@johngw/stream/test/sinks/SinkComposite.test.ts

Reactive programming tools using the WHATWG Streams API.

import { fromTimeline } from '@johngw/stream-jest'
import { SinkComposite } from '@johngw/stream/sinks/SinkComposite'

test('composing underlying sinks', async () => {
  const close = jest.fn()
  const start = jest.fn()
  const write = jest.fn()

  await fromTimeline(`
    --1--2--3--4--5--|
  `).pipeTo(
    new WritableStream(
      new SinkComposite([
        {
          close,
          start,
          write,
        },
        {
          close,
          start,
          write,
        },
      ])
    )
  )

  expect(close.mock.calls).toEqual([[], []])

  expect(start.mock.calls).toEqual([
    [expect.any(WritableStreamDefaultController)],
    [expect.any(WritableStreamDefaultController)],
  ])

  expect(write.mock.calls).toEqual([
    [1, expect.any(WritableStreamDefaultController)],
    [1, expect.any(WritableStreamDefaultController)],
    [2, expect.any(WritableStreamDefaultController)],
    [2, expect.any(WritableStreamDefaultController)],
    [3, expect.any(WritableStreamDefaultController)],
    [3, expect.any(WritableStreamDefaultController)],
    [4, expect.any(WritableStreamDefaultController)],
    [4, expect.any(WritableStreamDefaultController)],
    [5, expect.any(WritableStreamDefaultController)],
    [5, expect.any(WritableStreamDefaultController)],
  ])
})