Entry point: /faion-net — invoke this skill for automatic routing to the appropriate domain.

JavaScript Developer Skill

JavaScript and TypeScript development covering React, Node.js, Next.js, and modern JS ecosystem.

Purpose

Handles all JavaScript/TypeScript development including React frontends, Node.js backends, Next.js full-stack apps, and modern JS tooling.

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Context Discovery

Auto-Investigation

Detect JS/TS stack from project files:

Signal	How to Check	What It Tells Us
package.json	Read("package.json")	Dependencies, scripts, type
React	Grep("react", "package.json")	React framework used
Next.js	Grep("next", "package.json")	Next.js framework
Express	Grep("express", "package.json")	Express backend
Fastify	Grep("fastify", "package.json")	Fastify backend
TypeScript	Glob("**/tsconfig.json")	TypeScript enabled
Bun	Glob("**/bun.lockb")	Bun runtime
ESLint config	Glob("**/.eslintrc*")	Linting setup
Jest/Vitest	Grep("jest|vitest", "package.json")	Test framework

Read existing patterns:

• Check src/ structure for architecture
• Read existing components for patterns
• Check tsconfig.json for strictness level

Discovery Questions

Q1: Project Type

question: "What type of JS/TS project is this?"
header: "Type"
multiSelect: false
options:
  - label: "React frontend (SPA)"
    description: "Client-side React application"
  - label: "Next.js full-stack"
    description: "Server components, API routes, SSR"
  - label: "Node.js backend"
    description: "Express, Fastify, or plain Node"
  - label: "Library/package"
    description: "Reusable npm package"

Routing:

• "React" → react-*, component architecture
• "Next.js" → nextjs-app-router, server components
• "Node.js" → nodejs-express or nodejs-fastify
• "Library" → TypeScript strict, build config

Q2: TypeScript Strictness

question: "What TypeScript strictness level?"
header: "TypeScript"
multiSelect: false
options:
  - label: "Strict mode (recommended)"
    description: "Full type safety, no any"
  - label: "Standard"
    description: "Basic type checking"
  - label: "JavaScript only"
    description: "No TypeScript"
  - label: "Match existing config"
    description: "Follow tsconfig.json"

Q3: State Management (if React)

question: "How do you manage state?"
header: "State"
multiSelect: false
options:
  - label: "React hooks (useState, useContext)"
    description: "Built-in React state"
  - label: "Zustand"
    description: "Lightweight global state"
  - label: "Redux/RTK"
    description: "Full Redux toolkit"
  - label: "Server state (React Query/SWR)"
    description: "Remote data fetching"
  - label: "Not sure / recommend"
    description: "I'll suggest based on needs"

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When to Use

• React applications (hooks, components, state)
• Node.js backends (Express, Fastify)
• Next.js full-stack applications
• TypeScript strict mode and patterns
• Modern JavaScript (ES2024+)
• Bun runtime

Methodologies

Category	Methodology	File
React
Component architecture	React component patterns, composition	react-component-architecture.md
React hooks	useState, useEffect, custom hooks	react-hooks.md
React patterns	Modern React patterns, best practices	react-patterns.md
React decomposition	Breaking down React apps	decomposition-react.md
Next.js
Next.js App Router	App router, server components, routing	nextjs-app-router.md
Node.js
Node.js Express	Express.js patterns, middleware	nodejs-express.md
Node.js Fastify	Fastify framework, plugins, hooks	nodejs-fastify.md
Node.js patterns	Async patterns, error handling	nodejs-patterns.md
Node.js service layer	Service layer architecture	nodejs-service-layer-architecture.md
Node.js service implementation	Service layer implementation	nodejs-service-layer-implementation.md
TypeScript
TypeScript patterns	TS best practices, generics	typescript-patterns.md
TypeScript strict mode	Strict configuration, type safety	typescript-strict-mode.md
TypeScript React 2026	TS 5.x + React 19 + Next.js 15	typescript-react-2026.md
JavaScript
JavaScript basics	ES6+, async/await, modules	javascript.md
JavaScript modern	ES2024+ features, modern patterns	javascript-modern.md
JavaScript testing	Jest, Vitest patterns	javascript-testing.md
Runtime
Bun runtime	Bun.js patterns, performance	bun-runtime.md
Bun simple	Quick Bun reference	bun-runtime-simple.md

Tools

• Frameworks: React 19, Next.js 15, Express, Fastify
• Runtime: Node.js 20+, Bun 1.x
• Testing: Jest, Vitest, React Testing Library
• Bundlers: Vite, Turbopack, webpack
• Package managers: pnpm, npm, yarn, bun

Related Sub-Skills

Sub-skill	Relationship
faion-frontend-developer	UI components, styling
faion-api-developer	API design and integration
faion-testing-developer	Testing strategies
faion-devtools-developer	Build tools, monorepos

Integration

Invoked by parent skill faion-software-developer when working with JavaScript/TypeScript code.

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faion-javascript-developer v1.0 | 18 methodologies