How to run JUnit tests with Gradle?

Question

Currently I have the following build.gradle file:

apply plugin: 'java'

sourceSets {
    main {
        java {
            srcDir 'src/model'
        }
    }
}

dependencies {
    compile files('libs/mnist-tools.jar', 'libs/gson-2.2.4.jar')
    runtime fileTree(dir: 'libs', include: '*.jar')
}    

This build.gradle file is for my repository here. All of my main files are in src/model/ and their respective tests are in test/model.

How do I add a JUnit 4 dependency correctly and then run those tests in the folders of tests/model?

Answer 1

How do I add a junit 4 dependency correctly?

Assuming you're resolving against a standard Maven (or equivalent) repo:

dependencies {
    ...
    testCompile "junit:junit:4.11"  // Or whatever version
}

Run those tests in the folders of tests/model?

You define your test source set the same way:

sourceSets {
    ...

    test {
        java {
            srcDirs = ["test/model"]  // Note @Peter's comment below
        }
    }
}

Then invoke the tests as:

./gradlew test

EDIT: If you are using JUnit 5 instead, there are more steps to complete, you should follow this tutorial.

Answer 2

If you set up your project with the default gradle package structure, i.e.:

src/main/java
src/main/resources
src/test/java
src/test/resources

then you won't need to modify sourceSets to run your tests. Gradle will figure out that your test classes and resources are in src/test. You can then run as Oliver says above. One thing to note: Be careful when setting property files and running your test classes with both gradle and you IDE. I use Eclipse, and when running JUnit from it, Eclipse chooses one classpath (the bin directory) whereas gradle chooses another (the build directory). This can lead to confusion if you edit a resource file, and don't see your change reflected at test runtime.

Answer 3

If you created your project with Spring Initializr, everything should be configured correctly and all you need to do is run...

./gradlew clean test --info

• Drop --info if you don't want to see test output.
• Drop clean if you don't want to rerun tests that have already passed since the last change.

---

Dependencies required in build.gradle for testing in Spring Boot...

dependencies {
    compile('org.springframework.boot:spring-boot-starter')
    testCompile('org.springframework.boot:spring-boot-starter-test')
}

---

For some reason the test runner doesn't tell you this, but it produces an HTML report in build/reports/tests/test/index.html.