# keyval-db

A simple, type-safe wrapper for IndexedDB that eliminates the complexity of versions, upgrades, and store management the it was supposed to be.

## What is keyval-db?

`keyval-db` is a lightweight TypeScript library that simplifies working with IndexedDB by providing a Promise-based API. It automatically handles:

- Database connections and reconnections
- Object store creation
- Version management
- Upgrade processes
- Transaction retries on connection errors

With `keyval-db`, you can focus on storing and retrieving data without worrying about the complexities of IndexedDB's low-level API.

## Installation

### npm

```bash
npm install keyval-db
```

### pnpm

```bash
pnpm add keyval-db
```

### bun

```bash
bun add keyval-db
```

## API Reference

- [IDB Class](#idb-class)
- [getDB](#getdb)
- [get](#get)
- [getValues](#getvalues)
- [getKeys](#getkeys)
- [set](#set)
- [setMultiple](#setmultiple)
- [del](#del)
- [clearStore](#clearstore)
- [dropDB](#dropdb)

### IDB Class

The main class for interacting with IndexedDB through a key-value interface.

```typescript
import { IDB } from 'keyval-db';

// Create a new database connection
const db = new IDB('myDatabase', 'myStore');
```

#### Constructor Parameters

| Parameter | Type   | Description                                             |
| --------- | ------ | ------------------------------------------------------- |
| db_name   | string | The name of the IndexedDB database to connect to        |
| storeName | string | The name of the object store to use within the database |

### getDB

A factory function that creates and caches IDB instances cleaning up the cache when the database is dropped.

#### Benefits

- **Instance Caching**: Prevents duplicate database connections
- **Memory Efficient**: Reuses existing instances instead of creating new ones
- **Simplified API**: No need to manually manage database instances
- **Automatic Cleanup**: Instances are automatically removed from cache when database is dropped

```typescript
import { getDB } from 'keyval-db';

// Create or get a cached database connection
const db = getDB('myDatabase', 'myStore');

// Multiple calls with the same parameters return the same instance
const sameDb = getDB('myDatabase', 'myStore');
console.log(db === sameDb); // true

// Different database or table names create separate instances
const otherDb = getDB('otherDatabase', 'myStore');
const differentStore = getDB('myDatabase', 'otherStore');
```

#### Parameters

| Parameter | Type   | Description                                             |
| --------- | ------ | ------------------------------------------------------- |
| db_name   | string | The name of the IndexedDB database to connect to        |
| tableName | string | The name of the object store to use within the database |

#### Returns

`IDB` - A cached IDB instance with all the same methods available

#### Usage Examples

```typescript
// Basic usage with automatic caching
const userDB = getDB('myApp', 'users');
const settingsDB = getDB('myApp', 'settings');

// Store and retrieve data
await userDB.set('user-123', { name: 'John', email: 'john@example.com' });
const user = await userDB.get('user-123');

// The same instance is returned for subsequent calls
const sameUserDB = getDB('myApp', 'users');
await sameUserDB.set('user-456', { name: 'Jane', email: 'jane@example.com' });

// All IDB methods are available
const allUsers = await userDB.getValues();
const userKeys = await userDB.getKeys();
await userDB.setMultiple([
	{ key: 'user-789', value: { name: 'Bob', email: 'bob@example.com' } },
	{ key: 'user-101', value: { name: 'Alice', email: 'alice@example.com' } }
]);
await userDB.clearStore();

// Drop database (removes from cache automatically)
await userDB.dropDB(); // This removes the instance from cache
```

### get

Retrieves a value from the database by its key.

```typescript
// With TypeScript generics for type safety
const user = await db.get<{ name: string; age: number }>('user-123');
console.log(user.name); // Type-safe access

// Using Promise chain
db.get<string>('settings-theme')
	.then((theme) => {
		console.log(`Current theme: ${theme}`);
	})
	.catch((err) => {
		console.error('Failed to get theme:', err);
	});

// Try-catch with await
try {
	const count = await db.get<number>('visit-count');
	console.log(`Visit count: ${count}`);
} catch (err) {
	console.error('Failed to get visit count:', err);
} finally {
	console.log('Get operation completed');
}
```

#### Parameters

| Parameter | Type        | Description                        |
| --------- | ----------- | ---------------------------------- |
| key       | IDBValidKey | The key to look up in the database |

#### Returns

`Promise<T>` - A promise that resolves to the value associated with the key

### getValues

Retrieves all values stored in the database.

```typescript
// Get all items as an array with type safety
const allItems = await db.getValues<Array<{ id: string; content: string }>>();
for (const item of allItems) {
	console.log(item.id, item.content);
}

// Using Promise chain
db.getValues<string[]>()
	.then((values) => {
		console.log(`Found ${values.length} values`);
	})
	.catch((err) => {
		console.error('Failed to get values:', err);
	});
```

#### Returns

`Promise<T extends Array<any>>` - A promise that resolves to an array of all values

### getKeys

Retrieves all keys stored in the database.

```typescript
// Get all keys
const allKeys = await db.getKeys();
console.log(`Found ${allKeys.length} keys in the store`);

// Using Promise chain
db.getKeys()
	.then((keys) => {
		keys.forEach((key) => console.log(`Key: ${key}`));
	})
	.catch((err) => {
		console.error('Failed to get keys:', err);
	});
```

#### Returns

`Promise<Array<IDBValidKey>>` - A promise that resolves to an array of all keys

### set

Stores a value in the database with the specified key.

```typescript
// Simple value
await db.set('settings-theme', 'dark');

// Complex object
await db.set('user-profile', {
	name: 'John Doe',
	email: 'john@example.com',
	preferences: {
		notifications: true
	}
});

// Using Promise chain with type checking
db.set('counter', 5)
	.then((result) => {
		// result is typed as true
		console.log('Value saved:', result);
	})
	.catch((err) => {
		console.error('Failed to save:', err);
	});

// Try-catch with await
try {
	const result = await db.set('last-login', new Date().toISOString());
	console.log('Login time saved:', result); // result is true
} catch (err) {
	console.error('Failed to save login time:', err);
}
```

#### Parameters

| Parameter | Type        | Description                      |
| --------- | ----------- | -------------------------------- |
| key       | IDBValidKey | The key to store the value under |
| value     | unknown     | The value to store               |

#### Returns

`Promise<true>` - A promise that resolves to `true` when the operation is complete

### setMultiple

Stores multiple key-value pairs in the database in a single transaction.

```typescript
// Store multiple items in one transaction
await db.setMultiple([
	{ key: 'item-1', value: { name: 'Item 1', price: 10 } },
	{ key: 'item-2', value: { name: 'Item 2', price: 20 } },
	{ key: 'item-3', value: { name: 'Item 3', price: 30 } }
]);

// With type safety
type Product = { name: string; price: number };
const products: Array<{ key: string; value: Product }> = [
	{ key: 'product-1', value: { name: 'Product 1', price: 9.99 } },
	{ key: 'product-2', value: { name: 'Product 2', price: 19.99 } }
];
const result = await db.setMultiple<Product>(products);
console.log('Products saved:', result); // result is true

// Using Promise chain
db.setMultiple([
	{ key: 'setting-1', value: 'value-1' },
	{ key: 'setting-2', value: 'value-2' }
])
	.then((result) => {
		console.log('All settings saved:', result);
	})
	.catch((err) => {
		console.error('Failed to save settings:', err);
	});
```

#### Parameters

| Parameter | Type                                  | Description                                             |
| --------- | ------------------------------------- | ------------------------------------------------------- |
| items     | Array<{ key: IDBValidKey, value: T }> | An array of objects containing key-value pairs to store |

#### Returns

`Promise<true>` - A promise that resolves to `true` when all items have been stored

### del

Deletes a value from the database by its key.

```typescript
// Delete an item
await db.del('temporary-data');

// Using Promise chain to check result
db.del('session-token')
	.then((result) => {
		console.log('Token deleted:', result); // result is true
	})
	.catch((err) => {
		console.error('Failed to delete token:', err);
	});

// Try-catch with await
try {
	const result = await db.del('cache-item-123');
	console.log('Cache item deleted:', result); // result is true
} catch (err) {
	console.error('Failed to delete cache item:', err);
}
```

#### Parameters

| Parameter | Type        | Description                    |
| --------- | ----------- | ------------------------------ |
| key       | IDBValidKey | The key of the value to delete |

#### Returns

`Promise<true>` - A promise that resolves to `true` when the value has been deleted

### clearStore

Clears all data from the current object store.

```typescript
// Clear all data from the store
await db.clearStore();

// Using Promise chain
db.clearStore()
	.then((result) => {
		console.log('Store cleared:', result); // result is true
	})
	.catch((err) => {
		console.error('Failed to clear store:', err);
	});

// Try-catch with await
try {
	const result = await db.clearStore();
	console.log('All data cleared:', result); // result is true
} catch (err) {
	console.error('Failed to clear data:', err);
}
```

#### Returns

`Promise<true>` - A promise that resolves to `true` when the store has been cleared

### dropDB

Deletes the entire database.

```typescript
// Delete the entire database
await db.dropDB();

// Using Promise chain
db.dropDB()
	.then((result) => {
		console.log('Database deleted:', result); // result is true
	})
	.catch((err) => {
		console.error('Failed to delete database:', err);
	});

// Try-catch with await
try {
	const result = await db.dropDB();
	console.log('Database deleted successfully:', result); // result is true
} catch (err) {
	console.error('Failed to delete database:', err);
}
```

#### Returns

`Promise<true>` - A promise that resolves to `true` when the database has been deleted

## Complete Example

```typescript
import { IDB } from 'keyval-db';

// Define your data types
interface User {
	id: string;
	name: string;
	email: string;
	createdAt: string;
}

// Create a database connection
const userDB = new IDB('myApp', 'users');

// Store a user
async function saveUser(user: User) {
	try {
		await userDB.set(user.id, user);
		console.log(`User ${user.name} saved successfully!`);
	} catch (error) {
		console.error('Failed to save user:', error);
	}
}

// Retrieve a user
async function getUser(userId: string) {
	try {
		const user = await userDB.get<User>(userId);
		console.log(`Found user: ${user.name}`);
		return user;
	} catch (error) {
		console.error(`Failed to get user ${userId}:`, error);
		return null;
	}
}

// Delete a user
async function deleteUser(userId: string) {
	try {
		await userDB.del(userId);
		console.log(`User ${userId} deleted successfully!`);
	} catch (error) {
		console.error(`Failed to delete user ${userId}:`, error);
	}
}

// Get all users
async function getAllUsers() {
	try {
		const users = await userDB.getValues<User[]>();
		console.log(`Found ${users.length} users`);
		return users;
	} catch (error) {
		console.error('Failed to get users:', error);
		return [];
	}
}
```