import type { StateCreator, StoreMutatorIdentifier } from '../vanilla'

type Write<T, U> = Omit<T, keyof U> & U

export function combine<
    T extends object,
    U extends object,
    Mps extends [StoreMutatorIdentifier, unknown][] = [],
    Mcs extends [StoreMutatorIdentifier, unknown][] = []
>(initialState: T, create: StateCreator<T, Mps, Mcs, U>): StateCreator<Write<T, U>, Mps, Mcs> {
    return (...args) => Object.assign({}, initialState, (create as any)(...args))
}