Feature request:
add an option to pass custom values file for helm, for example:

--helm-values-file custom.yaml

Right now using --helm-extra-args unfortunately is also passed to helm test command so adding --values custom.yaml ends with error because it renders helm test .... --values custom.yaml which returns error because -values is unknown option for helm test.

This means that --helm-extra-args is actually limited to common helm parameters.