A Rails 7.0 migration includes the attribute t.bigint :status_id, default: 6 Which is invoked in the model as

belongs_to :status, class_name: 'Categoryminor'

If a test is run

shop = Shop.new(name: 'apatride')
assert shop.valid?

the Unit test will complain #<ActiveModel::Errors [#<ActiveModel::Error attribute=status, type=blank, options={:message=>:required}>]> notwithstanding the schema clearly states t.bigint "status_id", default: 6 and verifying with postgresql, that default value is well defined there.

Changing the class

belongs_to :status, class_name: 'Categoryminor', optional: true

allows the test to pass, but this is somewhat non-sensical. If there is a default value, the attribute cannot be blank.

What is the reasoning going on here?

CodePudding user response：

belongs_to relations have presence validation since rails 5. Putting a random status_id is not enough. There must be a record in CategoryMinor table with the id of 6, and in the case of tests, the fixture has to be properly invoked.

Two material ways to resolve this:

• add an id value to the fixture status: id: 6
• write the test to call the fixture object without the id ` The latter is not pithier, but less prone to further complications.