The javascript file handling a form's mandatory fields validation (whether it is a normal form or a "basic" form), "form-validation.js", is located in the forms_basic module, whereas mandatory fields can be used in both normal and basic forms. So, if the forms_basic plugin & module are not included in a project, the fields are not validated anymore.

Moreover, the principle of double validation (JS at submit-time + server validation when the request is received) is not so intuitive :

• In the case of a basic form, even if the user doesn't have JS activated, the validation is automatically realized by the server
• In the case of a "normal" form, if the user has JS activated, the form is checked by the JS and the request is not sent until all mandatory fields are filled in. If the user doesn't have JS activated, the request is sent to the specified server, who must validate the mandatory parameters itself. I think it should at least be mentioned in a doc, or readme.