Deno Patterns

When to use this skill

Use this skill when working on Deno projects and you want predictable module imports, permission-aware runtime behavior, and clean project structure.

Core patterns

Permissions are part of the contract

Deno requires explicit permissions. Make them intentional:

• --allow-net for network
• --allow-read for filesystem reads
• avoid --allow-all in production scripts

Project structure

Common:

• deno.json / deno.jsonc
• mod.ts as entrypoint for libraries
• main.ts for apps

Dependency management

• prefer import maps
• keep third-party imports centralized

Testing

• use deno test
• keep tests deterministic

Atlarix tool notes

• Explore: inspect deno.json and entrypoints; trace imports.
• Build: run deno test and deno fmt if configured.
• Debug: check permission errors first; they’re common.
• Review: verify permission flags are minimal and documented.

Common mistakes to avoid

• Using --allow-all by default
• Scattering dependencies across files
• Ignoring permission failures and “fixing” by widening permissions

Mini-checklist

• Minimal permissions
• Imports centralized
• Tests use deno tooling