* provider/aws: test empty plan with sns_topic policy with random order
If we setup a sns_topic policy with a policy with a different order
to the one set by the AWS API, terraform plan will be not empty between
runs.
* provider/aws: normalize json policy for sns topic
For the policy attribute of the resource aws_sns_topic, AWS returns the policy
in JSON format with the fields in a different order.
If we store and compare the values without normalizing, terraform
will unnecesary trigger and update of the resource.
To avoid that, we must add a normalization function in the StateFunc of
the policy attribute and also when we read the attribute from AWS.
throw an error:
* aws_sns_topic_subscription.checker: NotFound: Subscription does not
* exist
status code: 404, request id: b8ca0c27-1a62-57b3-8b96-43038a0ead86
Terraform wasn't refreshing the state when the topic gave a 404
Hector Rivas Gandara