lint

name	lint
description	Fix code style issues and ensure linting CI gates pass in S3Mock. Use when ktlint or Checkstyle violations are reported, when asked to fix formatting, or as a required final step after any code change. Runs ktlint for Kotlin source files and Checkstyle for Java and XML files.

Lint Skill

Entry Criteria

Use this skill when:

• ktlint or Checkstyle violations are reported
• Asked to fix formatting issues
• Invoked as a final step by the implement, test, or refactor skill

Tools

Tool	Target	Config	Auto-fix?
ktlint	Kotlin source files	.editorconfig	Yes — make format
Checkstyle	Java source + XML files	etc/checkstyle.xml	No — fix manually

Execution Steps

1. make format — auto-formats all Kotlin files with ktlint. Fixes the vast majority of Kotlin style issues.
2. make lint — reports ktlint and Checkstyle violations. Fix Checkstyle (Java/XML) violations manually.
3. make sort — run this if any pom.xml was added or modified during this task.
4. Fix any remaining violations manually (see resources below for style guides).
5. make install — confirm all linting CI gates pass before finishing.

Common Violations

ktlint (Kotlin)

make format auto-fixes most of these:

• Wrong indentation (2 spaces)
• Unused or wildcard imports
• Missing trailing newline
• Line too long (max 120 characters)

To check without modifying files: make lint

Checkstyle (Java / XML)

Fix these manually:

• Wrong indentation (2 spaces, per .editorconfig)
• Line too long (max 120 characters)
• Import ordering
• Missing or malformed Javadoc

Completion Criteria

• make format run (Kotlin auto-fixed)
• make lint passes with no violations
• make sort run if any pom.xml was modified
• make install passes all CI gates

Resources

• AGENTS.md — build command reference
• docs/KOTLIN.md — Kotlin style conventions
• docs/JAVA.md — Java style conventions
• etc/checkstyle.xml — Checkstyle configuration
• .editorconfig — indentation and line-length settings