[api] Multiple compile errors related to IGet<K, V>

[andrew8er]

I get multiple errors in package @thi.ng/associative:

node_modules/@thi.ng/associative/array-set.d.ts:18:5 - error TS2416: Property 'copy' in type 'ArraySet<T>' is not assignable to the same property in base type 'IEquivSet<T>'.
  Type '() => ArraySet<T>' is not assignable to type '() => IEquivSet<T>'.
    Type 'ArraySet<T>' is not assignable to type 'IEquivSet<T>'.
      Types of property 'get' are incompatible.
        Type '(x: T, notFound?: T | undefined) => T | undefined' is not assignable to type '(key: T, notfound?: T | undefined) => T'.
          Type 'T | undefined' is not assignable to type 'T'.
            Type 'undefined' is not assignable to type 'T'.

18     copy(): ArraySet<T>;
       ~~~~

I think the reason is an incorrect return type in IGet.get(), it should be V | undefined:

// @thi.ng/api/api.d.ts:
export interface IGet<K, V> {
    get(key: K, notfound?: V): V | undefined;
}

[postspectacular]

Hi @andrew8er - let me guess, you're having some TS "strict" compiler flags enabled? Coincidentally I've recently done some initial work on a local feature branch to finally enable "strict" (minus "strictNullChecks", which I find too intensive to fully support right now). Only updated around a dozen of the 90 packages in total so far, but will merge WIP into develop branch..

[andrew8er]

Yes, I always use strict, including strictNullChecks. I really think it forces me to write better code. Do you need some help?

[postspectacular]

Thanks, @andrew8er - I will push the updates done so far later today and if you've got time would very much appreciate your watchful eye passing over them and maybe even help w/ updating the rest. Have done some more last night and guessing around 50% done so far...

In general, I'm all for enabling strict (hence why I started already on this), but am also pragmatic (coming from Clojure) and went for low hanging fruits only so far...

[andrew8er]

I think you are referring to branch feature/strict? I will have a look at it. I only used @thi.ng/rstream and @thi.ng/transducers so far, so I might be most helpful with these.

[postspectacular]

Well, yes, with pushing updates, I did mean the #89 PR (feature/strict branch), but generally I was referring to the strict compiler flag. Btw. all packages are now updated with more type hints and in some cases minor new type additions, so yarn build will succeed now on that branch (with strict flag enabled for all). I started updating the tests too, but prob will take me another few days...