Skip to main content

TDD

Test Driven Development

  • The importance of writing tests
    • They force the developer to think of the class design
    • They provide a safety harness while refactoring
    • They ensure that the state of code is always stable
    • New developers can make changes comfortable with the knowledge that if they break something that was working, the tests will inform them
    • Test after development is not the same as test first development. Test after development does not reap all the benefits of test first development
  • Writing the tests
    • Think about the class it’s responsibilities and it’s API
    • Write the tests to test every method and various conditions in the methods
    • Whenever you think of writing a print statement or generate a log, it might be a scenario to include a test
    • Write enough production code to ensure that the tests compile and fail
    • Write production code to pass all tests one by one, while also ensuring that previous tests do not fail
  • What not to test
    • Database entities need not be tested
    • Do not go overboard with tests. First write tests that are most likely to fail. Think of the cost benefit ratio while writing tests
  • The test class
    • Tests classes end with the work Test. The test class for Account will be AccountTest
    • Test methods begin with the word test. The test method for creditAccount() will be testcreditAccount()
    • Tests can either exist in a different source tree in the same package as the class they are testing, or in the same source tree, but in a different package.
  • Managing dependencies
    • Unit tests should ideally not have any dependencies
    • Dependencies can be eliminated with mock objects (so that units can be tested in isolation)
  • AllTests
    • There should have one class AllTests that will run the entire test suite

    Requirements (Java Unit Tests):

    • JUnit 3.8 for JDK 1.4 and before
    • JUnit 4.x for JDK 1.5 and after
    • StrutsTestCase for testing Struts Action classes

    References:



Notes: This text was originally posted on my earlier blog at http://www.adaptivelearningonline.net
Labels:

Comments

Aditi said…
Very nice insight on TDD.
11:12 AM
Parag said…
Thanks Aditi
11:54 AM
Post a Comment

Popular posts from this blog

Running your own one person company

Recently there was a post on PuneTech on mom's re-entering the IT work force after a break. Two of the biggest concerns mentioned were : Coping with vast advances (changes) in the IT landscape Balancing work and family responsibilities Since I have been running a one person company for a good amount of time, I suggested that as an option. In this post I will discuss various aspects of running a one person company. Advantages: You have full control of your time. You can choose to spend as much or as little time as you would like. There is also a good chance that you will be able to decide when you want to spend that time. You get to work on something that you enjoy doing. Tremendous work satisfaction. You have the option of working from home. Disadvantages: It can take a little while for the work to get set, so you may not be able to see revenues for some time. It takes a huge amount of discipline to work without a boss, and without deadlines. You will not get the benefits (insuranc...
10 comments
Read more

Testing Groovy domain classes

If you are trying to test Grails domain class constraints by putting your unit test cases in the 'test/unit' directory, then your tests will fail because the domain objects will not have the 'valdate' method. This can be resolved in two ways: Place the test cases inside test/integration (which will slow things down) Use the method 'mockForConstraintsTests(Trail)' to create mock method in your domain class and continue writing your test cases in 'test/unit' What follows is some example code around this finding. I am working on a Groovy on Grails project for a website to help programmers keep up and refresh their skills. I started with some domain classes and then moved on to write some unit tests. When we create a Grails project using grails create-app , it creates several directories, one of which is a directory called 'test' for holding unit tests. This directory contains two directories, 'unit', and 'integration' for unit and ...
11 comments
Read more

My first impressions of Python for the second time

I had worked a bit in Python many years back. Since then I have forgotten almost everything I learned back then. I think the phrase "Out of sight out of mind" applies perfectly to my mind. Since the last few days, I have started relearning Python, and this time I am recording my impressions of Python after having come to it from a Java background. Indentation: Python uses indentation to specify blocks of code, instead of curly braces. I like this, because we anyways indent code to increase readability, so why not achieve two tasks together. Code looks much cleaner without the curly braces. However there may be a little downside. Everyone in the team will have to set up their IDE's in the same way. Things might fall apart if some people use tabs and others use spaces for indentation. Access modifiers: Python does not have public, private, and protected keywords. Everything is public. However, private members can be specified with a leading single underscore. If we use do...
6 comments
Read more