fraction.test.ts

import { Fraction } from '../src'
import JSBI from 'jsbi'

describe.only('Fraction', () => {
  describe('#quotient', () => {
    it('floor division', () => {
      expect(new Fraction(JSBI.BigInt(8), JSBI.BigInt(3)).quotient).toEqual(JSBI.BigInt(2)) // one below
      expect(new Fraction(JSBI.BigInt(12), JSBI.BigInt(4)).quotient).toEqual(JSBI.BigInt(3)) // exact
      expect(new Fraction(JSBI.BigInt(16), JSBI.BigInt(5)).quotient).toEqual(JSBI.BigInt(3)) // one above
    })
  })
  describe('#remainder', () => {
    it('returns fraction after divison', () => {
      expect(new Fraction(JSBI.BigInt(8), JSBI.BigInt(3)).remainder).toEqual(
        new Fraction(JSBI.BigInt(2), JSBI.BigInt(3))
      )
      expect(new Fraction(JSBI.BigInt(12), JSBI.BigInt(4)).remainder).toEqual(
        new Fraction(JSBI.BigInt(0), JSBI.BigInt(4))
      )
      expect(new Fraction(JSBI.BigInt(16), JSBI.BigInt(5)).remainder).toEqual(
        new Fraction(JSBI.BigInt(1), JSBI.BigInt(5))
      )
    })
  })
  describe('#invert', () => {
    it('flips num and denom', () => {
      expect(new Fraction(JSBI.BigInt(5), JSBI.BigInt(10)).invert().numerator).toEqual(JSBI.BigInt(10))
      expect(new Fraction(JSBI.BigInt(5), JSBI.BigInt(10)).invert().denominator).toEqual(JSBI.BigInt(5))
    })
  })
  describe('#add', () => {
    it('multiples denoms and adds nums', () => {
      expect(new Fraction(JSBI.BigInt(1), JSBI.BigInt(10)).add(new Fraction(JSBI.BigInt(4), JSBI.BigInt(12)))).toEqual(
        new Fraction(JSBI.BigInt(52), JSBI.BigInt(120))
      )
    })

    it('same denom', () => {
      expect(new Fraction(JSBI.BigInt(1), JSBI.BigInt(5)).add(new Fraction(JSBI.BigInt(2), JSBI.BigInt(5)))).toEqual(
        new Fraction(JSBI.BigInt(3), JSBI.BigInt(5))
      )
    })
  })
  describe('#subtract', () => {
    it('multiples denoms and subtracts nums', () => {
      expect(
        new Fraction(JSBI.BigInt(1), JSBI.BigInt(10)).subtract(new Fraction(JSBI.BigInt(4), JSBI.BigInt(12)))
      ).toEqual(new Fraction(JSBI.BigInt(-28), JSBI.BigInt(120)))
    })
    it('same denom', () => {
      expect(
        new Fraction(JSBI.BigInt(3), JSBI.BigInt(5)).subtract(new Fraction(JSBI.BigInt(2), JSBI.BigInt(5)))
      ).toEqual(new Fraction(JSBI.BigInt(1), JSBI.BigInt(5)))
    })
  })
  describe('#lessThan', () => {
    it('correct', () => {
      expect(
        new Fraction(JSBI.BigInt(1), JSBI.BigInt(10)).lessThan(new Fraction(JSBI.BigInt(4), JSBI.BigInt(12)))
      ).toBe(true)
      expect(new Fraction(JSBI.BigInt(1), JSBI.BigInt(3)).lessThan(new Fraction(JSBI.BigInt(4), JSBI.BigInt(12)))).toBe(
        false
      )
      expect(
        new Fraction(JSBI.BigInt(5), JSBI.BigInt(12)).lessThan(new Fraction(JSBI.BigInt(4), JSBI.BigInt(12)))
      ).toBe(false)
    })
  })
  describe('#equalTo', () => {
    it('correct', () => {
      expect(new Fraction(JSBI.BigInt(1), JSBI.BigInt(10)).equalTo(new Fraction(JSBI.BigInt(4), JSBI.BigInt(12)))).toBe(
        false
      )
      expect(new Fraction(JSBI.BigInt(1), JSBI.BigInt(3)).equalTo(new Fraction(JSBI.BigInt(4), JSBI.BigInt(12)))).toBe(
        true
      )
      expect(new Fraction(JSBI.BigInt(5), JSBI.BigInt(12)).equalTo(new Fraction(JSBI.BigInt(4), JSBI.BigInt(12)))).toBe(
        false
      )
    })
  })
  describe('#greaterThan', () => {
    it('correct', () => {
      expect(
        new Fraction(JSBI.BigInt(1), JSBI.BigInt(10)).greaterThan(new Fraction(JSBI.BigInt(4), JSBI.BigInt(12)))
      ).toBe(false)
      expect(
        new Fraction(JSBI.BigInt(1), JSBI.BigInt(3)).greaterThan(new Fraction(JSBI.BigInt(4), JSBI.BigInt(12)))
      ).toBe(false)
      expect(
        new Fraction(JSBI.BigInt(5), JSBI.BigInt(12)).greaterThan(new Fraction(JSBI.BigInt(4), JSBI.BigInt(12)))
      ).toBe(true)
    })
  })
  describe('#multiplty', () => {
    it('correct', () => {
      expect(
        new Fraction(JSBI.BigInt(1), JSBI.BigInt(10)).multiply(new Fraction(JSBI.BigInt(4), JSBI.BigInt(12)))
      ).toEqual(new Fraction(JSBI.BigInt(4), JSBI.BigInt(120)))
      expect(
        new Fraction(JSBI.BigInt(1), JSBI.BigInt(3)).multiply(new Fraction(JSBI.BigInt(4), JSBI.BigInt(12)))
      ).toEqual(new Fraction(JSBI.BigInt(4), JSBI.BigInt(36)))
      expect(
        new Fraction(JSBI.BigInt(5), JSBI.BigInt(12)).multiply(new Fraction(JSBI.BigInt(4), JSBI.BigInt(12)))
      ).toEqual(new Fraction(JSBI.BigInt(20), JSBI.BigInt(144)))
    })
  })
  describe('#divide', () => {
    it('correct', () => {
      expect(
        new Fraction(JSBI.BigInt(1), JSBI.BigInt(10)).divide(new Fraction(JSBI.BigInt(4), JSBI.BigInt(12)))
      ).toEqual(new Fraction(JSBI.BigInt(12), JSBI.BigInt(40)))
      expect(
        new Fraction(JSBI.BigInt(1), JSBI.BigInt(3)).divide(new Fraction(JSBI.BigInt(4), JSBI.BigInt(12)))
      ).toEqual(new Fraction(JSBI.BigInt(12), JSBI.BigInt(12)))
      expect(
        new Fraction(JSBI.BigInt(5), JSBI.BigInt(12)).divide(new Fraction(JSBI.BigInt(4), JSBI.BigInt(12)))
      ).toEqual(new Fraction(JSBI.BigInt(60), JSBI.BigInt(48)))
    })
  })
})