Fix parent record should not get saved with duplicate children records

[mechanicles]

• Fixes Error does not bubble up from duplicate associated record #32940

[rails-bot]

r? @kaspth

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[Mangara]

Thanks for taking a look at this so quickly! Could you verify that the fix also works with these test cases?

many-to-many relation
many-to-many :through

[Mangara]

I'm not sure if it's worth creating new models for the test cases. Would something similar to the tests in PR #11851 work here?

[mechanicles]

Removed newly created models and used existing ones.

[eugeneius]

This changes documented behaviour:

rails/activerecord/lib/active_record/associations.rb

Lines 1338 to 1339 in 6c574ac

	# [:validate]
	# When set to +true+, validates new objects added to association when saving the parent object. +true+ by default.

Associations specified with validate: false should not prevent the parent record from being saved.

[mechanicles]

@eugeneius Thanks. I will go through it.

[mechanicles]

@eugeneius I have updated the code. Please check.

[eugeneius]

Calling association_valid? on the line above validates the record:

rails/activerecord/lib/active_record/autosave_association.rb

Line 329 in 36390b6

unless valid = record.valid?(context)

Calling insert_record also validates the record:

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

Lines 376 to 382 in 36390b6

	def insert_record(record, validate = true, raise = false, &block)
	if raise
	record.save!(validate: validate, &block)
	else
	record.save(validate: validate, &block)
	end
	end

We should pass false as the second argument to insert_record, to avoid the unnecessary second validation.

[eugeneius]

Is there any reason to switch from reflection.validate? to this?

[eugeneius]

This was fine as an elsif, no need to change it.

[eugeneius]

There's no need to remove this line ✂️

[eugeneius]

#32939 was already fixed by #32796.

[mechanicles]

@eugeneius I have updated the code. Now I have passed the second argument false to insert_method. Please check and let me know if I missed something.

[jasonperrone]

I have a question about this code. Am I seeing it right that insert_record is called with validate=false if reflection.validate? is true, and called with validate=true if reflection.validate? is false?