Choosing a test runner

A test runner is a program that runs tests.

There are many popular JavaScript test runners, and Vue Test Utils works with all of them. It's test runner agnostic.

There are a few things to consider when choosing a test runner though: feature set, performance, and support for single-file component (SFC) pre-compilation. After carefully comparing existing libraries, here are two test runners that we recommend:

  • Jest is the most fully featured test runner. It requires the least configuration, sets up JSDOM by default, provides built-in assertions, and has a great command line user experience. However, you will need a preprocessor to be able to import SFC components in your tests. We have created the vue-jest preprocessor which can handle most common SFC features, but it currently does not have 100% feature parity with vue-loader.

  • mocha-webpack is a wrapper around webpack + Mocha, but with a more streamlined interface and watch mode. The benefits of this setup is that we can get complete SFC support via webpack + vue-loader, but it requires more configuration upfront.

Browser Environment

Vue Test Utils relies on a browser environment. Technically you can run it in a real browser, but it's not recommended due to the complexity of launching real browsers on different platforms. Instead, we recommend running the tests in Node with a virtual browser environment using JSDOM.

The Jest test runner sets up JSDOM automatically. For other test runners, you can manually set up JSDOM for the tests using jsdom-global in the entry for your tests:

npm install --save-dev jsdom jsdom-global

// in test setup / entry
require('jsdom-global')()

Testing Single-File Components

Single-file Vue components (SFCs) require pre-compilation before they can be run in Node or in the browser. There are two recommended ways to perform the compilation: with a Jest preprocessor, or directly use webpack.

The vue-jest preprocessor supports basic SFC functionalities, but currently does not handle style blocks or custom blocks, which are only supported in vue-loader. If you rely on these features or other webpack-specific configurations, you will need to use a webpack + vue-loader based setup.

Read the following guides for different setups:

Resources