Diffblue Cover now supports Java 17!

We have been working hard behind the scenes to get ready to support Java 17, and are delighted to announce that this work is now complete! Diffblue Cover can now be used with Java 8, Java 11 (but please note not version 11.0.7) and Java 17.

Diffblue Cover and Mockito

Diffblue Cover now gives a warning if you are using a version of Mockito that is not supported by the JVM. It also suggests an updated version of Mockito to use, to ensure you get the best outcome and number of tests written.

Support for IntelliJ IDEA 2022.1 - COMING SOON!

We are expecting the release of IntelliJ IDEA 2022.1 any day now, and will be able to support this very shortly. Please look out for the next release!

Developer Edition trial available

We are delighted to now offer a 14-day trial version of our Developer Edition, which includes the Diffblue Cover CLI, as part of our new licensing option. We're really excited that you can now "try before you buy"! To download your trial of Diffblue Cover Developer Edition, please click here. Full information on all our options is also available here.

How do I automatically maintain all of these tests?

Use Diffblue Cover on any CI platform to automatically update your unit tests and catch regressions for every commit - watch this video to learn more.


  • Cover now supports writing tests for projects using Java 17. Support for Java 17-specific features, like records and sealed classes, will come in a future release. [Ref: TG-16352]

  • Cover now supports Apple M1 CPUs. [Ref: TG-16543]

  • Cover now supports a properties rule, which can be specified in DiffblueRules.yml, to populate a Properties instance from a file or classpath resource. See 'Custom Inputs' documentation.. [Ref: TG-16683]

  • Cover now includes a Javadoc which links to the methods it has written tests for. [Ref: TG-16584]

  • Cover now provides a warning if the version of Mockito on the classpath is not compatible with the chosen JVM. [Ref: TG-16464]

Resolved Issues

  • IntelliJ Plugin: Resolved an issue which, in some circumstances, caused the "It looks like you haven't used Diffblue Cover [...]" survey to be shown too often. [Ref: TG-16721]

  • IntelliJ Plugin: Resolved an issue which caused the plugin settings scrollbar to not be at the top of the window when opened. [Ref: TG-16692]

  • Resolved an issue which, in certain circumstances, would provoke an F009 (Internal error) and fail to write a test for a method when generating large intermediate lists. [Ref: TG-16678]

Known Issues

  • CLI: The command dcover clean --failing does not work on Gradle projects. This command is now deprecated and dcover validate should be used instead. [Ref: TG-11707]

  • Cover may fail to write tests for Gradle projects using Java 17, and fails to create coverage reports when using Gradle on Java 17. [Ref: TG-16878]

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