Mapped type for combineReducers in index.d.ts

[mkusher]

From #2177

1. Added generic interface for Dispatch(from master)
2. Updated reducer type to support strict null checks
3. Added mapped type for combineReducers, so that result reducer type can be inferred from arguments

[timdorr]

Thanks!

[drewnoakes]

This looks great and I'd love to use it. As it's merged to next, is there an npm package containing this definition file somewhere?

[aikoven]

@drewnoakes For now you can use updated typings by adding this to your package.json dependencies:

"redux-next": "reactjs/redux#next"

And telling TypeScript to look for Redux typings there:

// tsconfig.json
{
  "compilerOptions": {
    "baseUrl": ".",
    "paths": {
      "redux": ["node_modules/redux-next"]
    }
  }
}

[drewnoakes]

@aikoven thanks very much, this looks great.

To confirm, redux-next is a different NPM package. It should be used in place of redux, or are you suggesting using redux-next in dev-dependencies and only taking its type declarations? Is that even possible?

[aikoven]

It is not an NPM package, "reactjs/redux#next means the files from Redux GitHub repository on the next branch. So you'll end up with two versions of Redux in your node_modules, but the next one will be called redux-next. Then you're just telling TS where the typings for redux are.

[MichaelTontchev]

@aikoven sorry to necro this old thread, but when can we expect this change to go through to @types/redux ?

[aikoven]

@MichaelTontchev Redux typings are bundled with redux NPM package so you don't have to install @types/redux separately.

Unfortunately, we can't release this change without bumping major version of redux, so we have to wait indefinitely until a critical mass of breaking changes forms v4 of Redux.

I'd be happy to put Redux typings to @types, but currently, it would mean that they must be kept in DefinitelyTyped which is not convenient for multiple reasons. Hopefully one day we can use @types while maintaining typings in a separate repo. And I guess this will happen before v4.

[MichaelTontchev]

Got it.

Just curious: any idea why there is a separate @types/redux, then? Is it different from the typings maintained in this repo?