add metadata truncation

Author: baileympearson

src/cmap/connect.ts

@@ -28,7 +28,7 @@ import { AuthMechanism } from './auth/providers';
 import { ScramSHA1, ScramSHA256 } from './auth/scram';
 import { X509 } from './auth/x509';
 import { CommandOptions, Connection, ConnectionOptions, CryptoConnection } from './connection';
-import type { ClientMetadata } from './handshake/client_metadata';
+import type { TruncatedClientMetadata } from './handshake/client_metadata';
 import {
   MAX_SUPPORTED_SERVER_VERSION,
   MAX_SUPPORTED_WIRE_VERSION,
@@ -193,7 +193,7 @@ export interface HandshakeDocument extends Document {
   ismaster?: boolean;
   hello?: boolean;
   helloOk?: boolean;
-  client: ClientMetadata;
+  client: TruncatedClientMetadata;
   compression: string[];
   saslSupportedMechs?: string;
   loadBalanced?: boolean;
@@ -214,7 +214,7 @@ export async function prepareHandshakeDocument(
   const handshakeDoc: HandshakeDocument = {
     [serverApi?.version ? 'hello' : LEGACY_HELLO_COMMAND]: 1,
     helloOk: true,
-    client: options.metadata,
+    client: options.truncatedClientMetadata,
     compression: compressors
   };
 

src/cmap/connection.ts

@@ -45,7 +45,7 @@ import {
 } from './command_monitoring_events';
 import { BinMsg, Msg, Query, Response, WriteProtocolMessageType } from './commands';
 import type { Stream } from './connect';
-import type { ClientMetadata } from './handshake/client_metadata';
+import type { ClientMetadata, TruncatedClientMetadata } from './handshake/client_metadata';
 import { MessageStream, OperationDescription } from './message_stream';
 import { StreamDescription, StreamDescriptionOptions } from './stream_description';
 import { getReadPreference, isSharded } from './wire_protocol/shared';
@@ -128,6 +128,9 @@ export interface ConnectionOptions
   socketTimeoutMS?: number;
   cancellationToken?: CancellationToken;
   metadata: ClientMetadata;
+
+  /** @internal */
+  truncatedClientMetadata: TruncatedClientMetadata;
 }
 
 /** @internal */

src/cmap/connection_pool.ts

@@ -227,7 +227,7 @@ export class ConnectionPool extends TypedEventEmitter<ConnectionPoolEvents> {
       waitQueueTimeoutMS: options.waitQueueTimeoutMS ?? 0,
       minPoolSizeCheckFrequencyMS: options.minPoolSizeCheckFrequencyMS ?? 100,
       autoEncrypter: options.autoEncrypter,
-      metadata: options.metadata
+      truncatedClientMetadata: options.truncatedClientMetadata
     });
 
     if (this.options.minPoolSize > this.options.maxPoolSize) {

src/cmap/handshake/client_metadata.ts

@@ -2,7 +2,7 @@ import { calculateObjectSize } from 'bson';
 import * as os from 'os';
 
 import type { MongoOptions } from '../../mongo_client';
-import type { DeepPartial } from '../../utils';
+import { deepCopy, DeepPartial } from '../../utils';
 import { applyFaasEnvMetadata, determineCloudProvider } from './faas_provider';
 
 /**
@@ -35,58 +35,58 @@ export interface ClientMetadata {
   };
 }
 
+/** @internal */
 export type TruncatedClientMetadata = DeepPartial<ClientMetadata>;
 
-export function truncateClientMetadata(metadata: ClientMetadata): ClientMetadata {
-  if (calculateObjectSize(metadata) <= 512) {
-    return metadata;
+export function truncateClientMetadata(metadata: ClientMetadata): TruncatedClientMetadata {
+  const copiedMetadata: TruncatedClientMetadata = deepCopy(metadata);
+  if (calculateObjectSize(copiedMetadata) <= 512) {
+    return copiedMetadata;
   }
 
-  // @ts-expect-error cannot be deleted
-  delete metadata.platform;
+  delete copiedMetadata.platform;
 
-  if (calculateObjectSize(metadata) <= 512) {
-    return metadata;
+  if (calculateObjectSize(copiedMetadata) <= 512) {
+    return copiedMetadata;
   }
 
-  if (metadata.env) {
-    metadata.env = { name: metadata.env.name };
+  if (copiedMetadata.env) {
+    copiedMetadata.env = { name: copiedMetadata.env.name };
   }
 
-  if (calculateObjectSize(metadata) <= 512) {
-    return metadata;
+  if (calculateObjectSize(copiedMetadata) <= 512) {
+    return copiedMetadata;
   }
 
-  // @ts-expect-error non-optional properties
-  metadata.os = { type: metadata.os.type };
+  if (copiedMetadata.os) {
+    copiedMetadata.os = { type: copiedMetadata.os.type };
+  }
 
-  if (calculateObjectSize(metadata) <= 512) {
-    return metadata;
+  if (calculateObjectSize(copiedMetadata) <= 512) {
+    return copiedMetadata;
   }
 
-  delete metadata.env;
+  delete copiedMetadata.env;
 
-  if (calculateObjectSize(metadata) <= 512) {
-    return metadata;
+  if (calculateObjectSize(copiedMetadata) <= 512) {
+    return copiedMetadata;
   }
 
-  // @ts-expect-error required properties
-  delete metadata.os;
+  delete copiedMetadata.os;
 
-  if (calculateObjectSize(metadata) <= 512) {
-    return metadata;
+  if (calculateObjectSize(copiedMetadata) <= 512) {
+    return copiedMetadata;
   }
 
-  // @ts-expect-error required properties
-  delete metadata.driver;
+  delete copiedMetadata.driver;
 
-  if (calculateObjectSize(metadata) <= 512) {
-    return metadata;
+  if (calculateObjectSize(copiedMetadata) <= 512) {
+    return copiedMetadata;
   }
 
-  delete metadata.application;
+  delete copiedMetadata.application;
 
-  return metadata;
+  return copiedMetadata;
 }
 
 /** @public */

src/connection_string.ts

@@ -6,7 +6,7 @@ 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 { makeClientMetadata } from './cmap/handshake/client_metadata';
+import { makeClientMetadata, truncateClientMetadata } from './cmap/handshake/client_metadata';
 import { Compressor, CompressorName } from './cmap/wire_protocol/compression';
 import { Encrypter } from './encrypter';
 import {
@@ -543,6 +543,8 @@ export function parseOptions(
   );
 
   mongoOptions.metadata = makeClientMetadata(mongoOptions);
+  Object.freeze(mongoOptions.metadata);
+  mongoOptions.truncatedClientMetadata = truncateClientMetadata(mongoOptions.metadata);
 
   return mongoOptions;
 }

src/index.ts

@@ -238,7 +238,11 @@ export type {
   WaitQueueMember,
   WithConnectionCallback
 } from './cmap/connection_pool';
-export type { ClientMetadata, ClientMetadataOptions } from './cmap/handshake/client_metadata';
+export type {
+  ClientMetadata,
+  ClientMetadataOptions,
+  TruncatedClientMetadata
+} from './cmap/handshake/client_metadata';
 export type {
   MessageStream,
   MessageStreamOptions,
@@ -464,6 +468,7 @@ export type { Transaction, TransactionOptions, TxnState } from './transactions';
 export type {
   BufferPool,
   Callback,
+  DeepPartial,
   EventEmitterWithState,
   HostAddress,
   List,

src/mongo_client.ts

@@ -8,7 +8,7 @@ import type { AuthMechanismProperties, MongoCredentials } from './cmap/auth/mong
 import type { AuthMechanism } from './cmap/auth/providers';
 import type { LEGAL_TCP_SOCKET_OPTIONS, LEGAL_TLS_SOCKET_OPTIONS } from './cmap/connect';
 import type { Connection } from './cmap/connection';
-import type { ClientMetadata } from './cmap/handshake/client_metadata';
+import type { ClientMetadata, TruncatedClientMetadata } from './cmap/handshake/client_metadata';
 import type { CompressorName } from './cmap/wire_protocol/compression';
 import { parseOptions, resolveSRVRecord } from './connection_string';
 import { MONGO_CLIENT_EVENTS } from './constants';
@@ -712,12 +712,24 @@ export interface MongoOptions
   compressors: CompressorName[];
   writeConcern: WriteConcern;
   dbName: string;
-  metadata: ClientMetadata;
   autoEncrypter?: AutoEncrypter;
   proxyHost?: string;
   proxyPort?: number;
   proxyUsername?: string;
   proxyPassword?: string;
+
+  metadata: ClientMetadata;
+
+  /**
+   * @internal
+   * `metadata` truncated to be less than 512 bytes, if necessary, to attach to handshakes.
+   * `metadata` is left untouched because it is public and to provide users a document they
+   * inspect to confirm their metadata was parsed correctly.
+   *
+   * If `metadata` `<=` 512 bytes, these fields are the same but the driver only uses `truncatedMetadata`.
+   */
+  truncatedClientMetadata: TruncatedClientMetadata;
+
   /** @internal */
   connectionType?: typeof Connection;
 

src/sdam/topology.ts

@@ -5,7 +5,7 @@ import type { BSONSerializeOptions, Document } from '../bson';
 import type { MongoCredentials } from '../cmap/auth/mongo_credentials';
 import type { ConnectionEvents, DestroyOptions } from '../cmap/connection';
 import type { CloseOptions, ConnectionPoolEvents } from '../cmap/connection_pool';
-import type { ClientMetadata } from '../cmap/handshake/client_metadata';
+import type { ClientMetadata, TruncatedClientMetadata } from '../cmap/handshake/client_metadata';
 import { DEFAULT_OPTIONS, FEATURE_FLAGS } from '../connection_string';
 import {
   CLOSE,
@@ -138,15 +138,14 @@ export interface TopologyOptions extends BSONSerializeOptions, ServerOptions {
   /** The name of the replica set to connect to */
   replicaSet?: string;
   srvHost?: string;
-  /** @internal */
   srvPoller?: SrvPoller;
   /** Indicates that a client should directly connect to a node without attempting to discover its topology type */
   directConnection: boolean;
   loadBalanced: boolean;
   metadata: ClientMetadata;
+  truncatedClientMetadata: TruncatedClientMetadata;
   /** MongoDB server API version */
   serverApi?: ServerApi;
-  /** @internal */
   [featureFlag: symbol]: any;
 }
 
@@ -661,8 +660,8 @@ export class Topology extends TypedEventEmitter<TopologyEvents> {
     if (typeof callback === 'function') callback(undefined, true);
   }
 
-  get clientMetadata(): ClientMetadata {
-    return this.s.options.metadata;
+  get clientMetadata(): TruncatedClientMetadata {
+    return this.s.options.truncatedClientMetadata;
   }
 
   isConnected(): boolean {

src/utils.ts

@@ -38,6 +38,7 @@ export type Callback<T = any> = (error?: AnyError, result?: T) => void;
 
 export type AnyOptions = Document;
 
+/** @internal */
 export type DeepPartial<T> = T extends object
   ? {
       [P in keyof T]?: DeepPartial<T[P]>;

test/integration/mongodb-handshake/mongodb-handshake.prose.test.ts

@@ -58,14 +58,14 @@ context('FAAS Environment Prose Tests', function () {
         ['FUNCTIONS_WORKER_RUNTIME', 'node']
       ]
     },
-    // TODO: truncation
-    // [
-    //   '6. Invalid - long string',
-    //   [
-    //     ['AWS_EXECUTION_ENV', 'AWS_Lambda_java8'],
-    //     ['AWS_REGION', 'a'.repeat(1024)]
-    //   ]
-    // ],
+    {
+      expectedProvider: 'aws',
+      context: '6. Invalid - long string',
+      env: [
+        ['AWS_EXECUTION_ENV', 'AWS_Lambda_java8'],
+        ['AWS_REGION', 'a'.repeat(1024)]
+      ]
+    },
     {
       //  TODO - clarify behavior here
       expectedProvider: 'aws',