Chapter 5. Testing with Gradle

The discussion of testing with Gradle takes two primary directions. The first is the simple testing of Java classes with existing test frameworks like JUnit and TestNG. The second is a full automation of the testing pipeline, including separating integration tests from unit test and the leveraging of more advanced testing frameworks like Spock and Geb.


The simplest JUnit example is almost entirely supplied by the java Gradle plug-in. It adds the test task to the build graph and needs only the appropriate JUnit JAR to be added to the classpath to fully activate test execution. This is demonstrated in Example 5-1.

Example 5-1. Testing Java source with JUnit
apply plugin: 'java'

repositories {

dependencies {
    testCompile 'junit:junit:4.8.2'

The report from the execution of the JUnit tests is quite handsome compared to its non-Gradle counterparts, as you can see in Figure 5-1. It offers a summary of the tests that were executed, succeeded, and failed.

JUnit Test Report
Figure 5-1. JUnit Test Report

When JUnit tests reach a certain level of proliferation within a project, there is a motivation to run them in parallel to get the results faster. However, there would be a great overhead to running every unit test in its own JVM. Gradle provides an intelligent compromise in that it offers a maxParallelForks that governs the maximum simultaneous JVMs that are spawned. ...

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