refactor(overmind): improve typing of derived

Author: christianalfoni

packages/node_modules/overmind/src/derived.test.ts

@@ -91,7 +91,7 @@ describe('Derived', () => {
 
   test('should dynamically add derived', () => {
     const addDerived: Action = ({ state }) => {
-      state.upperFoo = derived<Derive<typeof state, string>>((state) => state.foo.toUpperCase())
+      state.upperFoo = derived<typeof state, string>((state) => state.foo.toUpperCase())
     }
     const changeFoo: Action = ({ state }) => {
       state.foo = 'bar2'

packages/node_modules/overmind/src/index.ts

@@ -73,7 +73,7 @@ export { SERIALIZE, rehydrate } from './rehydrate'
 
 export { Statemachine, statemachine } from './statemachine'
 
-export const derived = <D extends IDerive<any, any, any>>(cb: D): D extends IDerive<any, any, infer U> ? U : never => cb as any
+export const derived = <S extends IState, V, C = Config>(cb: IDerive<C, S, V>): V => cb as any
 
 /** This type can be overwriten by app developers if they want to avoid
  * typing and then they can import `Action`,  `Operation` etc. directly from