phoenix-code-review

name	phoenix-code-review
description	Reviews Phoenix code for controller patterns, context boundaries, routing, and plugs. Use when reviewing Phoenix apps, checking controllers, routers, or context modules.

Phoenix Code Review

Quick Reference

Issue Type	Reference
Bounded contexts, Ecto integration	references/contexts.md
Actions, params, error handling	references/controllers.md
Pipelines, scopes, verified routes	references/routing.md
Custom plugs, authentication	references/plugs.md

Review Checklist

Controllers

• Business logic in contexts, not controllers
• Controllers return proper HTTP status codes
• Action clauses handle all expected patterns
• Fallback controllers handle errors consistently

Contexts

• Contexts are bounded by domain, not technical layer
• Public functions have clear, domain-focused names
• Changesets validate all user input
• No Ecto queries in controllers

Routing

• Verified routes (~p sigil) used, not string paths
• Pipelines group related plugs
• Resources use only needed actions
• Scopes group related routes

Plugs

• Authentication/authorization via plugs
• Plugs are composable and single-purpose
• Halt called after sending response in plugs

JSON APIs

• Proper content negotiation
• Consistent error response format
• Pagination for list endpoints

Valid Patterns (Do NOT Flag)

• Controller calling multiple contexts - Valid for orchestration
• Inline Ecto query in context - Context owns its data access
• Using action_fallback - Centralized error handling pattern
• Multiple pipelines per route - Composition is intentional
• Plug.Conn.halt/1 without send - May be handled by fallback

Context-Sensitive Rules

Issue	Flag ONLY IF
Missing changeset validation	Field accepts user input AND no validation exists
Controller too large	More than 7 actions OR actions > 20 lines
Missing authorization	Route is not public AND no auth plug in pipeline

Before Submitting Findings

Load and follow review-verification-protocol before reporting any issue.