Transient Fields

[mizdra]

ref: #1

Example

const BookFactory = defineBookFactory({
  defaultFields: {
    id: lazy(({ seq }) => `Book-${seq}`),
    title: lazy(({ seq }) => `ゆゆ式 ${seq}巻`),
    author: undefined,
  },
});
const AuthorFactory = defineAuthorFactoryWithTransientFields(
  {
    bookCount: 0,
  },
  {
    defaultFields: {
      id: lazy(({ seq }) => `Author-${seq}`),
      name: '三上小又',
      books: lazy(async ({ get }) => {
        const bookCount = await get('bookCount');
        // eslint-disable-next-line max-nested-callbacks
        return Promise.all(Array.from({ length: bookCount }, async () => BookFactory.build()));
      }),
    },
  },
);
const author1 = await AuthorFactory.build();
expect(author1).toStrictEqual({
  id: 'Author-0',
  name: '三上小又',
  books: [],
});
assertType<{
  id: string;
  name: string;
  books: { id: string; title: string; author: undefined }[];
}>(author1);
expectTypeOf(author1).not.toBeNever();

const author2 = await AuthorFactory.build({ bookCount: 3 });
expect(author2).toStrictEqual({
  id: 'Author-1',
  name: '三上小又',
  books: [
    { id: 'Book-0', title: 'ゆゆ式 0巻', author: undefined },
    { id: 'Book-1', title: 'ゆゆ式 1巻', author: undefined },
    { id: 'Book-2', title: 'ゆゆ式 2巻', author: undefined },
  ],
});
assertType<{
  id: string;
  name: string;
  books: {
    id: string;
    title: string;
    author: undefined;
  }[];
}>(author2);

[mizdra]

I really wanted to allow transientFields in the defineAuthorFactory, but I couldn't. For more information: #17