Add ability to pass options to javaagents (#50)

[ryandens]

Closes #50.

What

Adds support for the -javaagent:<jar>=<options> form of the flag so agents like the Prometheus JMX Exporter (=12345:config.yaml) can be configured.

API

A new javaagent { } extension exposes an agentOptions map. Options are keyed by dependency coordinate — group:name for module dependencies, project path for project dependencies — so they are independent of the resolved jar file name and survive version bumps.

dependencies {
    javaagent("io.prometheus.jmx:jmx_prometheus_javaagent:0.20.0")
}

javaagent {
    agentOptions.put("io.prometheus.jmx:jmx_prometheus_javaagent", "12345:config.yaml")
}

How

• JavaagentExtension — new agentOptions MapProperty, created once by JavaagentBasePlugin.
• AgentOptionsResolver — resolves the coordinate-keyed options against the configuration's resolved artifacts (via ResolvedArtifactResult component identifiers) into a fileName -> options map. Lazy and configuration-cache safe; written in Java for the same task-input serialization reason as JavaForkOptionsConfigurer.
• The map is threaded into all four -javaagent: sites: application run task, test task, application distribution start scripts, and jib container entrypoints. Agents without a matching entry get no suffix (existing behavior preserved).

Design decisions

Both settled up front (see the issue discussion):

• Key by coordinate rather than a single global value or by resolved jar name — robust for multiple agents, not brittle to version bumps.
• Single shared value across contexts for this first version; per-context overrides (tasks.run { javaagent { ... } }, etc.) are a deliberate follow-up.

Known limitation

Options containing spaces work for the run/test tasks (list-based JvmArgumentProvider) but may hit quoting issues in the single-token distribution start-script opt.

Tests

• New functional tests for run-task options, multi-agent (options applied only to the keyed agent), and distribution start-script rendering (Unix + Windows).
• New jib functional test asserting the container entrypoint carries =<options>.
• simple-agent now echoes its agentArgs so options are observable end-to-end.
• Existing no-options tests unchanged and green; plugin + jib functional/unit suites and spotlessCheck pass.

🤖 Generated with Claude Code

https://claude.ai/code/session_01FBTxQkVXBjJoBSfKPWyY3K

Note

Add options support to javaagent configuration via coordinate-keyed agentOptions map

• Adds a new JavaagentExtension DSL with an agentOptions map property, where keys are dependency coordinates (e.g. group:name) and values are option strings appended as =<options> to -javaagent flags.
• A new AgentOptionsResolver utility resolves coordinate keys to file-name-keyed maps in a configuration-cache-safe way.
• Options are propagated to all plugin surfaces: JavaExec/Test tasks via JavaForkOptionsConfigurer, application run task via JavaagentApplicationRunPlugin, distribution start scripts via JavaagentAwareStartScriptGenerator, and Jib container entrypoints via JavaagentJibPlugin.
• Agents without configured options are unaffected.

📊 Macroscope summarized de8ee7d. 8 files reviewed, 0 issues evaluated, 0 issues filtered, 0 comments posted

🗂️ Filtered Issues

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[testlens-app]

✅ All tests passed ✅

🏷️ Commit: 2ae86eb
▶️ Tests: 2 executed
⚪️ Checks: 3/3 completed

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