Run checkstyle as separate CI job on Linux with latest Java

[horgh]

Move checkstyle out of the test phase and into a dedicated CI job. This allows dependabot to update the checkstyle version and speeds up test runs on Windows/macOS by not running checkstyle there.

Checkstyle 13+ requires Java 21+, so we run it on Java 24 on Linux.

[gemini-code-assist]

Summary of Changes

Hello @horgh, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request streamlines the Checkstyle integration within the project's build system. By decoupling Checkstyle from the standard test phase and moving it to a dedicated CI job, the change facilitates easier version management through Dependabot and enhances build efficiency by selectively running Checkstyle only on Linux with the necessary Java version. This ensures code quality checks are performed effectively without impeding other platform-specific test executions.

Highlights

• Dedicated Checkstyle CI Job: Checkstyle execution is now a dedicated CI job, separate from the test phase.
• Dependabot Compatibility: Enabled independent updates for Checkstyle via Dependabot.
• Improved Test Performance: Improved test run speeds on Windows and macOS by excluding Checkstyle from those platforms.
• Java Version Alignment: Configured Checkstyle to run on Java 24 on Linux, meeting the Java 21+ requirement for Checkstyle 13+.

Ignored Files

• Ignored by pattern: .github/workflows/** (1)
  • .github/workflows/checkstyle.yml

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[gemini-code-assist]

Code Review

This pull request refactors the Checkstyle configuration by moving it from a profile-based execution during the test phase to a standalone plugin definition. This change is intended to facilitate running Checkstyle in a dedicated CI job, especially since it now requires Java 21+, and to speed up local builds on other platforms. The changes in pom.xml correctly implement this by removing the checkstyle-jdk21 profile and adding the maven-checkstyle-plugin to the main build plugins without an execution binding. My review includes a suggestion to improve maintainability by managing the plugin and dependency versions through properties, which is a common best practice in Maven projects.

[gemini-code-assist]

For better maintainability, it's a good practice to manage plugin and dependency versions in the <properties> section. This centralizes version numbers, making them easier to update and keep consistent.

You could define properties in the <properties> section like so:

<properties>
    ...
    <maven-checkstyle-plugin.version>3.6.0</maven-checkstyle-plugin.version>
    <checkstyle.version>13.0.0</checkstyle.version>
</properties>

And then reference them here. This makes future updates much simpler.

Suggested change

	<version>3.6.0</version>
	<configuration>
	<consoleOutput>true</consoleOutput>
	<configLocation>checkstyle.xml</configLocation>
	<suppressionsLocation>checkstyle-suppressions.xml</suppressionsLocation>
	<violationSeverity>warning</violationSeverity>
	</configuration>
	<dependencies>
	<dependency>
	<groupId>com.puppycrawl.tools</groupId>
	<artifactId>checkstyle</artifactId>
	<version>13.0.0</version>
	<version>${maven-checkstyle-plugin.version}</version>
	<configuration>
	<consoleOutput>true</consoleOutput>
	<configLocation>checkstyle.xml</configLocation>
	<suppressionsLocation>checkstyle-suppressions.xml</suppressionsLocation>
	<violationSeverity>warning</violationSeverity>
	</configuration>
	<dependencies>
	<dependency>
	<groupId>com.puppycrawl.tools</groupId>
	<artifactId>checkstyle</artifactId>
	<version>${checkstyle.version}</version>