Separate execution of unit and integration tests in Gradle

During development process, we often write unit and integration tests. While unit tests verify corectness of the small pieces of code, integration tests verify software as a whole project and sometimes can treat it as a black box where concrete results are expected. During development of the REST API, we can write integration tests for such API with REST Assured. Integration tests are usually slower, because they need to start the server and sometimes do other stuff. That’s why it’s good to separate their execution from regular unit tests. On the CI server we can even have separate job for them.

We can define the following project structure:

+ src
|
+- main
|  |
|  +- java
|    |
|    +- com ...
|
+- test
  |
  +- java
    |
    +- com ... (unit tests)
    |
    +- integration (integration tests)
    

In the java/com/ directory we can put unit tests and in the integration/ directory we can put integration tests.

Now, we can prepare the following configuration in the build.gradle:

test {
  if (System.properties['test.profile'] != 'integration') {
    exclude '**/*integration*'
  } else {
    exclude '**/*com/*'
  }
}

As you can see, when test.profile is different than integration/, we’re excluding integration/ directory from tests. Otherwise, we’re excluding com/ directory.

Now, when we want to execute unit tests only, we can type the following command:

./gradlew test

but when we want to run unit test, we can type:

./gradlew test -Dtest.profile=integration

When we want to execute all tests, we can redefine configuration above, write another gradle task or perform one execution after another:

./gradlew test && ./gradlew test -Dtest.profile=integration

That’s it!