From b94d6cf567773c239b4ff7fe7cad263180886977 Mon Sep 17 00:00:00 2001
From: David Peter <sharkdp@users.noreply.github.com>
Date: Tue, 26 Nov 2024 16:35:44 +0100
Subject: [PATCH] [red-knot] Fix panic related to f-strings in annotations
 (#14613)

## Summary

Fix panics related to expressions without inferred types in invalid
syntax examples like:
```py
x: f"Literal[{1 + 2}]" = 3
```
where the `1 + 2` expression (and its sub-expressions) inside the
annotation did not have an inferred type.

## Test Plan

Added new corpus test.
---
 crates/red_knot_python_semantic/src/types/infer.rs              | 1 +
 .../resources/test/corpus/95_annotation_fstring_invalid.py      | 1 +
 crates/red_knot_workspace/tests/check.rs                        | 2 +-
 3 files changed, 3 insertions(+), 1 deletion(-)
 create mode 100644 crates/red_knot_workspace/resources/test/corpus/95_annotation_fstring_invalid.py

diff --git a/crates/red_knot_python_semantic/src/types/infer.rs b/crates/red_knot_python_semantic/src/types/infer.rs
index 32104b0f07..7224ac0c9d 100644
--- a/crates/red_knot_python_semantic/src/types/infer.rs
+++ b/crates/red_knot_python_semantic/src/types/infer.rs
@@ -4229,6 +4229,7 @@ impl<'db> TypeInferenceBuilder<'db> {
                     "annotation-f-string",
                     format_args!("Type expressions cannot use f-strings"),
                 );
+                self.infer_fstring_expression(fstring);
                 Type::Unknown
             }
 
diff --git a/crates/red_knot_workspace/resources/test/corpus/95_annotation_fstring_invalid.py b/crates/red_knot_workspace/resources/test/corpus/95_annotation_fstring_invalid.py
new file mode 100644
index 0000000000..119b52201c
--- /dev/null
+++ b/crates/red_knot_workspace/resources/test/corpus/95_annotation_fstring_invalid.py
@@ -0,0 +1 @@
+x: f"Literal[{1 + 2}]" = 3
diff --git a/crates/red_knot_workspace/tests/check.rs b/crates/red_knot_workspace/tests/check.rs
index eeec8cee35..f3be665151 100644
--- a/crates/red_knot_workspace/tests/check.rs
+++ b/crates/red_knot_workspace/tests/check.rs
@@ -272,7 +272,7 @@ const KNOWN_FAILURES: &[(&str, bool, bool)] = &[
     ("crates/ruff_linter/resources/test/fixtures/pyupgrade/UP039.py", true, false),
     // related to circular references in type aliases (salsa cycle panic):
     ("crates/ruff_python_parser/resources/inline/err/type_alias_invalid_value_expr.py", true, true),
-    // related to f-strings in annotations (invalid syntax)
+    // related to circular references in f-string annotations (invalid syntax)
     ("crates/ruff_linter/resources/test/fixtures/pyflakes/F821_15.py", true, true),
     ("crates/ruff_linter/resources/test/fixtures/pyflakes/F821_14.py", false, true),
 ];