import { map, flat, filter, reject, reduce, find } from '../Array';
import { none, some } from '../Option';

describe('map', () => {
  it('works', () => {
    expect(map((num: number) => num * 2)([1, 2, 3, 4])).toEqual([2, 4, 6, 8]);
  });
});

describe('filter', () => {
  it('works', () => {
    expect(filter((num: number) => num % 2 === 0)([1, 2, 3, 4])).toEqual([
      2,
      4,
    ]);
  });
});

describe('reject', () => {
  it('works', () => {
    expect(reject((num: number) => num % 2 === 0)([1, 2, 3, 4])).toEqual([
      1,
      3,
    ]);
  });
});

describe('find', () => {
  it('returns value when found the item', () => {
    expect(find((num: number) => num % 2 === 0)([1, 2, 3, 4])).toEqual(some(2));
  });

  it('returns none when the item is not found', () => {
    expect(find((num: number) => num % 2 === 100)([1, 2, 3, 4])).toEqual(none);
  });
});

describe('reduce', () => {
  it('works', () => {
    expect(
      reduce((acc: number, curr: number) => acc + curr, 0)([1, 2, 3, 4])
    ).toEqual(10);
  });
});

describe('flat', () => {
  it('flattens the nested arrays', () => {
    expect(
      flat([
        [1, 2],
        [3, 4],
      ])
    ).toEqual([1, 2, 3, 4]);
  });
});