JUnit itself is not enough for most of today's Java projects. You also need a mocking library, maybe something else. In this mini HOW-TO I present the test dependencies you can start with in a new Java project.
All starts with JUnit
There are two artifacts in
junit group in Maven Repository:
junit and
junit-dep. Prior to version
4.9 the latter did not contain dependency to Hamcrest inlined. Today, we use
junit dependency as follows:
The
dependency:tree produces:
[INFO] \- junit:junit:jar:4.11:test
[INFO] \- org.hamcrest:hamcrest-core:jar:1.3:test
Mockito
The next dependency we usually need is a mocking framework. No doubts that
Mockito is one of the most popular one. It comes in two favors:
mockito-all and
mockito-core. The first is a single jar will all dependencies inlined inside, whereas the latter is just a Mockito. It is recommended to use
mockito-core with version
4.11 of JUnit. So let's add the dependency:
Now the
dependency:tree produces:
[INFO] +- junit:junit:jar:4.11:test
[INFO] | \- org.hamcrest:hamcrest-core:jar:1.3:test
[INFO] \- org.mockito:mockito-core:jar:1.9.5:test
[INFO] \- org.objenesis:objenesis:jar:1.0:test
Hamcrest
Knowing that
mockito-core is better for declarative dependency management, we will override dependencies to both Hamcrest and Objenesis as follows:
Having this we can easily add Hamcrest library, that provides a library of matcher objects, dependency:
And the
dependency:tree produces:
[INFO] +- junit:junit:jar:4.11:test
[INFO] +- org.mockito:mockito-core:jar:1.9.5:test
[INFO] +- org.hamcrest:hamcrest-core:jar:1.3:test
[INFO] +- org.hamcrest:hamcrest-library:jar:1.3:test
[INFO] \- org.objenesis:objenesis:jar:1.3:test
AssertJ
AssertJ - fluent assertions for java - provides a rich and intuitive set of strongly-typed assertions to use for unit testing. AssertJ is a fork of FEST Assert that I wrote about some time ago in this
post. And what about the dependency? Let's bave a look:
Which result in the following tree:
[INFO] +- junit:junit:jar:4.11:test
[INFO] +- org.mockito:mockito-core:jar:1.9.5:test
[INFO] +- org.assertj:assertj-core:jar:1.5.0:test
[INFO] +- org.hamcrest:hamcrest-core:jar:1.3:test
[INFO] +- org.hamcrest:hamcrest-library:jar:1.3:test
[INFO] \- org.objenesis:objenesis:jar:1.3:test
The Final Cut
The complete Maven structure looks as follows:
You can find this in
unit-testing-demo project on GitHub (link to
pom.xml) or you can try out my
spring-mvc-quickstart-archetype (link to
pom.xml).
