refactor(oxlint): enable useUnknownInCatchVariables tsconfig setting

apps/oxlint/conformance/src/capture.ts

@@ -126,13 +126,14 @@ export function it(code: string, fn: () => void): void {
     if (currentTest === null) throw new Error("Test case was not run with `RuleTester`");
 
     testResult.isPassed = true;
-  } catch (err) {
+  } catch (_err) {
+    let err: Error;
     if (currentTest === null) {
-      // oxlint-disable-next-line no-ex-assign
       err = new Error("Test case was not run with `RuleTester`");
       currentTest = { code };
-    } else if (!(err instanceof Error)) {
-      // oxlint-disable-next-line no-ex-assign
+    } else if (_err instanceof Error) {
+      err = _err;
+    } else {
       err = new Error("Unknown error");
     }
 

apps/oxlint/src-js/package/rule_tester.ts

@@ -1492,7 +1492,9 @@ function setupOptions(test: TestCase, cwd: string): number {
       workspaceUri: null,
     });
   } catch (err) {
-    throw new Error(`Failed to serialize options: ${err}`);
+    throw new Error(
+      `Failed to serialize options: ${err as (typeof globalThis)["Error"]["prototype"]}`,
+    );
   }
   setOptions(allOptionsJson);
 

apps/oxlint/test/fixtures/createOnce/plugin.ts

@@ -207,11 +207,11 @@ const plugin: Plugin = {
 
 export default plugin;
 
-function tryCatch(fn: () => unknown) {
+function tryCatch(fn: () => unknown): Error {
   try {
     fn();
   } catch (err) {
-    return err;
+    return err as Error;
   }
   throw new Error("Expected function to throw");
 }

apps/oxlint/test/rule_tester.test.ts

@@ -42,13 +42,13 @@ RuleTester.it = itHook;
  * @returns Array containing errors for each test case
  */
 function runCases(): (Error | null)[] {
-  const errors = [];
+  const errors: (Error | null)[] = [];
   for (const testCase of cases) {
     let error = null;
     try {
       testCase.fn();
     } catch (err) {
-      error = err;
+      error = err as Error;
     }
     errors.push(error);
   }

apps/oxlint/test/utils.ts

@@ -67,7 +67,7 @@ export function getFixtures(): Fixture[] {
     try {
       options = JSON.parse(readFileSync(pathJoin(dirPath, "options.json"), "utf8"));
     } catch (err) {
-      if (err?.code !== "ENOENT") throw err;
+      if ((err as NodeJS.ErrnoException)?.code !== "ENOENT") throw err;
       options = DEFAULT_OPTIONS;
     }
 

apps/oxlint/tsconfig.json

@@ -9,7 +9,8 @@
     "noImplicitAny": true,
     "strictNullChecks": true,
     "skipLibCheck": true,
-    "noUnusedLocals": true
+    "noUnusedLocals": true,
+    "useUnknownInCatchVariables": true
   },
   "exclude": ["node_modules", "fixtures", "test/fixtures/*/files", "conformance/submodules"]
 }