@rniv/base-n/test/test.js

## Installation

const chai = require('chai')
const should = chai.should()

const { BaseN } = require('../')
const bs16 = new BaseN('0123456789abcdef')
describe('BaseN', function () {
  describe('constructor(symbols)', function(){
    it('should throw error for invalid symbols', function () {
      should.Throw(function () {
        new BaseN('0123456789*')
      })
    })
    it('Should throw error for duplicate symbols', function () {
      should.Throw(function () {
        new BaseN('01234567899')
      })
    })
  })
  
  describe('encode(n)', function () {
    it('should return encoded string', function () {
      const result = bs16.encode(9007199254740991)
      result.should.equal('1fffffffffffff')
    })

    it('should return 0', function() {
      const result = bs16.encode('0')
      result.should.equal('0')
    })
  })

  describe('decode(s)', function () {
    it('should return decoded number', function () {
      const result = bs16.decode('1fffffffffffff')
      result.should.equal(9007199254740991)
    })
    it('should throw error for symbols other than base symbols', function(){
      should.Throw(function(){
        bs16.decode('1A')
      })
    })
  })
  
  describe('compare(s1, s2)', function() {
    it('should throw error for invalid symbols', function(){
      should.Throw(function(){
        bs16.compare('1A', '1B')
      })
    })
    it('should return 1 if s1 > s2', function(){
      bs16.compare('100', 'ff').should.equal(1)
    })
    it('should return -1 if s1 < s2', function(){
      bs16.compare('ff', '1ff').should.equal(-1)
    })
    it('should return 0 if s1 = s2', function(){
      bs16.compare('1ff', '1ff').should.equal(0)
    })
  })

  describe('add(s1, s2)', function(){
    it('should throw error for invalid symbols', function(){
      should.Throw(function(){
        bs16.add('1A', '1B')
      })
    })
    it('should return addition of two encoded strings', function(){
      bs16.add('1fffffffffffff', '10').should.equal('2000000000000f')
    })
    it('should return 10 if we add 00000,  10', function() {
      bs16.add('0000', '10').should.equal('10')
    })
  })
  
  describe('subtract(s1, s2, abs=true)', function(){
    it('should throw error for invalid symbols', function(){
      should.Throw(function(){
        bs16.subtract('1A', '1C')
      })
    })
    it('should return absolute subtraction of two encoded strings', function(){
      bs16.subtract('1fffffffffffff', '10').should.equal('1fffffffffffef')
    })
    it('should return absolute subtraction of two encoded strings', function(){
      bs16.subtract('10', '1fffffffffffff').should.equal('1fffffffffffef')
    })
    it('should return subtraction of two encoded strings', function(){
      bs16.subtract('10', '1fffffffffffff', false).should.equal('-1fffffffffffef')
    })
    it('should equal 10 if subtrack 0000, 10', function() {
      bs16.subtract('0000', '10').should.equal('10')
    })
  })
})