Tag Archives: Test-driven development

How can functional test coverage help rescue waterfall projects?

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:

Requirements gathering
Design of the solution / Architecture
Implementation
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.
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Learning Python through Katas, TDD and CyberDojo

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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.

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Test Driven Development (TDD): Best Practices Using Java Examples

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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.
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Test Driven Development (TDD): Example Walkthrough

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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
Run tests
Refactor code
Repeat

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.

Let’s start!
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Black-box vs White-box Testing

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Testing shows the presence, not the absence of bugs. Edsger W. Dijkstra

Two common types of testing are black-box and white-box testing. Both can drive or be driven by development.

Black-box testing

Black-box testing (also known as functional testing) treats software under test as a black-box without knowing its internals. Tests are using software interfaces and trying to ensure that they work as expected. As long as functionality of interfaces remains unchanged, tests should pass even if internals are changed. Tester is aware of what the program should do but does not have the knowledge of how it does it. Black-box testing is most commonly used type of testing in traditional organizations that have testers as a separate department, especially when they are not proficient in coding and have difficulties to understand the code. It provides external perspective of the software under test.
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Behavior Driven Development (BDD): Value Through Collaboration (Part 2: Narrative)

Narrative

“User stories are a promise for a conversation” (Ron Jeffries)

A BDD story consists of a narrative and one or more scenarios. A narrative is a short, simple description of a feature told from the perspective of a person or role that requires the new functionality. The intention of the narrative is NOT to provide a complete description of what is to be developed but to provide a basis for communication between all interested parties (business, analysts, developers, testers, etc.) The narrative shifts the focus from writing features to discussing them.

Even though it is usually very short, it tries to answer three basic questions that are often overlooked in traditional requirements. What is the benefit or value that should be produced (In order to)? Who needs it (As a)? And what is a feature or goal (I want to)? With those questions answered, the team can start defining the best solution in collaboration with the stakeholders. The narrative is further defined through scenarios that provide a definition of done, and acceptance criteria that confirm that narrative that was developed fulfills expectations.

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This post is part of the “Behavior Driven Development (BDD): Value Through Collaboration” series.

Introduction

The goal of software projects is to deliver value to stakeholders. Even though that might sound an obvious statement, it can be easily forgotten in traditional Waterfall projects. The very nature of the Waterfall process fosters the creation of different departments whose job is to receive work from the previous stage, produce something, and pass it on.

A simplified Waterfall model would be:

Requirements specification resulting in requirements document
Design resulting in software architecture document
Development resulting in actual software
Integration
Testing
Installation
Maintenance

Each of these phases tends to have separate teams and departments. BAs work with requirements, architects write design documents, developers code, integration engineers integrate, testers test, and someone installs the software. Each of these departments is waiting for others to produce something, to start working on their artifacts and, once finished, to pass it on to someone else. The value for the stakeholders is, in many cases, unknown or forgotten. Most people involved in such projects are concerned about “doing their part” and throw it “over the wall” to those coming next. Moreover, artifacts produced by one team are often not used or understood by another.

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