vue-node

A require hook for loading single-file vue components in node. Useful for testing without having to spin up web browsers!

Impending Deprecation Notice

The Vue team is going to be creating official testing tools based on avoriaz which already has complete examples of how to test Vue components in node-based testing frameworks without spinning up web browsers. My suggestion is for users of this library to migrate to avoriaz and then to the official testing tools once those are available. Once the official testing tools are available, I will mark this package as deprecated on npm.

Usage of this library will also require changes to your vue-loader configuration starting with version ^12.0.0. See issue #9 for more details.

Usage Example

Here is an example of using vue-node with AVA. The process should be similar for whatever node testing framework you want to use.

First, make sure you have vue-node and browser-env installed as development dependencies. If you are running an environment with vue-loader and webpack@2 then you will already have all required peer dependencies:

npm i -D vue-node browser-env

Now create a setup file called test/helpers/setup.js. Putting it in the test/helpers directory will let AVA know that this file is not a test.

const browserEnv = require('browser-env');
const hook = require('vue-node');
const { join } = require('path');

// Setup a fake browser environment
browserEnv();
// Pass an absolute path to your webpack configuration to the hook function.
hook(join(__dirname, 'webpack.config.test.js'));

Now you can configure AVA to require this file in all test processes. In package.json:

{
  "ava": {
    "require": [
      "./test/helpers/setup.js"
    ]
  }
}

Now you can require / import .vue files and test like you would in a browser! If you need to test DOM updates, you can use Vue.nextTick along with async / await.

import Vue from 'vue';
import test from 'ava';
import TestComponent from './test.vue';

test('renders the correct message', async (t) => {
  const Constructor = Vue.extend(TestComponent);
  const vm = new Constructor().$mount();
  t.is(vm.$el.querySelector('h1').textContent, 'Hello, World!');
  // Update
  vm.setName('Foo');
  await Vue.nextTick();
  t.is(vm.$el.querySelector('h1').textContent, 'Hello, Foo!');
});

See the test directory in this project for more examples!

Common Questions

How does this work?

Node allows developers to hook require to load files that aren't JavaScript or JSON. Unfortunately, require hooks have to be synchronous. Using vue-loader on the other hand, is inherently asynchronous. vue-node works by synchronously running webpack in a separate process and collecting the output to pass to node's module compilation system. The compilation is done completely in memory without writing to the filesystem. It also modifies your webpack configuration to automatically build for node and commonjs with all dependencies of your component externalized. This means that the built component modules are as small as possible with dependency resolution left up to node.

What if I am using vueify?

I am personally more familiar with webpack than browserify, so for the time being this will only work in combination with webpack. I will gladly accept a pull request to implement browserify functionality.

What about testing in web browsers?

Unit testing in web browsers is a very heavy process with many tradeoffs. Configuration and tooling is tricky as is getting browsers to run in CI. I personally like saving browsers for end-to-end testing with things like Nightwatch.js.

License

MIT

knpwrs/vue-node