bug: helm-converter - legacy VMAlert values produce an invalid empty notifier and omit supported settings

Chart name and version

chart: victoria-metrics-alert
version: v0.48.0

Describe the bug

This is related to https://github.com/VictoriaMetrics/operator/issues/2398.

I reproduced this with the latest released victoria-metrics-alert chart (v0.48.0) and the current helm-converter from the Operator master branch (4797937241b23fdc9f6e31e1ecee91f2f02c9c0a).

The Helm chart still supports the legacy VMAlert keys below, as documented in https://github.com/VictoriaMetrics/helm-charts/pull/2765:

server.notifier.alertmanager -> server.notifier
server.remote.read          -> server.remoteRead
server.remote.write         -> server.remoteWrite
bearer.token                -> bearerToken

However, the following command generates a VMAlert with spec.notifier: {}:

go run ./cmd/helm-converter \
  -chart victoria-metrics-alert \
  -input reproducer-values.yaml \
  -output converted.yaml \
  -name legacy-vmalert \
  -namespace monitoring

Applying this manifest is rejected by the Operator webhook:

Error from server (Forbidden): admission webhook "vmalerts.operator.victoriametrics.com" denied the request: incorrect cr.spec.notifier syntax: notifier.url and notifier.selector cannot be empty at the same time, provide at least one setting

The source has an empty server.notifier.alertmanager.url. Helm does not configure --notifier.url for it, so the converter should omit spec.notifier instead of emitting an empty object.

The converter also silently omits these values from the same source:

- datasource bearer token
- remote.read URL and bearer token
- remote.write URL
- license.secret.name and license.secret.key

license.forceOffline is preserved under extraArgs, but the license Secret reference is missing from spec.license.

Expected behavior: the converter should translate these legacy aliases, including generated Secret references for authentication and spec.license.keyRef; or reject unsupported legacy values explicitly. It must not generate an invalid VMAlert manifest.

Attached files:
converted.yaml
reproducer-values.yaml