feat(NODE-3699): add support for comment field

src/change_stream.ts

@@ -57,6 +57,7 @@ const CURSOR_OPTIONS = [
   'maxAwaitTimeMS',
   'collation',
   'readPreference',
+  'comment',
   ...CHANGE_STREAM_OPTIONS
 ] as const;
 
@@ -410,7 +411,7 @@ export class ChangeStream<TSchema extends Document = Document> extends TypedEven
 export interface ChangeStreamCursorOptions extends AbstractCursorOptions {
   startAtOperationTime?: OperationTime;
   resumeAfter?: ResumeToken;
-  startAfter?: boolean;
+  startAfter?: ResumeToken;
 }
 
 /** @internal */
@@ -617,7 +618,7 @@ function applyKnownOptions(source: Document, options: ReadonlyArray<string>) {
   const result: Document = {};
 
   for (const option of options) {
-    if (source[option]) {
+    if (option in source) {
       result[option] = source[option];
     }
   }

src/cmap/connection.ts

@@ -124,7 +124,15 @@ export interface GetMoreOptions extends CommandOptions {
   batchSize?: number;
   maxTimeMS?: number;
   maxAwaitTimeMS?: number;
-  comment?: Document | string;
+  /**
+   * Comment to apply to the operation.
+   *
+   * In server versions pre-4.4, 'comment' must be string.  A server
+   * error will be thrown if any other type is provided.
+   *
+   * In server versions 4.4 and above, 'comment' can be any valid BSON type.
+   */
+  comment?: unknown;
 }
 
 /** @public */
@@ -574,6 +582,11 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
     if (typeof options.maxAwaitTimeMS === 'number') {
       getMoreCmd.maxTimeMS = options.maxAwaitTimeMS;
     }
+    // we check for undefined specifically here to allow falsy values
+    // eslint-disable-next-line no-restricted-syntax
+    if (options.comment !== undefined) {
+      getMoreCmd.comment = options.comment;
+    }
 
     const commandOptions = Object.assign(
       {

src/cursor/abstract_cursor.ts

@@ -42,6 +42,8 @@ const kInitialized = Symbol('initialized');
 const kClosed = Symbol('closed');
 /** @internal */
 const kKilled = Symbol('killed');
+/** @internal */
+const kInit = Symbol('kInit');
 
 /** @public */
 export const CURSOR_FLAGS = [
@@ -77,7 +79,15 @@ export interface AbstractCursorOptions extends BSONSerializeOptions {
   readConcern?: ReadConcernLike;
   batchSize?: number;
   maxTimeMS?: number;
-  comment?: Document | string;
+  /**
+   * Comment to apply to the operation.
+   *
+   * In server versions pre-4.4, 'comment' must be string.  A server
+   * error will be thrown if any other type is provided.
+   *
+   * In server versions 4.4 and above, 'comment' can be any valid BSON type.
+   */
+  comment?: unknown;
   tailable?: boolean;
   awaitData?: boolean;
   noCursorTimeout?: boolean;
@@ -162,7 +172,9 @@ export abstract class AbstractCursor<
       this[kOptions].batchSize = options.batchSize;
     }
 
-    if (options.comment != null) {
+    // we check for undefined specifically here to allow falsy values
+    // eslint-disable-next-line no-restricted-syntax
+    if (options.comment !== undefined) {
       this[kOptions].comment = options.comment;
     }
 
@@ -620,6 +632,65 @@ export abstract class AbstractCursor<
 
     executeOperation(this, getMoreOperation, callback);
   }
+
+  /**
+   * @internal
+   *
+   * This function is exposed for the unified test runner's createChangeStream
+   * operation.  We cannot refactor to use the abstract _initialize method without
+   * a significant refactor.
+   */
+  [kInit](callback: Callback<TSchema | null>): void {
+    if (this[kSession] == null) {
+      if (this[kTopology].shouldCheckForSessionSupport()) {
+        return this[kTopology].selectServer(ReadPreference.primaryPreferred, {}, err => {
+          if (err) return callback(err);
+          return this[kInit](callback);
+        });
+      } else if (this[kTopology].hasSessionSupport()) {
+        this[kSession] = this[kTopology].startSession({ owner: this, explicit: false });
+      }
+    }
+
+    this._initialize(this[kSession], (err, state) => {
+      if (state) {
+        const response = state.response;
+        this[kServer] = state.server;
+        this[kSession] = state.session;
+
+        if (response.cursor) {
+          this[kId] =
+            typeof response.cursor.id === 'number'
+              ? Long.fromNumber(response.cursor.id)
+              : response.cursor.id;
+
+          if (response.cursor.ns) {
+            this[kNamespace] = ns(response.cursor.ns);
+          }
+
+          this[kDocuments] = response.cursor.firstBatch;
+        }
+
+        // When server responses return without a cursor document, we close this cursor
+        // and return the raw server response. This is often the case for explain commands
+        // for example
+        if (this[kId] == null) {
+          this[kId] = Long.ZERO;
+          // TODO(NODE-3286): ExecutionResult needs to accept a generic parameter
+          this[kDocuments] = [state.response as TODO_NODE_3286];
+        }
+      }
+
+      // the cursor is now initialized, even if an error occurred or it is dead
+      this[kInitialized] = true;
+
+      if (err || cursorIsDead(this)) {
+        return cleanupCursor(this, { error: err }, () => callback(err, nextDocument(this)));
+      }
+
+      callback();
+    });
+  }
 }
 
 function nextDocument<T>(cursor: AbstractCursor): T | null | undefined {
@@ -653,61 +724,12 @@ function next<T>(cursor: AbstractCursor, blocking: boolean, callback: Callback<T
 
   if (cursorId == null) {
     // All cursors must operate within a session, one must be made implicitly if not explicitly provided
-    if (cursor[kSession] == null) {
-      if (cursor[kTopology].shouldCheckForSessionSupport()) {
-        return cursor[kTopology].selectServer(ReadPreference.primaryPreferred, {}, err => {
-          if (err) return callback(err);
-          return next(cursor, blocking, callback);
-        });
-      } else if (cursor[kTopology].hasSessionSupport()) {
-        cursor[kSession] = cursor[kTopology].startSession({ owner: cursor, explicit: false });
-      }
-    }
-
-    cursor._initialize(cursor[kSession], (err, state) => {
-      if (state) {
-        const response = state.response;
-        cursor[kServer] = state.server;
-        cursor[kSession] = state.session;
-
-        if (response.cursor) {
-          cursor[kId] =
-            typeof response.cursor.id === 'number'
-              ? Long.fromNumber(response.cursor.id)
-              : response.cursor.id;
-
-          if (response.cursor.ns) {
-            cursor[kNamespace] = ns(response.cursor.ns);
-          }
-
-          cursor[kDocuments] = response.cursor.firstBatch;
-        } else {
-          // NOTE: This is for support of older servers (<3.2) which do not use commands
-          cursor[kId] =
-            typeof response.cursorId === 'number'
-              ? Long.fromNumber(response.cursorId)
-              : response.cursorId;
-          cursor[kDocuments] = response.documents;
-        }
-
-        // When server responses return without a cursor document, we close this cursor
-        // and return the raw server response. This is often the case for explain commands
-        // for example
-        if (cursor[kId] == null) {
-          cursor[kId] = Long.ZERO;
-          // TODO(NODE-3286): ExecutionResult needs to accept a generic parameter
-          cursor[kDocuments] = [state.response as TODO_NODE_3286];
-        }
-      }
-
-      // the cursor is now initialized, even if an error occurred or it is dead
-      cursor[kInitialized] = true;
-
-      if (err || cursorIsDead(cursor)) {
-        return cleanupCursor(cursor, { error: err }, () => callback(err, nextDocument(cursor)));
+    cursor[kInit]((err, value) => {
+      if (err) return callback(err);
+      if (value) {
+        return callback(undefined, value);
       }
-
-      next(cursor, blocking, callback);
+      return next(cursor, blocking, callback);
     });
 
     return;

src/operations/aggregate.ts

@@ -2,8 +2,7 @@ import type { Document } from '../bson';
 import { MongoInvalidArgumentError } from '../error';
 import type { Server } from '../sdam/server';
 import type { ClientSession } from '../sessions';
-import type { Callback } from '../utils';
-import { maxWireVersion, MongoDBNamespace } from '../utils';
+import { Callback, maxWireVersion, MongoDBNamespace } from '../utils';
 import { CollationOptions, CommandOperation, CommandOperationOptions } from './command';
 import { Aspect, defineAspects, Hint } from './operation';
 
@@ -31,6 +30,7 @@ export interface AggregateOptions extends CommandOperationOptions {
   hint?: Hint;
   /** Map of parameter names and values that can be accessed using $$var (requires MongoDB 5.0). */
   let?: Document;
+
   out?: string;
 }
 
@@ -121,6 +121,12 @@ export class AggregateOperation<T = Document> extends CommandOperation<T> {
       command.let = options.let;
     }
 
+    // we check for undefined specifically here to allow falsy values
+    // eslint-disable-next-line no-restricted-syntax
+    if (options.comment !== undefined) {
+      command.comment = options.comment;
+    }
+
     command.cursor = options.cursor || {};
     if (options.batchSize && !this.hasWriteStage) {
       command.cursor.batchSize = options.batchSize;

src/operations/command.ts

@@ -45,8 +45,15 @@ export interface CommandOperationOptions
   /** Collation */
   collation?: CollationOptions;
   maxTimeMS?: number;
-  /** A user-provided comment to attach to this command */
-  comment?: string | Document;
+  /**
+   * Comment to apply to the operation.
+   *
+   * In server versions pre-4.4, 'comment' must be string.  A server
+   * error will be thrown if any other type is provided.
+   *
+   * In server versions 4.4 and above, 'comment' can be any valid BSON type.
+   */
+  comment?: unknown;
   /** Should retry failed writes */
   retryWrites?: boolean;
 

src/operations/delete.ts

@@ -12,8 +12,6 @@ import { Aspect, defineAspects, Hint } from './operation';
 export interface DeleteOptions extends CommandOperationOptions, WriteConcernOptions {
   /** If true, when an insert fails, don't execute the remaining writes. If false, continue with remaining inserts when one fails. */
   ordered?: boolean;
-  /** A user-provided comment to attach to this command */
-  comment?: string | Document;
   /** Specifies the collation to use for the operation */
   collation?: CollationOptions;
   /** Specify that the update query should only consider plans using the hinted index */
@@ -43,8 +41,6 @@ export interface DeleteStatement {
   collation?: CollationOptions;
   /** A document or string that specifies the index to use to support the query predicate. */
   hint?: Hint;
-  /** A user-provided comment to attach to this command */
-  comment?: string | Document;
 }
 
 /** @internal */
@@ -80,6 +76,12 @@ export class DeleteOperation extends CommandOperation<Document> {
       command.let = options.let;
     }
 
+    // we check for undefined specifically here to allow falsy values
+    // eslint-disable-next-line no-restricted-syntax
+    if (options.comment !== undefined) {
+      command.comment = options.comment;
+    }
+
     if (options.explain != null && maxWireVersion(server) < 3) {
       return callback
         ? callback(
@@ -175,10 +177,6 @@ export function makeDeleteStatement(
     op.hint = options.hint;
   }
 
-  if (options.comment) {
-    op.comment = options.comment;
-  }
-
   return op;
 }
 

src/operations/find.ts

@@ -46,8 +46,6 @@ export interface FindOptions<TSchema extends Document = Document> extends Comman
   min?: Document;
   /** The exclusive upper bound for a specific index */
   max?: Document;
-  /** You can put a $comment field on a query to make looking in the profiler logs simpler. */
-  comment?: string | Document;
   /** Number of milliseconds to wait before aborting the query. */
   maxTimeMS?: number;
   /** The maximum amount of time for the server to wait on new documents to satisfy a tailable cursor query. Requires `tailable` and `awaitData` to be true */
@@ -241,7 +239,9 @@ function makeFindCommand(ns: MongoDBNamespace, filter: Document, options: FindOp
     findCommand.singleBatch = options.singleBatch;
   }
 
-  if (options.comment) {
+  // we check for undefined specifically here to allow falsy values
+  // eslint-disable-next-line no-restricted-syntax
+  if (options.comment !== undefined) {
     findCommand.comment = options.comment;
   }
 

src/operations/find_and_modify.ts

@@ -82,6 +82,15 @@ interface FindAndModifyCmdBase {
   maxTimeMS?: number;
   let?: Document;
   writeConcern?: WriteConcern | WriteConcernSettings;
+  /**
+   * Comment to apply to the operation.
+   *
+   * In server versions pre-4.4, 'comment' must be string.  A server
+   * error will be thrown if any other type is provided.
+   *
+   * In server versions 4.4 and above, 'comment' can be any valid BSON type.
+   */
+  comment?: unknown;
 }
 
 function configureFindAndModifyCmdBaseUpdateOpts(
@@ -140,6 +149,12 @@ class FindAndModifyOperation extends CommandOperation<Document> {
       this.cmdBase.let = options.let;
     }
 
+    // we check for undefined specifically here to allow falsy values
+    // eslint-disable-next-line no-restricted-syntax
+    if (options.comment !== undefined) {
+      this.cmdBase.comment = options.comment;
+    }
+
     // force primary read preference
     this.readPreference = ReadPreference.primary;