AsyncMappedFactory

Creates output values asynchronously by mapping a completed input object.

Use this factory when producing the value is asynchronous, such as when the entity has to be created in a database, a client or a simulator, or when the value has to be fetched, signed or encoded by something that returns a promise. Each call to make builds the input defaults, applies deep partial overrides, and passes the completed input to the mapper function.

The overrides describe what is asked for, and the return value is what comes back, so the two are separate types in the same way as MappedFactory.

The mapper function can also declare dependencies, which are passed to make after the overrides. Only the mapper function is awaited, so anything that has to be fetched first is fetched before make is called and passed in as an override or a dependency.

Usage

interface NewUser {
  name: string;
  email: string;
}

interface User extends NewUser {
  id: string;
}

interface UserDatabase {
  insertUser(newUser: NewUser): Promise<User>;
}

const userFactory = new AsyncMappedFactory<
  NewUser,
  User,
  { database: UserDatabase }
>(
  () => ({
    name: "Test User",
    email: "test.user@example.com",
  }),
  (newUser, { database }) => database.insertUser(newUser),
);

const user = await userFactory.make({}, { database });
// { id: "...", name: "Test User", email: "test.user@example.com" }

const namedUser = await userFactory.make({ name: "Foo" }, { database });
// { id: "...", name: "Foo", email: "test.user@example.com" }

Source

Source file: src/mapped/async-mapped-factory.ts