import * as B from "."
import { constant, map, never, toProperty } from "./index"
import { expectPropertyEvents, expectStreamEvents, series } from "./test-utils"

const times2 = (x: number) => x * 2
const toString = (x: number) => "" + x

describe("Property.map", () => {
  describe("maps property values", () => {
    expectPropertyEvents(() => {
      const x = series(1, [2]).pipe(toProperty(1), map(toString))
      return x
    }, ["1", "2"])
  })

  it("Minimizes calls to mapping function", () => {
    let count = 0
    const property = B.constant("foo")
    const mapped = property.pipe(
      B.map((value: string) => {
        count++
      })
    )
    mapped.forEach((value) => {})
    expect(count).toEqual(1)
  })
})

describe("EventStream.map", () => {
  describe("should map with given function", () =>
    expectStreamEvents(() => map(times2)(series(1, [1, 2, 3])), [2, 4, 6]))

  describe("can map to a Property value", () => {
    expectStreamEvents(() => map(constant(2))(series(1, [1, 2, 3])), [2, 2, 2])
  })
  it("toString", () => {
    expect(map(() => true)(never()).toString()).toEqual(
      "EventStream never.map(fn)"
    )
  })
})