gistfile1.txt

// features/example/
example.jsmodule.exports = function () 
{
  this.Given(/^I have entered (.*) into the calculator$/, function (value, callback) 
  {
    if (!this.valueStack) 
    {
      this.valueStack = [];   
    }     
    this.valueStack.push(Number(value));  
    callback();
  });    
    
  this.Given(/^I press divide$/, function (callback) 
  {
    if (!this.operatorStack) 
    {
      this.operatorStack = []; 
    }
    this.operatorStack.push("divide"); 
    callback();  
  });

  this.When(/^I press equal/, function (callback) 
  {
    var operator = this.operatorStack.pop();  
    switch (operator) 
    {
      case "divide":     
        var right = this.valueStack.pop();     
        var left = this.valueStack.pop();      
        this.result = left / right;       
        break;    
    }
    callback(); 
  });  

  this.Then(/^The result should be (.*) on the screen$/, function (result, callback) 
  {
    if (this.result === Number(result)) 
    {
      callback();    
    } 
    else
    {
      callback(new Error("Expected " + result + " actual " + this.result));   
    }
  });
};