feat: create a JS helpers class

[a2937]

Checklist:

• I have read freeCodeCamp's contribution guidelines.
• My pull request has a descriptive title (not a vague title like Update index.md)

Closes #XXXXX

In my opinion, it does come up fairly often that we use regex to ensure that variables are actually present in functions with default values; and I think the potential spacing issues aren't generally worth with it when we can just manually extract them.

I also tried to do some house-keeping and hopefully keep eslint from reformatting the fixtures as it is very space sensitive. As I use Visual Studio to edit Typescript, I also added some of the contents of VisualStudio.gitignore to the local gitignore. I will be be happy to remove the unrelated content and discuss them at a later date.

[naomi-lgbt]

The first thing that stands out is that this would break for valid single-parameter syntax:

const myFunc = name => console.log("Name");

[a2937]

Did I get it, as all tests seem to pass?

[ojeytonwilliams]

Hi @a2937, thanks for putting this together. The code looks like it does the job well, thanks. The only issue is that it's a little hard to read, so I made some suggestions for how that could be improved:

[ojeytonwilliams]

This looks great. Thanks @a2937!

@naomi-lgbt If you're happy, merge away.

[naomi-lgbt]

Ship it