gitlab-org--gitlab-foss/spec/frontend/lib/utils/number_utility_spec.js

import {
  formatRelevantDigits,
  bytesToKiB,
  bytesToMiB,
  bytesToGiB,
  numberToHumanSize,
  sum,
} from '~/lib/utils/number_utils';

describe('Number Utils', () => {
  describe('formatRelevantDigits', () => {
    it('returns an empty string when the number is NaN', () => {
      expect(formatRelevantDigits('fail')).toBe('');
    });

    it('returns 4 decimals when there is 4 plus digits to the left', () => {
      const formattedNumber = formatRelevantDigits('1000.1234567');
      const rightFromDecimal = formattedNumber.split('.')[1];
      const leftFromDecimal = formattedNumber.split('.')[0];

      expect(rightFromDecimal.length).toBe(4);
      expect(leftFromDecimal.length).toBe(4);
    });

    it('returns 3 decimals when there is 1 digit to the left', () => {
      const formattedNumber = formatRelevantDigits('0.1234567');
      const rightFromDecimal = formattedNumber.split('.')[1];
      const leftFromDecimal = formattedNumber.split('.')[0];

      expect(rightFromDecimal.length).toBe(3);
      expect(leftFromDecimal.length).toBe(1);
    });

    it('returns 2 decimals when there is 2 digits to the left', () => {
      const formattedNumber = formatRelevantDigits('10.1234567');
      const rightFromDecimal = formattedNumber.split('.')[1];
      const leftFromDecimal = formattedNumber.split('.')[0];

      expect(rightFromDecimal.length).toBe(2);
      expect(leftFromDecimal.length).toBe(2);
    });

    it('returns 1 decimal when there is 3 digits to the left', () => {
      const formattedNumber = formatRelevantDigits('100.1234567');
      const rightFromDecimal = formattedNumber.split('.')[1];
      const leftFromDecimal = formattedNumber.split('.')[0];

      expect(rightFromDecimal.length).toBe(1);
      expect(leftFromDecimal.length).toBe(3);
    });
  });

  describe('bytesToKiB', () => {
    it('calculates KiB for the given bytes', () => {
      expect(bytesToKiB(1024)).toEqual(1);
      expect(bytesToKiB(1000)).toEqual(0.9765625);
    });
  });

  describe('bytesToMiB', () => {
    it('calculates MiB for the given bytes', () => {
      expect(bytesToMiB(1048576)).toEqual(1);
      expect(bytesToMiB(1000000)).toEqual(0.95367431640625);
    });
  });

  describe('bytesToGiB', () => {
    it('calculates GiB for the given bytes', () => {
      expect(bytesToGiB(1073741824)).toEqual(1);
      expect(bytesToGiB(10737418240)).toEqual(10);
    });
  });

  describe('numberToHumanSize', () => {
    it('should return bytes', () => {
      expect(numberToHumanSize(654)).toEqual('654 bytes');
    });

    it('should return KiB', () => {
      expect(numberToHumanSize(1079)).toEqual('1.05 KiB');
    });

    it('should return MiB', () => {
      expect(numberToHumanSize(10485764)).toEqual('10.00 MiB');
    });

    it('should return GiB', () => {
      expect(numberToHumanSize(10737418240)).toEqual('10.00 GiB');
    });
  });

  describe('sum', () => {
    it('should add up two values', () => {
      expect(sum(1, 2)).toEqual(3);
    });

    it('should add up all the values in an array when passed to a reducer', () => {
      expect([1, 2, 3, 4, 5].reduce(sum)).toEqual(15);
    });
  });
});