Domain Test for Mocha

gistfile1.js

var domain = require('domain');
var should = require('should');

//////////////
// Function //
//////////////

var add = function(a,b,callback){
  if(!isNumber(a)) { throw new Error(a + "is not a number"); }
  if(!isNumber(b)) { throw new Error(b + "is not a number"); }
  var response = a + b;
  callback(response);
}

var isNumber = function(n) {
  return !isNaN(parseFloat(n)) && isFinite(n);
}

//////////////////////
// domain container //
//////////////////////

var containWithDomain = function(a,b,callback){
  var wrapper = domain.create();
  wrapper.on("error", function(err){
    callback("caught by domain");
  });
  wrapper.run(function(){
    var response = add(a,b, function(response){
      callback(response);
    });
  });
}

////////////////////
// normal running //
////////////////////

// containWithDomain(1,{},function(response){
//  console.log(response);
// })

///////////
// TESTS //
///////////

describe('test', function(){
  it('works normally', function(done){
    add(1,2,function(response){
      response.should.equal(3);
      done();
    })
  });
  it('breaks normally', function(done){
    try{
      // this should thow an error, and does.
      add(1,{},function(response){
        done();
      })
    }catch(e){
      String(e).should.eql("Error: [object Object]is not a number")
      done();
    }
  });
  it('works within the domain container', function(done){
    containWithDomain(1,2,function(response){
      response.should.equal(3);
      done();
    })
  });
  it('should have errors caught by the domain and not raise the exception', function(done){
    containWithDomain(1,{},function(response){
      // this should not throw an error, but does :(
      response.should.equal("caught by domain");
      done();
    })
  });
});