ArgoCD Application silently ignores when duplicate helm values are used for the same helm chart in the same Argo App

[jayganesh-asu]

Easy to reproduce: Deploy any Argo App with duplicate helm values, however, it didn't report any SyncError or ComparisonError when syncing.

Observation: Argo App was synced and healthy when having repetition or duplicate helm values with different valid configurations.
Seems like it was silently ignored, shouldn't helm lint under the hood have reported error for duplication? We are using Helm 3.

Below is sample:

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: sample-argo-app
  namespace: argocd
spec:
  source:
    targetRevision: 1.2.3
    helm:
      values: |
        someValueA:
          someSubValueA:
            enabled: false
        someValueA:
          someSubValueB:
            enabled: true

NOTE: Argo App was marked as synced and healthy even upon resyncing. I could see the latest commit it was pointing to, which was correct, but this error would have been reported on the ArgoCD UI or argocd-application-controller or ArgoCD App CustomResource` itself, right?

Version: ArgoCD v2.9.6

[ChristianCiach]

shouldn't helm lint under the hood have reported error for duplication?

No, helm lint will never see the duplicated key. Any duplicated keys are lost after Argo-CD parses the string using json.Unmarshal.

See

• encoding/json: unmarshal accepts duplicate keys golang/go#24415

[jayganesh-asu]

Thanks @ChristianCiach so much for the response.

One sanity check: So, if I were to use valuesObject instead values, will it report error for duplication then as those are not treated as strings, rather structured objects?