What's New > Version 2021.08.03

More tests and empowering the user experience

Release date: Sep 01, 2021

More tests and empowering the user experience

Continuing with our improvements to both test writing and the user experience, this release we have added some additional environment checks and guidance messaging. 

Plugin updates

The event log output has now been moved into a Diffblue Cover tool panel. The events are categorized into Prepare, Index and Write Tests.

Coming soon

Next release, Diffblue are introducing licensing to both the CLI and Plugin versions. We’re very excited about this enhancement and will provide full details in the 2021.09.01 release!

Diffblue Cover Community Edition is available for use with commercial code

Community Edition allows you to write tests for both open source and commercial code. This means you can now use Diffblue Cover Community Edition at work completely for free. Visit our documentation to learn more about how you can use Diffblue Cover at work, and also see our End-User License Agreement.


If you have feedback, questions or requests regarding the Diffblue Cover IntelliJ Plugin, please contact us on the Community Forum. We would love to hear about what is important to you and what you would like to see in upcoming releases.

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.

Full Release Notes


  • IntelliJ Plugin: Cover now includes a ‘Diffblue Cover tool panel’ which provides categorized test creation output. [Ref: TG-15071]

  • Cover now supports Spring Core 4.2.5+. [Ref: TG-15229]

  • Cover is now able to write tests, which use mocks, for more code paths. [Ref: TG-15201]

  • Cover now provides a warning if the versions of Spring and JDK, currently in use, are incompatible. [Ref: TG-14391]

Resolved Issues

  • Resolved an issue which caused Cover to write timezone-sensitive tests which resulted in non-deterministic tests. [Ref: TG-15174]

  • Resolved an issue which, in some circumstances with time/date related tests, resulted in non-deterministic tests being written. Cover no longer uses the system default timezone, but instead uses a fixed timezone. [Ref: TG-14707]

  • CLI: Resolved an issue which caused Cover to not provide remediation advice when it is unable to write to a logfile. [Ref: TG-14897]

  • CLI: Resolved an issue which caused Cover to not provide remediation advice when the java executable cannot be found on Windows. [Ref: TG-15257]

Known Issues

  • CLI: dcover clean --failing fails when used with a Gradle project. [Ref: TG-11707]

  • IntelliJ Plugin: Diffblue Cover was unable to create an index error may appear if switching project happens before Cover has finished indexing. [Ref: TG-13772]