> For the complete documentation index, see [llms.txt](https://cover-docs.diffblue.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cover-docs.diffblue.com/updates-and-upgrades/release-archive/2025-05-02.md).

# 2025-05-02

## 2025-05-02

This release enhances test generation for Spring controllers and `String`s with validation annotations, introduces a new CLI test management command, and resolves issues with JUnit 5 test retention and Gradle coverage reporting.

* **Test Generation & Quality**:
  * More precise mock parameters for Spring controller tests, improving coverage and Spring-specific scenarios.
  * Improved inputs for `String` types with Java Beans Validation, JPA `@Column`, or Hibernate `@Length` annotations, yielding more suitable inputs and tests.
  * Simplified factory method specifications in `DiffblueRules.yaml` (name and parameters), removing need for verbose descriptors.
  * Fix for JUnit 5 `@DisplayName` issue; whole test classes no longer discarded on single method failure, improving test retention.
* **CLI Enhancements & User Control**:
  * New `dcover remove` CLI command for project-wide deletion of generated tests.
* **Reports**:
  * Fix for `dcover coverage-reports` showing 0% for Gradle projects with no manual tests; Cover-generated test coverage now correctly shown.

## Important Notices

### Changes to test code

* **Test formatting**: In a future release, Cover will switch the default test formatting style to `google-java-format`. This will cause a one-time churn, resulting in larger-than-usual diffs in your test code. If you prefer a different style, an alternative formatter configured in your build system will override this new default.

### Enhancements

* CLI: Diffblue Cover now writes tests for Spring controllers by creating mock parameters with greater precision. This results in more comprehensive test coverage and better generation of Spring-specific test scenarios. \[Ref: TG-23011]
* Diffblue Cover now creates tests with improved inputs for `String`s governed by Java Beans Validation, JPA's `@Column`, or Hibernate's `@Length` annotations. This results in more suitable test inputs, increasing the number of tests produced. \[Ref: TG-23010]
* CLI: Diffblue Cover now enables project-wide deletion of its generated unit tests via the new `dcover remove` command. This function is particularly useful for cleaning up tests after a trial or when changing test file organization. \[Ref: TG-22923]
* Diffblue Cover now uses simplified factory method specifications in `DiffblueRules.yaml` for guiding test generation, identifying methods by name and parameters. Providing the full, verbose descriptor is no longer necessary, simplifying the configuration. \[Ref: TG-22492]

### Resolved Issues

* CLI: Resolved an issue which caused Cover to discard whole JUnit 5 test classes that utilized `@DisplayName` annotations if any single test method failed. Users now retain more passing tests as validation correctly targets only individual failing tests. \[Ref: TG-23156]
* CLI & Reports: Resolved an issue where `dcover coverage-reports` would incorrectly show 0% coverage for Gradle projects with no manual tests. Coverage from Diffblue Cover-generated tests is now correctly shown in CLI output and Cover Reports. \[Ref: TG-23138]

### Known Issues

* Plugin: Cover incorrectly provides a menu option to write tests for a test file. \[Ref: TG-17163]
* 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]
* Reports: Cover only counts Java code towards the total line count metrics. Kotlin code is not currently included. \[Ref: TG-22088]
* Reports: Total lines of code metric can incorrectly count a multi-line comment at the end of a line of code, resulting in fewer than expected lines counted. \[Ref: TG-22089]
* Reports: Following an upgrade, the 'Total Lines of Code' card may show 0 until a new reports bundle has been uploaded. \[Ref: TG-22094]
* In some circumstances, Cover may write more simplistic tests with less meaningful assertions when Spring Boot dependency injection is disabled. \[Ref: TG-22102]
* In some circumstances, Cover will still write Spring Boot tests when Spring Boot dependency injection is disabled. \[Ref: TG-22103]
* Cover may write failing TestNG tests when Spring Boot dependency injection is disabled. \[Ref: TG-22107]
* Plugin: On some displays, the Test Review subsection title "Tests for review" can be malformed. \[Ref: TG-22805]
* Cover does not currently support Java 24. Please switch your JDK version to 21 or lower. \[Ref: TG-22920]