Javascript Tricks Arrays Easily convert NodeList/HTMLCollection to Array with ES6 spread operator const arr = [...document.querySelectorAll('div')]; Vue Unique ID generator for keys. Reuse uid if already exist on object.
Unit Testing vs. End to End Testing: Unit/Component: Test a single Component, Service, Pipe etc. Test a single specific behaviour in a controlled environment Mock everything you need to test this functionality Use code coverage analysis to make sure everything is covered (Usually) Improves code structure and quality Test edge cases on the most detailed level Know if a change breaks a specific behaviour