An elementary question about $scope and this in AngularJS, as well as the need to test the code?

Question

JavaScript

Elementary question.
I am learning to work with AngularJS from the book "AngularJS Up & Running". Applied everywhere
this.propertyName
Although in other examples, I often see the use of $scope controller injection and use it accordingly in the code.
I read that such changes since 1.2 version of AngularJS.
1) What to use?
And one more question, I want to immediately start writing tests using the Karma + Jasmine bundle. 2) How relevant is this now for production and how would you recommend learning testing, after mastering the basics of AngularJS or in the learning process?

Answer 1

The sooner you start and learn how to write tests, the better.
In the long run, tests, if they don’t save you time, will certainly save nerve cells.

Answer 2

1) by and large, who likes what 2) I join Konstantin Kitmanov

Answer 3

this is used in conjunction with the controller as syntax, which can be handy if you're using nested controllers. Although personally, I think using data from parent controllers in templates is a very bad practice.