@171h/dayjs-business-time/test/subtractBusinessHours.spec.ts

A [Day.js](https://github.com/iamkun/dayjs) plugin that allows you to work with Business Time.

import dayjs from 'dayjs';
import businessTime from '../src';

describe('Subtract Business Hours', () => {
  beforeAll(() => {
    dayjs.extend(businessTime);

    const holidays = ['2021-01-01', '2021-01-25', '2021-06-03'];

    dayjs.setHolidays(holidays);

    // Setting wednesday working hours for 2 segments
    //   with 3 and 5 hours respectively
    const businessHours = dayjs.getBusinessTime();
    businessHours.wednesday = [
      { start: '09:00:00', end: '12:00:00' },
      { start: '13:00:00', end: '18:00:00' },
    ];
  });

  it('should subtract 3 business hours on a date', () => {
    const date = dayjs('2021-02-08 12:00:00');
    const expected = dayjs('2021-02-08 09:00:00');

    const newDate = date.subtractBusinessHours(3);

    expect(newDate).toBeDefined();
    expect(newDate).toStrictEqual(expected);
  });

  it('should subtract 5 business hours on a date in a day with 2 working segments', () => {
    const date = dayjs('2021-02-03 17:30:00');
    const expected = dayjs('2021-02-03 11:30:00');

    const newDate = date.subtractBusinessHours(5);

    expect(newDate).toBeDefined();
    expect(newDate).toStrictEqual(expected);
  });

  it('should subtract 4 business hours on a date after a weekend', () => {
    // february 25th, 2021 is a monday
    const date = dayjs('2021-02-22 11:00:00');

    // february 19th, 2021 is a friday
    const expected = dayjs('2021-02-19 15:00:00');

    const newDate = date.subtractBusinessHours(4);

    expect(newDate).toBeDefined();
    expect(newDate).toStrictEqual(expected);
  });

  it('should subtract 2 business hours on a date after a holiday', () => {
    // june 4th, 2021 is a friday
    //   after corpus christ holiday
    const date = dayjs('2021-06-04 10:00:00');

    // june 2nd, 2021 is a wednesday
    const expected = dayjs('2021-06-02 17:00');

    const newDate = date.subtractBusinessHours(2);

    expect(newDate).toBeDefined();
    expect(newDate).toStrictEqual(expected);
  });

  it('should subtract 16 business hours on a date after a long weekend', () => {
    // january 26th, 2021 is a tuesday
    //   after São Paulo City anniversary
    const date = dayjs('2021-01-26 12:00:00');

    // january 21nd, 2021 is a thusrday
    const expected = dayjs('2021-01-21 12:00:00');

    const newDate = date.subtractBusinessHours(16);

    expect(newDate).toBeDefined();
    expect(newDate).toStrictEqual(expected);
  });
});