Using both a validator and asRequired on a combo box results in the asRequired flag supressing validation errors

[brp-benjamin]

Binding a combo box with a custom validator as well as making the field required will surpress validation errors from the custom validator.

An implementation that demonstrates this can be found at:
https://github.com/brp-benjamin/skeleton-starter-flow/tree/combobox-validator-and-required-error

See the following screenshot as a demonstration of the error

[denis-anisimov]

Thanks a lot for exact steps to reproduce.

This is a bug.
asRequired uses setRequiredIndicatorVisible method which by default sets required property.
This property enables the client side validation which is inconsistent with the server side validation.
TextField has a special code which turns off the client side validation in case setRequiredIndicatorVisible is called.
And the contract of setRequiredIndicatorVisible explicitly mentions that this method should disable the client side validation.