Add Gradle cache cleanup using temporary project with gradlew --no-daemon

[markcallen]

Summary

The current gradle target in mac-cache-cleaner only reports the size of ~/.gradle/caches and ~/.gradle/wrapper/dists but has no cleanup commands. Unlike other tools (npm, pip, cargo), Gradle doesn't provide a native CLI command to clean its global cache.

Proposed Solution

Create a cleanup mechanism that:

1. Creates a temporary minimal Gradle project with a wrapper
2. Runs ./gradlew --no-daemon which performs cleanup when it completes
3. Removes the temporary project directory

This approach leverages Gradle's built-in behavior where running with --no-daemon ensures cleanup happens when the JVM exits, avoiding orphaned daemon processes and their associated cache locks.

Implementation Details

• Create a temp directory with minimal build.gradle.kts or build.gradle
• Include settings.gradle.kts with project name
• Run gradle wrapper to generate gradlew (or include pre-generated wrapper files)
• Execute ./gradlew --no-daemon clean or a custom cleanup task
• Clean up the temporary directory

Current State

{Name: "gradle", Enabled: true, Notes: "Gradle build caches and wrappers", 
 Paths: []string{"~/.gradle/caches", "~/.gradle/wrapper/dists"}, 
 Cmds: [][]string{},  // <-- No cleanup commands
 Tools: []Tool{{Name: "gradle", InstallCmd: "brew install gradle"}}},

Considerations

• Requires Gradle or Java to be installed
• Should handle cases where Gradle is not available gracefully
• May need to stop running Gradle daemons first (gradle --stop)
• Consider which cache directories are safe to clean:
  • ~/.gradle/caches/build-cache-* - Build cache (safe)
  • ~/.gradle/caches/transforms-* - Transform cache (safe)
  • ~/.gradle/caches/modules-* - Dependency cache (will re-download)
  • ~/.gradle/wrapper/dists/ - Downloaded Gradle distributions

Alternatives Considered

1. Direct rm -rf ~/.gradle/caches/ - Works but violates "safety first" principle of using official CLI commands
2. Gradle cache cleanup plugin - Requires modifying user's Gradle setup
3. gradle --stop only - Frees memory but not disk space

[markcallen]

The following will cleanup the gradle cache directory after exiting:

mkdir clean-gradle
cd clean-gradle
gradle init --type basic --project-name clean-gradle --dsl kotlin --use-defaults
command -v jenv >/dev/null 2>&1 && jenv local system
./gradlew --no-daemon