Svelte Cheat Sheet

Svelte cheat sheet with real commands and snippets for setup, core workflows, debugging, and production-safe automation patterns. If you are working across tools, pair this with the Vue Cheat Sheet and Storybook Cheat Sheet.

Setup and Installation

Goal: Create a fresh project

# Scaffold project using official starter
npx sv create my-svelte-app

# Install dependencies after scaffold completes
cd my-svelte-app && npm install

Goal: Verify local toolchain versions

# Print Node.js runtime version
node --version

# Print npm version for lockfile consistency
npm --version

# Inspect package scripts in project
cat package.json | rg "scripts" -n

Core Development Workflow

Goal: Run local development server

# Start framework dev server with hot reload
npm run dev

# Check local endpoint health
curl -I http://localhost:3000 || curl -I http://localhost:5173 || true

Goal: Build and preview production output

# Build optimized production assets
npm run build

# Run production preview server
npm run preview

Goal: Implement a core feature snippet

<!-- Component with reactive state -->
<script>
  let count = 0;
  $: doubled = count * 2;
</script>

<button on:click={() => count += 1}>Count: {count}</button>
<p>Doubled: {doubled}</p>

Testing and Quality

Goal: Run tests and static checks

# Execute project tests
npm test

# Run type checking when available
npm run check || npx tsc --noEmit || true

# Run linting for fast feedback
npm run lint || true

Deployment and Operations

Goal: Prepare deployment artifacts

# Create production build before deployment
npm run build

# Validate environment variables are set
node -e "console.log('NODE_ENV=', process.env.NODE_ENV || 'unset')"

# Smoke-test production route after deploy
curl -I https://devcheatsheets.com

Debugging and Troubleshooting

Goal: Inspect build and runtime failures

# Reinstall dependencies from lockfile
rm -rf node_modules && npm ci

# Re-run build with clean cache
npm run build

# Search source for suspect route/config patterns
rg "route|middleware|config" src app -n

Common Gotchas

• Run Svelte builds locally before shipping to CI/CD environments.
• Keep environment secrets outside the repository and load them per environment.
• Avoid stale dependency locks by using npm ci in automation.
• Validate route and middleware behavior with explicit smoke tests.
• Keep framework and plugin versions aligned to avoid build regressions.

Related Sheets

• Vue Cheat Sheet — daily Vue commands and production-ready examples.
• Storybook Cheat Sheet — daily Storybook commands and production-ready examples.
• Linux Cheat Sheet — filesystem, process, and service troubleshooting.