The ARK Explorer is currently missing a real test suite as Core v2 development is consuming all time so we are running a bounty for a test suite that provides unit tests and e2e tests.
You should be familiar with Vue.js as a framework for the front-end. When it comes to tests you should know how to write meaningful tests with Jest and Nightwatch.js.
Vue.js - https://vuejs.org/
Vue Test Utils - https://github.com/vuejs/vue-t...
Nightwatch.js - http://nightwatchjs.org/