Relations validate: true only runs on create

[jhaesus]

Steps to reproduce

class Parent < ApplicationRecord
  has_many :items, validate: true
end

class Item < ApplicationRecord
  belongs_to :parent
  validates :name, presence: true
end

Expected behavior

item1 = Item.new
parent1 = Parent.new
parent1.items << item1
parent1.save! => Validation error

item2 = Item.new(name: "bla")
parent2 = Parent.new
parent2.items << item2
parent2.save! => true
item2.name = nil
item2.save(validate: false)
parent2.reload.save! => true

Actual behavior

items are not validated on update

System configuration

Rails version: 5.0.0.beta3

Ruby version: 2.3.0

[tomash]

I don't think it's a bug. From what I see in the code, validate option only ensures validation when inserting new record into association:

rails/activerecord/lib/active_record/associations/has_many_association.rb

Line 41 in 52ce6ec

def insert_record(record, validate = true, raise = false)

rails/activerecord/lib/active_record/associations/has_many_through_association.rb

Line 38 in 52ce6ec

def insert_record(record, validate = true, raise = false)

If you want to ensure all associated records are revalidated on every update, you should use validates_associated. Here, I've added test cases demonstrating what you expect (and that they fail if validates_associated is not used:

tomash@b701d92

[tomash]

My personal suggestion: update the docs to reflect that validate: true causes validation only on inserting new member of association, not that it's the same as validated_associated. Current description "If false, don't validate the associated objects when saving the parent object. true by default." can lead to confusion. I can file a docs pull request if maintainers are OK with this idea?

[vipulnsward]

Even validated_associated doesn't work.

[tomash]

@vipulnsward works for the test cases I've written. Is there a case that fails?

[sgrif]

I'd be fine with changing the docs to clarify this. Even if this was considered a bug, it would be extremely difficult to change. Since validate: true is the default for collection associations, changing the behavior of that option would be a massive breaking change.