This release includes enhancements and fixes across Cover CLI, CI, Plugin, and Reports. The Plugin now ensures that sufficient JVM heap memory is configured for optimal test writing performance. Cover Reports has received performance enhancements to reduce load times on the Coverage Details tab. CI users can now provide offline license files through an environment variable. Full details of these updates can be found in the release notes.

Please note that support for JUnit versions 4.7 through 4.10 is now deprecated. Cover will provide a warning and recommend upgrading your JUnit version if these versions are used for writing tests. The ability to write tests using JUnit 4.7 through 4.10 will be removed in a future release.


  • CI & CLI: Cover is now able to accept an offline license file in CI environments via the new DIFFBLUE_OFFLINE_LICENSE_ACTIVATION_FILE_CONTENTS environment variable. [Ref: TG-21469]

  • Plugin: Cover's Environment Checks now ensure that IntelliJ is configured with sufficient JVM heap memory for writing tests. A 'Fix Issue' button is provided to easily update the heap memory size to the recommended value. [Ref: TG-21435]

  • Cover now displays an 'unsupported version' warning if JUnit 4.7-4.10 is in use and provides a recommendation to upgrade to a more recent version of JUnit 4. Future releases will require a more recent version of JUnit 4 (or 5) to write tests. [Ref: TG-21432]

  • Reports: The Coverage Details tab now loads faster. Additionally, the Coverage Details tab is also no longer accessible from Project Groups. [Ref: TG-21390]

Resolved Issues

  • Resolved an issue which caused Cover to write exception tests for trivial exceptions such as ArithmeticException or NegativeArrayIndexException. [Ref: TG-21502]

  • Resolved an issue which, in some circumstances, caused Cover to write tests with redundant chains of getters in the assert section. [Ref: TG-21245]

  • Resolved an issue which, in some circumstances, caused Cover to write assertions which compare the result of an observer to a corresponding field. [Ref: TG-21244]

  • Resolved an issue which, in some circumstances, caused Cover to not write an assertion for trivial methods returning collections. [Ref: TG-20233]

Known Issues

  • Plugin: Cover incorrectly provides a menu option to write tests for a test file. [Ref: TG-17163]

  • CLI & Plugin: Cover may write tests for JUnit 4.10 and lower that do not compile due to the use of assertNotEquals. [Ref: TG-17605]

  • Cover supports Open JDK and Oracle JDK; results with other JDKs may differ due to the variability in their implementations of Java. [Ref: TG-19345]

  • In rare circumstances Cover may encounter an F009: Internal error while writing tests using Mockito 5. To avoid this issue use a version of Mockito earlier than 5. [Ref: TG-19610]

  • Under some circumstances, when writing Java tests for Kotlin code, Cover may produce non-compiling tests. [Ref: TG-20759]

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