New: Add type arguments and parameters to AST

[Pajn]

For prettier/prettier/issues/13 this information must be preserved in the AST.
I had no idea how to create the test so I just did what seemed reasonable but please correct me if it's wrong.

[jsf-clabot]

All committers have signed the CLA.

[eslintbot]

Thanks for the pull request, @Pajn! I took a look to make sure it's ready for merging and found some changes are needed:

• Pull requests with code require an issue to be mentioned at the end of the commit summary, such as (fixes #1234). Please update the commit summary with an issue (file a new issue if one doesn't already exist).

Can you please update the pull request to address these?

(More information can be found in our pull request guide.)

[eslintbot]

LGTM

[soda0289]

I think you will want to use convertTSTypeParametersToTypeParametersDeclaration() to convert the typescript type parameters instead of convertTypeArgumentsToTypeParameters()

I'm not a 100% sure thou. @JamesHenry do you know why there are two functions it seems one is only used for class declarations?

The tests look fine to me.

[eslintbot]

LGTM

[Pajn]

I understood it as convertTSTypeParametersToTypeParametersDeclaration is for declaring them (introducing them in the scope) and convertTypeArgumentsToTypeParameters is for passing them, which is what is done in CallExpressions.

I realized that primitive types did not work, which is in my second commit. I'm unsure if I should include that in this PR or not. But I guess the above confusion must be solved first to even see if I modified the correct function :)

[eslintbot]

LGTM

[eslintbot]

LGTM

[soda0289]

@Pajn you could be correct. I just saw that convertTypeArgumentsToTypeParameters() is only used for class declarations.

Reading the code I don't think the new expression const a = new A<B>(); is also not keeping the type arguments. Is this correct? Do you want to add support for this as well?

[soda0289]

I also think class declarations do not record the generic type argument, only the implement clauses do. For example:

class A<T> {

}

[eslintbot]

LGTM

[eslintbot]

LGTM

[Pajn]

Good catches! Might as well get as many cases as possible fixed.

[soda0289]

Nice looks good!

[eslintbot]

LGTM

[JamesHenry]

This LGTM, thanks @Pajn! It just needs to be rebased against master. You could also squash the commits down into a single one whilst you do that.

[eslintbot]

LGTM

[Pajn]

Done. I was unsure on New/Fix again, I can change to what you prefer.

I must say thank you to both of you for being both helpful and very responsive on these PRs!