Code Documentation Prompt Templates

# FastCache

A lightweight, high-performance in-memory caching library for Node.js with automatic expiration and LRU eviction.

## Quick Start

```bash
npm install fastcache
```

```typescript
import { Cache } from 'fastcache';

const cache = new Cache({ maxSize: 1000, ttl: 60000 });
cache.set('user:123', userData);
const user = cache.get('user:123');
```

## Features

- **TTL Support** - Automatic expiration with per-key TTL
- **LRU Eviction** - Memory-efficient with least-recently-used eviction
- **Clustering** - Distributed cache across Node.js cluster workers

[Continues with full sections...]

## Create User

Creates a new user account and returns the user object.

### Request

`POST /api/v1/users`

**Headers:**
| Header | Required | Description |
|--------|----------|-------------|
| X-API-Key | Yes | Your API key |
| Content-Type | Yes | application/json |

**Body:**
```json
{
 "email": "user@example.com",
 "password": "securePassword123!",
 "name": "Jane Doe"
}
```

| Field | Type | Required | Description |
|-------|------|----------|-------------|
| email | string | Yes | Valid email address |
| password | string | Yes | Min 8 chars, 1 uppercase, 1 number |
| name | string | Yes | User's display name |

### Response

**Success (201 Created):**
```json
{
 "id": "usr_abc123",
 "email": "user@example.com",
 "name": "Jane Doe",
 "created_at": "2024-01-15T10:30:00Z"
}
```

### Errors

| Status | Code | Description |
|--------|------|-------------|
| 400 | INVALID_EMAIL | Email format is invalid |
| 400 | WEAK_PASSWORD | Password doesn't meet requirements |
| 409 | EMAIL_EXISTS | Email already registered |

```python
def process_payment(
 order_id: str,
 payment_method_id: str,
 amount_cents: int,
 idempotency_key: str | None = None
) -> PaymentResult:
 """
 Process a payment through Stripe and update order status.
 
 Charges the customer's payment method and marks the order as paid
 if successful. Uses idempotency keys to prevent duplicate charges.
 
 Args:
 order_id: The order to process payment for. Must exist in database.
 payment_method_id: Stripe payment method ID (pm_xxx).
 amount_cents: Amount to charge in cents. Must be positive.
 idempotency_key: Optional key for idempotent requests. If not
 provided, generates one from order_id.
 
 Returns:
 PaymentResult with status, charge_id, and any error details.
 
 Raises:
 OrderNotFoundError: If order_id doesn't exist.
 PaymentDeclinedError: If card is declined or invalid.
 StripeConnectionError: If Stripe API is unreachable.
 
 Example:
 >>> result = payment_service.process_payment(
... order_id="ord_123"... payment_method_id="pm_card_visa"... amount_cents=2999
... )
 >>> result.status
 'succeeded'
 
 Note:
 This method is NOT idempotent without an idempotency_key.
 Always provide one for retry logic.
 """
```

```javascript
function calculateShipping(cart, destination) {
 const baseRate = 5.99;
 let total = 0;
 
 // Free shipping threshold varies by membership tier
 // Premium: $35, Standard: $50, Guest: $75
 const freeShippingThreshold = getFreeThreshold(cart.membershipTier);
 
 if (cart.subtotal >= freeShippingThreshold) {
 return 0;
 }
 
 // Weight-based calculation for items over 5lbs
 // Using dimensional weight if greater than actual weight
 // (carrier billing policy as of 2024)
 for (const item of cart.items) {
 const dimWeight = (item.length * item.width * item.height) / 139;
 const billedWeight = Math.max(item.weight, dimWeight);
 
 if (billedWeight > 5) {
 // Rate increases $2 per lb over 5lbs, capped at $25 surcharge
 total += Math.min((billedWeight - 5) * 2, 25);
 }
 }
 
 // Hawaii/Alaska surcharge (USPS Zone 8 rates)
 // TODO: Refactor when we add international shipping
 if (['HI', 'AK'].includes(destination.state)) {
 total += 12.99;
 }
 
 return baseRate + total;
}
```