Jasmine Spy Example

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  <head>
    <title>Jasmine Spec Runner</title>
    <link rel="shortcut icon" type="image/png" href="lib/jasmine-1.3.0/jasmine_favicon.png" />
    <!-- include source files here... -->
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    <script data-require="jasmine@*" data-semver="2.0.0" src="//cdn.jsdelivr.net/jasmine/2.0.0rc2/jasmine.js"></script>
    <script data-require="jasmine@*" data-semver="2.0.0" src="//cdn.jsdelivr.net/jasmine/2.0.0rc2/jasmine-html.js"></script>
    <script data-require="jasmine@*" data-semver="2.0.0" src="//cdn.jsdelivr.net/jasmine/2.0.0rc2/boot.js"></script>
    <script data-require="json2@*" data-semver="0.0.2012100-8" src="//cdnjs.cloudflare.com/ajax/libs/json2/20121008/json2.js"></script>
    
    <!-- include src files here... -->
    <script type="text/javascript" src="Logger.js"></script>
    <script type="text/javascript" src="Calculator.js"></script>
    
    <!-- include spec files here... -->
    <script type="text/javascript" src="Calculator.spec.js"></script>
    
    
  </head>

  <body></body>

</html>

function Calculator(logger) {
  var add = function() {
    var operands = Array.prototype.slice.call(arguments);
    var sum = 0;
    for(var i = 0; i < operands.length; i++) {
      sum += operands[i];
    }
    
    logger.log(operands.join(' + ') + ' = ' + sum);
    
    return sum;
  }
  
  return {
    add: add
  };
}

describe('Given the Calculator', function() {
  var logger = Logger(),
    calc = Calculator(logger),
    sum; 
    
  beforeEach(function() {
    spyOn(logger, "log");
    //spyOn(logger, "log").and.callThrough();
    //spyOn(logger, "log").and.callFake(function() {console.debug('Spy Called')}); 
  });
  
  afterEach(function() {
    logger.log.calls.reset();
  });

  it('Then it contains an add method', function() {
    expect(calc.add).toBeDefined();
  });

  describe('When I add two numbers', function() {
    beforeEach(function() {
      sum = calc.add(1, 2);
    });
    
    it('Then the I get the correct answer', function() {
      expect(sum).toBe(3);
    });
    
    it('Then the logger should have been called once', function() {
      expect(logger.log).toHaveBeenCalled();
      expect(logger.log.calls.count()).toBe(1);
    });
  });

  describe('When I add three numbers', function() {
    beforeEach(function() {
      sum = calc.add(1, 2, 7);
    })
      
    it('Then the I get the correct answer', function() {
      expect(sum).toBe(10);
    });
    
    it('Then the logger should have been called once', function() {
      expect(logger.log).toHaveBeenCalled();
      expect(logger.log.calls.count()).toBe(1);
    });
  });
});

function Logger() {
  var log = function(message) {
    console.log(message);
  }
  
  return {
    log: log
  };
}