OPA | Conftest incorrect parse yaml file

Question

ResourceQuota object definition involves limits keys with dots and there is issue to get the value of the limits:

policy.rego

package main

deny_incorrect_memory_unit[msg] {
  input.kind == "ResourceQuota"
  memoryLimit := input.spec.hard.limits.memory

  not regex.match("^[0-9]+M$", memoryLimit)
  msg := sprintf("%s: Incorrect value %s. Memory Limit in ResourceQuota must be defined in Megabytes (M) unit", [input.metadata.namespace, memoryLimit])
}

resource-quota.yaml

apiVersion: v1
kind: ResourceQuota
metadata:
  name: app
  namespace: backend
spec:
  hard:
    pods: 1
    limits.cpu: 3
    limits.memory: "1G"

In above example test finishes with success, despite of wrong unit in limits.memory After replacing yaml file to the below structure (which are not supported by k8s) test finish with expected result - failure:

spec:
  hard:
    pods: 1
    limits:
        cpu: 3
        memory: "1G"