When attempting to deploy an AutoScalingGroup, I receive the following error:

[3/4] Thu Nov 08 2018 14:44:55 GMT+1100 (Australian Eastern Daylight Time)  UPDATE_FAILED       [AWS::AutoScaling::AutoScalingGroup] AutoScalingGroupASG804C35BE Invalid Autoscaling rolling update policy: PauseTime must be in the ISO8601 time period format and must be no greater than PT3600S seconds, e.g. "PT5M30S" specifies a pause time of 5 minutes and 30 seconds.

The snippet from my code:

const asg = new autoscaling.AutoScalingGroup(this, 'AutoScalingGroup', {
            vpc,
            ..snip..
            updateType: autoscaling.UpdateType.RollingUpdate,
            rollingUpdateConfiguration: {
                waitOnResourceSignals: true,
            }
        });

Synthesising this as yaml we can see that PauseTime is set to an invalid value PT:

AutoScalingGroupASG804C35BE:
  Type: 'AWS::AutoScaling::AutoScalingGroup'
  ..snip..
  UpdatePolicy:
    AutoScalingRollingUpdate:
        WaitOnResourceSignals: false
        PauseTime: PT
        SuspendProcesses:
            - HealthCheck
            - ReplaceUnhealthy
            - AZRebalance
            - AlarmNotification
            - ScheduledActions

Looking at the definition of RollingUpdateConfiguration, it implies that it is an optional parameter, and that a sane default will be used:

/**
 * The pause time after making a change to a batch of instances.
 *
 * This is intended to give those instances time to start software applications.
 *
 * Specify PauseTime in the ISO8601 duration format (in the format
 * PT#H#M#S, where each # is the number of hours, minutes, and seconds,
 * respectively). The maximum PauseTime is one hour (PT1H).
 *
 * @default 300 if the waitOnResourceSignals property is true, otherwise 0
 */
pauseTimeSec?: number;

It seems that when I am using the waitOnResourceSignals as suggested, there is no default value being set. Based on this, I would call this issue a bug. The documentation also implies that I should be providing a formatted string, yet the types enforce a number.

Expected value in my synthesised yaml would be based on the above documentation is:

AutoScalingGroupASG804C35BE:
  Type: 'AWS::AutoScaling::AutoScalingGroup'
  ..snip..
  UpdatePolicy:
    AutoScalingRollingUpdate:
        WaitOnResourceSignals: false
        PauseTime: PT300S

Manually setting the pauseTimeSec key to 300 results in an expected yaml output: PauseTime: PT5M