Protocol: pre-execution errors with mutations / queries.

[nrbnlulu]

The protocol states that Error message should be sent when

This can occur before execution starts, usually due to validation errors, or during the execution of the request.

Does it applies for mutation / queries as well?
Because the protocol also states that

Server dispatches the result with the Next message

[enisdenjo]

Yes, it applies to any operation type. Validation happens on all requests.