Does it support specific JavaScript runtimes?

Yes, it includes specialized diagnostic steps for Node.js, Deno, and Bun, including runtime-specific environment detection.

Why would my Gleam code behave differently on Erlang vs JS?

Common causes include differences in string encoding, synchronous vs. asynchronous execution models, and how complex types like tuples are represented in the underlying target language.

How does it help with Foreign Function Interface (FFI) issues?

The skill provides checklists and comparison steps to ensure that return types, error handling, and function exports match between Erlang (.erl) and JavaScript (.mjs) files.

What is the debug-cross-platform skill used for?

It is designed to identify and fix bugs that appear on one Gleam target (like Erlang) but not the other (like JavaScript), specifically focusing on FFI and runtime logic.

Cross-Platform Gleam Debugger

Name: Cross-Platform Gleam Debugger
Author: tylerbutler

bytylerbutler

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Security & Testing

Diagnoses and resolves behavioral inconsistencies between Erlang and JavaScript targets in cross-platform Gleam projects.

This skill provides a systematic framework for debugging issues that occur on only one Gleam target, such as when tests pass on Erlang but fail on JavaScript. It guides developers through identifying Foreign Function Interface (FFI) mismatches, platform-specific API discrepancies, asynchronous race conditions, and type coercion differences. Specifically tailored for multi-target library development like Birch, it ensures consistent behavior across the Erlang VM and various JavaScript runtimes including Node.js, Deno, and Bun.

Key Features

01Detection of platform-specific API usage (Node.js vs. Erlang OTP)

02Automated FFI implementation comparison between Erlang and JavaScript

03Diagnostic steps for JavaScript-specific asynchronous behavior and Promises

04Targeted runtime testing for Node.js, Deno, Bun, and Browser environments

051 GitHub stars

06Mapping of Gleam type coercion across different runtime environments

Use Cases

01Fixing terminal color or TTY detection issues across different operating systems

02Identifying return type mismatches between .erl and .mjs FFI implementations

03Troubleshooting a library that passes tests on Erlang but fails on JavaScript runtimes

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add tylerbutler/birch debug-cross-platform

For use in Claude.ai and ChatGPT

Download Skill