import { it, assert, assertEq } from 'folktest'
import { dispatch } from '../../src/fantasy-land.js'

const test = (re, str = '') => re instanceof RegExp ? re.test(str) : new RegExp(re).test(str)

const assertErr = (f, err) => {
  try {
    f()
  } catch (e) {
    if (typeof err === 'string' || err instanceof RegExp) {
      assert(test(err, e.message), `${err} did not match ${e.message}`)
    } else if (typeof err === 'function') {
      assert(e.constructor === err)
    }

    return
  }

  const expected = err ? `"${err}" ` : ""
  assert(false, `expecting error ${expected}but function did not throw`)
}

const wrong = msg => assert(false, msg)

export const Dispatch = [
  it('should dispatch to any listed method or fallback', () => {
    const a1 = {
      ['fantasy-land/test']: x => assertEq(x, 1),
      test: () => wrong(`a1['test'] should not have been called`)
    }

    const f1 = dispatch(['fantasy-land/test', 'test'], (v, x) => {
      wrong(`f1 fallback should not have been called for ${JSON.stringify(x)}`)
    })

    f1(1, a1)

    delete a1['fantasy-land/test']

    assertErr(() => {
      f1(1, a1)
    })

    const f2 = dispatch(['test', 'fantasy-land/test'], (v, x) => {
      wrong(`f2 fallback should not have been called for ${JSON.stringify(x)}`)
    })

    const a2 = {
      ['fantasy-land/test']: () => wrong(`a2['fantasy-land/test'] should not have been called`),
      test: x => assertEq(x, 2)
    }

    f2(2, a2)

    const f3 = dispatch(['fantasy-land/test', 'test'], x => {
      assertEq(x, 3)
    })

    f3(3, {})
  })
]