tools: Skill for Claude Code

Protogen Skill

Generate and use the compile-time-safe protobuf builders produced by code/protogen-maven-plugin. The point of this module is shift-left: stock protobuf builders only detect a missing required field at runtime (an UninitializedMessageException from build()), while the generated builder chain makes the same mistake fail to compile.

How the plugin is wired

The plugin runs after protobuf classes exist, so it consumes the compiled *.proto output and emits builder sources. Bind its code-generator goal to a generate-sources phase, point it at the packages holding the generated protobuf messages, and name an output package for the builders:

<plugin>
    <groupId>io.github.adamw7</groupId>
    <artifactId>protogen-maven-plugin</artifactId>
    <!-- Use the latest release: https://github.com/adamw7/tools/releases/latest -->
    <configuration>
        <generatedSourcesDir>${project.basedir}/target/generated-sources/</generatedSourcesDir>
        <pkgs>
            <param>io.github.adamw7.tools.code.protos</param>
        </pkgs>
        <outputpackage>io.github.adamw7.tools.code.builders</outputpackage>
    </configuration>
    <executions>
        <execution>
            <phase>generate-sources</phase>
            <goals>
                <goal>code-generator</goal>
            </goals>
        </execution>
    </executions>
</plugin>

Mojo goal / parameters (CodeMojo, defaultPhase = GENERATE_SOURCES):

Add the output directory as a source root (e.g. build-helper-maven-plugin's add-source / add-test-source) so the builders are compiled with the rest of the module.

How the goal talks to its user

This module is the one place in the repository whose production code does not log through log4j2, and ProtogenArchitectureTest.pluginLogsThroughTheMojoLog holds it to that: