Stop enforcing to have a default value in ThreeStateBooleanColumn

[shouichi]

Is your feature request related to a problem? Please describe.

A not-null constraint is enough to prevent three states in a boolean column. Enforcing to have a default value feels too restrictive. Some apps might want to set values explicitly in ruby.

Describe the solution you'd like

Stop enforcing to have a default value in ThreeStateBooleanColumn.

Describe alternatives you've considered

Additional context

[koic]

This cop behavior is based on https://rails.rubystyle.guide/#three-state-boolean. If the default behavior is hard to use, please suggest it to the style guide.

If RuboCop Rails provides a new option like RequireDefaultValue: false, it is synonymous with Rails/NotNullColumn. So if you don't like it, just disable Rails/ThreeStateBooleanColumn.

[dgmora]

I've seen the discussion in rubocop/rails-style-guide#363. Would you consider not enforcing the default for create_table ?