[ty] Improve disambiguation of types in many cases (#22019)

crates/ty_python_semantic/resources/mdtest/attributes.md

@@ -1208,7 +1208,7 @@ def _(flag: bool):
     reveal_type(C1.y)  # revealed: int | str
 
     C1.y = 100
-    # error: [invalid-assignment] "Object of type `Literal["problematic"]` is not assignable to attribute `y` on type `<class 'C1'> | <class 'C1'>`"
+    # error: [invalid-assignment] "Object of type `Literal["problematic"]` is not assignable to attribute `y` on type `<class 'mdtest_snippet.<locals of function '_'>.C1 @ src/mdtest_snippet.py:3'> | <class 'mdtest_snippet.<locals of function '_'>.C1 @ src/mdtest_snippet.py:8'>`"
     C1.y = "problematic"
 
     class C2:

crates/ty_python_semantic/resources/mdtest/diagnostics/invalid_argument_type.md

@@ -195,3 +195,52 @@ class C:
 c = C()
 c.square("hello")  # error: [invalid-argument-type]
 ```
+
+## Types with the same name but from different files
+
+`module.py`:
+
+```py
+class Foo: ...
+
+def needs_a_foo(x: Foo): ...
+```
+
+`main.py`:
+
+```py
+from module import needs_a_foo
+
+class Foo: ...
+
+needs_a_foo(Foo())  # error: [invalid-argument-type]
+```
+
+## TypeVars with bounds that have the same name but are from different files
+
+In this case, using fully qualified names is *not* necessary.
+
+```toml
+[environment]
+python-version = "3.12"
+```
+
+`module.py`:
+
+```py
+class Foo: ...
+
+def needs_a_foo(x: Foo): ...
+```
+
+`main.py`:
+
+```py
+from module import needs_a_foo
+
+class Foo: ...
+
+def f[T: Foo](x: T) -> T:
+    needs_a_foo(x)  # error: [invalid-argument-type]
+    return x
+```

crates/ty_python_semantic/resources/mdtest/mro.md

@@ -393,7 +393,7 @@ else:
 # revealed: (<class 'B'>, <class 'X'>, <class 'Y'>, <class 'O'>, <class 'object'>) | (<class 'B'>, <class 'Y'>, <class 'X'>, <class 'O'>, <class 'object'>)
 reveal_mro(B)
 
-# error: 12 [unsupported-base] "Unsupported class base with type `<class 'B'> | <class 'B'>`"
+# error: 12 [unsupported-base] "Unsupported class base with type `<class 'mdtest_snippet.B @ src/mdtest_snippet.py:25'> | <class 'mdtest_snippet.B @ src/mdtest_snippet.py:28'>`"
 class Z(A, B): ...
 
 reveal_mro(Z)  # revealed: (<class 'Z'>, Unknown, <class 'object'>)

crates/ty_python_semantic/resources/mdtest/snapshots/attribute_assignment…_-_Attribute_assignment_-_Setting_attributes_o…_(467e26496f4c0c13).snap

@@ -37,7 +37,7 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/diagnostics/attribute_as
 # Diagnostics
 
 ```
-error[invalid-assignment]: Object of type `Literal[1]` is not assignable to attribute `attr` on type `<class 'C1'> | <class 'C1'>`
+error[invalid-assignment]: Object of type `Literal[1]` is not assignable to attribute `attr` on type `<class 'mdtest_snippet.<locals of function '_'>.C1 @ src/mdtest_snippet.py:3'> | <class 'mdtest_snippet.<locals of function '_'>.C1 @ src/mdtest_snippet.py:7'>`
   --> src/mdtest_snippet.py:11:5
    |
 10 |     # TODO: The error message here could be improved to explain why the assignment fails.

crates/ty_python_semantic/resources/mdtest/snapshots/invalid_argument_typ…_-_Invalid_argument_typ…_-_TypeVars_with_bounds…_(25b61918ea9f5644).snap

@@ -0,0 +1,53 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: invalid_argument_type.md - Invalid argument type diagnostics - TypeVars with bounds that have the same name but are from different files
+mdtest path: crates/ty_python_semantic/resources/mdtest/diagnostics/invalid_argument_type.md
+---
+
+# Python source files
+
+## module.py
+
+```
+1 | class Foo: ...
+2 | 
+3 | def needs_a_foo(x: Foo): ...
+```
+
+## main.py
+
+```
+1 | from module import needs_a_foo
+2 | 
+3 | class Foo: ...
+4 | 
+5 | def f[T: Foo](x: T) -> T:
+6 |     needs_a_foo(x)  # error: [invalid-argument-type]
+7 |     return x
+```
+
+# Diagnostics
+
+```
+error[invalid-argument-type]: Argument to function `needs_a_foo` is incorrect
+ --> src/main.py:6:17
+  |
+5 | def f[T: Foo](x: T) -> T:
+6 |     needs_a_foo(x)  # error: [invalid-argument-type]
+  |                 ^ Expected `Foo`, found `T@f`
+7 |     return x
+  |
+info: Function defined here
+ --> src/module.py:3:5
+  |
+1 | class Foo: ...
+2 |
+3 | def needs_a_foo(x: Foo): ...
+  |     ^^^^^^^^^^^ ------ Parameter declared here
+  |
+info: rule `invalid-argument-type` is enabled by default
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/invalid_argument_typ…_-_Invalid_argument_typ…_-_Types_with_the_same_…_(34531e82322f6f21).snap

@@ -0,0 +1,51 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: invalid_argument_type.md - Invalid argument type diagnostics - Types with the same name but from different files
+mdtest path: crates/ty_python_semantic/resources/mdtest/diagnostics/invalid_argument_type.md
+---
+
+# Python source files
+
+## module.py
+
+```
+1 | class Foo: ...
+2 | 
+3 | def needs_a_foo(x: Foo): ...
+```
+
+## main.py
+
+```
+1 | from module import needs_a_foo
+2 | 
+3 | class Foo: ...
+4 | 
+5 | needs_a_foo(Foo())  # error: [invalid-argument-type]
+```
+
+# Diagnostics
+
+```
+error[invalid-argument-type]: Argument to function `needs_a_foo` is incorrect
+ --> src/main.py:5:13
+  |
+3 | class Foo: ...
+4 |
+5 | needs_a_foo(Foo())  # error: [invalid-argument-type]
+  |             ^^^^^ Expected `module.Foo`, found `main.Foo`
+  |
+info: Function defined here
+ --> src/module.py:3:5
+  |
+1 | class Foo: ...
+2 |
+3 | def needs_a_foo(x: Foo): ...
+  |     ^^^^^^^^^^^ ------ Parameter declared here
+  |
+info: rule `invalid-argument-type` is enabled by default
+
+```

crates/ty_python_semantic/src/types/call/bind.rs

@@ -21,7 +21,6 @@ use rustc_hash::{FxHashMap, FxHashSet};
 use smallvec::{SmallVec, smallvec, smallvec_inline};
 
 use super::{Argument, CallArguments, CallError, CallErrorKind, InferContext, Signature, Type};
-use crate::Program;
 use crate::db::Db;
 use crate::dunder_all::dunder_all_names;
 use crate::module_resolver::KnownModule;
@@ -52,6 +51,7 @@ use crate::types::{
     enums, list_members, todo_type,
 };
 use crate::unpack::EvaluationMode;
+use crate::{DisplaySettings, Program};
 use ruff_db::diagnostic::{Annotation, Diagnostic, SubDiagnostic, SubDiagnosticSeverity};
 use ruff_python_ast::{self as ast, ArgOrKeyword, PythonVersion};
 
@@ -4156,8 +4156,13 @@ impl<'db> BindingError<'db> {
                     return;
                 };
 
-                let provided_ty_display = provided_ty.display(context.db());
+                let display_settings = DisplaySettings::from_possibly_ambiguous_types(
-                let expected_ty_display = expected_ty.display(context.db());
+                    context.db(),
+                    [provided_ty, expected_ty],
+                );
+                let provided_ty_display =
+                    provided_ty.display_with(context.db(), display_settings.clone());
+                let expected_ty_display = expected_ty.display_with(context.db(), display_settings);
 
                 let mut diag = builder.into_diagnostic(format_args!(
                     "Argument{} is incorrect",

crates/ty_python_semantic/src/types/display.rs

@@ -76,14 +76,15 @@ impl<'db> DisplaySettings<'db> {
     }
 
     #[must_use]
-    pub fn from_possibly_ambiguous_types(
+    pub fn from_possibly_ambiguous_types<I, T>(db: &'db dyn Db, types: I) -> Self
-        db: &'db dyn Db,
+    where
-        types: impl IntoIterator<Item = Type<'db>>,
+        I: IntoIterator<Item = T>,
-    ) -> Self {
+        T: Into<Type<'db>>,
+    {
         let collector = AmbiguousClassCollector::default();
 
         for ty in types {
-            collector.visit_type(db, ty);
+            collector.visit_type(db, ty.into());
         }
 
         Self {
@@ -422,6 +423,8 @@ impl<'db> super::visitor::TypeVisitor<'db> for AmbiguousClassCollector<'db> {
                 inner: Protocol::FromClass(class),
                 ..
             }) => return self.visit_type(db, Type::from(class)),
+            // no need to recurse into TypeVar bounds/constraints
+            Type::TypeVar(_) => return,
             _ => {}
         }
 
@@ -439,7 +442,7 @@ impl<'db> Type<'db> {
     pub fn display(self, db: &'db dyn Db) -> DisplayType<'db> {
         DisplayType {
             ty: self,
-            settings: DisplaySettings::default(),
+            settings: DisplaySettings::from_possibly_ambiguous_types(db, [self]),
             db,
         }
     }