Detect runtime-evaluated base classes defined in the current file

crates/ruff_linter/resources/test/fixtures/flake8_type_checking/module/direct.py

@@ -0,0 +1,11 @@
+from __future__ import annotations
+
+from collections.abc import Sequence
+
+
+class MyBaseClass:
+    pass
+
+
+class Foo(MyBaseClass):
+    foo: Sequence

crates/ruff_linter/resources/test/fixtures/flake8_type_checking/module/import.py

@@ -0,0 +1,9 @@
+from __future__ import annotations
+
+from collections.abc import Sequence
+
+from module.direct import MyBaseClass
+
+
+class Foo(MyBaseClass):
+    foo: Sequence

crates/ruff_linter/resources/test/fixtures/flake8_type_checking/module/undefined.py

@@ -0,0 +1,7 @@
+from __future__ import annotations
+
+from collections.abc import Sequence
+
+
+class Foo(MyBaseClass):
+    foo: Sequence

crates/ruff_linter/resources/test/fixtures/flake8_type_checking/runtime_evaluated_base_classes_5.py

@@ -0,0 +1,11 @@
+from __future__ import annotations
+
+from collections.abc import Sequence  # TCH003
+
+
+class MyBaseClass:
+    pass
+
+
+class Foo(MyBaseClass):
+    foo: Sequence

crates/ruff_linter/src/rules/flake8_type_checking/mod.rs

@@ -144,6 +144,28 @@ mod tests {
         Ok(())
     }
 
+    #[test_case(Rule::TypingOnlyStandardLibraryImport, Path::new("module/direct.py"))]
+    #[test_case(Rule::TypingOnlyStandardLibraryImport, Path::new("module/import.py"))]
+    #[test_case(
+        Rule::TypingOnlyStandardLibraryImport,
+        Path::new("module/undefined.py")
+    )]
+    fn base_class_same_file(rule_code: Rule, path: &Path) -> Result<()> {
+        let snapshot = format!("{}_{}", rule_code.as_ref(), path.to_string_lossy());
+        let diagnostics = test_path(
+            Path::new("flake8_type_checking").join(path).as_path(),
+            &settings::LinterSettings {
+                flake8_type_checking: super::settings::Settings {
+                    runtime_evaluated_base_classes: vec!["module.direct.MyBaseClass".to_string()],
+                    ..Default::default()
+                },
+                ..settings::LinterSettings::for_rule(rule_code)
+            },
+        )?;
+        assert_messages!(snapshot, diagnostics);
+        Ok(())
+    }
+
     #[test_case(
         r#"
         from __future__ import annotations

crates/ruff_linter/src/rules/flake8_type_checking/snapshots/ruff_linter__rules__flake8_type_checking__tests__typing-only-standard-library-import_module__direct.py.snap

@@ -0,0 +1,4 @@
+---
+source: crates/ruff_linter/src/rules/flake8_type_checking/mod.rs
+---
+

crates/ruff_linter/src/rules/flake8_type_checking/snapshots/ruff_linter__rules__flake8_type_checking__tests__typing-only-standard-library-import_module__import.py.snap

@@ -0,0 +1,4 @@
+---
+source: crates/ruff_linter/src/rules/flake8_type_checking/mod.rs
+---
+

crates/ruff_linter/src/rules/flake8_type_checking/snapshots/ruff_linter__rules__flake8_type_checking__tests__typing-only-standard-library-import_module__undefined.py.snap

@@ -0,0 +1,25 @@
+---
+source: crates/ruff_linter/src/rules/flake8_type_checking/mod.rs
+---
+undefined.py:3:29: TCH003 [*] Move standard library import `collections.abc.Sequence` into a type-checking block
+  |
+1 | from __future__ import annotations
+2 | 
+3 | from collections.abc import Sequence
+  |                             ^^^^^^^^ TCH003
+  |
+  = help: Move into type-checking block
+
+ℹ Unsafe fix
+1 1 | from __future__ import annotations
+2 2 | 
+3   |-from collections.abc import Sequence
+  3 |+from typing import TYPE_CHECKING
+  4 |+
+  5 |+if TYPE_CHECKING:
+  6 |+    from collections.abc import Sequence
+4 7 | 
+5 8 | 
+6 9 | class Foo(MyBaseClass):
+
+

crates/ruff_python_semantic/src/model.rs

@@ -686,6 +686,16 @@ impl<'a> SemanticModel<'a> {
                 Some(resolved)
             }
             BindingKind::Builtin => Some(smallvec!["", head.id.as_str()]),
+            BindingKind::ClassDefinition(_) | BindingKind::FunctionDefinition(_) => {
+                let value_path = collect_call_path(value)?;
+                let resolved: CallPath = self
+                    .module_path?
+                    .iter()
+                    .map(String::as_str)
+                    .chain(value_path)
+                    .collect();
+                Some(resolved)
+            }
             _ => None,
         }
     }