Home » Tag Archives: JUnit (page 7)

Tag Archives: JUnit

Understanding JUnit’s Runner architecture

Some weeks ago I started creating a small JUnit Runner (Oleaster) that allows you to use the Jasmine way of writing unit tests in JUnit. I learned that creating custom JUnit Runners is actually quite simple. In this post I want to show you how JUnit Runners work internally and how you can use custom Runners to modify the test ...

Read More »

JUnit in a Nutshell: Test Structure

Despite the existence of books and articles about JUnit testing, I still meet quite often programmers, who at most have a vague understanding of the tool and its proper usage. Hence I had the idea to write a multi-part tutorial, that explains the essentials from my point of view. Maybe the hands-on approach taken in this mini-series might be appropriate ...

Read More »

Clean JUnit Throwable-Tests with Java 8 Lambdas

Recently I was involved in a short online discussion on twitter and google+ which concerned the question why the arrival of Java 8 Lambda expressions makes the catch-exception library1 obsolete. This was triggered by a brief announcement that the library won’t be longer maintained as lambdas will make it redundant. The answer I came up with at that time has ...

Read More »

A JUnit Rule to Run a Test in Its Own Thread

Occasionally it would be helpful to be able to run a JUnit test in a separate thread. In particular when writing integration tests that interact with encapsulated ThreadLocals or the like this could come in handy. A separate thread would implicitly ensure that the thread related reference of the threadlocal is uninitialized for each test run. This post introduces a ...

Read More »

JUnit: testing exception with Java 8 and Lambda Expressions

In JUnit there are many ways of testing exceptions in test code, including try-catch idiom, JUnit @Rule, with catch-exception library. As of Java 8 we have another way of dealing with exceptions: with lambda expressions. In this short blog post I will demonstrate a simple example how one can utilize the power of Java 8 and lambda expressions to test ...

Read More »

Writing Clean Tests – Divide and Conquer

A good unit test should fail for only one reason. This means that a proper unit test tests only one logical concept. If we want to write clean tests, we have to identify those logical concepts, and write only one test case per logical concept. This blog post describes how we can identify the logical concepts found from our tests, ...

Read More »

Writing Clean Tests – Beware of Magic

It is pretty hard to figure out a good definition for clean code because everyone of us has our own definition for the word clean. However, there is one definition which seems to be universal: Clean code is easy to read. This might come as a surprise to some of you, but I think that this definition applies to test ...

Read More »