[ty] Improve several "Did you mean?" suggestions (#21597)

crates/ty_python_semantic/resources/mdtest/annotations/literal_string.md

@@ -35,6 +35,8 @@ bad_nesting: Literal[LiteralString]  # error: [invalid-type-form]
 
 `LiteralString` cannot be parameterized.
 
+<!-- snapshot-diagnostics -->
+
 ```py
 from typing_extensions import LiteralString
 
@@ -42,7 +44,6 @@ from typing_extensions import LiteralString
 a: LiteralString[str]
 
 # error: [invalid-type-form]
-# error: [unresolved-reference] "Name `foo` used when not defined"
 b: LiteralString["foo"]
 ```
 

crates/ty_python_semantic/resources/mdtest/snapshots/invalid.md_-_Tests_for_invalid_ty…_-_Diagnostics_for_comm…_-_Module-literal_used_…_(652fec4fd4a6c63a).snap

@@ -34,29 +34,27 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/annotations/invalid.md
 # Diagnostics
 
 ```
-error[invalid-type-form]: Variable of type `<module 'datetime'>` is not allowed in a type expression
+error[invalid-type-form]: Module `datetime` is not valid in a type expression
  --> src/foo.py:3:10
   |
 1 | import datetime
 2 |
 3 | def f(x: datetime): ...  # error: [invalid-type-form]
-  |          ^^^^^^^^
+  |          ^^^^^^^^ Did you mean to use the module's member `datetime.datetime`?
   |
-info: Did you mean to use the module's member `datetime.datetime` instead?
 info: rule `invalid-type-form` is enabled by default
 
 ```
 
 ```
-error[invalid-type-form]: Variable of type `<module 'PIL.Image'>` is not allowed in a type expression
+error[invalid-type-form]: Module `PIL.Image` is not valid in a type expression
  --> src/bar.py:3:10
   |
 1 | from PIL import Image
 2 |
 3 | def g(x: Image): ...  # error: [invalid-type-form]
-  |          ^^^^^
+  |          ^^^^^ Did you mean to use the module's member `Image.Image`?
   |
-info: Did you mean to use the module's member `Image.Image` instead?
 info: rule `invalid-type-form` is enabled by default
 
 ```

crates/ty_python_semantic/resources/mdtest/snapshots/literal_string.md_-_`LiteralString`_-_Usages_-_Parameterized_(ec84ce49ea235791).snap

@@ -0,0 +1,52 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: literal_string.md - `LiteralString` - Usages - Parameterized
+mdtest path: crates/ty_python_semantic/resources/mdtest/annotations/literal_string.md
+---
+
+# Python source files
+
+## mdtest_snippet.py
+
+```
+1 | from typing_extensions import LiteralString
+2 | 
+3 | # error: [invalid-type-form]
+4 | a: LiteralString[str]
+5 | 
+6 | # error: [invalid-type-form]
+7 | b: LiteralString["foo"]
+```
+
+# Diagnostics
+
+```
+error[invalid-type-form]: `LiteralString` expects no type parameter
+ --> src/mdtest_snippet.py:4:4
+  |
+3 | # error: [invalid-type-form]
+4 | a: LiteralString[str]
+  |    ^^^^^^^^^^^^^^^^^^
+5 |
+6 | # error: [invalid-type-form]
+  |
+info: rule `invalid-type-form` is enabled by default
+
+```
+
+```
+error[invalid-type-form]: `LiteralString` expects no type parameter
+ --> src/mdtest_snippet.py:7:4
+  |
+6 | # error: [invalid-type-form]
+7 | b: LiteralString["foo"]
+  |    -------------^^^^^^^
+  |    |
+  |    Did you mean `Literal`?
+  |
+info: rule `invalid-type-form` is enabled by default
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/typed_dict.md_-_`TypedDict`_-_Error_cases_-_`typing.TypedDict`_i…_(9df67eb93e3df341).snap

@@ -0,0 +1,34 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: typed_dict.md - `TypedDict` - Error cases - `typing.TypedDict` is not allowed in type expressions
+mdtest path: crates/ty_python_semantic/resources/mdtest/typed_dict.md
+---
+
+# Python source files
+
+## mdtest_snippet.py
+
+```
+1 | from typing import TypedDict
+2 | 
+3 | # error: [invalid-type-form] "The special form `typing.TypedDict` is not allowed in type expressions"
+4 | x: TypedDict = {"name": "Alice"}
+```
+
+# Diagnostics
+
+```
+error[invalid-type-form]: The special form `typing.TypedDict` is not allowed in type expressions
+ --> src/mdtest_snippet.py:4:4
+  |
+3 | # error: [invalid-type-form] "The special form `typing.TypedDict` is not allowed in type expressions"
+4 | x: TypedDict = {"name": "Alice"}
+  |    ^^^^^^^^^
+  |
+help: You might have meant to use a concrete TypedDict or `collections.abc.Mapping[str, object]`
+info: rule `invalid-type-form` is enabled by default
+
+```

crates/ty_python_semantic/resources/mdtest/typed_dict.md

@@ -1407,10 +1407,12 @@ msg.content
 
 ### `typing.TypedDict` is not allowed in type expressions
 
+<!-- snapshot-diagnostics -->
+
 ```py
 from typing import TypedDict
 
-# error: [invalid-type-form] "The special form `typing.TypedDict` is not allowed in type expressions."
+# error: [invalid-type-form] "The special form `typing.TypedDict` is not allowed in type expressions"
 x: TypedDict = {"name": "Alice"}
 ```