Clean Code

Clean Code – Pragmatic AI Coding Standards

> CRITICAL SKILL – Be concise, direct, and solution-focused.

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Core Principles

| Principle | Rule |

|———–|——|

| SRP | Single Responsibility – each function/class does ONE thing |

| DRY | Don’t Repeat Yourself – extract duplicates, reuse |

| KISS | Keep It Simple – simplest solution that works |

| YAGNI | You Aren’t Gonna Need It – don’t build unused features |

| Boy Scout | Leave code cleaner than you found it |

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Naming Rules

| Element | Convention |

|———|————|

| Variables | Reveal intent: userCount not n |

| Functions | Verb + noun: getUserById() not user() |

| Booleans | Question form: isActive, hasPermission, canEdit |

| Constants | SCREAMING_SNAKE: MAX_RETRY_COUNT |

> Rule: If you need a comment to explain a name, rename it.

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Function Rules

| Rule | Description |

|——|————-|

| Small | Max 20 lines, ideally 5-10 |

| One Thing | Does one thing, does it well |

| One Level | One level of abstraction per function |

| Few Args | Max 3 arguments, prefer 0-2 |

| No Side Effects | Don’t mutate inputs unexpectedly |

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Code Structure

| Pattern | Apply |

|———|——-|

| Guard Clauses | Early returns for edge cases |

| Flat > Nested | Avoid deep nesting (max 2 levels) |

| Composition | Small functions composed together |

| Colocation | Keep related code close |

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AI Coding Style

| Situation | Action |

|———–|——–|

| User asks for feature | Write it directly |

| User reports bug | Fix it, don’t explain |

| No clear requirement | Ask, don’t assume |

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Anti-Patterns (DON’T)

| ❌ Pattern | ✅ Fix |

|———–|——-|

| Comment every line | Delete obvious comments |

| Helper for one-liner | Inline the code |

| Factory for 2 objects | Direct instantiation |

| utils.ts with 1 function | Put code where used |

| “First we import…” | Just write code |

| Deep nesting | Guard clauses |

| Magic numbers | Named constants |

| God functions | Split by responsibility |

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🔴 Before Editing ANY File (THINK FIRST!)

Before changing a file, ask yourself:

| Question | Why |

|———-|—–|

| What imports this file? | They might break |

| What does this file import? | Interface changes |

| What tests cover this? | Tests might fail |

| Is this a shared component? | Multiple places affected |

Quick Check:

File to edit: UserService.ts
└── Who imports this? → UserController.ts, AuthController.ts
└── Do they need changes too? → Check function signatures

> 🔴 Rule: Edit the file + all dependent files in the SAME task.

> 🔴 Never leave broken imports or missing updates.

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Summary

| Do | Don’t |

|—-|——-|

| Write code directly | Write tutorials |

| Let code self-document | Add obvious comments |

| Fix bugs immediately | Explain the fix first |

| Inline small things | Create unnecessary files |

| Name things clearly | Use abbreviations |

| Keep functions small | Write 100+ line functions |

> Remember: The user wants working code, not a programming lesson.

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🔴 Self-Check Before Completing (MANDATORY)

Before saying “task complete”, verify:

| Check | Question |

|——-|———-|

| ✅ Goal met? | Did I do exactly what user asked? |

| ✅ Files edited? | Did I modify all necessary files? |

| ✅ Code works? | Did I test/verify the change? |

| ✅ No errors? | Lint and TypeScript pass? |

| ✅ Nothing forgotten? | Any edge cases missed? |

> 🔴 Rule: If ANY check fails, fix it before completing.

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Verification Scripts (MANDATORY)

> 🔴 CRITICAL: Each agent runs ONLY their own skill’s scripts after completing work.

Agent → Script Mapping

| Agent | Script | Command |

|——-|——–|———|

| frontend-specialist | UX Audit | python ~/.claude/skills/frontend-design/scripts/ux_audit.py . |

| frontend-specialist | A11y Check | python ~/.claude/skills/frontend-design/scripts/accessibility_checker.py . |

| backend-specialist | API Validator | python ~/.claude/skills/api-patterns/scripts/api_validator.py . |

| mobile-developer | Mobile Audit | python ~/.claude/skills/mobile-design/scripts/mobile_audit.py . |

| database-architect | Schema Validate | python ~/.claude/skills/database-design/scripts/schema_validator.py . |

| security-auditor | Security Scan | python ~/.claude/skills/vulnerability-scanner/scripts/security_scan.py . |

| seo-specialist | SEO Check | python ~/.claude/skills/seo-fundamentals/scripts/seo_checker.py . |

| seo-specialist | GEO Check | python ~/.claude/skills/geo-fundamentals/scripts/geo_checker.py . |

| performance-optimizer | Lighthouse | python ~/.claude/skills/performance-profiling/scripts/lighthouse_audit.py <url> |

| test-engineer | Test Runner | python ~/.claude/skills/testing-patterns/scripts/test_runner.py . |

| test-engineer | Playwright | python ~/.claude/skills/webapp-testing/scripts/playwright_runner.py <url> |

| Any agent | Lint Check | python ~/.claude/skills/lint-and-validate/scripts/lint_runner.py . |

| Any agent | Type Coverage | python ~/.claude/skills/lint-and-validate/scripts/type_coverage.py . |

| Any agent | i18n Check | python ~/.claude/skills/i18n-localization/scripts/i18n_checker.py . |

> ❌ WRONG: test-engineer running ux_audit.py

> ✅ CORRECT: frontend-specialist running ux_audit.py

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🔴 Script Output Handling (READ → SUMMARIZE → ASK)

When running a validation script, you MUST:

• Run the script and capture ALL output
• Parse the output – identify errors, warnings, and passes
• Summarize to user in this format:

## Script Results: [script_name.py]

### ❌ Errors Found (X items)
- [File:Line] Error description 1
- [File:Line] Error description 2

### ⚠️ Warnings (Y items)
- [File:Line] Warning description

### ✅ Passed (Z items)
- Check 1 passed
- Check 2 passed

**Should I fix the X errors?**

• Wait for user confirmation before fixing
• After fixing → Re-run script to confirm

> 🔴 VIOLATION: Running script and ignoring output = FAILED task.

> 🔴 VIOLATION: Auto-fixing without asking = Not allowed.

> 🔴 Rule: Always READ output → SUMMARIZE → ASK → then fix.