shancheas
0b0bdd9c4b
- Introduced backend patterns skill with guidelines on API design, database optimization, and server-side best practices. - Added coding standards skill outlining universal coding principles for TypeScript, NestJS, and Node.js development. - Implemented continuous learning skill to automatically extract reusable patterns from Cursor sessions. - Created NestJS best practices skill detailing architecture patterns, dependency injection, error handling, and security measures. - Included various rules and templates for NestJS best practices to ensure production-ready applications.
77 lines
1.5 KiB
Plaintext
77 lines
1.5 KiB
Plaintext
---
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description: Immutability, file organization, error handling, and input validation
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globs: "**/*.{ts,tsx,js,jsx}"
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alwaysApply: false
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---
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# Coding Style
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## Immutability (CRITICAL)
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ALWAYS create new objects, NEVER mutate:
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```javascript
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// WRONG: Mutation
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function updateUser(user, name) {
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user.name = name // MUTATION!
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return user
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}
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// CORRECT: Immutability
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function updateUser(user, name) {
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return {
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...user,
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name
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}
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}
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```
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## File Organization
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MANY SMALL FILES > FEW LARGE FILES:
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- High cohesion, low coupling
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- 200-400 lines typical, 800 max
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- Extract utilities from large components
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- Organize by feature/domain, not by type
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## Error Handling
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ALWAYS handle errors comprehensively:
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```typescript
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try {
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const result = await riskyOperation()
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return result
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} catch (error) {
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console.error('Operation failed:', error)
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throw new Error('Detailed user-friendly message')
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}
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```
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## Input Validation
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ALWAYS validate user input with class-validator DTOs (and Zod where DTOs are not used):
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```typescript
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import { z } from 'zod'
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const schema = z.object({
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email: z.string().email(),
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age: z.number().int().min(0).max(150)
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})
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const validated = schema.parse(input)
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```
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## Code Quality Checklist
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Before marking work complete:
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- [ ] Code is readable and well-named
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- [ ] Functions are small (<50 lines)
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- [ ] Files are focused (<800 lines)
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- [ ] No deep nesting (>4 levels)
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- [ ] Proper error handling
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- [ ] No console.log statements
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- [ ] No hardcoded values
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- [ ] No mutation (immutable patterns used)
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