MongoDB Naming Conventions

This rule applies to files matching the patterns above.

# MongoDB Naming Conventions

## Rule
All MongoDB identifiers MUST follow consistent naming conventions: camelCase for fields, lowercase plural for collections, and descriptive names for indexes.

## Format
```
Databases:     lowercase, hyphens ok     → my-app, user-service
Collections:   plural camelCase          → users, orderItems, productCategories
Fields:        singular camelCase        → firstName, createdAt, isActive
Indexes:       idx_{collection}_{fields} → idx_users_email, idx_orders_status_createdAt
```

## Requirements

### 1. Collection Names
```javascript
// GOOD: plural, camelCase
db.users
db.orderItems
db.productReviews
db.userSessions

// BAD: singular, inconsistent casing
db.User          // PascalCase
db.order_items   // snake_case
db.PRODUCTS      // UPPERCASE
db.product       // singular
```

### 2. Field Names
```javascript
// GOOD: camelCase, descriptive
{
  firstName: "Jane",
  lastName: "Smith",
  emailAddress: "jane@example.com",
  isVerified: true,
  orderCount: 42,
  lastLoginAt: ISODate("2025-03-01"),
  createdAt: ISODate("2025-01-01"),
  updatedAt: ISODate("2025-03-01")
}

// BAD: inconsistent casing, abbreviated
{
  first_name: "Jane",   // snake_case
  LastName: "Smith",     // PascalCase
  email: "jane@...",     // ambiguous (address? verified?)
  verified: true,        // missing "is" prefix for boolean
  cnt: 42                // abbreviated
}
```

### 3. Boolean Fields Use "is/has/can" Prefix
```javascript
{
  isActive: true,
  isVerified: false,
  hasSubscription: true,
  canEdit: false
}
```

### 4. Date Fields Use "At" Suffix
```javascript
{
  createdAt: ISODate("..."),
  updatedAt: ISODate("..."),
  deletedAt: ISODate("..."),
  lastLoginAt: ISODate("..."),
  expiresAt: ISODate("...")
}
```

## Anti-Patterns
- Mixing camelCase and snake_case in the same collection
- Using reserved words as field names (type, id, class)
- Single-character field names for "space savings" (a, b, c)
- Prefixing fields with collection name (user_email in users collection)

## Enforcement
Use a linter or code review checklist to verify naming conventions. Document conventions in a CONTRIBUTING.md file for the team.