From 8941484275a22fe482a5251171ed27add03f8ffb Mon Sep 17 00:00:00 2001
From: Shantanu Jain <hauntsaninja@gmail.com>
Date: Sat, 28 Dec 2024 03:23:47 -0800
Subject: [PATCH 1/2] Don't erase type object args in diagnostics

Fixes https://github.com/python/mypy/issues/16875
---
 mypy/messages.py                         | 2 +-
 test-data/unit/check-generics.test       | 3 +--
 test-data/unit/check-inference.test      | 2 +-
 test-data/unit/check-newsemanal.test     | 6 ++----
 test-data/unit/fine-grained-inspect.test | 2 +-
 5 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/mypy/messages.py b/mypy/messages.py
index 6b0760cd79c6..40b0e7ee695a 100644
--- a/mypy/messages.py
+++ b/mypy/messages.py
@@ -2700,7 +2700,7 @@ def format_literal_value(typ: LiteralType) -> str:
         if func.is_type_obj():
             # The type of a type object type can be derived from the
             # return type (this always works).
-            return format(TypeType.make_normalized(erase_type(func.items[0].ret_type)))
+            return format(TypeType.make_normalized(func.items[0].ret_type))
         elif isinstance(func, CallableType):
             if func.type_guard is not None:
                 return_type = f"TypeGuard[{format(func.type_guard)}]"
diff --git a/test-data/unit/check-generics.test b/test-data/unit/check-generics.test
index 08dfb3b54b3a..5d6ad8e19631 100644
--- a/test-data/unit/check-generics.test
+++ b/test-data/unit/check-generics.test
@@ -1773,8 +1773,7 @@ T = TypeVar('T')
 class C(Generic[T]):
     def __init__(self) -> None: pass
 x = C # type: Callable[[], C[int]]
-y = C # type: Callable[[], int] # E: Incompatible types in assignment (expression has type "Type[C[Any]]", variable has type "Callable[[], int]")
-
+y = C # type: Callable[[], int] # E: Incompatible types in assignment (expression has type "Type[C[T]]", variable has type "Callable[[], int]")
 
 -- Special cases
 -- -------------
diff --git a/test-data/unit/check-inference.test b/test-data/unit/check-inference.test
index bec3a9a07593..560092ed1a43 100644
--- a/test-data/unit/check-inference.test
+++ b/test-data/unit/check-inference.test
@@ -2488,7 +2488,7 @@ T = TypeVar('T')
 class C(Sequence[T], Generic[T]): pass
 C[0] = 0
 [out]
-main:4: error: Unsupported target for indexed assignment ("Type[C[Any]]")
+main:4: error: Unsupported target for indexed assignment ("Type[C[T]]")
 main:4: error: Invalid type: try using Literal[0] instead?
 
 [case testNoCrashOnPartialMember]
diff --git a/test-data/unit/check-newsemanal.test b/test-data/unit/check-newsemanal.test
index 81b0066dbf81..7ac90d07e504 100644
--- a/test-data/unit/check-newsemanal.test
+++ b/test-data/unit/check-newsemanal.test
@@ -2743,13 +2743,11 @@ T = TypeVar('T')
 
 class C(Generic[T]):
     pass
-# TODO: Error message is confusing
+
 C = C[int]  # E: Cannot assign to a type \
-            # E: Incompatible types in assignment (expression has type "Type[C[Any]]", variable has type "Type[C[Any]]")
+            # E: Incompatible types in assignment (expression has type "Type[C[int]]", variable has type "Type[C[T]]")
 x: C
 reveal_type(x) # N: Revealed type is "__main__.C[Any]"
-[out]
-[out2]
 
 [case testNewAnalyzerClassVariableOrdering]
 def foo(x: str) -> None: pass
diff --git a/test-data/unit/fine-grained-inspect.test b/test-data/unit/fine-grained-inspect.test
index ed89f2f099f9..0e05769370a2 100644
--- a/test-data/unit/fine-grained-inspect.test
+++ b/test-data/unit/fine-grained-inspect.test
@@ -23,7 +23,7 @@ NameExpr -> "C[T]"
 MemberExpr -> "T"
 NameExpr -> "C[T]"
 MemberExpr -> "T"
-12:5:12:5 -> "Type[foo.C[Any]]"
+12:5:12:5 -> "Type[foo.C[builtins.int]]"
 12:5:12:9 -> "foo.C[builtins.int]"
 12:1:12:10 -> "builtins.int"
 CallExpr:12:5:12:9 -> "C[int]"

From 6b072b4ce25d90ce111004fcee8cd35ab84934dd Mon Sep 17 00:00:00 2001
From: Shantanu Jain <hauntsaninja@gmail.com>
Date: Sat, 28 Dec 2024 03:47:59 -0800
Subject: [PATCH 2/2] pyeval

---
 test-data/unit/pythoneval.test | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test-data/unit/pythoneval.test b/test-data/unit/pythoneval.test
index 70003545754c..66ceafb91370 100644
--- a/test-data/unit/pythoneval.test
+++ b/test-data/unit/pythoneval.test
@@ -823,7 +823,7 @@ class MyDDict(t.DefaultDict[int,T], t.Generic[T]):
 MyDDict(dict)['0']
 MyDDict(dict)[0]
 [out]
-_program.py:7: error: Argument 1 to "defaultdict" has incompatible type "Type[List[Any]]"; expected "Optional[Callable[[], str]]"
+_program.py:7: error: Argument 1 to "defaultdict" has incompatible type "Type[List[_T]]"; expected "Optional[Callable[[], str]]"
 _program.py:10: error: Invalid index type "str" for "defaultdict[int, str]"; expected type "int"
 _program.py:10: error: Incompatible types in assignment (expression has type "int", target has type "str")
 _program.py:20: error: Argument 1 to "tst" has incompatible type "defaultdict[str, List[Never]]"; expected "defaultdict[int, List[Never]]"