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:

1. Run the script and capture ALL output
2. Parse the output - identify errors, warnings, and passes
3. 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?**

4. Wait for user confirmation before fixing
5. 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.