feat(linter): add fix support for tsgolint diagnostics

apps/oxlint/fixtures/tsgolint_fix/fix.ts

@@ -0,0 +1,6 @@
+// This file has a fixable tsgolint error: no-unnecessary-type-assertion
+// The type assertion `as string` is unnecessary because str is already a string
+const str: string = 'hello';
+const redundant = str as string;
+
+export { redundant };

apps/oxlint/fixtures/tsgolint_fix/tsconfig.json

@@ -0,0 +1,9 @@
+{
+  "compilerOptions": {
+    "strict": true,
+    "target": "ES2020",
+    "module": "ESNext",
+    "moduleResolution": "bundler"
+  },
+  "include": ["*.ts"]
+}

apps/oxlint/src/lint.rs

@@ -1433,4 +1433,30 @@ mod test {
         let args = &["--type-aware"];
         Tester::new().with_cwd("fixtures/tsgolint_rule_options".into()).test_and_snapshot(args);
     }
+
+    #[test]
+    #[cfg(all(not(target_os = "windows"), not(target_endian = "big")))]
+    fn test_tsgolint_fix() {
+        // Note: tsgolint fixes this lint rule by providing two string manipulations
+        // the first removing `as` and the second removing `string` This results in the two spaces
+        // after `str` but before `;`, this is ok, as it's not guaranteed that our fixers are stylistically correct.
+        Tester::test_fix_with_args(
+            "fixtures/tsgolint_fix/fix.ts",
+            "// This file has a fixable tsgolint error: no-unnecessary-type-assertion
+// The type assertion `as string` is unnecessary because str is already a string
+const str: string = 'hello';
+const redundant = str as string;
+
+export { redundant };
+",
+            "// This file has a fixable tsgolint error: no-unnecessary-type-assertion
+// The type assertion `as string` is unnecessary because str is already a string
+const str: string = 'hello';
+const redundant = str  ;
+
+export { redundant };
+",
+            &["--type-aware", "-D", "no-unnecessary-type-assertion"],
+        );
+    }
 }

apps/oxlint/src/tester.rs

@@ -47,18 +47,26 @@ impl Tester {
     }
 
     pub fn test_fix(file: &str, before: &str, after: &str) {
+        Self::test_fix_with_args(file, before, after, &[]);
+    }
+
+    /// Test fix with additional CLI arguments (e.g., `--type-aware` for tsgolint)
+    pub fn test_fix_with_args(file: &str, before: &str, after: &str, extra_args: &[&str]) {
         use std::fs;
         #[expect(clippy::disallowed_methods)]
         let content_original = fs::read_to_string(file).unwrap().replace("\r\n", "\n");
         assert_eq!(content_original, before);
 
-        Tester::new().test(&["--fix", file]);
+        let mut args = vec!["--fix"];
+        args.extend(extra_args);
+        args.push(file);
+        Tester::new().test(&args);
 
         #[expect(clippy::disallowed_methods)]
         let new_content = fs::read_to_string(file).unwrap().replace("\r\n", "\n");
         assert_eq!(new_content, after);
 
-        Tester::new().test(&["--fix", file]);
+        Tester::new().test(&args);
 
         // File should not be modified if no fix is applied.
         let modified_before: std::time::SystemTime =

crates/oxc_linter/src/lint_runner.rs

@@ -222,7 +222,7 @@ impl LintRunner {
         self.lint_service.run(fs, files.to_owned(), &tx_error);
 
         if let Some(type_aware_linter) = self.type_aware_linter.take() {
-            type_aware_linter.lint(files, self.directives_store.map(), tx_error)?;
+            type_aware_linter.lint(files, self.directives_store.map(), tx_error, fs)?;
         } else {
             drop(tx_error);
         }