Test-Driven Development is a process that relies on the repetition of very short development cycle. It is based on the test-first concept of Extreme Programming (XP) that encourages simple design with high level of confidence.
In this article we'll go through the exercise of writing a method that will write string content to the specified file. There will be an option to specify whether we should overwrite an existing file. In addition, directories should be created if they do not already exist.
Programming language is Scala and testing framework that will be used is Specs2. In the spirit of unit testing, instead of interactions with the file system we'll use mocks with Mockito (already included in Specs2). All the code will be done using Test-Driven Development (TDD).
Behavior-Driven Development (BDD) is a process or it can be a tool. In many cases, BDD is both. However, it should not be a goal in itself. The goal of software development is to deliver quality as fast and as cheap as possible. The only real measure of quality is whether it fulfills user needs in a reliable manner. The best way we can take to accomplish that goal is through continuous integration, deployment and delivery. For the sake of this article I will ignore the differences between those three and refer to all of them as continuous integration or CI. Continue reading →
Documentation needs to be comprehensive, always up-to-date and accessible. By comprehensive I mean that it must cover all important areas of the code as well as all functions of the application. While importance of documentation is obvious to most, many struggle without success to have it accurate and up-to-date. Response to "poor" documentation is often assignment of more resources and more time. More often than not, documentation is created for wrong reasons.
A typical waterfall project has well defined phases that go from the idea conception until putting the solution in production, being the most typical of them:
Design of the solution / Architecture
Testing phase (including all kinds of tests)
User Acceptance Test
Go Live (put in production)
Post Go-Live support
It's very common in big companies that there's a functional team responsible for each phase. Thus, we get:
Business Analysts to gather requirements
Architects, Systems Engineers or Software Analysts to design the solutions
Programmers or coders to implement it
Quality Testers or Quality Assurance engineers to check its quality
The customer to test the delivered solution
However, one of the big problems from this approach is that usually these teams work in silos. The right hand doesn't know what the left hand is doing and this causes inefficiencies. To make it worse, sometimes the way to try to reduce silos is through an immense increase in bureaucracy, forcing teams to communicate through documentation. Continue reading →
DISCLAIMER: This is not a tutorial on how to learn Python, in fact, I have never used Python before so don't take me as example. What I want to share with you is how to learn a new language, strenghen the TDD principles and practice a Kata in an easy way.
Last week I attended the Global day of Code retreat in Barcelona. It was a wonderful experience that generated me a lot of energy to code again (I became a manager some time ago and I don't code as often as I'd like to). That day we used the Conway's Game of Life which I recommend to practice the TDD approach.
After investigating about several other katas I stumbled upon the Cyber dojo online tool. Basically this is a web page in which you can practice any kata and choose among more than 20 languages you want to learn without the need to do any setup at all. In other words, if you want to grasp the basics for a new language, this is the perfect place.
Also, one of the nice features from Cyber dojo is that after you're done with all the coding you wanted to do, you can download all your changes into a zipped Git file and then you have the repository with all the changes that you worked on.
In the previous article Test Driven Development (TDD): Example Walkthrough an example of TDD was given. It went from writing first test and its implementation to having a set of requirements fully tested and developed. Now it's time to learn what the best TDD practices are. This article will be built on examples from the previous one.
Best practices are solutions to a set of problems under certain situations. Not following them would make us "reinvent the wheel" and struggle with the same problems already solved by others. On the other hand, best practices should not be followed blindly. They should be tried out. With an informed decision at hand, they can be adopted as they are, modified to serve better specific situation or fully discarded.
Some of the best practices described here are inherited from other sets of practices and used when doing TDD. For example, most (if not all) unit testing practices should be used when doing TDD. Continue reading →
Test-driven development (TDD) is a software development process that relies on the repetition of a very short development cycle: first the developer writes an (initially failing) automated test case that defines a desired improvement or new function, then produces the minimum amount of code to pass that test, and finally refactors the new code to acceptable standards.
The following sequence of steps is generally followed:
Add a test
Run all tests and see if the new one fails
Write some code
There's a plenty of articles written on TDD and Wikipedia is always a good start. This article will focus on the actual test and implementation using variation of one of the Roy Osherove Katas. Do not click the link until you're finished with this article. This excercise is best done when not all requirements are known in advance.
Below you will find the test code related to each requirement and afterwards the actual implementation. Try to read only one requirement, write the tests and the implementation yourself and compare it with the results from this article. Remember that there are many different ways to write tests and implementation. This article is only one out of many possible solutions.
If you are still working in a waterfall methodology, you should know that the world is moving towards new methodologies... some famous concepts would be Agile, XP or Scrum and surely those words will sound familiar to you especially during the recent years.
Especially in the case of scrum, the first scrum team in which Jeff Sutherland participated took place in 1993, literally 20 years ago, and now it's mature enough to be taken by big companies.
When moving from the traditional waterfall process with manual testing towards BDD with automated execution of scenarios, one of the often asked questions is "how do you measure your test coverage?". What it really wants to say is "we have high test coverage with manual testing, can you guarantee the same or more with the BDD?". From there on usually comes the suggestion to transfer one-to-one manual tests to the BDD format. That's not a good idea since the result would be less than adequate transformation to the different format without any tangible change. BDD is not only about automation but about the way we construct and deliver software.
Code Coverage Analysis
Main usages of code coverage analysis is to:
Find areas of software under test that were not exercised by a set of test cases.
Help in creation of additional test cases to increase the coverage.
Provide quantitative measure of test coverage as indirect measure of quality.
Identify redundant test cases that do not increase coverage