Testing JavaScript ( Kent C. Dodds ) Free Download – Google Drive Links
Learn the smart, efficient way to test any JavaScript application.
—YOUR ESSENTIAL Manual for FLAWLESS TESTING —

What is the point of testing your JavaScript?
At the point when a client encounters a bug they seem to be this: ????
Bugs grind work to a halt.
Bugs cause financial harm.
Each and every time a bug is encountered, client trust dissolves.
Bugs are bad.
And who gets blamed?
You.
The developer.
You realize you ought to squash bugs before your code is conveyed.
You realize you want to transport code that:
Takes each opportunity to guarantee that it works.
Doesn't rebuff clients with unnecessary bugs.
Doesn't play whack-a-mole with features, fixing one thing just to break another.
Is maintainable and understandable to your co-laborers.