How to run Gradle test when all tests are UP-TO-DATE?

java

gradle

test

build-cache

byAlex Kataev·Jan 22, 2025

Force Gradle tests to rerun by appending the --rerun-tasks flag to your command:

./gradlew test --rerun-tasks

Or, circumvent the UP-TO-DATE check for tests directly in your build.gradle file:

test {
    outputs.upToDateWhen { false }
}

On the other hand, you can use the cleanTest task to reset prior test outcome without altering build.gradle:

./gradlew cleanTest test

This ensures you re-run tests without a complete project rebuild.

Gradle configuration adjustments

Updating test tasks for uninterrupted testing

In cases where continuous testing is paramount (like in CI/CD pipelines), update the test task in your build.gradle to disable UP-TO-DATE checks, forcing tests to run regardless of any modifications:

tasks.withType(Test) {
    // As the legendary Bob Ross once said, there's no such thing as mistakes, only happy accidents (if we know of them)
    outputs.upToDateWhen { false }
}

Merging performance and rigor

Avoid compromising the test accuracy while boosting the build performance by coupling your test task with the --no-build-cache flag:

./gradlew test --no-build-cache

This bypasses the build cache but utilizes previous build results where applicable.

Utilizing task inputs to run tests

Changes to the code aren't the sole factor that can trigger test execution. Tweaking task inputs, such as adjusting resources required by the tests, also reinitiate a test run.

Gradle's caching mechanism

Understanding Gradle's caching mechanism can significantly decrease your build times but knowing when and how to override it is equally important. Pairing tasks that need a fresh execution with the --no-build-cache flag is a handy tip for those moments when you need to force a test run without altering the input parameters.

Clearing the stage for test reruns

Here you have some flaky tests due to environmental nasties. To rerun the tests without influencing other tasks, the cleanTest task can come to your rescue:

./gradlew cleanTest test -i

Need to diagnose issues? Add the -i flag to get some extra intel.

Handling dependencies like a pro

Some tests might lean on other tasks such as processResources. Ensure these tasks are also UP-TO-DATE by selectively pairing them with the clean command:

./gradlew cleanTest cleanProcessResources test

This ensures both the tests and their dependencies are ready before you hit 'run'.

Dodging common impediments

Keep in mind some frequent roadblocks:

Misguidedly skipping the --rerun-tasks flag leading to tests not reflecting recent changes.
Erroneously utilizing --no-rebuild potentially forbidding necessary compilers.
Misunderstanding the difference between a clean task and a targeted cleanup like cleanTest.