Skillshub kotlin-best-practices

Core patterns for robust Kotlin code including scope functions and backing properties. Use when writing idiomatic Kotlin, choosing between scope functions (let/apply/run/also/with), encapsulating mutable state with backing properties, or exposing read-only collection interfaces. (triggers: **/*.kt, apply, let, run, also, with, runCatching, backing property, MutableList, internal, private set)

install

source · Clone the upstream repo

git clone https://github.com/ComeOnOliver/skillshub

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/ComeOnOliver/skillshub "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/HoangNguyen0403/agent-skills-standard/kotlin-best-practices" ~/.claude/skills/comeonoliver-skillshub-kotlin-best-practices && rm -rf "$T"

manifest: skills/HoangNguyen0403/agent-skills-standard/kotlin-best-practices/SKILL.md

source content

Kotlin Best Practices

Priority: P1 (HIGH)

Engineering standards for clean, maintainable Kotlin systems.

Implementation Guidelines

Scope Functions:
- ```
apply
```
  : Object configuration (returns object).
- ```
also
```
  : Side effects / validation / logging (returns object).
- ```
let
```
  : Null checks (
```
?.let
```
  ) or mapping (returns result).
- ```
run
```
  : Object configuration and mapping (returns result).
- ```
with
```
  : Grouping multiple method calls on an object (returns result).
Backing Properties: Use
```
_state
```
(private mutable, e.g.,
```
private val _state = MutableStateFlow(initial)
```
) exposed as
```
val state = _state.asStateFlow()
```
(public read-only). Pattern:
```
_prop
```
private,
```
prop
```
public.
Collections: Expose
```
List
```
/
```
Map
```
(read-only) publicly; keep
```
MutableList
```
internal.
Error Handling: Use
```
runCatching
```
for simple error handling over try/catch blocks.
Visibility: Default to
```
private
```
or
```
internal
```
. Minimize
```
public
```
surface area.
Top-Level: Prefer top-level functions/constants over implementation-less
```
object
```
singletons.

Anti-Patterns

No Deep Scope Nesting: Limit let/apply nesting to 2 levels; deeper destroys readability.
No Public var: Use private set or backing properties for encapsulation.
No Global Mutable State: Avoid mutable top-level variables.

References

Backing Property & Scope Function Examples