deno-expert

# Deno Expert Knowledge

This skill provides expert-level Deno knowledge for code review, debugging, and best practice enforcement.

## When to Use This Skill

- Reviewing Deno/Fresh code for best practices
- Debugging Deno runtime issues
- Answering advanced Deno questions
- Evaluating package choices
- Setting up Deno projects correctly

## Core Expertise Areas

Understanding these topics deeply:
- **Deno runtime** - Permissions, built-in tools, TypeScript support
- **Fresh framework** - Island architecture, routing, components
- **JSR packages** - The modern registry, @std/* library
- **Preact** - Components, hooks, signals
- **Deno Deploy** - Edge deployment, environment variables
- **Deno Sandboxes** - Safe code execution with @deno/sandbox

## Package Recommendation Principles

When recommending or reviewing package choices:

1. **First choice:** `jsr:` packages (e.g., `jsr:@std/http`)
2. **Second choice:** `npm:` packages when no JSR alternative exists
3. **Never recommend:** `https://deno.land/x/` - this is deprecated

The standard library is at `jsr:@std/*`, not `deno.land/std`.

## Built-in Tool Usage

Encourage using Deno's integrated tooling:
- `deno fmt` - Format code
- `deno lint` - Lint for issues
- `deno test` - Run tests
- `deno doc <package>` - View package documentation
- `deno add <package>` - Add dependencies
- `deno deploy` - Deploy to Deno Deploy

## Code Review Checklist

### Import Statements
- [ ] Uses `jsr:` for Deno-native packages
- [ ] Uses `npm:` only when no JSR alternative exists
- [ ] No `https://deno.land/x/` imports (deprecated)
- [ ] No `https://deno.land/std/` imports (use `jsr:@std/*`)
- [ ] Standard library uses `jsr:@std/*`

### Configuration
- [ ] Has a proper `deno.json` configuration
- [ ] Import maps defined in `deno.json` (not separate file)
- [ ] Correct permissions in run commands

### Fresh Applications
- [ ] Islands are small and focused (minimal JavaScript to client)
- [ ] Props passed to islands are JSON-serializab