improve tests

Author: ikonst

test-data/unit/check-attr.test

@@ -1896,21 +1896,47 @@ c = attr.evolve(c, b=Other())  # E: Argument "b" to "evolve" has incompatible ty
 c = attr.evolve(c, name=42)  # E: Argument "name" to "evolve" has incompatible type "int"; expected "str"
 c = attr.evolve(c, foobar=42)  # E: Unexpected keyword argument "foobar" for "evolve"
 
+# test passing instance as 'inst' kw
+c = attr.evolve(inst=c, name='foo')
+
+# test determining type of first argument's expression from something that's not NameExpr
 def f() -> C:
     return c
 
-
-# Determining type of first argument's expression
 c = attr.evolve(f(), name='foo')
 
-# First argument type check
+# test 'inst' arg type check
 attr.evolve(42, name='foo')  # E: Argument 1 to "evolve" has incompatible type "Literal[42]?"; expected an attrs class
 attr.evolve(None, name='foo')  # E: Argument 1 to "evolve" has incompatible type "None"; expected an attrs class
 
-# All bets are off for 'Any'
+# test that all bets are off for 'Any'
 any: Any
 ret = attr.evolve(any, name='foo')
 reveal_type(ret)  # N: Revealed type is "Any"
 
-[builtins fixtures/dict.pyi]
+[builtins fixtures/attr.pyi]
+[typing fixtures/typing-medium.pyi]
+
+[case testEvolveVariants]
+from typing import Any
+import attr
+import attrs
+
+
+@attr.s(auto_attribs=True)
+class C:
+    name: str
+
+c = C(name='foo')
+
+c = attr.assoc(c, name='test')
+c = attr.assoc(c, name=42)  # E: Argument "name" to "assoc" has incompatible type "int"; expected "str"
+
+c = attrs.evolve(c, name='test')
+c = attrs.evolve(c, name=42)  # E: Argument "name" to "evolve" has incompatible type "int"; expected "str"
+
+c = attrs.assoc(c, name='test')
+c = attrs.assoc(c, name=42)  # E: Argument "name" to "assoc" has incompatible type "int"; expected "str"
+
+[builtins fixtures/attr.pyi]
 [typing fixtures/typing-medium.pyi]