Android Ktlint Formatting

Android KtLint Formatting Excellence 🧹💎

Standardized formatting rules for Android developers based on the official Kotlin and Android Style Guides.

⚡ When to Use

• Code Cleanup: Automatically reformatting messy files.
• Pre-commit Audit: Ensuring the code is perfectly formatted before pushing.
• CI/CD Configuration: Setting up a gatekeeper for code style.
• New Project Setup: Initializing a project with the correct .editorconfig.

🏗️ Core Rules (Android Style)

1. Indentation

• Use 4 spaces for indentation.
• No TAB characters allowed.
• Follow "Continuation Indents" for long method calls (8 spaces).

2. Imports

• Rule: Avoid wildcard imports (import com.example.*).
• Order alphabetically.
• Group by java.*, kotlin.*, then external libraries.

3. Blank Lines

• Single blank line between classes, properties, and methods.
• NO trailing whitespace at the end of lines.
• NO multiple blank lines.

4. Naming

• Classes/Interfaces: PascalCase.
• Properties/Variables: camelCase.
• Functions: camelCase.
• Constants: SCREAMING_SNAKE_CASE.

🛠️ Essential Commands

Check Formatting

./gradlew ktlintCheck

Auto-Fix Formatting

• Rule: ALWAYS run this before committing if formatting changes are extensive.

./gradlew ktlintFormat

📜 Configuration (.editorconfig)

Ensure your project has a .editorconfig that KtLint reads:

[*.{kt,kts}]
indent_size=4
insert_final_newline=true
max_line_length=120
ij_kotlin_allow_trailing_comma=true

🚀 Performance & Tips

• [ ] IDE Integration: Install the "KtLint" or "Kotlin" plugin and enable "On Save" actions.
• [ ] Trailing Comma: Use trailing commas for all multi-line collections and arguments for better diffs.
• [ ] Imports Cleanup: Periodically run Alt+Enter → "Optimize Imports".

🧪 Verification Checklist

• [ ] No Wildcards: All imports are explicit.
• [ ] No Tabs: Only spaces.
• [ ] EndOfLine: File ends with exactly one newline.
• [ ] No Redundant Semicolons: Clean up all unnecessary ;.

🔗 Related Resources

• Official Pinterest KtLint
• Android Kotlin Style Guide
• [Code Review Expert](../android-code-review-expert/SKILL.md)

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: prasad-vennam
• Source: prasad-vennam/Awesome-Android-AI-Agent-Skills
• License: MIT

Install and usage instructions live in the source repository linked above.