Jest + Vue Hack Session
Getting started
hub clone jonboiser/jest-hack-session
yarn install
yarn run test
Running in watch mode
During exercises, run it in watch mode:
yarn run test:dev
Sometimes you will need to press w to see some options.
Features to try
Auto-detecting changed files
In watch mode, only tests related to recently changed files (uncommitted changes in git) will be run. Modify some bit of test or application code and see which tests get run.
Also check out the cool diffs and stack traces you get with errors.
Snapshot tests
One test HelloWorldSnap.spec.js is designed as a snapshot test. Modify HelloWorldSnap.vue in way that changes how it would appear in the DOM and fix the failing test by editing its snapshot.
You can fix the snapshot manually (recommended) or automatically in the CLI by pressing u.
Mocking functions
The tests Mocking.spec.js are failing because the component Mocking.vue relies on an HTTP call made on its beforeMount lifecycle hook. We need to mock a method in Mocking.vue to get it to work.
vue-test-utils docs on mocking
Async tests
In asyncStuff.js there is a function promiser that returns a Promise<string>. Write a test for it. For fun, add a test that handles the error case as well.
Put the test in the same directory as asyncStuff.js, but in a sub folder __tests__ (Jest will look for tests in directories with this name).