nodemock
v0.3.5A simple Yet Powerful Mocking Framework for NodeJs
NodeMock is a 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
- Ability to provide functions to determine valid input for mocked functions
- Ability to provide functions to generate output from mocked functions
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");
Name a mock for clarity
var mocks = [
nodemock.named('mock1').mock('foo').takes(1),
nodemock.named('mock2').mock('foo').takes(1)
],
i;
for(i = 0; i < mocks.length; i += 1) {
mocks[i].assert(); // Prints that «mockName».foo(1) was not called.
}
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.
*/
Creating a mock function that takes variable parameters
var mocked = nodemock.mock("foo").takes(function(args) {
return(args % 2 == 0)
});
mocked.foo(4) // works
mocked.foo(5) // fails
Creating a mock function that takes variable parameters and returns dynamic values
var mocked = nodemock.mock("foo").takesF(function(args) {
return(args % 2 == 0)
}).returnsF(function(args) {
return(args * 2)
});
mocked.foo(4) // returns 8
mocked.foo(5) // fails
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(); //throws 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(); //throws 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 = nodemock.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 = nodemock.ignore('hello');
mocked.mock('foo').returns(100);
mock.foo(); //returns 100
mock.hello(); //do nothing but the method exists
mock.assert(); // return true, assert ignores 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.takesF(function)
As opposed to takes(), in which we can only specify static values,
takesF() (note the "F" in the name to indicate that it takes a function)
allows client code to provide a predicate that determines whether the
mocked function should accept ("take") the value and allowing mock code
to be a bit more dynamic.
mocked.takesAll()
A shorthand function that tells the mock function to accept any input.
mocked.returns(returnValue)
Specify the return value of the function
mocked.returnsF(function)
Similar to takesF(), returnsF() allows to provide a function that will
dynamically generate values that will be returned from mock calls. The
function will be provided with the parameters that were passed to the
mock call.
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.
Copyright
Copyright (c) 2011 Arunoda Susiripala
Modifications from the mockingbird
fork,
Copyright (c) 2013 Oscar Renalias
Remaining copyrights owned by individual contributors.