test: validate relationships after action changes

[rapidfsub]

Didn't fix the bug.
I just wrote a simple failing test.

In create_with_default_comment action, I am setting default value of comment text attribute.
However, because of the order of validations, this form cannot be submitted.

[zachdaniel]

The fix for this is complex. The way that forms provide intelligent errors up front is by "pre-validating" the inputs. If you want to handle that error you're going to need to add an error_handler, or when submitting use force?: true to force submission even though a child form is invalid.

[rapidfsub]

generated?: true option can be a workaround for this? @zachdaniel

[zachdaniel]

On the destination action (of the related resource), you could add allow_nil_input [:the, :action], would potentially be one way to solve it.