fix(NODE-5044): Write Concern 0 Must Not Affect Read Operations (#3541) (#3575)

Co-authored-by: Warren James <warren.james.dev@gmail.com>
Co-authored-by: Neal Beeken <neal.beeken@mongodb.com>

Author: 3 people

src/change_stream.ts

@@ -82,7 +82,7 @@ export type OperationTime = Timestamp;
  * Options that can be passed to a ChangeStream. Note that startAfter, resumeAfter, and startAtOperationTime are all mutually exclusive, and the server will error if more than one is specified.
  * @public
  */
-export interface ChangeStreamOptions extends AggregateOptions {
+export interface ChangeStreamOptions extends Omit<AggregateOptions, 'writeConcern'> {
   /**
    * Allowed values: 'updateLookup', 'whenAvailable', 'required'.
    *
@@ -533,7 +533,14 @@ export class ChangeStream<
   TChange extends Document = ChangeStreamDocument<TSchema>
 > extends TypedEventEmitter<ChangeStreamEvents<TSchema, TChange>> {
   pipeline: Document[];
-  options: ChangeStreamOptions;
+  /**
+   * @remarks WriteConcern can still be present on the options because
+   * we inherit options from the client/db/collection.  The
+   * key must be present on the options in order to delete it.
+   * This allows typescript to delete the key but will
+   * not allow a writeConcern to be assigned as a property on options.
+   */
+  options: ChangeStreamOptions & { writeConcern?: never };
   parent: MongoClient | Db | Collection;
   namespace: MongoDBNamespace;
   type: symbol;
@@ -586,7 +593,8 @@ export class ChangeStream<
     super();
 
     this.pipeline = pipeline;
-    this.options = options;
+    this.options = { ...options };
+    delete this.options.writeConcern;
 
     if (parent instanceof Collection) {
       this.type = CHANGE_DOMAIN_TYPES.COLLECTION;

src/operations/aggregate.ts

@@ -44,7 +44,7 @@ export class AggregateOperation<T = Document> extends CommandOperation<T> {
   constructor(ns: MongoDBNamespace, pipeline: Document[], options?: AggregateOptions) {
     super(undefined, { ...options, dbName: ns.db });
 
-    this.options = options ?? {};
+    this.options = { ...options };
 
     // Covers when ns.collection is null, undefined or the empty string, use DB_AGGREGATE_COLLECTION
     this.target = ns.collection || DB_AGGREGATE_COLLECTION;
@@ -65,6 +65,8 @@ export class AggregateOperation<T = Document> extends CommandOperation<T> {
 
     if (this.hasWriteStage) {
       this.trySecondaryWrite = true;
+    } else {
+      delete this.options.writeConcern;
     }
 
     if (this.explain && this.writeConcern) {

src/operations/find.ts

@@ -14,7 +14,8 @@ import { Aspect, defineAspects, Hint } from './operation';
  * @typeParam TSchema - Unused schema definition, deprecated usage, only specify `FindOptions` with no generic
  */
 // eslint-disable-next-line @typescript-eslint/no-unused-vars
-export interface FindOptions<TSchema extends Document = Document> extends CommandOperationOptions {
+export interface FindOptions<TSchema extends Document = Document>
+  extends Omit<CommandOperationOptions, 'writeConcern'> {
   /** Sets the limit of documents returned in the query. */
   limit?: number;
   /** Set to sort the documents coming back from the query. Array of indexes, `[['a', 1]]` etc. */
@@ -66,7 +67,14 @@ export interface FindOptions<TSchema extends Document = Document> extends Comman
 
 /** @internal */
 export class FindOperation extends CommandOperation<Document> {
-  override options: FindOptions;
+  /**
+   * @remarks WriteConcern can still be present on the options because
+   * we inherit options from the client/db/collection.  The
+   * key must be present on the options in order to delete it.
+   * This allows typescript to delete the key but will
+   * not allow a writeConcern to be assigned as a property on options.
+   */
+  override options: FindOptions & { writeConcern?: never };
   filter: Document;
 
   constructor(
@@ -77,7 +85,8 @@ export class FindOperation extends CommandOperation<Document> {
   ) {
     super(collection, options);
 
-    this.options = options;
+    this.options = { ...options };
+    delete this.options.writeConcern;
     this.ns = ns;
 
     if (typeof filter !== 'object' || Array.isArray(filter)) {

src/operations/indexes.ts

@@ -102,7 +102,7 @@ export interface IndexDescription
 }
 
 /** @public */
-export interface CreateIndexesOptions extends CommandOperationOptions {
+export interface CreateIndexesOptions extends Omit<CommandOperationOptions, 'writeConcern'> {
   /** Creates the index in the background, yielding whenever possible. */
   background?: boolean;
   /** Creates an unique index. */
@@ -382,20 +382,28 @@ export class DropIndexesOperation extends DropIndexOperation {
 }
 
 /** @public */
-export interface ListIndexesOptions extends CommandOperationOptions {
+export interface ListIndexesOptions extends Omit<CommandOperationOptions, 'writeConcern'> {
   /** The batchSize for the returned command cursor or if pre 2.8 the systems batch collection */
   batchSize?: number;
 }
 
 /** @internal */
 export class ListIndexesOperation extends CommandOperation<Document> {
-  override options: ListIndexesOptions;
+  /**
+   * @remarks WriteConcern can still be present on the options because
+   * we inherit options from the client/db/collection.  The
+   * key must be present on the options in order to delete it.
+   * This allows typescript to delete the key but will
+   * not allow a writeConcern to be assigned as a property on options.
+   */
+  override options: ListIndexesOptions & { writeConcern?: never };
   collectionNamespace: MongoDBNamespace;
 
   constructor(collection: Collection, options?: ListIndexesOptions) {
     super(collection, options);
 
-    this.options = options ?? {};
+    this.options = { ...options };
+    delete this.options.writeConcern;
     this.collectionNamespace = collection.s.namespace;
   }
 

src/operations/list_collections.ts

@@ -7,7 +7,7 @@ import { CommandOperation, CommandOperationOptions } from './command';
 import { Aspect, defineAspects } from './operation';
 
 /** @public */
-export interface ListCollectionsOptions extends CommandOperationOptions {
+export interface ListCollectionsOptions extends Omit<CommandOperationOptions, 'writeConcern'> {
   /** Since 4.0: If true, will only return the collection name in the response, and will omit additional info */
   nameOnly?: boolean;
   /** Since 4.0: If true and nameOnly is true, allows a user without the required privilege (i.e. listCollections action on the database) to run the command when access control is enforced. */
@@ -18,7 +18,14 @@ export interface ListCollectionsOptions extends CommandOperationOptions {
 
 /** @internal */
 export class ListCollectionsOperation extends CommandOperation<string[]> {
-  override options: ListCollectionsOptions;
+  /**
+   * @remarks WriteConcern can still be present on the options because
+   * we inherit options from the client/db/collection.  The
+   * key must be present on the options in order to delete it.
+   * This allows typescript to delete the key but will
+   * not allow a writeConcern to be assigned as a property on options.
+   */
+  override options: ListCollectionsOptions & { writeConcern?: never };
   db: Db;
   filter: Document;
   nameOnly: boolean;
@@ -28,7 +35,8 @@ export class ListCollectionsOperation extends CommandOperation<string[]> {
   constructor(db: Db, filter: Document, options?: ListCollectionsOptions) {
     super(db, options);
 
-    this.options = options ?? {};
+    this.options = { ...options };
+    delete this.options.writeConcern;
     this.db = db;
     this.filter = filter;
     this.nameOnly = !!this.options.nameOnly;