isRequired validation doesn't allow "falsy" values

[petr-egert]

The documentation for isRequired states

Checks if the value is present

The current implementation however does not only check if the value is present, but also checks if the value is truthy

validarium/packages/validations/src/isRequired.js

Line 19 in 8be494a

export default ifElse(isTruthy, alwaysNull, always({ message: m.isRequired }));

This is confusing, because valid values, such as 0, are resolved as invalid. I think 0 is a perfectly reasonable value for a "required" numerical input or select box. The same applies to boolean values - the validation should force the user to "make a choice", not to "pick true"