forem/forem ⭐ 22,600

# Forem AI Context & Rules (AGENTS.md)

This file contains instructions for AI coding assistants working on the Forem codebase (the platform that powers dev.to).
Follow these rules and patterns to ensure high-quality contributions.

## General Philosophy
- **Follow Patterns**: Application consistency is key. Mimic existing patterns for controllers, services, and specs.
- **Smaller is Better**: Prefer atomic, focused modifications over sprawling refactors.
- **Re-usability**: Changes should strengthen Forem as a platform, avoiding DEV-specific hardcoding unless absolutely necessary.

## Testing Standards
- **Regression Tests are Mandatory**: specific regression tests to verify your code works are required for almost all PRs.
- **Follow Test Patterns**: Use `create(:factory)` syntax (FactoryBot) and standard RSpec expectations.
- **Frontend vs Backend**: We are currently focused on robust backend regression tests. Frontend changes require more manual user review, so clear descriptions of UI changes are vital.

## Internationalization (i18n)
- **Update All Locales**: If your change involves new or modified text, you MUST update the corresponding i18n files for ALL supported languages found in `config/locales`.
- **Supported Languages**:
  - `en` (English)
  - `fr` (French)
  - `pt` (Portuguese)
  - And any others present in `config/locales`.

## Performance & Caching
- **Avoid `current_user` in Cache**: Never use `current_user` objects in cached pages or partials to prevent cache leaks and private data exposure.
- **Database Indexes**:
  - Add indexes concurrently using `algorithm: :concurrently`.
  - Use `disable_ddl_transaction!` in the migration class.
  - Ideally, place index additions in their own separate migration files.

## Frontend
- We are transitioning to a Preact-first frontend.
- Use `app/javascript` and `app/assets` patterns as established.

## Documentation
- If you find documentation that contradicts the codebase, trust the codebase patterns but note the discrepancy.