nodemock

Node Mock - Simple Yet Powerful Mocking Framework for NodeJs

NodeMock is a very simple to use mocking framework which can be used to mock functions in JavaScript objects. NodeMock creates mock methods in less code with more expressive manner

Features

Besides it's simplicity it supports following features

• Does not need an existing object to create the mock
• Verify arguments (we check deeply on objects and arrays to check the validity)
• Allow a return to be sent
• Assertion to check whether all the rules executed
• Callbacks can also be executed with providing arguments
• Multiple mock functions in one object
• Alter a mock function later on
• Method chaining allows creating mocks super easy
• Fail support added when calling method that should not be called
• Mock support to call a single method more than once
• Repetitive support
• ignore methods from mocking behaviour

Testing

Node JS can be used with any testing framework. And we've used it with Nodeunit and it's a perfect match. See Examples

Install

npm install nodemock

Usage

Load the Module

var nodemock = require("nodemock");

Creating a mock function with taking arguments and return value

var mocked = nodemock.mock("foo").takes(10, [10, 20, 30]).returns(98);

mocked.foo(10, [10, 20, 30]); // this will return 98

mocked.foo(10); //throws execption

Creating a mock with callback support

var mocked = nodemock.mock("foo").takes(20, function(){}).calls(1, [30, 40]);

mocked.foo(20, function(num, arr) {
	console.log(num); //prints 30
	console.log(arr); //prints 40
});

/*
	When you invoke foo() nodemock will calls the callback(sits in argument index 1 - as specified)
	with the parameters 30 and 40 respectively. 
*/

Controlling callbacks

With the asynchronous nature of NodeJS(and brower with AJAX too) it'll be great if we can control the execution of the callback in the testing environment. And ctrl() of nodemock helps that

var ctrl = {};
var mocked = nodemock.mock('foo').takes(10, function() {}).ctrl(1, ctrl);
//where ever in your codebase
ctrl.trigger(10, 20); // you can call this as many as you want

Add multiple mock functions

var mocked = nodemock.mock("foo").takes(10).returns(30);
mocked.foo(10); //gives 30

mocked.mock("bar").takes(true).returns(40);
mocked.bar(true); // gives 40

Assertion Support

var mocked = nodemock.mock("foo").takes(20);
var mocked = nodemock.mock("bar").takes(40);

mocked.foo(20);
mocked.bar(40);

//check whether what we've defined is actually executed
mocked.assert(); //returns true

Fails when calls any method in the mock object

var mocked = nodemock.fail();
mocked.foo(); //thorws an exception
mocked.bar(); //throws an exception

Fails when calls some particular method in the mock object

var mocked = nodemock.mock("foo").fail();
mocked.mock("bar").takes(10);
mocked.foo(); //thorws an exception
mocked.bar(10); //works perfectly

calls a single mocked method, multiple times

var mocked = nodemock.mock("foo").takes(10, 20).times(2);

mocked.foo(10, 20);
mocked.foo(10, 20);

calls a single mocked method, multiple times with different returns

var mocked = nodemock.mock("foo").takes(10, 20).returns(100);
mocked.mock('foo').takes(10, 20).returns(200);

mocked.foo(10, 20); //returns 100
mocked.foo(10, 20); //returns 200

mock a single method more than once

var mocked = nodemock.mock("foo").takes(10, 20);
mocked.mock("foo").takes(20, 30);
mocked.mock("foo").takes(500);

mocked.foo(10, 20);
mocked.foo(20, 30)
mocked.foo(500);

//check whether everything has done
mocked.assert(); //returns true

reset the mock

var mocked = nm.mock('foo').returns(100);
mocked.foo(); //returns 100
mocked.assert(); //returns true
	
mocked.reset();

mocked.mock('doo').returns(300);
mocked.doo(); //returns 300
mock.assert() //returns true

ignore method

Sometime we need to ignore some methods going through mocking rules. But we need to have those methods but doing nothing.

var mocked = mock.ignore('hello');
mocked.mock('foo').returns(100);

mock.foo(); //returns 100
mock.hello(); //do nothing but the method exists

mock.assert(); // return true, assert have nothing to do with ignored methods

API Documentation

Construction

var mocked = require('nodemock').mock('foo');
	Creating a object with mock function "foo"

mocked.mock(methodName)
	Used to alter or create a new mock method and add rules to it as usual
	

Rules

mocked.takes(arg1, args2, ...)
	Specify arguments of the function and verify then when calling
	
mocked.returns(returnValue)
	Specify the return value of the function
	
mocked.calls(callbackPosition, argumentsArray)		 
	Calls a callback at the arguments in index `callbackPosition`
	with the arguments specified in the "argumentsArray"
	
	when using this you've to define a function signature as a callback in the argument list
	for a callback at index 2 .takes() function will be as,
	mocked.takes(10, 20, function(){})

	
mocked.fail()
	If calls at very begining afterword any call on the mocked objects will fail
	Otherwise current mock method will fails someone called that. 
	
mocked.times(repetitiveCount);
	We can rule the mocked method to be called multiple times with same parameters
	Finally we can check that using above assert method;

mocked.reset()
	Reset all the rules and mocks created. And bring mocked object into a stage when 

it's created

mocked.ignore()
	Ignore Some methods from the mocking behaviour

Confirm

mocked.assert();
	Checks whether rules we've defined using other methods were executed.
	If all the rules were executed return true, otherwise false

mocked.assertThrows();
	Same as the mocked.assert() but throws an execption if rules breaks.
	

License

The MIT License

Copyright (c) 2011 Arunoda Susiripala

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.