Systematic Code Refactoring
luongnv89/claude-howto
Guides refactoring in phases based on Martin Fowler's method: research, test coverage check, planning and small tested steps, with your approval at each phase.
A skill your agent uses when refactoring for duplication, complexity, or dead code — includes the plugin's on-demand analysis scripts.
Install Code Quality
$ npx skills add j-morgan6/elixir-phoenix-guide --skill code-quality -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install j-morgan6/elixir-phoenix-guide code-quality --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/j-morgan6/elixir-phoenix-guide.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/code-quality .claude/skills/code-quality && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "code-quality" agent skill from https://github.com/j-morgan6/elixir-phoenix-guide/tree/main/skills/code-quality into .claude/skills/code-quality/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "code-quality", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/j-morgan6/elixir-phoenix-guide/tree/main/skills/code-qualityType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add j-morgan6/elixir-phoenix-guide --skill code-quality -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install j-morgan6/elixir-phoenix-guide code-quality --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/j-morgan6/elixir-phoenix-guide.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/code-quality .agents/skills/code-quality && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "code-quality" agent skill from https://github.com/j-morgan6/elixir-phoenix-guide/tree/main/skills/code-quality into .agents/skills/code-quality/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "code-quality", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add j-morgan6/elixir-phoenix-guide --skill code-quality -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install j-morgan6/elixir-phoenix-guide code-quality --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/j-morgan6/elixir-phoenix-guide.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/code-quality .cursor/skills/code-quality && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "code-quality" agent skill from https://github.com/j-morgan6/elixir-phoenix-guide/tree/main/skills/code-quality into .cursor/skills/code-quality/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "code-quality", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/j-morgan6/elixir-phoenix-guide.git --path skills/code-quality--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add j-morgan6/elixir-phoenix-guide --skill code-quality -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install j-morgan6/elixir-phoenix-guide code-quality --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/j-morgan6/elixir-phoenix-guide.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/code-quality .gemini/skills/code-quality && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "code-quality" agent skill from https://github.com/j-morgan6/elixir-phoenix-guide/tree/main/skills/code-quality into .gemini/skills/code-quality/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "code-quality", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install j-morgan6/elixir-phoenix-guide code-qualityInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add j-morgan6/elixir-phoenix-guide --skill code-quality -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/j-morgan6/elixir-phoenix-guide.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/code-quality .github/skills/code-quality && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "code-quality" agent skill from https://github.com/j-morgan6/elixir-phoenix-guide/tree/main/skills/code-quality into .github/skills/code-quality/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "code-quality", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add j-morgan6/elixir-phoenix-guide --skill code-quality -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install j-morgan6/elixir-phoenix-guide code-quality --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/j-morgan6/elixir-phoenix-guide.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/code-quality .opencode/skills/code-quality && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "code-quality" agent skill from https://github.com/j-morgan6/elixir-phoenix-guide/tree/main/skills/code-quality into .opencode/skills/code-quality/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "code-quality", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
code-quality- GitHub stars
- 166
- Token cost
- ~1.4k tokens
- SKILL.md length
- 413 words
- Files
- 1
- Skills in repo
- 19
- Repo updated
- First seen
- Licence
- MIT
At a glance
A skill your agent uses when refactoring for duplication, complexity, or dead code — includes the plugin's on-demand analysis scripts.
- Works in 7 steps: Duplicated functions must be extracted —… → Functions must stay below ABC complexity… → Unused private functions must be removed… → …
- Refactoring for duplication
- SKILL.md covers RULES — Follow these with no…, What Gets Detected, Running Analysis and Testing
- Calls bash
What it does
Code Quality is an agent skill from j-morgan6/elixir-phoenix-guide. Use when refactoring for duplication, complexity, or dead code — includes the plugin's on-demand analysis scripts.
Its SKILL.md is about 1.4k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Development, covering Code quality and Refactoring. The licence is MIT.
When your agent uses it
- Refactoring for duplication
- Dead code — includes the plugins on-demand analysis scripts
Example prompts
- “/code-quality”
Workflow steps
7 steps, taken from the first numbered list in SKILL.md.
- Duplicated functions must be extracted — when 2+ modules share >70% identical function implementations, create a shared module
- Functions must stay below ABC complexity 30 — break complex functions into smaller helpers with single responsibilities
- Unused private functions must be removed — dead code increases maintenance burden and confusion
- Duplicated templates must become components — when 2+ HEEx files share >40% identical markup, extract to a function component
- Run full analysis before major refactors — use run_analysis.sh to establish a baseline before and after
- Address duplication before complexity — extracting shared code often reduces complexity as a side effect
- Prefer composition over inheritance — extract shared functions into modules imported/used where needed, not into base modules
What it can do on your machine
Read from SKILL.md and the folder at commit cdfddac. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
bash
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Code Quality loads about 1.4k tokens when it runs. Until then it costs about 32 tokens; SKILL.md has 413 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from j-morgan6/elixir-phoenix-guide at commit cdfddac, republished under its MIT licence (© j-morgan6). 413 words, ~1,373 tokens.
Download SKILL.mdSave it as
.claude/skills/code-quality/SKILL.md (or your agent's skills folder).- name
- code-quality
- description
- Use when refactoring for duplication, complexity, or dead code — includes the plugin's on-demand analysis scripts.
- file_patterns
- **/*.ex, **/*.heex
- auto_suggest
- true
Code Quality Automation
Automated detection of code quality issues in Elixir projects. These checks run automatically via hooks when files are written, and can be run on-demand for full project analysis.
RULES — Follow these with no exceptions
- Duplicated functions must be extracted — when 2+ modules share >70% identical function implementations, create a shared module
- Functions must stay below ABC complexity 30 — break complex functions into smaller helpers with single responsibilities
- Unused private functions must be removed — dead code increases maintenance burden and confusion
- Duplicated templates must become components — when 2+ HEEx files share >40% identical markup, extract to a function component
- Run full analysis before major refactors — use
run_analysis.shto establish a baseline before and after - Address duplication before complexity — extracting shared code often reduces complexity as a side effect
- Prefer composition over inheritance — extract shared functions into modules imported/used where needed, not into base modules
What Gets Detected
Code Duplication
Detects when the same function appears in multiple modules with >70% body similarity.
How it works: AST-based analysis parses function bodies and compares them using trigram similarity. Functions with the same name, arity, and similar bodies are flagged.
Example output:
Duplication Detected
Function `format_time/1` (85% similar)
lib/app_web/live/cycle_time.ex:45
lib/app_web/live/lead_time.ex:52
Suggestion: Extract to a shared moduleHow to fix:
# Create: lib/app_web/live/helpers.ex
defmodule AppWeb.Live.Helpers do
def format_time(%Decimal{} = seconds) do
seconds |> Decimal.to_float() |> format_time()
end
def format_time(seconds) when is_number(seconds) do
# shared formatting logic
end
end
# In each LiveView:
import AppWeb.Live.Helpers, only: [format_time: 1]ABC Complexity
Measures function complexity using the ABC metric (Assignments, Branches, Conditions).
- A (Assignments):
=operators - B (Branches):
case,cond,if,unless,with,->clauses - C (Conditions):
&&,||,and,or,==,!=,>,<,>=,<=,whenguards
ABC = sqrt(A² + B² + C²) — threshold is 30.
Example output:
High Complexity Detected
Function `calculate_trend_line/1` — ABC complexity 41 (threshold: 30)
lib/app_web/live/helpers.ex:45
Suggestion: Break into smaller functions with single responsibilitiesHow to fix:
# Before: one large function (complexity 41)
def calculate_trend_line(data) do
# 50 lines of assignments, branches, conditions
end
# After: composed smaller functions (complexity <20 each)
def calculate_trend_line(data) do
sums = calculate_regression_sums(data)
slope = calculate_slope(sums)
intercept = calculate_intercept(sums, slope)
build_trend_points(data, slope, intercept)
endShow full SKILL.md (171 more words)Show less
Unused Private Functions
Detects defp functions that are defined but never called within the module.
Example output:
Unused Private Functions
`old_format_date` defined at line 123 but never called
Suggestion: Remove if no longer neededCommon after refactoring — when you extract code to a shared module, the original private functions may become dead code.
Template Duplication
Detects when HEEx templates in the same directory share >40% identical markup.
Example output:
Template Duplication Detected
86 identical lines (72%) between:
cycle_time.html.heex
lead_time.html.heex
Suggestion: Extract shared markup to a function componentHow to fix:
# Create a function component for the shared markup
defmodule AppWeb.Live.Components do
use Phoenix.Component
def metric_filters(assigns) do
~H"""
<div class="filters">
<!-- shared filter markup -->
</div>
"""
end
endRunning Analysis
Automatic (via hooks)
Code quality checks run automatically when files are written or edited:
.ex/.exsfiles trigger duplication, complexity, and unused function checks.heexfiles trigger template duplication checks
On-Demand (full project)
Run a complete analysis from a checkout of this repo:
bash scripts/run_analysis.shOr target specific checks:
# Single file analysis
elixir scripts/code_quality.exs all lib/app_web/live/my_live.ex
# Specific check
elixir scripts/code_quality.exs complexity lib/app_web/live/my_live.ex
elixir scripts/code_quality.exs duplication lib/app_web/live/my_live.ex
elixir scripts/code_quality.exs unused lib/app_web/live/my_live.ex
# Scan entire lib/ directory
elixir scripts/code_quality.exs scan lib/When installed as a plugin, the scripts live inside the plugin install directory rather than at a fixed path in the project — run the commands above from a checkout of this repo instead.
Testing
For testing guidance, see testing-essentials. When writing tests for refactored shared modules, ensure:
- Original test coverage is maintained
- New shared module has its own test file
- All callers still pass their tests after extraction
© j-morgan6, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
Just SKILL.md in skills/code-quality of j-morgan6/elixir-phoenix-guide.
Open the folder on GitHubat commit cdfddac
Compare with similar skills
Code Quality next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Code Quality this skillj-morgan6/elixir-phoenix-guide | 166 | — | ~1.4k | Automated safety check: Pass | MIT | |
| Systematic Code Refactoringluongnv89/claude-howto | 42k | — | ~3k | Automated safety check: Pass | MIT | |
| Ponytail Lazy Developer ModeDietrichGebert/ponytail | 158k | — | ~871 | Automated safety check: Pass | MIT | |
| Dignified Python Standardsdocling-project/docling | 69k | — | ~1.5k | Automated safety check: Pass | Apache-2.0 | |
| Clean Code GuardamElnagdy/guard-skills | 1.3k | 2 repos | ~4.3k | Automated safety check: Pass | MIT | |
| Code Refactoring Workflowluongnv89/claude-howto | 42k | — | ~3.1k | Automated safety check: Pass | MIT |
Similar skills
Ponytail Lazy Developer Mode
DietrichGebert/ponytail
Makes the agent pick the laziest solution that works: skip unneeded work, reuse what exists, prefer the standard library and platform features, and keep diffs small.
Dignified Python Standards
docling-project/docling
Applies opinionated production Python conventions chosen by the project's Python version: modern type syntax, pathlib, explicit checks and interface guidance.
Clean Code Guard
amElnagdy/guard-skills
Reviews generated or changed production code against Clean Code, SOLID, DRY, KISS, YAGNI and LLM-specific failure modes before it ships, in any language.
Code Refactoring Workflow
luongnv89/claude-howto
Guides systematic, test-backed refactoring in the style of Martin Fowler, moving through research, planning and small incremental changes with your approval at each phase.
Maintainable Code for iPolloWork
Devin-AXIS/iPolloWork
A code-change gate for the iPolloWork repository: search and reuse first, keep one source of truth, justify every new file or dependency, and audit the change.
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Related
Categories
Questions about Code Quality
What does Code Quality do?
A skill your agent uses when refactoring for duplication, complexity, or dead code — includes the plugin's on-demand analysis scripts. Code Quality is an agent skill from j-morgan6/elixir-phoenix-guide. Use when refactoring for duplication, complexity, or dead code — includes the plugin's on-demand analysis scripts.
When should I use Code Quality?
Code Quality fits situations like: refactoring for duplication; dead code — includes the plugins on-demand analysis scripts.
How do I install Code Quality in Claude Code?
Run `npx skills add j-morgan6/elixir-phoenix-guide --skill code-quality -a claude-code`. Or copy the skill folder (skills/code-quality in j-morgan6/elixir-phoenix-guide) into .claude/skills/code-quality in your project. Claude Code loads it when a task matches its description.
How do I install Code Quality in Codex?
Run `npx skills add j-morgan6/elixir-phoenix-guide --skill code-quality -a codex`. Or copy the skill folder (skills/code-quality in j-morgan6/elixir-phoenix-guide) into .agents/skills/code-quality in your project. Codex loads it when a task matches its description.
Can I use Code Quality in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add j-morgan6/elixir-phoenix-guide --skill code-quality -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/code-quality, .gemini/skills/code-quality, .github/skills/code-quality and .opencode/skills/code-quality in your project.
What does Code Quality need to run?
Going by SKILL.md and its folder, Code Quality needs the command-line tools its instructions call (bash).
Does Code Quality access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is Code Quality safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Code Quality use?
Code Quality is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Code Quality use?
About 1.4k tokens (SKILL.md is roughly 5.5k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Code Quality?
Skills that share tags, products or a category with Code Quality: Systematic Code Refactoring (luongnv89/claude-howto, 42k stars), Ponytail Lazy Developer Mode (DietrichGebert/ponytail, 158k stars), Dignified Python Standards (docling-project/docling, 69k stars) and Clean Code Guard (amElnagdy/guard-skills, 1.3k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Code Quality?
j-morgan6 (a GitHub user) maintains it in j-morgan6/elixir-phoenix-guide, which has 166 GitHub stars. The repository holds 19 skills in this directory. The repository was last updated on July 6, 2026.
Source: j-morgan6/elixir-phoenix-guide on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.