skill-auditor

---

name: skill-auditor description: Audits and improves Rails skill files in a project. Use when reviewing a SKILL.md file for correctness, completeness, and best practices. Triggers on: "audit skill", "review skill", "check skill", "improve skill", "verify skill", or when asked to verify that skill code examples are correct. allowed-tools: Read, Write, Edit, Glob, Grep

Skill Auditor

Overview

This skill systematically reviews skills/*/SKILL.md files for:

1. Structural completeness — correct frontmatter and required sections
2. Code correctness — bugs, wrong APIs, anti-patterns in examples
3. Rails best practices — adherence to project conventions
4. Documentation quality — clarity, Related Skills, decision guides

Workflow Checklist

Skill Audit Progress:
- [ ] Step 1: Read target SKILL.md completely
- [ ] Step 2: Run structural checklist
- [ ] Step 3: Run code correctness checklist
- [ ] Step 4: Run Rails conventions checklist
- [ ] Step 5: Run documentation quality checklist
- [ ] Step 6: Generate findings report with severity
- [ ] Step 7: Apply fixes
- [ ] Step 8: Verify fixes don't break intent

Step 1: Load the Skill

Read the target skill file completely before auditing:

# Find all skills to audit
ls skills/*/SKILL.md

# Or audit a specific skill
cat skills/[skill-name]/SKILL.md

If no skill is specified, ask: "Which skill should I audit? Run ls skills/ to list available skills."

---

Step 2: Structural Checklist

Verify the SKILL.md has required structure:

Structural Checks:
- [ ] YAML frontmatter present (--- block at top)
- [ ] `name` field in frontmatter matches directory name
- [ ] `description` field present and describes WHEN to use (not just what)
- [ ] `allowed-tools` field lists needed tools
- [ ] Markdown body starts with H1 title
- [ ] Has "Overview" or equivalent intro section
- [ ] Has "When to Use" guidance (table, list, or prose)
- [ ] Has at least one code example
- [ ] Under 500 lines (if longer, link to references/)

Report format per issue:

🔴 CRITICAL | Frontmatter missing `allowed-tools` field
🟡 WARNING  | No "When to Use" section — readers won't know when to apply this
🔵 INFO     | Consider adding a Related Skills section

---

Step 3: Code Correctness Checklist

Scan all code blocks in the skill for these known bugs:

3.1 dry-monads API

- [ ] Uses Success() not success()  (correct: Success("value"), not success("value"))
- [ ] Uses Failure() not failure()  (correct: Failure("error"), not failure("error"))
- [ ] Uses result.value! not result.value or result.data
- [ ] Uses result.failure not result.error or result.errors
- [ ] Does NOT use errors.merge!(result.error) → use errors.add(:base, result.failure)

Examples:

# ❌ Wrong dry-monads API
def call
  success(user)              # ❌ — lowercase, not a monad
  failure("invalid email")   # ❌ — lowercase, not a monad
end
result.value                 # ❌ — NoMethodError
result.data                  # ❌ — NoMethodError
result.error                 # ❌ — NoMethodError
errors.merge!(result.error)  # ❌ — wrong method + wrong accessor

# ✅ Correct dry-monads API
def call
  Success(user)              # ✅
  Failure("invalid email")   # ✅
end
result.value!                # ✅
result.failure               # ✅
errors.add(:base, result.failure)  # ✅

3.2 Callback Side Effects (CRITICAL)

- [ ] No after_create_commit with email/notification/job
- [ ] No after_save with email/notification/job
- [ ] No after_commit with email/notification/job
- [ ] No after_destroy with email/notification/job
- [ ] ONLY allowed: before_validation (normalization), before_save (defaults)

Examples:

# ❌ Side effects in callbacks
class Post < ApplicationRecord
  after_create_commit :send_notification   # ❌
  after_save :update_search_index          # ❌
  after_commit :broadcast_changes          # ❌
end

# ✅ Side effects in controller
def create
  if @post.save
    PostMailer.notify(@post).deliver_later   # ✅
    SearchIndexJob.perform_later(@post)      # ✅
  end
end

3.3 Spec Paths

- [ ] Uses spec/requests/ not spec/controllers/
- [ ] Uses RSpec.describe [ClassName], type: :request for HTTP specs

Examples:

# ❌ Old path
spec/controllers/posts_controller_spec.rb

# ✅ Correct path
spec/requests/posts_spec.rb

3.4 Turbo/Rails 7+ HTML Attributes

- [ ] Uses data: { turbo_method: :delete } not method: :delete
- [ ] Uses data: { turbo_confirm: "..." } not data: { confirm: "..." }
- [ ] Does NOT use local: true in form_with (disables Turbo)

Examples:

<%# ❌ Rails 6 syntax %>
<%= link_to "Delete", post_path(@post), method: :delete, data: { confirm: "Sure?" } %>
<%= form_with model: @post, local: true do |f| %>

<%# ✅ Rails 7 / Turbo syntax %>
<%= link_to "Delete", post_path(@post), data: { turbo_method: :delete, turbo_confirm: "Sure?" } %>
<%= form_with model: @post do |f| %>

3.5 Nil-Safety on Current User

- [ ] Uses user&.admin? not user.admin? when user can be nil (guest/visitor)
- [ ] Uses user&.role? not user.role?

Examples:

# ❌ NoMethodError for nil visitor
def admin?
  user.admin?
end

# ✅ Safe nil check
def admin?
  user&.admin?
end

3.6 String Methods

- [ ] truncate already appends "..." — don't add manually
- [ ] 5.business_days does not exist in Rails (use 5.days or require a gem)

Examples:

# ❌ Double ellipsis
post.title.truncate(50) + "..."  # → "Very long title that gets cut..." + "..."

# ✅ truncate already adds omission
post.title.truncate(50)          # → "Very long title that gets cut..."

# ❌ business_days not in Rails core
7.business_days.from_now         # ❌ NoMethodError

# ✅ Use plain days or business_time gem
7.days.from_now                  # ✅

3.7 Mailer Test Helpers

- [ ] Uses have_enqueued_mail(Mailer, :method) not have_enqueued_job(ActionMailer::MailDeliveryJob)
- [ ] Uses change { ActionMailer::Base.deliveries.count }.by(1) for deliver_now

Examples:

# ❌ Brittle mailer test
expect { call }.to have_enqueued_job(ActionMailer::MailDeliveryJob)
  .with("UserMailer", "welcome_email", ...)

# ✅ Semantic mailer test
expect { call }.to have_enqueued_mail(UserMailer, :welcome_email)

3.8 Turbo Stream Mixing

- [ ] Does NOT render turbo_stream tags inside regular HTML partials
- [ ] turbo_stream.append/prepend/replace only inside format.turbo_stream blocks

Examples:

# ❌ turbo_stream in partial served as HTML (stream tags silently ignored)
# _pagination.html.erb:
<%= turbo_stream.append "posts", partial: "post", locals: { post: @post } %>

# ✅ format-conditional stream response
def create
  respond_to do |format|
    format.turbo_stream { render turbo_stream: turbo_stream.append("posts", ...) }
    format.html { redirect_to posts_path }
  end
end

3.9 Migration Safety

- [ ] rename_column uses multi-step (add + backfill + drop), NOT inline rename
- [ ] Concurrent index creation uses disable_ddl_transaction! + algorithm: :concurrently

Examples:

# ❌ Dangerous inline rename (breaks zero-downtime deploys)
rename_column :users, :name, :full_name

# ✅ Zero-downtime: add new + backfill + drop old in separate migrations
add_column :users, :full_name, :string
User.update_all("full_name = name")
remove_column :users, :name

# ❌ Missing concurrency for index on large table
add_index :orders, :user_id

# ✅ Concurrent non-blocking index
disable_ddl_transaction!
add_index :orders, :user_id, algorithm: :concurrently

3.10 ViewComponent XSS Risk

- [ ] Does NOT use .map { "#{k}='#{v}'" }.join.html_safe (XSS + broken for nested hashes)
- [ ] Uses tag.attributes(html_attrs).deep_merge(...) pattern instead

Examples:

# ❌ XSS risk + broken for nested hashes
def html_attributes
  @attrs.map { |k, v| "#{k}='#{v}'" }.join(" ").html_safe
end

# ✅ Rails-safe attribute merging
def html_attributes
  { class: "card" }.deep_merge(@html_attributes)
end

---

Step 4: Rails Conventions Checklist

- [ ] Namespaced classes use module prefix (module Posts; class CreateService)
- [ ] Service objects include Dry::Monads[:result] not custom Result structs
- [ ] Query objects use method chaining with .then { |rel| filter(rel, param) }
- [ ] Policies use ApplicationPolicy base class
- [ ] ViewComponents inherit from ViewComponent::Base
- [ ] Jobs inherit from ApplicationJob
- [ ] Mailers inherit from ApplicationMailer
- [ ] Specs use FactoryBot (create/build) not fixtures
- [ ] Specs use let/let! not instance variables in before blocks

---

Step 5: Documentation Quality Checklist

- [ ] Has "Related Skills" section listing complementary skills
- [ ] Has "When to Use X vs Y" decision guide (table or prose)
- [ ] Examples have both ❌ wrong and ✅ correct patterns
- [ ] Code examples are complete enough to be copy-paste useful
- [ ] No broken cross-references or dead links to templates/references

Related Skills section template:

## Related Skills

| Skill | Use When |
|-------|----------|
| `rails-service-object` | Business logic, multiple models |
| `tdd-cycle` | Writing tests first |
| `rails-architecture` | Overall structure decisions |

**This skill vs Service Object:**
- Use this skill for [specific case]
- Use `rails-service-object` when [other case]

---

Step 6: Generate Findings Report

After running all checklists, output:

Skill Audit Report: [skill-name]
================================

Score: X/10

🔴 CRITICAL (must fix — causes bugs or broken behavior)
  - [issue description + line reference + fix]

🟡 WARNING (should fix — bad practices, misleading examples)
  - [issue description + line reference + fix]

🔵 INFO (nice to have — completeness, clarity)
  - [issue description + suggestion]

Summary:
  Critical issues: N
  Warnings: N
  Info: N
  Estimated fix time: [minutes]

Score guide:

• 9-10: Minor improvements only
• 7-8: 1-3 issues, still usable
• 5-6: Several issues, may mislead users
• < 5: Major issues, needs significant rework

---

Step 7: Apply Fixes

For each CRITICAL or WARNING issue, propose the exact fix:

## Fix 1: [issue title]
**File:** skills/[name]/SKILL.md:L42
**Change:**
- Before: `result.value`
- After:  `result.value!`
**Reason:** dry-monads uses value! (raises if Failure), not value (returns nil)

Ask before applying if there are 3+ fixes. Apply one at a time for CRITICAL issues.

---

Step 8: Verify Fixes

After editing, re-read the changed sections and confirm:

• The fix is syntactically correct Ruby
• The fix doesn't contradict other examples in the same skill
• The fix aligns with the project's established patterns

---

Common Bugs Quick Reference

Use this as a fast scan during audits:

Bug Pattern	Correct Pattern	Severity
success(x)	Success(x)	🔴
failure(x)	Failure(x)	🔴
result.value	result.value!	🔴
result.error	result.failure	🔴
result.data	result.value!	🔴
errors.merge!(result.error)	errors.add(:base, result.failure)	🔴
after_create_commit :send_email	explicit in controller	🔴
spec/controllers/	spec/requests/	🟡
method: :delete	data: { turbo_method: :delete }	🟡
data: { confirm: }	data: { turbo_confirm: }	🟡
local: true in form_with	remove it	🟡
user.admin? (nil possible)	user&.admin?	🟡
.truncate(50) + "..."	.truncate(50)	🟡
5.business_days	5.days or explicit gem	🟡
rename_column inline	multi-step migration	🟡
have_enqueued_job(ActionMailer...)	have_enqueued_mail(Mailer, :method)	🟡
turbo_stream.* in HTML partial	inside format.turbo_stream block	🟡
.map {...}.html_safe in component	deep_merge + tag.attributes	🟡
Missing Related Skills	add section	🔵
Missing ❌/✅ examples	add both patterns	🔵
No decision guide	add when-to-use table	🔵

---

Related Skills

Skill	Use When
tdd-cycle	Verifying code in skills follows TDD patterns
rails-architecture	Validating structural decisions in skills
rails-service-object	Auditing service-related skill examples

This skill vs manual review:

• Use skill-auditor for systematic, repeatable audits with a consistent checklist
• Use manual review when evaluating overall skill purpose or project fit