Function cursorInit

src/cursor/abstract_cursor.ts:904–937

* @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.

()

   * a significant refactor.
   */
  private async cursorInit(): Promise<void> {
    if (this.cursorOptions.timeoutMS != null) {
      this.timeoutContext ??= new CursorTimeoutContext(
        TimeoutContext.create({
          serverSelectionTimeoutMS: this.client.s.options.serverSelectionTimeoutMS,
          timeoutMS: this.cursorOptions.timeoutMS
        }),
        this
      );
    }
    try {
      this.cursorSession ??= this.cursorClient.startSession({ owner: this, explicit: false });
      const state = await this._initialize(this.cursorSession);
      // Set omitMaxTimeMS to the value needed for subsequent getMore calls
      this.cursorOptions.omitMaxTimeMS = this.cursorOptions.timeoutMS != null;
      const response = state.response;
      this.selectedServer = state.server;
      this.cursorId = response.id;
      this.cursorNamespace = response.ns ?? this.namespace;
      this.documents = response;
      this.initialized = true; // the cursor is now initialized, even if it is dead
    } catch (error) {
      // the cursor is now initialized, even if an error occurred
      this.initialized = true;
      await this.cleanup(undefined, error);
      throw error;
    }

    if (this.isDead) {
      await this.cleanup();
    }

    return;
  }

  /** @internal Attempt to obtain more documents */
  private async fetchBatch(): Promise<void> {