[java] How to run JUnit tests with Gradle?

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?

If you want to add a sourceSet for testing in addition to all the existing ones, within a module regardless of the active flavor:

sourceSets {
    test {
        java.srcDirs += [
                'src/customDir/test/kotlin'
        ]
        print(java.srcDirs)   // Clean
    }
}

Pay attention to the operator += and if you want to run integration tests change test to androidTest.

GL

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.

testCompile is deprecated. Gradle 7 compatible:

dependencies {
...
   testImplementation 'junit:junit:4.13'
}

and if you use the default folder structure (src/test/java/...) the test section is simply:

test {
    useJUnit()
}

Finally:

gradlew clean test

Alos see: https://docs.gradle.org/current/userguide/java_testing.html

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

• Use --info if you want to see test output.
• Use clean if you want to re-run 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.