Modeling Nested API Calls

export const getPost = (id: number): Effect.Effect<never, never, Post> =>
  Effect.gen(function* (_) {
    yield* _(Effect.sleep('0.3 seconds'))
    return { id, title: 'Love them futures' }
  })

export const getComments = (id: number): Effect.Effect<never, never, string[]> =>
  Effect.gen(function* (_) {
    yield* _(Effect.sleep('0.3 seconds'))
    return ['This book should be illegal', 'Monads are like space burritos']
  })

const renderComments = (xs: string[]) =>
  xs.reduce((acc: string, c: string): string => `${acc}<li>${c}</li>`, '')
const render =
  ({ title }: Post) =>
  (cs: string[]) =>
    `<div>${title}</div><ul>${renderComments(cs)}</ul>`
// renderDOM :: Effect<never,never,HTML>
const renderDOM = pipe(Option.lift2(render), getPost(2), getComments(2))
const html = await Effect.runPromise(renderDOM)
expect(html).toBe(
  '<div>Love them futures</div><ul><li>This book should be illegal</li><li>Monads are like space burritos</li></ul>'
    )