import { later } from "."
import { constant, never, update } from "./index"
import { expectPropertyEvents, testScope } from "./test-utils"

describe("update", function () {
  describe("Updates value based on stream events", () =>
    expectPropertyEvents(
      function () {
        const a = later(1, "x")
        const b = later(2, "y")

        return update(0, [a, (acc, x) => acc + x], [b, (acc, x) => acc + x])
      },
      [0, "0x", "0xy"]
    ))

  describe("Support property value capture", () =>
    expectPropertyEvents(
      function () {
        const a = later(1, "x")
        const b = later(2, "y")
        const p = constant("C")

        return update(
          0,
          [a, (acc, x) => acc + x],
          [b, p, (acc, x, c) => acc + x + c]
        )
      },
      [0, "0x", "0xyC"]
    ))

  describe("Supports constant result value", () =>
    expectPropertyEvents(
      function () {
        const a = later(1, "x")
        const b = later(2, "y")

        return update(0, [a, (acc, x) => acc + x], [b, 666])
      },
      [0, "0x", 666]
    ))

  describe("Scoped version", () =>
    expectPropertyEvents(
      function () {
        const a = later(1, "x")
        const b = later(2, "y")

        return update(testScope(), 0, [a, (acc, x) => acc + x], [b, 666])
      },
      [0, "0x", 666]
    ))

  it("toString", () => {
    expect(update(0, [never(), (state, v) => state]).toString()).toEqual(
      "PropertySeed update(0,[[never,fn]])"
    )
  })
})