diff --git a/src/features/todos/__snapshots__/todosSlice.spec.js.snap b/src/features/todos/__snapshots__/todosSlice.spec.js.snap
new file mode 100644
index 0000000..ead51ae
--- /dev/null
+++ b/src/features/todos/__snapshots__/todosSlice.spec.js.snap
@@ -0,0 +1,16 @@
+// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
+
+exports[`todos reducer > should handle initial state 1`] = `
+[
+  {
+    "completed": false,
+    "id": 1708982768968,
+    "text": "Hit the gym",
+  },
+  {
+    "completed": true,
+    "id": 1708982943626,
+    "text": "Meet George",
+  },
+]
+`;
diff --git a/src/features/todos/todosSlice.spec.js b/src/features/todos/todosSlice.spec.js
new file mode 100644
index 0000000..b19c070
--- /dev/null
+++ b/src/features/todos/todosSlice.spec.js
@@ -0,0 +1,47 @@
+/* eslint-env jest */
+import { vi } from 'vitest';
+import todosReducer, { addTodo, deleteTodo, editTodo, toggleComplete } from './todosSlice';
+
+describe('todos reducer', () => {
+  let initialState;
+  let date;
+
+  beforeEach(() => {
+    initialState = [
+      { id: 1708982768968, text: 'Hit the gym', completed: false },
+      { id: 1708982943626, text: 'Meet George', completed: true }
+    ];
+    date = new Date(2022, 2, 22);
+
+    vi.useFakeTimers();
+    vi.setSystemTime(date);
+  });
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  test('should handle initial state', () => {
+    expect(todosReducer(undefined, { type: 'unknown' })).toMatchSnapshot();
+  });
+
+  test('should handle addTodo', () => {
+    const actual = todosReducer(initialState, addTodo('Newly added item message'));
+    expect(actual[2].text).toEqual('Newly added item message');
+  });
+
+  test('should handle deleteTodo', () => {
+    const actual = todosReducer(initialState, deleteTodo(1708982768968));
+    expect(actual.length).toEqual(1);
+    expect(actual[0].text).toBe('Meet George');
+  });
+
+  test('should handle editTodo', () => {
+    const actual = todosReducer(initialState, editTodo({id: 1708982768968, text: 'Hit the library'}));
+    expect(actual[0].text).toBe('Hit the library');
+  });
+
+  test('should handle toggleComplete', () => {
+    const actual = todosReducer(initialState, toggleComplete(1708982768968));
+    expect(actual[0].completed).toBeTruthy();
+  });
+});
diff --git a/tsconfig.json b/tsconfig.json
index bcfa6c0..d9f85f3 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -23,7 +23,6 @@
 
     /* allow the incremential inclusion of JavaScript files */
     "allowJs": true,
-    "checkJs": false,
     "noImplicitAny": true,
 
     "baseUrl": ".",
diff --git a/vite.config.ts b/vite.config.ts
index c34805e..17da149 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -17,7 +17,6 @@ export default defineConfig({
       '**/*.{test,spec}.?(c|m)[jt]s?(x)',
     ],
     exclude: [
-      '**/*.test.js',
       '**/node_modules/**',
       '**/dist/**',
       '**/coverage/**',