feat(NODE-7009): add client metadata on demand

Author: durran

src/mongo_client.ts

@@ -14,7 +14,7 @@ import { type TokenCache } from './cmap/auth/mongodb_oidc/token_cache';
 import { 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, makeClientMetadata } 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';
@@ -455,6 +455,15 @@ export class MongoClient extends TypedEventEmitter<MongoClientEvents> implements
     await this.close();
   }
 
+  /**
+   * Append metadata to the client metadata after instantiation.
+   * @param driverInfo - Information abou the application or libraary.
+   */
+  appendMetadata(driverInfo: DriverInfo) {
+    this.s.options.driverInfo = driverInfo;
+    this.s.options.metadata = makeClientMetadata(this.s.options);
+  }
+
   /** @internal */
   private checkForNonGenuineHosts() {
     const documentDBHostnames = this.options.hosts.filter((hostAddress: HostAddress) =>

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

@@ -194,3 +194,11 @@ describe('Handshake Prose Tests', function () {
     });
   });
 });
+
+describe('Client Metadata Update Prose Tests', function () {
+  let client: MongoClient;
+
+  afterEach(async function () {
+    await client?.close();
+  });
+});

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

@@ -0,0 +1,8 @@
+import { join } from 'path';
+
+import { loadSpecTests } from '../../spec';
+import { runUnifiedSuite } from '../../tools/unified-spec-runner/runner';
+
+describe('MongoDB Handshake Tests (Unified)', function () {
+  runUnifiedSuite(loadSpecTests(join('mongodb-handshake')));
+});

test/spec/mongodb-handshake/metadata-not-propagated.json

@@ -0,0 +1,100 @@
+{
+  "description": "client metadata is not propagated to the server",
+  "schemaVersion": "1.9",
+  "runOnRequirements": [
+    {
+      "minServerVersion": "6.0"
+    }
+  ],
+  "createEntities": [
+    {
+      "client": {
+        "id": "client",
+        "observeEvents": [
+          "commandSucceededEvent",
+          "commandFailedEvent",
+          "connectionClosedEvent",
+          "connectionCreatedEvent"
+        ]
+      }
+    },
+    {
+      "database": {
+        "id": "database",
+        "client": "client",
+        "databaseName": "test"
+      }
+    }
+  ],
+  "tests": [
+    {
+      "description": "metadata append does not create new connections or close existing ones and no hello command is sent",
+      "operations": [
+        {
+          "name": "runCommand",
+          "object": "database",
+          "arguments": {
+            "commandName": "ping",
+            "command": {
+              "ping": 1
+            }
+          },
+          "expectResult": {
+            "ok": 1
+          }
+        },
+        {
+          "name": "appendMetadata",
+          "object": "client",
+          "arguments": {
+            "driverInfoOptions": {
+              "name": "framework",
+              "version": "2.0",
+              "platform": "Framework Platform"
+            }
+          }
+        },
+        {
+          "name": "runCommand",
+          "object": "database",
+          "arguments": {
+            "commandName": "ping",
+            "command": {
+              "ping": 1
+            }
+          },
+          "expectResult": {
+            "ok": 1
+          }
+        }
+      ],
+      "expectEvents": [
+        {
+          "client": "client",
+          "eventType": "cmap",
+          "events": [
+            {
+              "connectionCreatedEvent": {}
+            }
+          ]
+        },
+        {
+          "client": "client",
+          "eventType": "command",
+          "events": [
+            {
+              "commandSucceededEvent": {
+                "commandName": "ping"
+              }
+            },
+            {
+              "commandSucceededEvent": {
+                "commandName": "ping"
+              }
+            }
+          ]
+        }
+      ]
+    }
+  ]
+}

test/spec/mongodb-handshake/metadata-not-propagated.yml

@@ -0,0 +1,58 @@
+description: client metadata is not propagated to the server
+schemaVersion: '1.9'
+runOnRequirements:
+  - minServerVersion: '6.0'
+createEntities:
+  - client:
+      id: &client client
+      observeEvents:
+        - commandSucceededEvent
+        - commandFailedEvent
+        - connectionClosedEvent
+        - connectionCreatedEvent
+  - database:
+      id: &database database
+      client: *client
+      databaseName: test
+tests:
+  # Test that appending metadata after `MongoClient` initialization does not close existing
+  # connections, create new ones, and that no new `hello` command is sent.
+  - description: metadata append does not create new connections or close existing ones and no hello command is sent
+    operations:
+      - name: runCommand
+        object: *database
+        arguments:
+          commandName: ping
+          command:
+            ping: 1
+        expectResult:
+          ok: 1
+      - name: appendMetadata
+        object: *client
+        arguments:
+          driverInfoOptions:
+            name: framework
+            version: '2.0'
+            platform: Framework Platform
+      - name: runCommand
+        object: *database
+        arguments:
+          commandName: ping
+          command:
+            ping: 1
+        expectResult:
+          ok: 1
+    expectEvents:
+      - client: *client
+        eventType: cmap
+        events:
+          # Expect only one connection to be created for the first 'ping' command.
+          - connectionCreatedEvent: { }
+      - client: *client
+        eventType: command
+        events:
+          - commandSucceededEvent:
+              commandName: ping
+          - commandSucceededEvent:
+              commandName: ping
+

test/tools/unified-spec-runner/operations.ts

@@ -665,6 +665,11 @@ operations.set('recordTopologyDescription', async ({ entities, operation }) => {
   entities.set(id, description!);
 });
 
+operations.set('appendMetadata', async ({ entities, operation }) => {
+  const client = entities.getEntity('client', operation.object);
+  client.appendMetadata(operation.arguments.driverInfoOptions);
+});
+
 operations.set('assertTopologyType', async ({ entities, operation }) => {
   const {
     topologyDescription,