First, we need to look at what a unit-testing framework is, and at what it enables us to do that we couldn’t and wouldn’t have done without it.

2.1 Frameworks for unit testing

Consider the advantages an integrated development environment (IDE) gives you as a developer. Unit-testing frameworks offer similar advantages for testing.

To this day, in many IDEs for other environments (such as Unix), the steps involved in getting a final binary output from your code aren’t as simple, and may require manually calling other external tools to do parts of this big task. When using a modern IDE like Visual Studio

.NET or Eclipse for Java, you do all your coding tasks within that environment, in a structured manner. You write the code, you compile it, you build any resources (like graphics and text) into it, and you create the final binary—all that building and compiling with no more than a couple of keystrokes.

Doing things completely manually would be error-prone and time-con- suming, and people would defer doing that as much as possible. These problems are alleviated by tooling. In the same way, unit-testing frameworks help developers write tests more quickly with a set of known APIs, execute those tests automatically, and review the results of those tests easily.

2.1.1What unit-testing frameworks offer

Up to now, the tests you’ve done were limited:

They were not structured.

You had to reinvent the wheel every time you wanted to test a feature. One test might look like a console application, another uses a UI form, and another uses a web form. You don’t have that time to spend on testing, and the tests fail the “easy to implement” requirement.

They were not repeatable.

Neither you nor your team members could run the tests you’d written in the past. That breaks the “repeatedly” requirement and pre-

vents you from finding regression bugs. With a framework, you can more easily and automatically write tests that are repeatable.

They were not on all your code.

The tests didn’t test all the code that matters. That means all the code with logic in it, because each and every one of those could contain a potential bug. (Property getters and setters don’t count as logic, unless you have some sort of logic inside them.) If it were easier to write the tests, you’d be more inclined to write more of them, and get better coverage.

In short, what you’ve been missing is a framework for writing, running, and reviewing unit tests and their results. Figure 2.1 shows the areas in software development where a unit-testing framework has influence.

Figure 2.1 Unit tests are written as code, using libraries from the unit-testing framework. Then the tests are run from a separate unit-testing tool, and the results are reviewed (either in the UI or as text) by the developer or an automated build process.