API: combineAsync

Utility for merging multiple builder functions into a single flat API of asynchronous methods. Each builder receives a shared context (self) and returns an object of async functions; combineAsync binds them into one API, preserving original signatures.

function combineAsync<
  T extends Record<string, (self: any) => Record<string, (...args: any[]) => Promise<any>>>
>(
  builders: T,
  store: any
): CombinedAsync<T>

Parameters

• builders (T): A record of builder functions. Each builder is (self: any) => Record<string, (...args: any[]) => Promise<any>>, returning an object of async methods.
• store (any): The shared self object passed to every builder.

Return Value

• Returns CombinedAsync<T> — an object combining all async methods from each builder. Each method has signature (...args: OriginalParameters) => Promise<OriginalReturnType>.

Behavior

• Iterates over all keys in builders.
• Calls each builder with store to retrieve its methods.
• Exposes each async method on the result object, forwarding arguments and return value.
• Methods remain bound to the provided store and preserve their Promise-based return types.

Example

// userApi.ts
import type { TState } from "../chunk"

export const userApi = (store: TState) => ({
  async fetchUser(id: number) {
    // your async code
  },
  async updateUser(user: User) {
    // your async code
  },
})

// postApi.ts
export const postApi = (store: TState) => ({
  async fetchPost(id: number) {
    // your async code
  },
})

// api.ts
import { combineAsync } from 'mobx-chunk'
import { userApi } from './userApi'
import { postApi } from './postApi'

const asyncActions = combineAsync({ userApi, postApi })

export const exampleStore = createChunk<
  {},
  {},
  TAsyncActions,
  {}
>({
  initialState: {} satisfies TState,
  name: "example",

  asyncActions,
})

Use combineAsync when you need to unify multiple asynchronous modules under a common store without shadowing individual method signatures.