JavaScript Best Practices

Idiomatic JavaScript patterns and conventions for maintainable code. Use when writing or refactoring JavaScript following idiomatic patterns and conventions. (triggers: **/*.js, **/*.mjs, module, import, export, error, validation)

385 stars

Best use case

JavaScript Best Practices is best used when you need a repeatable AI agent workflow instead of a one-off prompt.

Idiomatic JavaScript patterns and conventions for maintainable code. Use when writing or refactoring JavaScript following idiomatic patterns and conventions. (triggers: **/*.js, **/*.mjs, module, import, export, error, validation)

Teams using JavaScript Best Practices should expect a more consistent output, faster repeated execution, less prompt rewriting.

When to use this skill

  • You want a reusable workflow that can be run more than once with consistent structure.

When not to use this skill

  • You only need a quick one-off answer and do not need a reusable workflow.
  • You cannot install or maintain the underlying files, dependencies, or repository context.

Installation

Claude Code / Cursor / Codex

$curl -o ~/.claude/skills/javascript-best-practices/SKILL.md --create-dirs "https://raw.githubusercontent.com/HoangNguyen0403/agent-skills-standard/main/skills/javascript/javascript-best-practices/SKILL.md"

Manual Installation

  1. Download SKILL.md from GitHub
  2. Place it in .claude/skills/javascript-best-practices/SKILL.md inside your project
  3. Restart your AI agent — it will auto-discover the skill

How JavaScript Best Practices Compares

Feature / AgentJavaScript Best PracticesStandard Approach
Platform SupportNot specifiedLimited / Varies
Context Awareness High Baseline
Installation ComplexityUnknownN/A

Frequently Asked Questions

What does this skill do?

Idiomatic JavaScript patterns and conventions for maintainable code. Use when writing or refactoring JavaScript following idiomatic patterns and conventions. (triggers: **/*.js, **/*.mjs, module, import, export, error, validation)

Where can I find the source code?

You can find the source code on GitHub using the link provided at the top of the page.

Related Guides

SKILL.md Source

# JavaScript Best Practices

## **Priority: P1 (OPERATIONAL)**

Conventions and patterns for writing maintainable JavaScript.

## Implementation Guidelines

- **Naming**: `camelCase` (vars/funcs), `PascalCase` (classes), `UPPER_SNAKE` (constants).
- **Errors**: Throw `Error` objects only. Handle all async errors.
- **Comments**: JSDoc for APIs. Explain "why" not "what".
- **Files**: One entity per file. `index.js` for exports.
- **Modules**: Named exports only. Order: Ext -> Int -> Rel.

## Anti-Patterns

- **No Globals**: Encapsulate state.
- **No Magic Numbers**: Use `const`.
- **No Nesting**: Guard clauses/early returns.
- **No Defaults**: Use named exports.
- **No Side Effects**: Keep functions pure.

## Code & Reference

See [references/REFERENCE.md](references/REFERENCE.md) for constants, custom errors, async patterns, and module structure examples.

## Related Topics

language | tooling

Related Skills

swift-best-practices

385
from HoangNguyen0403/agent-skills-standard

Apply Guard, Value Types, Immutability, and Naming conventions in Swift. Use when writing idiomatic Swift using guard, value types, immutability, or naming conventions. (triggers: **/*.swift, guard, let, struct, final)

spring-boot-best-practices

385
from HoangNguyen0403/agent-skills-standard

Apply core coding standards, dependency injection, and configuration for Spring Boot 3. Use when applying Spring Boot 3 coding standards or configuring dependency injection. (triggers: application.properties, **/*Service.java, autowired, requiredargsconstructor, configuration-properties, slf4j)

php-best-practices

385
from HoangNguyen0403/agent-skills-standard

Write PHP following best practices, PSR standards, and code quality guidelines. Use when writing PHP following PSR standards, SOLID principles, or improving code quality. (triggers: **/*.php, psr-12, camelCase, PascalCase, dry, solid)

kotlin-best-practices

385
from HoangNguyen0403/agent-skills-standard

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)

JavaScript Tooling

385
from HoangNguyen0403/agent-skills-standard

Configure development tools, linting, and testing for JavaScript projects. Use when configuring ESLint, Prettier, or test runners for JavaScript projects. (triggers: .eslintrc.*, jest.config.*, package.json, eslint, prettier, jest, test, lint, build)

javascript-language

385
from HoangNguyen0403/agent-skills-standard

Modern JavaScript (ES2022+) patterns for clean, maintainable code. Use when working with modern JavaScript features like optional chaining, nullish coalescing, or ESM. (triggers: **/*.js, **/*.mjs, **/*.cjs, const, let, arrow, async, await, promise, destructuring, spread, class)

java-best-practices

385
from HoangNguyen0403/agent-skills-standard

Apply core Effective Java patterns for robust, maintainable code. Use when applying SOLID principles, choosing between inheritance and composition, refactoring Java code smells, or reviewing class design. (triggers: **/*.java, refactor, SOLID, builder, factory, composition, immutable, Optional, checked exception, clean code)

dart-best-practices

385
from HoangNguyen0403/agent-skills-standard

Dart code quality conventions: naming, const/final/var hierarchy, single quotes, trailing commas, collection idioms, tear-offs, and import organization. Use when writing new Dart code or reviewing for style violations — wrong import style, global variables, var misuse, anonymous lambdas where tear-offs fit, or missing trailing commas. (triggers: **/*.dart, naming, convention, trailing comma, import, tear-off)

typescript-best-practices

385
from HoangNguyen0403/agent-skills-standard

Write idiomatic TypeScript patterns for clean, maintainable code. Use when writing or refactoring TypeScript classes, functions, modules, or async logic. (triggers: **/*.ts, **/*.tsx, class, function, module, import, export, async, promise)

JavaScript Language Patterns

385
from HoangNguyen0403/agent-skills-standard

Modern JavaScript (ES2022+) patterns for clean, maintainable code.

common-best-practices

385
from HoangNguyen0403/agent-skills-standard

Enforce SOLID principles, guard-clause style, function size limits, and intention-revealing naming across all languages. Use when refactoring for readability, applying clean-code patterns, reviewing naming conventions, or reducing function complexity. (triggers: **/*.ts, **/*.tsx, **/*.go, **/*.dart, **/*.java, **/*.kt, **/*.swift, **/*.py, solid, kiss, dry, yagni, naming, conventions, refactor, clean code)

swift-tooling

385
from HoangNguyen0403/agent-skills-standard

Configure SPM packages, SwiftLint, and build settings for Swift projects. Use when managing Swift packages with SPM, configuring build settings, or enforcing Swift code quality. (triggers: Package.swift, .swiftlint.yml, package, target, dependency)