[JS] Example of Automated Test with Jasmine

jasmine-MathServiceSpec.js

describe('MathService',function(){
  it('should sum two integer numbers', function(){
    expect(MathService.add(1,2)).toBe(3);
  });
  
  it('should sum one number or more', function() {
    expect(MathService.add(1)).toBe(1);
    expect(MathService.add(1,2)).toBe(3);
    expect(MathService.add(1,2,3)).toBe(6);
  });
  
  it('should sum two string numbers', function() {
    expect(MathService.add('1','2')).toBe(3);
    expect(MathService.add('010','2')).toBe(12);
  });
  
  it('should return null for a invalid number', function () {
    expect(MathService.add('little potato',2)).toBe(null);
  });
  
  it('should return null if there is no numbers specified', function (){
    expect(MathService.add('','')).toBe(null);
  });
});

MathService.js

var MathService = {
  
  add: function() {
   var amount = arguments.length;
   var total = 0;
   
   if(amount > 0) {
     for(var i=0; i<amount; i++) {
       var currentNumber = parseInt(arguments[i], 10);
       if(isNaN(currentNumber)) return null;
       total += currentNumber;
     }
     return total;
   }
   
   return null;
  }
  
};