In the client’s codebase I found a length validation for presence (minimum: 1) of an object connected via an association. Usually the length association is used for something like minimum amount of characters of a username or a password. Validation

:minimum - The attribute cannot have less than the specified length.

:maximum - The attribute cannot have more than the specified length.

:in (or :within) - The attribute length must be included in a given interval. The value for this option must be a range.

:is - The attribute length must be equal to the given value.

The validation looks like this validates :ice_cream_flavors, length: {minimum: 3} validates :username, lenghth: {minimum: 8}

The key in the i18n file will be too_short (or too_long), in case we want to overwrite the error message.

rails repo

I see why finding the too_short on its own confused me, ans I rather expected a presence: true type of validation.

Still from the docs

when :minimum is 1 you should provide a custom message or use presence: true instead

Still, it seems like scratching the side of your face with the opposite hand. :) But at least now I understand why it was written this way.