Technical Debt Detection

Find and eliminate duplicate code patterns, anti-patterns, and refactoring opportunities in Elixir/Phoenix projects.

Iron Laws - Never Violate These

•Search before refactoring - Understand full scope of duplication before extracting
•Three strikes rule - Extract shared code only after 3+ duplications
•Prefer composition - Use behaviours and protocols over inheritance-style abstractions
•Test coverage first - Ensure tests exist before refactoring duplicated code

Analysis Checklist

1. Run Credo for Automated Detection

bash

mix credo --strict

Focus on:

•Design issues (duplication, complexity)
•Consistency issues (naming, patterns)
•Refactoring opportunities

2. Find Duplicate Ecto Query Patterns

bash

# Repeated Repo calls
grep -r "Repo.get!\|Repo.get\|Repo.one" lib/ --include="*.ex"

# Duplicate query patterns
grep -r "from.*in.*where" lib/ --include="*.ex"

3. Find Duplicate Validation Logic

bash

# Changeset patterns
grep -r "def changeset" lib/ --include="*.ex" | wc -l

# Repeated validations
grep -r "validate_required\|validate_format" lib/ --include="*.ex"

4. Find Copy-Pasted Controller Actions

bash

# Similar action patterns
grep -r "def create\|def update\|def delete" lib/*_web/ --include="*.ex"

Common Duplication Patterns

Pattern	Symptom	Solution
Repeated queries	Same `Repo.get` in multiple contexts	Create shared query module
Duplicate validations	Same `validate_*` calls	Extract to shared changeset
Similar controllers	Copy-pasted CRUD actions	Use Phoenix generators consistently
Repeated transforms	Same `Enum.map` patterns	Extract to domain module

Reporting Format

For each duplication found, report:

•Location: File paths and line numbers
•Pattern: What code is duplicated
•Extraction: Suggested shared function/module
•Effort: Low/Medium/High to fix

Usage

Run /phx:techdebt to analyze the codebase and generate a prioritized report of technical debt with specific remediation steps.