When running tests with molecule:
molecule tests
and some files are protected with ansible vault, the --vault-password-file must be specified to provide the password to decrypt their content.
Although it is possible to do that with converge
 molecule converge -- --vault-password-file ~/.vault.txt
it fails with molecule tests
 $ molecule test -- --vault-password-file ~/.vault.txt
 Usage: molecule test [OPTIONS]
 Error: Got unexpected extra arguments (--vault-password-file ~/.vault.txt)