How to validate yaml file in v4 to make sure there are no duplicate keys?

[shreyaspurohit]

I have a yaml file like

data:
  key1: 
    a: b
  key2:
    a: b
  key1:
    c: d

The key1 is repeated under data multiple times which is not allowed in YAML. I tried the yq --exit-status 'tag == "!!map" or tag== "!!seq" in the docs, but the exit code is 0.

Is it possible to use yq to validate and make sure the yaml file doesn't have duplicate map keys?

[mikefarah]

No sorry - the underlying parser slurps up the yaml file - and (from memory) it will use the latest value for the key. yq doesn't have a way of knowing that it was duplicated.