TDD

BDD using SpecFlow on ASP.NET MVC Application

Rajesh Pillai — Sat, 22 May 2010 14:19:35 GMT

I usually love doing TDD and am moving towards understanding BDD (Behaviour Driven Development). My learnings are documented in the form of an article at CodeProject.

The URL is http://www.codeproject.com/KB/architecture/BddWithSpecFlow.aspx

I will keep this updated as and when I learn a couple of more things.

Hope you like it.

Cheers !!!

Summary of MVP in Action - Unit Testing

Rajesh Pillai — Mon, 30 Nov 2009 12:01:08 GMT

MVP in Action - Unit Test

Read the post here..geekswithblogs.net/rajeshpillai/archive/2009/11/30/mvp2.aspx

Synopsis

This is in continuation to the article geekswithblogs.net/rajeshpillai/archive/2009/11/29/mvp1.aspx. This post will deal with
writing simple unit test case for the "User" user creation use case we covered in the above blog post.

Background

Unit testing means testing a piece of code or a method. White unit testing we need to stub or fake out external dependencies
so that the test can run in isolation. The following two test cases we will cover

When saving a user with valid data should display "Successfully submitted the user." message on the view.
When saving a user with empty name should display "<ul><li>user:User name cannot be empty</li></ul>" the
following message on the view.

Read the post here..geekswithblogs.net/rajeshpillai/archive/2009/11/30/mvp2.aspx

Some notes from my tdd session

Rajesh Pillai — Sat, 28 Nov 2009 11:17:01 GMT

Here's a quick notes from the TDD session which I conducted some time back.

Introduction

Writing test before writing production code.
Design as you go along.
Follow Red-Green-Refactor paradigm

Benefits

Spot design flow early.
Test before the production code is built.
Identify poort requirements or requirement gaps.
Reduced testing time.
The test forms the functional document for your code.
Quickly identify bugs.
Reduces the cost of bugs in the long run.
Low level regression test suite.

Road blocks to TDD

When doing TDD the following road blocks you may hit.

Real objects are slow
Ral objecs are difficult to mock.
Rad object may be unavailable.
Real object may be costly.
Real object does not yet exits.

Here "Real Object" is the object under test.

The solution - Enter Mocking

What is a mock object?
- Mock objects are stand-in-object for real object.
Use of mock object
- Real object has non-deterministic behaviour.
- Real object is slow.
- Real object is difficult to setup.
- Real object is expensive.

Rhino Mock (The mocking framework)

A dynamic mock object framework for the .NET platform.
Objective is to ease testing by allowing the developer to create mock implementation of custom
objects and verify the interactions using unit testing.

Stubs and Mocks

A mock is an object that we can set expectations on, and which will verify that the expected actions have
indeed occurred.
A stub is an object that you use in order to pass to the code under test. You can setup expectations on it,
so it would act in certain ways, but those expectations will never be verified. A stub's properties will
automatically behave like normal properties and you cann't set expectations on them.
If you want to verify the behaviour of the code under test, you wil use a mock with the appropriate
expectation and verify that. I you want to just pass a value that may need to act in a certain way, but isn't the
focus of the test you will use a stub.

IMPORTANT: A stub will never cause a test to fail.

Rhino Mocks - 1

CreateMock / StrickMock
- For strict mockign
DynamicMock
- Flexible
PartialMock
- Mock concrete class
- Only mock virtual methods

AAA approach

A - Arrange
- Arrange your tests. Setup your values.
A - Act/action
- Execute the testing condition.
A - Assert
- Assert on expectations.

Happy TDD'ing....