Pulumi unable to serialize non-integers(?)

[chrsmith]

I'm seeing the following behavior: Pulumi is applying integer rounding before updating resources.

Repro. (I assume the AWS component isn't required.)

const alarmArgs: aws.cloudwatch.MetricAlarmArgs = {
    name: "bug repro",
    alarmDescription: "",
    actionsEnabled: true,
    alarmActions: [],
    namespace: "AWS/ApplicationELB",
    metricName: "TargetResponseTime",
    dimensions: {
        "TargetGroup": "NA",
        "LoadBalancer": "NA",
    },
    statistic: "Average",
    evaluateLowSampleCountPercentiles: undefined,
    treatMissingData: "ignore",
    comparisonOperator: "GreaterThanThreshold",
    evaluationPeriods: 1,
    period: 60,

    // I really need this to be a floating point value.
    threshold: 2.9,
};

let tooHighLatencyAlarm = new aws.cloudwatch.MetricAlarm(
    "bug-repro", alarmArgs,
    undefined, []);

If you set alarmArgs.threshold to be any non-integer, the Pulumi update creates/updates the resource with the integer value.

e.g. the diff looks like:

setting threshold to 0.5, created with value 0.

setting threshold to 1.1

        statistic         : "Average"
      - threshold         : 0
      + threshold         : 1
        treatMissingData  : "ignore"

setting threshold to 2.9

        statistic         : "Average"
      - threshold         : 1
      + threshold         : 2
        treatMissingData  : "ignore"