Important Notes on JUnit 5.12.0+ in Gradle

TL;DR

When upgrading to JUnit 5.12.0 or later, be sure to add:

testRuntimeOnly("org.junit.platform:junit-platform-launcher")

(The version is omitted under the assumption that you're using a BOM.)

If you don't add this, the test task will fail to execute, so you'll likely notice the issue right away.

Why

If you don't explicitly declare a dependency on junit-platform-launcher, Gradle will implicitly use its bundled version.
As of Gradle 8.13, the bundled version is 1junit-platform-launcher 1.8.2` (whereas the latest version currently is 1.12.0).

JUnit 5.12 is incompatible with junit-platform-launcher 1.8.2, which results in test execution failures.

Gradle was aware of such potential issues and, starting with Gradle 8, recommended explicitly specifying junit-platform-launcher.

See the official Gradle upgrade guide: Gradle 8 Upgrade Guide

Ref

• https://github.com/junit-team/junit5/issues/4335
• https://github.com/junit-team/junit5/pull/4358