What's New > Version 2021.10.02

Test writing can now be cancelled in the IntelliJ plugin

Release date: Oct 25, 2021

Improved JSON reports

The JSON format output by the --report option has been updated to be more human-readable, and to contain additional information (both the command that was run and a timestamp).  The properties in the summary, classes and methods have also been updated for consistency. Diffblue Cover now uses only this new format output, but for convenience Cover Reports accepts both the old and new versions.

IntelliJ Plugin: Test writing can now be cancelled

Test writing can now be cancelled in the IntelliJ Plugin. This can be useful if, for example, you accidentally start test writing on the wrong module.

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 handles multi-module Gradle projects with non-default layouts. [Ref: TG-15621]

  • The JSON format output by the --report option has been reordered to be more human-readable. It also now includes both the command that was run and a timestamp, and the properties have also been changed for consistency. [Ref: TG-15388]

  • IntelliJ Plugin: Error reports are now being sent automatically. [Ref: TG-15219]

  • Cover now has improved log messages for Gradle projects. [Ref: TG-14985]

  • Cover now writes tests for methods inherited from abstract parent classes. [Ref: TG-13634]

Resolved Issues

  • Resolved an issue which caused Cover to time out when constructing large Spring contexts. [Ref: TG-15655]

  • Cover now creates more tests by mocking Spring’s RestTemplate and RestTemplateBuilder. [Ref: TG-15617]

  • Resolved an issue which caused Cover to use a null pointer instead of creating an ObjectInputStream. [Ref: TG-15614]

  • Resolved an issue by improving handling of methods with single string arguments. [Ref: TG-15613]

  • IntelliJ Plugin: Resolved an issue where the plugin would produce an assertion exception. [Ref: TG-15580]

  • IntelliJ Plugin: Resolved an issue where an index out of bounds exception was produced. [Ref: TG-15508]

  • IntelliJ Plugin: More types of error now appear in the Diffblue Tool panel. [Ref: TG-15445]

  • Resolved an issue where, in some cases, Cover would erroneously report an output code R013 when unable to create a method mock. This has been resolved by the introduction of a new output code - R029. [Ref: TG-14840]

  • Resolved an issue so that users can now cancel test creation. [Ref: TG-14411]

Known Issues

  • The command dcover clean --failing does not work on Gradle projects. [Ref: TG-11707]

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

  • If the internet connection is lost during test creation, an extra 10 consumptions is deducted from the test creation allowance. [Ref: TG-15706]