Clean Code - Pragmatic AI Coding Standards
CRITICAL SKILL - Be concise, direct, and solution-focused.
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 |
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.
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 |
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 |
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 |
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 |
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:
code
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.
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.
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.