CR comments - move connectToMongoDB to the session

Author: nirinchev

src/config.ts

@@ -4,6 +4,13 @@ import argv from "yargs-parser";
 
 import { ReadConcernLevel, ReadPreferenceMode, W } from "mongodb";
 
+export interface ConnectOptions {
+    readConcern: ReadConcernLevel;
+    readPreference: ReadPreferenceMode;
+    writeConcern: W;
+    timeoutMS: number;
+}
+
 // If we decide to support non-string config options, we'll need to extend the mechanism for parsing
 // env variables.
 export interface UserConfig {
@@ -13,12 +20,7 @@ export interface UserConfig {
     telemetry?: "enabled" | "disabled";
     logPath: string;
     connectionString?: string;
-    connectOptions: {
-        readConcern: ReadConcernLevel;
-        readPreference: ReadPreferenceMode;
-        writeConcern: W;
-        timeoutMS: number;
-    };
+    connectOptions: ConnectOptions;
     disabledTools: Array<string>;
     readOnly?: boolean;
 }

src/server.ts

@@ -11,7 +11,6 @@ import { type ServerEvent } from "./telemetry/types.js";
 import { type ServerCommand } from "./telemetry/types.js";
 import { CallToolRequestSchema, CallToolResult } from "@modelcontextprotocol/sdk/types.js";
 import assert from "assert";
-import { connectToMongoDB } from "./tools/mongodb/mongodbTool.js";
 
 export interface ServerOptions {
     session: Session;
@@ -201,7 +200,7 @@ export class Server {
 
         if (this.userConfig.connectionString) {
             try {
-                await connectToMongoDB(this.userConfig.connectionString, this.userConfig, this.session);
+                await this.session.connectToMongoDB(this.userConfig.connectionString, this.userConfig.connectOptions);
             } catch (error) {
                 console.error(
                     "Failed to connect to MongoDB instance using the connection string from the config: ",

src/session.ts

@@ -2,6 +2,7 @@ import { NodeDriverServiceProvider } from "@mongosh/service-provider-node-driver
 import { ApiClient, ApiClientCredentials } from "./common/atlas/apiClient.js";
 import { Implementation } from "@modelcontextprotocol/sdk/types.js";
 import EventEmitter from "events";
+import { ConnectOptions } from "./config.js";
 
 export interface SessionOptions {
     apiBaseUrl: string;
@@ -58,4 +59,21 @@ export class Session extends EventEmitter<{
             this.emit("close");
         }
     }
+
+    async connectToMongoDB(connectionString: string, connectOptions: ConnectOptions): Promise<void> {
+        const provider = await NodeDriverServiceProvider.connect(connectionString, {
+            productDocsLink: "https://docs.mongodb.com/todo-mcp",
+            productName: "MongoDB MCP",
+            readConcern: {
+                level: connectOptions.readConcern,
+            },
+            readPreference: connectOptions.readPreference,
+            writeConcern: {
+                w: connectOptions.writeConcern,
+            },
+            timeoutMS: connectOptions.timeoutMS,
+        });
+
+        this.serviceProvider = provider;
+    }
 }

src/tools/mongodb/mongodbTool.ts

@@ -4,31 +4,12 @@ import { NodeDriverServiceProvider } from "@mongosh/service-provider-node-driver
 import { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
 import { ErrorCodes, MongoDBError } from "../../errors.js";
 import logger, { LogId } from "../../logger.js";
-import { UserConfig } from "../../config.js";
-import { Session } from "../../session.js";
 
 export const DbOperationArgs = {
     database: z.string().describe("Database name"),
     collection: z.string().describe("Collection name"),
 };
 
-export async function connectToMongoDB(connectionString: string, config: UserConfig, session: Session): Promise<void> {
-    const provider = await NodeDriverServiceProvider.connect(connectionString, {
-        productDocsLink: "https://docs.mongodb.com/todo-mcp",
-        productName: "MongoDB MCP",
-        readConcern: {
-            level: config.connectOptions.readConcern,
-        },
-        readPreference: config.connectOptions.readPreference,
-        writeConcern: {
-            w: config.connectOptions.writeConcern,
-        },
-        timeoutMS: config.connectOptions.timeoutMS,
-    });
-
-    session.serviceProvider = provider;
-}
-
 export abstract class MongoDBToolBase extends ToolBase {
     protected category: ToolCategory = "mongodb";
 
@@ -90,6 +71,6 @@ export abstract class MongoDBToolBase extends ToolBase {
     }
 
     protected connectToMongoDB(connectionString: string): Promise<void> {
-        return connectToMongoDB(connectionString, this.config, this.session);
+        return this.session.connectToMongoDB(connectionString, this.config.connectOptions);
     }
 }