junit5-migration-gradle

junit5-migration-gradle

The junit5-migration-gradle project demonstrates how to execute tests based on JUnit 5 using Gradle. In addition, it showcases that existing JUnit 4 based tests can be executed in the same test suite as JUnit Jupiter based tests or any other tests supported on the JUnit Platform.

This sample project does not aim to demonstrate how to use the JUnit Jupiter APIs. For detailed information on the JUnit Jupiter programming and extension models, please consult the User Guide.

Enabling the JUnit Platform

To use the JUnit Platform with Gradle, you need to configure build.gradle as follows.

test {
	useJUnitPlatform()
}

Configuring the Test task

Optionally, you can configure the test task as follows.

test {
	useJUnitPlatform {
		// includeEngines("junit-jupiter", "junit-vintage")
		// excludeEngines("custom-engine")

		// includeTags("fast")
		excludeTags("slow")
	}
	testLogging {
		events("passed", "skipped", "failed")
	}
}

By default all engines and tags are included in the test plan.

If you supply a Test Engine ID via includeEngines(...) or excludeEngines(...), Gradle will only run tests for the desired test engines.

If you supply a tag via includeTags(...), Gradle will only run tests that are tagged accordingly (e.g., via the @Tag annotation for JUnit Jupiter based tests). Similarly, if you supply a tag via excludeTags(...), Gradle will not run tests that are tagged accordingly.

Configuring Test Engines

In order to have Gradle's test task run any tests at all, a TestEngine implementation must be on the classpath.

To configure support for JUnit Jupiter based tests, configure a testImplementation dependency on the junit-jupiter artifact. That will cause testImplementation dependency on the JUnit Jupiter API and a testRuntimeOnly dependency on the JUnit Jupiter TestEngine.

dependencies {
	testImplementation("org.junit.jupiter:junit-jupiter:5.6.0")
}

Gradle can also run JUnit 3 and JUnit 4 based tests as long as you configure a testImplementation dependency on JUnit 4 and a testRuntimeOnly dependency on the JUnit Vintage TestEngine implementation similar to the following.

dependencies {
	testImplementation("junit:junit:4.13")
	testRuntimeOnly("org.junit.vintage:junit-vintage-engine:5.6.0")
}

Executing Tests on the JUnit Platform

Once the JUnit Platform Gradle plugin has been applied and configured, you can use the standard test task as usual.

Invoking gradlew clean test from the command line will execute all tests within the project. This will result in output similar to the following:

> Task :test

com.example.project.SecondTest > mySecondTest() SKIPPED

com.example.project.OtherTests > testThisThing() PASSED

com.example.project.OtherTests > testThisOtherThing() PASSED

com.example.project.FirstTest > myFirstTest(TestInfo) PASSED

com.example.project.JUnit4Test > test PASSED

BUILD SUCCESSFUL in 2s
4 actionable tasks: 3 executed, 1 up-to-date

If you comment out the @Disabled annotation on SecondTest#mySecondTest(), you will then see the build fail with output similar to the following:

> Task :test FAILED

com.example.project.OtherTests > testThisThing() PASSED

com.example.project.OtherTests > testThisOtherThing() PASSED

com.example.project.FirstTest > myFirstTest(TestInfo) PASSED

com.example.project.SecondTest > mySecondTest() FAILED
    org.opentest4j.AssertionFailedError at SecondTest.java:24

com.example.project.JUnit4Test > test PASSED

5 tests completed, 1 failed

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':test'.
> There were failing tests. See the report at: file:///Users/junit-team/junit5-samples/junit5-migration-gradle/build/reports/tests/test/index.html

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 2s
4 actionable tasks: 3 executed, 1 up-to-date

Test Reports

Gradle writes XML test reports to build/test-results/test and HTML test reports to build/reports/tests/test.