Thin MongoDB ODM built for Standard Schema
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mongodb
zod
deno
1import { type Db, type MongoClientOptions, MongoClient } from "mongodb";
2
3interface Connection {
4 client: MongoClient;
5 db: Db;
6}
7
8let connection: Connection | null = null;
9
10export interface ConnectOptions extends MongoClientOptions {};
11
12/**
13 * Health check details of the MongoDB connection
14 *
15 * @property healthy - Overall health status of the connection
16 * @property connected - Whether a connection is established
17 * @property responseTimeMs - Response time in milliseconds (if connection is healthy)
18 * @property error - Error message if health check failed
19 * @property timestamp - Timestamp when health check was performed
20 */
21export interface HealthCheckResult {
22 healthy: boolean;
23 connected: boolean;
24 responseTimeMs?: number;
25 error?: string;
26 timestamp: Date;
27}
28
29/**
30 * Connect to MongoDB with options including connection pooling
31 *
32 * @param uri - MongoDB connection string
33 * @param dbName - Name of the database to connect to
34 * @param options - Connection options including connection pooling
35 *
36 * @example
37 * ```ts
38 * await connect("mongodb://localhost:27017", "mydb", {
39 * maxPoolSize: 10,
40 * minPoolSize: 2,
41 * maxIdleTimeMS: 30000,
42 * connectTimeoutMS: 10000,
43 * socketTimeoutMS: 45000,
44 * });
45 * ```
46 */
47export async function connect(
48 uri: string,
49 dbName: string,
50 options?: ConnectOptions,
51): Promise<Connection> {
52 if (connection) {
53 return connection;
54 }
55
56 const client = new MongoClient(uri, options);
57 await client.connect();
58 const db = client.db(dbName);
59
60 connection = { client, db };
61 return connection;
62}
63
64export async function disconnect(): Promise<void> {
65 if (connection) {
66 await connection.client.close();
67 connection = null;
68 }
69}
70
71export function getDb(): Db {
72 if (!connection) {
73 throw new Error("MongoDB not connected. Call connect() first.");
74 }
75 return connection.db;
76}
77
78/**
79 * Check the health of the MongoDB connection
80 *
81 * Performs a ping operation to verify the database is responsive
82 * and returns detailed health information including response time.
83 *
84 * @example
85 * ```ts
86 * const health = await healthCheck();
87 * if (health.healthy) {
88 * console.log(`Database healthy (${health.responseTimeMs}ms)`);
89 * } else {
90 * console.error(`Database unhealthy: ${health.error}`);
91 * }
92 * ```
93 */
94export async function healthCheck(): Promise<HealthCheckResult> {
95 const timestamp = new Date();
96
97 // Check if connection exists
98 if (!connection) {
99 return {
100 healthy: false,
101 connected: false,
102 error: "No active connection. Call connect() first.",
103 timestamp,
104 };
105 }
106
107 try {
108 // Measure ping response time
109 const startTime = performance.now();
110 await connection.db.admin().ping();
111 const endTime = performance.now();
112 const responseTimeMs = Math.round(endTime - startTime);
113
114 return {
115 healthy: true,
116 connected: true,
117 responseTimeMs,
118 timestamp,
119 };
120 } catch (error) {
121 return {
122 healthy: false,
123 connected: true,
124 error: error instanceof Error ? error.message : String(error),
125 timestamp,
126 };
127 }
128}