While in ES5 ‘this’ referred to the parent of the function, in ES6, arrow functions use lexical scoping — ‘this’ refers to it’s current surrounding scope and no further. Thus the inner, and not to the object’s method or the object itself.
The cycle for adding new features, including any refactoring, is roughly this: write failing test; code; get to green; make it right. If you’re doing it right, you’re executing a lot of unit tests along the way, sometimes a focused set and sometimes the entire suite.
It is a long established fact that a reader will be distracted by the readable con tent of a page nomao when loing at its layout. The point of using Ipsum is that it has a more-or-less normal distribution of letters readable content of a page.