fix(NODE-7138): prevent duplicate metadata from being appended to handshake metadata

src/cmap/handshake/client_metadata.ts

@@ -2,13 +2,30 @@ import * as os from 'os';
 import * as process from 'process';
 
 import { BSON, type Document, Int32 } from '../../bson';
-import { MongoInvalidArgumentError, MongoRuntimeError } from '../../error';
-import type { MongoOptions } from '../../mongo_client';
+import { MongoInvalidArgumentError } from '../../error';
+import type { DriverInfo, MongoOptions } from '../../mongo_client';
 import { fileIsAccessible } from '../../utils';
 
 // eslint-disable-next-line @typescript-eslint/no-require-imports
 const NODE_DRIVER_VERSION = require('../../../package.json').version;
 
+/** @internal */
+export function isDriverInfoEqual(info1: DriverInfo, info2: DriverInfo): boolean {
+  /** for equality comparison, we consider "" as unset */
+  const nonEmptyCmp = (s1: string | undefined, s2: string | undefined): boolean => {
+    s1 ||= undefined;
+    s2 ||= undefined;
+
+    return s1 === s2;
+  };
+
+  return (
+    nonEmptyCmp(info1.name, info2.name) &&
+    nonEmptyCmp(info1.platform, info2.platform) &&
+    nonEmptyCmp(info1.version, info2.version)
+  );
+}
+
 /**
  * @public
  * @deprecated This interface will be made internal in the next major release.
@@ -90,10 +107,7 @@ export class LimitedSizeDocument {
   }
 }
 
-type MakeClientMetadataOptions = Pick<
-  MongoOptions,
-  'appName' | 'driverInfo' | 'additionalDriverInfo'
->;
+type MakeClientMetadataOptions = Pick<MongoOptions, 'appName'>;
 /**
  * From the specs:
  * Implementors SHOULD cumulatively update fields in the following order until the document is under the size limit:
@@ -102,34 +116,28 @@ type MakeClientMetadataOptions = Pick<
  * 3. Omit the `env` document entirely.
  * 4. Truncate `platform`. -- special we do not truncate this field
  */
-export function makeClientMetadata(options: MakeClientMetadataOptions): ClientMetadata {
+export function makeClientMetadata(
+  driverInfoList: DriverInfo[],
+  { appName = '' }: MakeClientMetadataOptions
+): ClientMetadata {
   const metadataDocument = new LimitedSizeDocument(512);
 
-  const { appName = '' } = options;
   // Add app name first, it must be sent
   if (appName.length > 0) {
     const name =
       Buffer.byteLength(appName, 'utf8') <= 128
-        ? options.appName
+        ? appName
         : Buffer.from(appName, 'utf8').subarray(0, 128).toString('utf8');
     metadataDocument.ifItFitsItSits('application', { name });
   }
 
-  const { name = '', version = '', platform = '' } = options.driverInfo;
-
   const driverInfo = {
-    name: name.length > 0 ? `nodejs|${name}` : 'nodejs',
-    version: version.length > 0 ? `${NODE_DRIVER_VERSION}|${version}` : NODE_DRIVER_VERSION
+    name: 'nodejs',
+    version: NODE_DRIVER_VERSION
   };
 
-  if (options.additionalDriverInfo == null) {
-    throw new MongoRuntimeError(
-      'Client options `additionalDriverInfo` must always default to an empty array'
-    );
-  }
-
   // This is where we handle additional driver info added after client construction.
-  for (const { name: n = '', version: v = '' } of options.additionalDriverInfo) {
+  for (const { name: n = '', version: v = '' } of driverInfoList) {
     if (n.length > 0) {
       driverInfo.name = `${driverInfo.name}|${n}`;
     }
@@ -145,13 +153,10 @@ export function makeClientMetadata(options: MakeClientMetadataOptions): ClientMe
   }
 
   let runtimeInfo = getRuntimeInfo();
-  if (platform.length > 0) {
-    runtimeInfo = `${runtimeInfo}|${platform}`;
-  }
-
-  for (const { platform: p = '' } of options.additionalDriverInfo) {
-    if (p.length > 0) {
-      runtimeInfo = `${runtimeInfo}|${p}`;
+  // This is where we handle additional driver info added after client construction.
+  for (const { platform = '' } of driverInfoList) {
+    if (platform.length > 0) {
+      runtimeInfo = `${runtimeInfo}|${platform}`;
     }
   }
 
@@ -210,7 +215,9 @@ async function getContainerMetadata() {
  * Re-add each metadata value.
  * Attempt to add new env container metadata, but keep old data if it does not fit.
  */
-export async function addContainerMetadata(originalMetadata: ClientMetadata) {
+export async function addContainerMetadata(
+  originalMetadata: ClientMetadata
+): Promise<ClientMetadata> {
   const containerMetadata = await getContainerMetadata();
   if (Object.keys(containerMetadata).length === 0) return originalMetadata;
 
@@ -233,7 +240,7 @@ export async function addContainerMetadata(originalMetadata: ClientMetadata) {
     extendedMetadata.ifItFitsItSits('env', extendedEnvMetadata);
   }
 
-  return extendedMetadata.toObject();
+  return extendedMetadata.toObject() as ClientMetadata;
 }
 
 /**

src/connection_string.ts

@@ -5,7 +5,6 @@ import { URLSearchParams } from 'url';
 import type { Document } from './bson';
 import { MongoCredentials } from './cmap/auth/mongo_credentials';
 import { AUTH_MECHS_AUTH_SRC_EXTERNAL, AuthMechanism } from './cmap/auth/providers';
-import { addContainerMetadata, makeClientMetadata } from './cmap/handshake/client_metadata';
 import { Compressor, type CompressorName } from './cmap/wire_protocol/compression';
 import { Encrypter } from './encrypter';
 import {
@@ -535,16 +534,6 @@ export function parseOptions(
     }
   );
 
-  // Set the default for the additional driver info.
-  mongoOptions.additionalDriverInfo = [];
-
-  mongoOptions.metadata = makeClientMetadata(mongoOptions);
-
-  mongoOptions.extendedMetadata = addContainerMetadata(mongoOptions.metadata).then(
-    undefined,
-    squashError
-  ); // rejections will be handled later
-
   return mongoOptions;
 }
 

src/mongo_client.ts

@@ -18,6 +18,7 @@ import type { Connection } from './cmap/connection';
 import {
   addContainerMetadata,
   type ClientMetadata,
+  isDriverInfoEqual,
   makeClientMetadata
 } from './cmap/handshake/client_metadata';
 import type { CompressorName } from './cmap/wire_protocol/compression';
@@ -430,12 +431,16 @@ export class MongoClient extends TypedEventEmitter<MongoClientEvents> implements
       | 'extendedMetadata'
     >;
 
+  private driverInfoList: DriverInfo[] = [];
+
   constructor(url: string, options?: MongoClientOptions) {
     super();
     this.on('error', noop);
 
     this.options = parseOptions(url, this, options);
 
+    this.appendMetadata(this.options.driverInfo);
+
     const shouldSetLogger = Object.values(this.options.mongoLoggerOptions.componentSeverities).some(
       value => value !== SeverityLevel.OFF
     );
@@ -492,8 +497,13 @@ export class MongoClient extends TypedEventEmitter<MongoClientEvents> implements
    * @param driverInfo - Information about the application or library.
    */
   appendMetadata(driverInfo: DriverInfo) {
-    this.options.additionalDriverInfo.push(driverInfo);
-    this.options.metadata = makeClientMetadata(this.options);
+    const isDuplicateDriverInfo = this.driverInfoList.some(info =>
+      isDriverInfoEqual(info, driverInfo)
+    );
+    if (isDuplicateDriverInfo) return;
+
+    this.driverInfoList.push(driverInfo);
+    this.options.metadata = makeClientMetadata(this.driverInfoList, this.options);
     this.options.extendedMetadata = addContainerMetadata(this.options.metadata)
       .then(undefined, squashError)
       .then(result => result ?? {}); // ensure Promise<Document>

test/integration/connection-monitoring-and-pooling/connection.test.ts

@@ -49,10 +49,8 @@ describe('Connection', function () {
           ...commonConnectOptions,
           connectionType: Connection,
           ...this.configuration.options,
-          metadata: makeClientMetadata({ driverInfo: {}, additionalDriverInfo: [] }),
-          extendedMetadata: addContainerMetadata(
-            makeClientMetadata({ driverInfo: {}, additionalDriverInfo: [] })
-          )
+          metadata: makeClientMetadata([], {}),
+          extendedMetadata: addContainerMetadata(makeClientMetadata([], {}))
         };
 
         let conn;
@@ -74,10 +72,8 @@ describe('Connection', function () {
           connectionType: Connection,
           ...this.configuration.options,
           monitorCommands: true,
-          metadata: makeClientMetadata({ driverInfo: {}, additionalDriverInfo: [] }),
-          extendedMetadata: addContainerMetadata(
-            makeClientMetadata({ driverInfo: {}, additionalDriverInfo: [] })
-          )
+          metadata: makeClientMetadata([], {}),
+          extendedMetadata: addContainerMetadata(makeClientMetadata([], {}))
         };
 
         let conn;
@@ -108,10 +104,8 @@ describe('Connection', function () {
           connectionType: Connection,
           ...this.configuration.options,
           monitorCommands: true,
-          metadata: makeClientMetadata({ driverInfo: {}, additionalDriverInfo: [] }),
-          extendedMetadata: addContainerMetadata(
-            makeClientMetadata({ driverInfo: {}, additionalDriverInfo: [] })
-          )
+          metadata: makeClientMetadata([], {}),
+          extendedMetadata: addContainerMetadata(makeClientMetadata([], {}))
         };
 
         let conn;