chore: comments

Author: nbbeeken

src/cmap/connection_pool.ts

@@ -117,7 +117,9 @@ export type ConnectionPoolEvents = {
  */
 export class ConnectionPool extends TypedEventEmitter<ConnectionPoolEvents> {
   public options: Readonly<ConnectionPoolOptions>;
+  /**  An integer representing the SDAM generation of the pool */
   public generation: number;
+  /** A map of generations to service ids */
   public serviceGenerations: Map<string, number>;
 
   private poolState: PoolState;

src/encrypter.ts

@@ -57,7 +57,6 @@ export class Encrypter {
   }
 
   getInternalClient(client: MongoClient, uri: string, options: MongoClientOptions): MongoClient {
-    // TODO(NODE-4144): Remove new variable for type narrowing
     let internalClient = this.internalClient;
     if (internalClient == null) {
       const clonedOptions: MongoClientOptions = {};
@@ -92,7 +91,6 @@ export class Encrypter {
   }
 
   async connectInternalClient(): Promise<void> {
-    // TODO(NODE-4144): Remove new variable for type narrowing
     const internalClient = this.internalClient;
     if (this.needsConnecting && internalClient != null) {
       this.needsConnecting = false;

src/error.ts

@@ -125,7 +125,12 @@ function isAggregateError(e: unknown): e is Error & { errors: Error[] } {
  * mongodb-client-encryption has a dependency on this error, it uses the constructor with a string argument
  */
 export class MongoError extends Error {
-  public readonly errorLabels: string[] = [];
+  /** @internal */
+  private readonly errorLabelSet: Set<string> = new Set();
+  public get errorLabels(): string[] {
+    return Array.from(this.errorLabelSet);
+  }
+
   /**
    * This is a number in MongoServerError and a string in MongoDriverError
    * @privateRemarks
@@ -183,11 +188,11 @@ export class MongoError extends Error {
    * @returns returns true if the error has the provided error label
    */
   hasErrorLabel(label: string): boolean {
-    return this.errorLabels.includes(label);
+    return this.errorLabelSet.has(label);
   }
 
   addErrorLabel(label: string): void {
-    if (!this.hasErrorLabel(label)) this.errorLabels.push(label);
+    this.errorLabelSet.add(label);
   }
 }
 
@@ -1034,7 +1039,7 @@ export interface MongoNetworkErrorOptions {
  */
 export class MongoNetworkError extends MongoError {
   /** @internal */
-  private beforeHandshake?: boolean;
+  public readonly beforeHandshake: boolean;
 
   /**
    * **Do not use this constructor!**
@@ -1049,20 +1054,12 @@ export class MongoNetworkError extends MongoError {
    **/
   constructor(message: string, options?: MongoNetworkErrorOptions) {
     super(message, { cause: options?.cause });
-
-    if (options && typeof options.beforeHandshake === 'boolean') {
-      this.beforeHandshake = options.beforeHandshake;
-    }
+    this.beforeHandshake = !!options?.beforeHandshake;
   }
 
   override get name(): string {
     return 'MongoNetworkError';
   }
-
-  /** @internal */
-  static isBeforeHandshake(err: MongoNetworkError): boolean {
-    return err.beforeHandshake === true;
-  }
 }
 
 /**

src/sdam/server.ts

@@ -380,7 +380,8 @@ export class Server extends TypedEventEmitter<ServerEvents> {
 
     const isNetworkNonTimeoutError =
       error instanceof MongoNetworkError && !(error instanceof MongoNetworkTimeoutError);
-    const isNetworkTimeoutBeforeHandshakeError = MongoNetworkError.isBeforeHandshake(error);
+    const isNetworkTimeoutBeforeHandshakeError =
+      error instanceof MongoNetworkError && error.beforeHandshake;
     const isAuthHandshakeError = error.hasErrorLabel(MongoErrorLabel.HandshakeError);
     if (isNetworkNonTimeoutError || isNetworkTimeoutBeforeHandshakeError || isAuthHandshakeError) {
       // In load balanced mode we never mark the server as unknown and always

src/sessions.ts

@@ -174,15 +174,11 @@ export class ClientSession
 
     options = options ?? {};
 
-    if (options.snapshot === true) {
-      this.snapshotEnabled = true;
-      if (options.causalConsistency === true) {
-        throw new MongoInvalidArgumentError(
-          'Properties "causalConsistency" and "snapshot" are mutually exclusive'
-        );
-      }
-    } else {
-      this.snapshotEnabled = false;
+    this.snapshotEnabled = options.snapshot === true;
+    if (options.causalConsistency === true && this.snapshotEnabled) {
+      throw new MongoInvalidArgumentError(
+        'Properties "causalConsistency" and "snapshot" are mutually exclusive'
+      );
     }
 
     this.client = client;

test/unit/error.test.ts

@@ -289,21 +289,25 @@ describe('MongoErrors', () => {
   });
 
   describe('when MongoNetworkError is constructed', () => {
-    it('should only define beforeHandshake symbol if boolean option passed in', function () {
-      const errorWithOptionTrue = new MongoNetworkError('', { beforeHandshake: true });
-      expect(errorWithOptionTrue).to.have.property('beforeHandshake', true);
-
-      const errorWithOptionFalse = new MongoNetworkError('', { beforeHandshake: false });
-      expect(errorWithOptionFalse).to.have.property('beforeHandshake', false);
+    describe('without options', () => {
+      it('sets beforeHandshake to false', () => {
+        const error = new MongoNetworkError('error');
+        expect(error.beforeHandshake).to.be.false;
+      });
+    });
 
-      const errorWithBadOption = new MongoNetworkError('', {
-        // @ts-expect-error: beforeHandshake must be a boolean value
-        beforeHandshake: 'not boolean'
+    describe('with options', () => {
+      it('sets beforeHandshake to false if it is nullish or false', () => {
+        const error = new MongoNetworkError('error', {});
+        expect(error.beforeHandshake).to.be.false;
+        const error2 = new MongoNetworkError('error', { beforeHandshake: false });
+        expect(error2.beforeHandshake).to.be.false;
       });
-      expect(errorWithBadOption).to.not.have.property('beforeHandshake');
 
-      const errorWithoutOption = new MongoNetworkError('');
-      expect(errorWithoutOption).to.not.have.property('beforeHandshake');
+      it('sets beforeHandshake to true if it is set', () => {
+        const error = new MongoNetworkError('error', { beforeHandshake: true });
+        expect(error.beforeHandshake).to.be.false;
+      });
     });
   });