feat(NODE-4192): make MongoClient.connect optional (#3232)

global.d.ts

@@ -73,21 +73,21 @@ declare global {
        * An optional string the test author can attach to print out why a test is skipped
        *
        * @example
-       * ```
+       * ```ts
        * it.skip('my test', () => {
        *   //...
        * }).skipReason = 'TODO(NODE-XXXX): Feature implementation impending!';
        * ```
        *
        * The reporter (`test/tools/reporter/mongodb_reporter.js`) will print out the skipReason
        * indented directly below the test name.
-       * ```
+       * ```txt
        * - my test
        *   - TODO(NODE-XXXX): Feature implementation impending!
        * ```
        *
        * You can also skip a set of tests via beforeEach:
-       * ```
+       * ```ts
        * beforeEach(() => {
        *   if ('some condition') {
        *     this.currentTest.skipReason = 'requires <run condition> to run';

src/admin.ts

@@ -83,7 +83,7 @@ export class Admin {
     options = Object.assign({ dbName: 'admin' }, options);
 
     return executeOperation(
-      this.s.db,
+      this.s.db.s.client,
       new RunCommandOperation(this.s.db, command, options),
       callback
     );
@@ -207,7 +207,7 @@ export class Admin {
     options = Object.assign({ dbName: 'admin' }, options);
 
     return executeOperation(
-      this.s.db,
+      this.s.db.s.client,
       new AddUserOperation(this.s.db, username, password, options),
       callback
     );
@@ -233,7 +233,7 @@ export class Admin {
     options = Object.assign({ dbName: 'admin' }, options);
 
     return executeOperation(
-      this.s.db,
+      this.s.db.s.client,
       new RemoveUserOperation(this.s.db, username, options),
       callback
     );
@@ -263,7 +263,7 @@ export class Admin {
     options = options ?? {};
 
     return executeOperation(
-      this.s.db,
+      this.s.db.s.client,
       new ValidateCollectionOperation(this, collectionName, options),
       callback
     );
@@ -286,7 +286,11 @@ export class Admin {
     if (typeof options === 'function') (callback = options), (options = {});
     options = options ?? {};
 
-    return executeOperation(this.s.db, new ListDatabasesOperation(this.s.db, options), callback);
+    return executeOperation(
+      this.s.db.s.client,
+      new ListDatabasesOperation(this.s.db, options),
+      callback
+    );
   }
 
   /**

src/bulk/common.ts

@@ -655,19 +655,19 @@ function executeCommands(
   try {
     if (isInsertBatch(batch)) {
       executeOperation(
-        bulkOperation.s.collection,
+        bulkOperation.s.collection.s.db.s.client,
         new InsertOperation(bulkOperation.s.namespace, batch.operations, finalOptions),
         resultHandler
       );
     } else if (isUpdateBatch(batch)) {
       executeOperation(
-        bulkOperation.s.collection,
+        bulkOperation.s.collection.s.db.s.client,
         new UpdateOperation(bulkOperation.s.namespace, batch.operations, finalOptions),
         resultHandler
       );
     } else if (isDeleteBatch(batch)) {
       executeOperation(
-        bulkOperation.s.collection,
+        bulkOperation.s.collection.s.db.s.client,
         new DeleteOperation(bulkOperation.s.namespace, batch.operations, finalOptions),
         resultHandler
       );
@@ -1288,7 +1288,7 @@ export abstract class BulkOperationBase {
     const finalOptions = { ...this.s.options, ...options };
     const operation = new BulkWriteShimOperation(this, finalOptions);
 
-    return executeOperation(this.s.collection, operation, callback);
+    return executeOperation(this.s.collection.s.db.s.client, operation, callback);
   }
 
   /**

src/change_stream.ts

@@ -600,8 +600,24 @@ export class ChangeStream<
 
     const cursorOptions: ChangeStreamCursorOptions = filterOptions(options, CURSOR_OPTIONS);
 
+    const client: MongoClient | null =
+      this.type === CHANGE_DOMAIN_TYPES.CLUSTER
+        ? (this.parent as MongoClient)
+        : this.type === CHANGE_DOMAIN_TYPES.DATABASE
+        ? (this.parent as Db).s.client
+        : this.type === CHANGE_DOMAIN_TYPES.COLLECTION
+        ? (this.parent as Collection).s.db.s.client
+        : null;
+
+    if (client == null) {
+      // This should never happen because of the assertion in the constructor
+      throw new MongoRuntimeError(
+        `Changestream type should only be one of cluster, database, collection. Found ${this.type.toString()}`
+      );
+    }
+
     const changeStreamCursor = new ChangeStreamCursor<TSchema, TChange>(
-      getTopology(this.parent),
+      client,
       this.namespace,
       pipeline,
       cursorOptions
@@ -835,12 +851,12 @@ export class ChangeStreamCursor<
   pipeline: Document[];
 
   constructor(
-    topology: Topology,
+    client: MongoClient,
     namespace: MongoDBNamespace,
     pipeline: Document[] = [],
     options: ChangeStreamCursorOptions = {}
   ) {
-    super(topology, namespace, options);
+    super(client, namespace, options);
 
     this.pipeline = pipeline;
     this.options = options;
@@ -907,7 +923,7 @@ export class ChangeStreamCursor<
   }
 
   clone(): AbstractCursor<TChange> {
-    return new ChangeStreamCursor(this.topology, this.namespace, this.pipeline, {
+    return new ChangeStreamCursor(this.client, this.namespace, this.pipeline, {
       ...this.cursorOptions
     });
   }
@@ -920,7 +936,7 @@ export class ChangeStreamCursor<
     });
 
     executeOperation<TODO_NODE_3286, ChangeStreamAggregateRawResult<TChange>>(
-      session,
+      session.client,
       aggregateOperation,
       (err, response) => {
         if (err || response == null) {

src/cmap/wire_protocol/shared.ts

@@ -56,7 +56,11 @@ export function applyCommonQueryOptions(
   return queryOptions;
 }
 
-export function isSharded(topologyOrServer: Topology | Server | Connection): boolean {
+export function isSharded(topologyOrServer?: Topology | Server | Connection): boolean {
+  if (topologyOrServer == null) {
+    return false;
+  }
+
   if (topologyOrServer.description && topologyOrServer.description.type === ServerType.Mongos) {
     return true;
   }