Validation that either email/sns topic is presented, with threshold

[EreminAnton]

No description provided.

[EreminAnton]

We can use this example for variables validations:
locals {
is_sns_or_email_set = length(var.cost_anomaly_detection_subscriber_sns_topic_arns) > 0 || length(var.cost_anomaly_detection_subscriber_email_addresses) > 0
is_threshold_set = var.cost_anomaly_detection_threshold != null
should_create = var.create_cost_anomaly_detection_alert

validate_condition = local.should_create && (!local.is_sns_or_email_set || !local.is_threshold_set)
validation_message = "If create_cost_anomaly_detection_alert is set to true, either SNS or email must be set, and the threshold must be non-null."

validate_check = regex(
"^${local.validation_message}$",
( !local.validate_condition
? local.validation_message
: "" ) )
}