Question

I am a college student that makes his programs here and there in C#, mostly scientific simulations. Is there any use in learning NUnit?

I keep hearing people talking about it but I don’t fully grasp what it is in the first place. Is it something that every programmer should use, or something that is more suited for big projects with lots of people?

Answer 1

Testing is a vital part of writing software – any kind of software. Whether you are writing a little routine to sort numbers, or a system to launch space ships to Mars.

Now it used to be that developers would write their code, and then exercise it by hand – often in a debugger – to verify that it did what they expected. This was a painful and tedious way to test their code. Not only was it tedious and painful – but it wasn’t repeatable. This meant that every time you made a change you had to manually repeat the tests and hope you didn’t forget anything or do things slightly differently. Quality suffered – and there was much sorrow and weeping.

Eventually, developers realized that they could write a separate program that would exercise their code by running it through the conditions that they expected it to handle, and having that code verify the results. Things started to get better. This approach to testing was often called a test harness.

Writing test harnesses helped, but there was a lot of repetitive code – there is quite a bit of infrastructure related to running and verifying tests. However, some really smart developers out their said: “We’re not going to write boiler plate code over and over … we’ll make a library to do it for us.” And so unit testing tools like JUnit and NUnit (and many others) were born.

These libraries (and tools) help you structure, organize, and execute your tests. They provide convenient methods to verify conditions, trap and trace exceptions, and report which tests passed and which ones failed. Finally, developers could focus on the important part: writing the tests and verification logic that would help assure that the code they wrote worked. These tests were repeatable. They could be run as part of an automated build process. They could be handed down through the generations and added to by others as new failure points were found and fixed. They could be re-run by the original developer months and years after the original code had been written to make sure things still work.

If you plan to be a successful software developer at any level, in any size organization (even if it’s just yourself) – you should learn about – and embrace unit testing.

Here are some resources to help you on your way:

• NUnit Documentation and Samples
• The Art of Unit Testing
• Unit Testing Best Practices
• Write Maintainable Unit Tests That Will Save You Time And Tears