Add eslint vitest plugin.

eslint.config.mjs

@@ -18,6 +18,7 @@ import globals from "globals";
 import babelParser from "@babel/eslint-parser";
 import eslintPluginPrettierRecommended from "eslint-plugin-prettier/recommended";
 import unusedImports from "eslint-plugin-unused-imports";
+import vitestPlugin from "eslint-plugin-vitest";
 
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = path.dirname(__filename);
@@ -34,6 +35,7 @@ export default [
     files: ["**/*.{mjs,js,jsx}"],
     plugins: {
       "unused-imports": unusedImports,
+      vitest: vitestPlugin,
     },
     languageOptions: {
       parser: babelParser,
@@ -48,6 +50,14 @@ export default [
         ...globals.node,
         fixture: true,
         test: true,
+        describe: true,
+        it: true,
+        expect: true,
+        beforeEach: true,
+        afterEach: true,
+        beforeAll: true,
+        afterAll: true,
+        vi: true,
       },
     },
     rules: {
@@ -115,6 +125,10 @@ export default [
 
       "import/no-named-as-default-member": "off",
       "import/no-named-as-default": "off",
+      "vitest/expect-expect": "error",
+      "vitest/no-disabled-tests": "warn",
+      "vitest/no-focused-tests": "error",
+      "vitest/no-identical-title": "error",
     },
   },
   {

package.json

@@ -111,6 +111,7 @@
     "eslint-plugin-react": "^7.37.2",
     "eslint-plugin-testcafe": "^0.2.1",
     "eslint-plugin-unused-imports": "^3.2.0",
+    "eslint-plugin-vitest": "^0.5.4",
     "fs-extra": "^11.2.0",
     "glob": "^11.0.0",
     "globals": "^15.11.0",

test/unit/lib/utils/numberAwareCompareFunction.spec.js

@@ -55,8 +55,11 @@ describe("numberAwareCompareFunction", () => {
   });
 
   it("handles non-strings", () => {
-    [undefined, null, 0, 42, { a: "foo" }, "foo"].sort(
-      numberAwareCompareFunction,
-    );
+    const values = [undefined, null, 0, 42, { a: "foo" }, "foo"];
+    const result = values.sort(numberAwareCompareFunction);
+    expect(result).toBeDefined();
+    expect(result).toHaveLength(values.length);
+    // Verify the function doesn't throw errors for non-string values
+    expect(() => values.sort(numberAwareCompareFunction)).not.toThrow();
   });
 });