ruby - Calling save on a destroyed object returns true, but doesn't save -

getting weird behavior when trying save mongoid object has been destroyed. given class definition:

class foo   include mongoid::document end 

after saving instance, deleting it, unable save again:

foo.count # => 0 f = foo.create # => #<foo _id: 522744a78d46b9b09f000001, > foo.count # => 1 f.destroy # => true foo.count # => 0 f.save # => true # lied - didn't save: foo.count # => 0 # these may relevant: f.persisted? # => false f.destroyed? # => true f.new_record? # => false f.changed? # => false 

here's failing rspec test expect pass:

describe foo   'should allow saving foo instance after destroying it'     expect(foo.count).to eq(0)     f = foo.create     expect(foo.count).to eq(1)     foo.all.destroy     expect(foo.count).to eq(0)     f.save # => true     expect(foo.count).to eq(1) # error - returns 0   end end 

is expected behavior? use case using singleton object (didn't want make question more complicated mentioning though); foo.instance returns same object destroyed foo.all.destroy gumming things.

model#save

saves changed attributes database atomically, or insert document if new. raise error of validations fail.

after destruction, document not new , there no attributes have changed, save returns without errors. in strict sense seems expected behavior.

you use model#upsert:

performs mongodb upsert on document. if document exists in database, overwritten current attributes of document in memory. if document not exist in database, inserted.

this save document using same id, still frozen? , marked destroyed?. therefore might better clone document suggested insane-36 in comments.