Vue Route: Uncaught TypeError: window.Vue.use is not a function

The error `Uncaught TypeError: window.Vue.use is not a function` typically arises when the `Vue` instance in the global `window` object doesn’t have the `use` method. This can happen for a few reasons, particularly if Vue is included in a manner inconsistent with how you’re trying to use it or if there’s a mismatch in how Vue is imported or bundled.

In a Laravel project using Vue, here’s how to ensure that the error is resolved:

Understanding the Issue

1. Vue 3 and Vue 2 Differences:
Vue 2 : Uses `Vue.use()` for plugins like Vue Router.
Vue 3 : Uses `app.use()` for plugins and doesn’t rely on `window.Vue`.

2. Webpack vs Global Vue:
If Vue is included via a CDN in your Blade templates, it might not be compatible with the version or way you’re importing Vue in your JavaScript files.

Resolving the Error

1. Ensure Vue and Vue Router Versions Match

Check the versions of Vue and Vue Router you’re using and ensure they are compatible:
-> For Vue 2.x: Use Vue Router 3.x.
-> For Vue 3.x: Use Vue Router 4.x.

2. Verify Your Project Configuration

For Vue 2.x Projects:

1. Install Vue and Vue Router via NPM/Yarn:
npm install vue@2 vue-router@3

2. Set Up Your JavaScript Entry File (e.g., `resources/js/app.js`):

import Vue from 'vue';
import VueRouter from 'vue-router';
import App from './App.vue';

Vue.use(VueRouter);
const router = new VueRouter({
    routes: [{ path: '/user/:id', component: () => import('./components/UserComponent.vue') }],
});
new Vue({
    router,
    el: '#app',
    render: h => h(App),
});

3. Update `webpack.mix.js`:

const mix = require('laravel-mix');
mix.js('resources/js/app.js', 'public/js')
    .vue() // Enables Vue single-file components
    .sass('resources/sass/app.scss', 'public/css');

For Vue 3.x Projects:

1. Install Vue and Vue Router via NPM/Yarn:
npm install vue@next vue-router@4

2. Set Up Your JavaScript Entry File (e.g., `resources/js/app.js`):

import { createApp } from 'vue';
import { createRouter, createWebHistory } from 'vue-router';
import App from './App.vue';

const routes = [{ path: '/user/:id', component: () => import('./components/UserComponent.vue') }];
const router = createRouter({
    history: createWebHistory(),
    routes,
});
const app = createApp(App);
app.use(router);
app.mount('#app');

3. Update `webpack.mix.js`:

 const mix = require('laravel-mix');
  mix.js('resources/js/app.js', 'public/js')
      .vue({ version: 3 }) // For Vue 3.x
      .sass('resources/sass/app.scss', 'public/css');

3. Avoid Conflicting Global Vue Instances

If you are using Vue via a CDN in your Blade template or elsewhere globally, ensure it doesn’t conflict with your bundled Vue instance.

1. Check Blade Template for Vue CDN:

If you include Vue via a CDN in your Blade template, remove it to prevent conflicts:

< !--Remove this if you use Vue via NPM / Yarn-- >
 < !-- < script src = "https://cdn.jsdelivr.net/npm/vue@2" > -->

2. Ensure Your Bundled Vue is Used:
Make sure you’re not mixing global Vue instances with your bundled Vue.

4. Compile Assets

Compile your assets after setting up:
npm run dev
or
yarn dev

5. Debugging

If the error persists:

-> Check Console:
Ensure `window.Vue` is not used elsewhere. You should use the Vue instance created via Webpack and not the global `window.Vue`.

-> Inspect Vue Instance:
Open the browser console and inspect `window.Vue` to ensure it is properly initialized and has the `use` method (for Vue 2.x):

console.log(window.Vue); // Check if Vue is correctly loaded