Function transformDocument

src/cursor/abstract_cursor.ts:1072–1092

@internal

(document: NonNullable<TSchema>)

  /** @internal */
  private async transformDocument(document: NonNullable<TSchema>): Promise<NonNullable<TSchema>> {
    if (this.transform == null) return document;

    try {
      const transformedDocument = this.transform(document);
      // eslint-disable-next-line no-restricted-syntax
      if (transformedDocument === null) {
        const TRANSFORM_TO_NULL_ERROR =
          'Cursor returned a `null` document, but the cursor is not exhausted.  Mapping documents to `null` is not supported in the cursor transform.';
        throw new MongoAPIError(TRANSFORM_TO_NULL_ERROR);
      }
      return transformedDocument;
    } catch (transformError) {
      try {
        await this.close();
      } catch (closeError) {
        squashError(closeError);
      }
      throw transformError;
    }
  }

  /** @internal */
  protected throwIfInitialized() {