Add test

parser/src/snapshots/rustpython_parser__string__tests__parse_fstring_escaped_brackets.snap

@@ -0,0 +1,15 @@
+---
+source: parser/src/string.rs
+expression: parse_ast
+---
+[
+    Constant(
+        ExprConstant {
+            range: 0..10,
+            value: Str(
+                "\\{x\\}",
+            ),
+            kind: None,
+        },
+    ),
+]

parser/src/string.rs

@@ -960,6 +960,13 @@ mod tests {
         insta::assert_debug_snapshot!(parse_ast);
     }
 
+    #[test]
+    fn test_parse_fstring_escaped_brackets() {
+        let source = "\\{{x\\}}";
+        let parse_ast = parse_fstring(source).unwrap();
+        insta::assert_debug_snapshot!(parse_ast);
+    }
+
     #[test]
     fn test_parse_string_concat() {
         let source = "'Hello ' 'world'";