kevinthompson / rails-nested-validation-test

Sample application for nested validation testing.

Issue

It was discovered that when you have two objects that are related through a has_many relationship and the parent object accepts_nested_attributes for the child object, if any of the associated child objects are not valid, but the last associated child object is valid and it checks the validity of the parent object, the parent objects validity returns true when it should return false.

Code

class Parent < ApplicationRecord
  has_many :children
  accepts_nested_attributes_for :children
end

class Child < ApplicationRecord
  belongs_to :parent
  validates :name, presence: true
  validate -> { errors.add(:base, 'Parent is invalid') unless parent.valid? }
end

class ParentTest < ActiveSupport::TestCase
  test "invalid when nested object is invalid" do
    parent = Parent.new(children_attributes: [{}, { name: 'Second Child'}])
    assert_equal false, parent.children.first.valid?
    assert_equal false, parent.valid?
  end
end

rails-nested-validation-test (master) $ bin/rake
Running via Spring preloader in process 10560
Run options: --seed 29533

# Running:

F

Failure:
ParentTest#test_invalid_when_nested_object_is_invalid [/Users/kevinthompson/Code/rails-nested-validation-test/test/models/parent_test.rb:7]:
Expected: false
  Actual: true


bin/rails test test/models/parent_test.rb:4



Finished in 0.054285s, 18.4213 runs/s, 36.8426 assertions/s.
1 runs, 2 assertions, 1 failures, 0 errors, 0 skips

Additional Examples

irb(main):001:0> Parent.new(children_attributes: []).valid?
=> true
irb(main):002:0> Parent.new(children_attributes: [{}]).valid?
=> false
irb(main):003:0> Parent.new(children_attributes: [{}, { name: 'Second' }]).valid?
=> true
irb(main):004:0> Parent.new(children_attributes: [{ name: 'First' }, {}]).valid?
=> false
irb(main):005:0> Parent.new(children_attributes: [{ name: 'First' }, {}, { name: 'Third' }]).valid?
=> true