected "Optional[str]"
+tmp/a.py:18: error: Argument 5 to "SubBB" has incompatible type "int"; expected "Optional[str]"
 
 [case testAttrsIncrementalConverterInFunction]
 import attr
@@ -3895,9 +3921,9 @@ def foo() -> None:
     reveal_type(A)
 [builtins fixtures/list.pyi]
 [out1]
-main:8: error: Revealed type is 'def (x: str?) -> __main__.A@5'
+main:8: error: Revealed type is 'def (x: builtins.str) -> __main__.A@5'
 [out2]
-main:8: error: Revealed type is 'def (x: str?) -> __main__.A@5'
+main:8: error: Revealed type is 'def (x: builtins.str) -> __main__.A@5'
 
 [case testAttrsIncrementalConverterInSubmoduleForwardRef]
 from a.a import A