everything-claude-code/.cursor/rules/kotlin-coding-style.md

description, globs, alwaysApply

description	globs	alwaysApply
Kotlin coding style extending common rules	**/*.kt **/*.kts **/build.gradle.kts	false

Kotlin Coding Style

This file extends the common coding style rule with Kotlin-specific content.

Formatting

• Auto-formatting via ktfmt or ktlint (configured in kotlin-hooks.md)
• Use trailing commas in multiline declarations

Immutability

The global immutability requirement is enforced in the common coding style rule. For Kotlin specifically:

• Prefer val over var
• Use immutable collection types (List, Map, Set)
• Use data class with copy() for immutable updates

Null Safety

• Avoid !! -- use ?., ?:, require, or checkNotNull
• Handle platform types explicitly at Java interop boundaries

Expression Bodies

Prefer expression bodies for single-expression functions:

fun isAdult(age: Int): Boolean = age >= 18

Reference

See skill: kotlin-patterns for comprehensive Kotlin idioms and patterns.