private async doPoll()

in packages/@aws-cdk/toolkit-lib/lib/api/stack-events/stack-event-poller.ts [97:158]
48 lines of code
17 McCabe index (conditional complexity)

  private async doPoll(): Promise<ResourceEvent[]> {
    const events: ResourceEvent[] = [];
    try {
      let nextToken: string | undefined;
      let finished = false;

      while (!finished) {
        const page = await this.cfn.describeStackEvents({ StackName: this.props.stackName, NextToken: nextToken });
        for (const event of page?.StackEvents ?? []) {
          // Event from before we were interested in 'em
          if (this.props.startTime !== undefined && event.Timestamp!.valueOf() < this.props.startTime) {
            return events;
          }

          // Already seen this one
          if (this.eventIds.has(event.EventId!)) {
            return events;
          }
          this.eventIds.add(event.EventId!);

          // The events for the stack itself are also included next to events about resources; we can test for them in this way.
          const isParentStackEvent = event.PhysicalResourceId === event.StackId;

          if (isParentStackEvent && this.props.stackStatuses?.includes(event.ResourceStatus ?? '')) {
            return events;
          }

          // Fresh event
          const resEvent: ResourceEvent = {
            event: event,
            parentStackLogicalIds: this.props.parentStackLogicalIds ?? [],
            isStackEvent: isParentStackEvent,
          };
          events.push(resEvent);

          if (
            !isParentStackEvent &&
              event.ResourceType === 'AWS::CloudFormation::Stack' &&
              isStackBeginOperationState(event.ResourceStatus)
          ) {
            // If the event is not for `this` stack and has a physical resource Id, recursively call for events in the nested stack
            this.trackNestedStack(event, [...(this.props.parentStackLogicalIds ?? []), event.LogicalResourceId ?? '']);
          }

          if (isParentStackEvent && isStackTerminalState(event.ResourceStatus)) {
            this.complete = true;
          }
        }

        nextToken = page?.NextToken;
        if (nextToken === undefined) {
          finished = true;
        }
      }
    } catch (e: any) {
      if (!(e.name === 'ValidationError' && formatErrorMessage(e) === `Stack [${this.props.stackName}] does not exist`)) {
        throw e;
      }
    }

    return events;
  }