Feature request: Implicit typing of actions using TypeScript type guards

[ikorolev93]

If you have a function with a signature like (action: any) => action is FooAction in your type field, action should be FooAction in the hooks.
Proof of concept:

interface FooAction {
  type: "FOO";
  payload: {
    foo: number;
  }
}
type TypeGuard<A> = (action: any) => action is A;
declare const isFoo: TypeGuard<FooAction>;
interface LogicConfig<A> {
  type: TypeGuard<A>;
  process: (data: { action: A }) => void;
}
declare function createLogic<A>(cfg: LogicConfig<A>): void;
createLogic({
  type: isFoo,
  process({ action }) {
    action.payload.foo.toFixed(); // no error
    action.payload.bar; // error
  }
});

Unfortunately I'm not too familiar with this project's definitions to make a PR in the near future.

[ikorolev93]

Made a PR not using the type guards, but the return type of the action creator: #134