added option to use generic for Transition.params

[csvn]

Proposed fix for #16. This should not introduce any breaking changes, it should just give you the additional option of specifying which properties do appear in .params (with types).

Example in typescript playground.

[christopherthielen]

I completely agree. Being limited to the array notation is frustrating. I've gotten used to params()['fooid'] though, since it seems to be idiomatic typescript.

I think it might be even more ergonomic to developers to simply return any.

trans.params().id

The downside is that you lose the ability to do compile-time checking like your example.

I propose changing the signature to:

   params(pathname: string = "to"): any;
   params<T>(pathname: string = "to"): T {
      return this._treeChanges[pathname].map(prop("paramValues")).reduce(mergeR, {});
    }

Omitting the type parameter gives you any

trans.params().id

but including a type parameter gives you a typed object

trans.params<SomeInterface>().asdfasdf // compile time error

[csvn]

Yeah, the usefulness of { [key: string: any } compared to just using any is a bit limited, but I was hesitant to change that for the initial commit in this pull request.

I like your suggestion, seems to cover any use cases I come up with. Pull request updated.

Interesting sidenote: Using the generic in the method signature (like your example) did not work. Swapping the order of the rows does work though (example in playground). Not sure if this is a bug or by design, but it seems weird to me.

Edit: fixed bugged link (share button works only once)

[csvn]

You can ignore the last part of my comment above. Seems I just misunderstood the type declaration when used in classes. I have used interfaces mostly when I needed multiple signatures.

class Test {
  foo(): number;
  foo<T>(): T { ... }
}
// is equivalent to:
interface Test {
  foo(): number;
}

[christopherthielen]

^ That threw me for a loop too!