What's New > Version 2021.10.01

Update for Community Edition users and new Developer Edition trial available

Release date: Oct 11, 2021

Diffblue Cover Community Edition now requires an active internet connection

In this release, we launch our new licensing feature. Community Edition users of our IntelliJ Plugin can now seamlessly buy and upgrade to a paid plan from our website. Please be aware that Community Edition users now require an active internet connection.

New 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, but a short summary is below:

Community Edition Developer Edition Full versions
100 Tests/Day 250 Tests/Day 5,000+ Tests/Day
IntelliJ Plugin IntelliJ Plugin IntelliJ Plugin 
  CLI Tool CLI Tool
Write tests for classes and methods + Write tests for packages, and modules + Write tests for whole projects
Community support Basic support Professional support
    Coverage analytics
    CI pipeline integrations


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


  • Cover now writes tests for methods that return java.util.Date. [Ref: TG-15634]

  • Cover now adds Spring EntityScan annotations to repository tests if entities are not in the same package as the repository. [Ref: TG-15557]

  • Cover can now write tests for Spring components in a Spring 5 project without the spring-boot-test dependency present. [Ref: TG-15499]

  • CLI: Cover now provides warning messages, rather than error messages, when potentially incompatible versions of Spring components are detected. [Ref: TG-15546]

  • CLI: Cover now provides a warning if the Maven Surefire Plugin is not found in a JUnit 5 Maven project’s dependencies. [Ref: TG-15418]

Resolved Issues

  • Resolved an issue which caused Cover to report Missing or unsupported JUnit dependency when JUnit 5.4.0 was detected. [Ref: TG-15598]

  • Resolved an issue which, in some circumstances, caused assertions in some tests to be produced in a non-deterministic order. [Ref: TG-15583]

  • Resolved an issue which, in some circumstances, caused Cover to write a test which would not compile because a type argument was instantiated with an incompatible class. [Ref: TG-15475]

  • Resolved an issue which, in some circumstances, caused Cover to write a test which would not compile because a type argument was not instantiated in a local variable declaration. [Ref: TG-15474]

  • CLI: Resolved an issue which, in some circumstances, could result in an internal assertion failure during processing of Enum classes when the --existing-coverage and --merge are used. [Ref: TG-15537]

  • IntelliJ Plugin: Resolved an issue which caused Cover to throw a NullPointerException - java.lang.IllegalArgumentException: Argument for @NotNull parameter 'module'. [Ref: TG-15591]

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]