code-patternslisted
Install: claude install-skill aiskillstore/marketplace
# Code Patterns Reference
Quick reference for common patterns. Use these as starting points, not rigid templates.
## Creational Patterns
### Factory
```typescript
// When: Creating objects without specifying exact class
interface Product { use(): void }
class ConcreteProductA implements Product {
use() { console.log('Using A') }
}
class ProductFactory {
static create(type: string): Product {
const products = { a: ConcreteProductA };
return new products[type]();
}
}
```
### Builder
```typescript
// When: Complex object construction with many optional params
class QueryBuilder {
private query = { select: '*', from: '', where: [] };
select(fields: string) { this.query.select = fields; return this; }
from(table: string) { this.query.from = table; return this; }
where(condition: string) { this.query.where.push(condition); return this; }
build() { return this.query; }
}
// Usage
const query = new QueryBuilder()
.select('name, email')
.from('users')
.where('active = true')
.build();
```
### Singleton
```typescript
// When: Exactly one instance needed (use sparingly!)
class Database {
private static instance: Database;
private constructor() {}
static getInstance(): Database {
if (!Database.instance) {
Database.instance = new Database();
}
return Database.instance;
}
}
```
## Structural Patterns
### Adapter
```typescript
// When: Making incompatible interfaces work together
interface ModernLogger { log(msg: string):