import { flatMap, never } from "."
import { fromArray } from "./fromarray"
import { expectStreamEvents, series } from "./test-utils"
import { nop } from "./util"

describe("EventStream.flatMap", function () {
  describe("should spawn new stream for each value and collect results into a single stream", () =>
    expectStreamEvents(() => {
      const op = flatMap((value: number) => series(2, [value, value]))
      const s = series(1, [1, 2]).pipe(op)
      return s
    }, [1, 2, 1, 2]))
  describe("works in combination with fromArray", () =>
    expectStreamEvents(() => {
      const op = flatMap((value: number) => fromArray([value, value]))
      const s = series(1, [1, 2]).pipe(op)
      return s
    }, [1, 1, 2, 2]))
  /*
  describe("Works also when f returns a Property instead of an EventStream", () =>
    expectStreamEvents(
      () => flatMap(constant)(series(1, [1,2])),
      [1,2])
  );
  */
  it("toString", () =>
    expect(flatMap(nop as any)(never()).toString()).toEqual(
      "EventStreamSeed never.flatMap(fn)"
    ))
})