In this release, Diffblue Cover will now write tests and provide community support for non-LTS Java versions (9, 10, 12-16) - note that Diffblue only supports LTS versions 8,11, and 17 in production use. Also, the release includes an update to Cover Plugin changing the default name of test classes from ${CLASS_NAME}Test to ${CLASS_NAME}DiffblueTest. See the full Release Notes below for details of all enhancements and resolved issues covered by this release.


  • Reports: Cover Reports now has a simplified docker build to remove redundant components. To update Cover Reports, see the Update Cover Documentation. [Ref: TG-19467]

  • Pipeline: Cover Pipeline now enables the Cover CLI --batch option by default when the environment variable CI=true is set. [Ref: TG-20088]

  • Plugin: By default, tests written by Cover Plugin will now be suffixed with *DiffblueTest. [Ref: TG-20060]

  • Cover: Diffblue Cover can now write tests using the BigDecimal(String) constructor which improves assertions. [Ref: TG-20006]

  • Plugin: UI improvement. Cover Plugin now provides a Cancel button during test creation. [Ref: TG-19795]

  • Cover: Diffblue Cover now attempts to write tests for non-LTS Java versions (9, 10, 12-16) if strict mode is not used. [Ref: TG-19761]

  • Cover: Diffblue Cover no longer writes tests for Java 17 auto-generated Record methods. [Ref: TG-18143]

Resolved Issues

  • Reports: Resolved an issue which in some circumstances caused Cover Reports to incorrectly display links in the Safari browser. [Ref: TG-19835]

  • Plugin: Resolved an issue where Cover Plugin run configuration templates were not retained. [Ref: TG-19749]

Known Issues

  • Plugin: Cover Plugin incorrectly gives the option to write tests for a test file using the menu option, while in the IDE editor. [Ref: TG-17163]

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

  • Cover: Diffblue 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]

  • Cover: 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]

  • Plugin: Cover Plugin may display tests links which do not work when writing tests for multiple methods at once. To avoid this, write tests at the class level or for a single method. [Ref: TG-20050]

  • Plugin: Cover Plugin will get stuck during the 'Preparing' phase if the run configurations created by the plugin are used. To avoid this issue, do not use the run configurations created by the plugin. [Ref: TG-20061]

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