[flake8-type-checking] Skip quoting annotation if it becomes invalid syntax (TCH001)

crates/ruff_linter/resources/test/fixtures/flake8_type_checking/quote3.py

@@ -53,3 +53,17 @@ def f():
     def test_annotated_non_typing_reference(user: Annotated[str, Depends(get_foo)]):
         pass
 
+
+def f():
+    from typing import Literal
+    from third_party import Type
+
+    def test_string_contains_opposite_quote_do_not_fix(self, type1: Type[Literal["'"]], type2: Type[Literal["\'"]]):
+        pass
+
+def f():
+    from typing import Literal
+    from third_party import Type
+
+    def test_quote_contains_backslash(self, type1: Type[Literal["\n"]], type2: Type[Literal["\""]]):
+        pass

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

@@ -272,6 +272,11 @@ pub(crate) fn quote_annotation(
     let quote = stylist.quote();
     let mut quote_annotator = QuoteAnnotator::new(semantic, stylist);
     quote_annotator.visit_expr(expr);
+    if quote_annotator.failed {
+        return Err(anyhow::anyhow!(
+            "Annotation already contains quotes that require escaping"
+        ));
+    }
     let annotation = quote_annotator.into_annotation();
 
     Ok(Edit::range_replacement(
@@ -313,6 +318,7 @@ pub(crate) struct QuoteAnnotator<'a> {
     semantic: &'a SemanticModel<'a>,
     state: Vec<QuoteAnnotatorState>,
     annotation: String,
+    failed: bool,
 }
 
 impl<'a> QuoteAnnotator<'a> {
@@ -322,6 +328,7 @@ impl<'a> QuoteAnnotator<'a> {
             semantic,
             state: Vec::new(),
             annotation: String::new(),
+            failed: false,
         }
     }
 
@@ -388,10 +395,13 @@ impl<'a> source_order::SourceOrderVisitor<'a> for QuoteAnnotator<'a> {
                 let source = match self.state.last().copied() {
                     Some(QuoteAnnotatorState::Literal | QuoteAnnotatorState::AnnotatedRest) => {
                         let mut source = generator.expr(expr);
-                        source = source.replace(
-                            self.stylist.quote().as_char(),
-                            &self.stylist.quote().opposite().as_char().to_string(),
-                        );
+                        let opposite_quote = &self.stylist.quote().opposite().as_char().to_string();
+                        // If the quotes we are going to insert in this source already exists set the auto quote outcome
+                        // to failed. Because this means we are inserting quotes that are in the string and they collect.
+                        if source.contains(opposite_quote) || source.contains('\\') {
+                            self.failed = true;
+                        }
+                        source = source.replace(self.stylist.quote().as_char(), opposite_quote);
                         source
                     }
                     None

crates/ruff_linter/src/rules/flake8_type_checking/snapshots/ruff_linter__rules__flake8_type_checking__tests__quote_typing-only-third-party-import_quote.py.snap

@@ -1,5 +1,6 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_type_checking/mod.rs
+snapshot_kind: text
 ---
 quote.py:2:24: TCH002 [*] Move third-party import `pandas.DataFrame` into a type-checking block
   |

crates/ruff_linter/src/rules/flake8_type_checking/snapshots/ruff_linter__rules__flake8_type_checking__tests__quote_typing-only-third-party-import_quote2.py.snap

@@ -1,5 +1,6 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_type_checking/mod.rs
+snapshot_kind: text
 ---
 quote2.py:2:44: TCH002 [*] Move third-party import `django.contrib.auth.models.AbstractBaseUser` into a type-checking block
   |

crates/ruff_linter/src/rules/flake8_type_checking/snapshots/ruff_linter__rules__flake8_type_checking__tests__quote_typing-only-third-party-import_quote3.py.snap

@@ -1,5 +1,6 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_type_checking/mod.rs
+snapshot_kind: text
 ---
 quote3.py:4:44: TCH002 [*] Move third-party import `django.contrib.auth.models.AbstractBaseUser` into a type-checking block
   |
@@ -150,4 +151,26 @@ quote3.py:40:37: TCH002 [*] Move third-party import `django.contrib.auth.models`
    45 |+    def test_attribute_typing_literal(arg: 'models.AbstractBaseUser[Literal["admin"]]'):
 43 46 |         pass
 44 47 | 
-45 48 |
+45 48 | 
+
+quote3.py:59:29: TCH002 Move third-party import `third_party.Type` into a type-checking block
+   |
+57 | def f():
+58 |     from typing import Literal
+59 |     from third_party import Type
+   |                             ^^^^ TCH002
+60 | 
+61 |     def test_string_contains_opposite_quote_do_not_fix(self, type1: Type[Literal["'"]], type2: Type[Literal["\'"]]):
+   |
+   = help: Move into type-checking block
+
+quote3.py:66:29: TCH002 Move third-party import `third_party.Type` into a type-checking block
+   |
+64 | def f():
+65 |     from typing import Literal
+66 |     from third_party import Type
+   |                             ^^^^ TCH002
+67 | 
+68 |     def test_quote_contains_backslash(self, type1: Type[Literal["\n"]], type2: Type[Literal["\""]]):
+   |
+   = help: Move into type-checking block