Rails - May 2013 - validates :uniqueness apparently doesn't

ruby 2.0.0p0 (2013-02-24 revision 39474) [x86_64-darwin12.3.0]
Rails 3.2.13

I have a validates ... :uniqueness constraint on one of the attributes
of an ActiveRecord class.

In my test suite, I set the attribute from the same attribute in a
record in the fixture. I then send invalid? to the object under test.
invalid? returns _false_, and the .errors object for the record shows no
errors.

A :uniqueness constraint on another attribute does invalidate the
record. All validations on other attributes behave as expected.

I''ve done what I could to search the Rails docs, Google, Stack
Overflow,
and this forum for similar problems, and found nothing.

What''s wrong?

====
All code is excerpted.

Fixture:

active_1:
  name: Thomas Jefferson
  tracking_code: tj_001_TC01
...

Class declaration:

class Family < ActiveRecord::Base
  attr_accessible ... :tracking_code
  validates :tracking_code, :presence => true, :length => { :maximum =>
20, :minimum => 8 }, :uniqueness => true

Test case:

  setup do
    @copy = families(:active_1).dup
    attrs = { :tracking_code => "copy01_ext", ... }
    @copy.attributes = attrs
  end

  test "validate tracking" do
    @copy.tracking_code = nil
    assert @copy.invalid?, "Nil tracking code is illegal."
    # Assertion does not fire.

    @copy.tracking_code = families(:active_1).tracking_code
    assert @copy.tracking_code == families(:active_1).tracking_code
    @copy.save  # Not sending "save" has no effect on the apparent bug
    is_invalid = @copy.invalid?
    assert is_invalid, "Duplicate tracking code should be invalid."
    # Assertion fires
    ...

====
-- 
Posted via http://www.ruby-forum.com/.

-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
For more options, visit https://groups.google.com/groups/opt_out.

Fritz Anderson wrote in post #1108098:
> ruby 2.0.0p0 (2013-02-24 revision 39474) [x86_64-darwin12.3.0]
> Rails 3.2.13
>
> I have a validates ... :uniqueness constraint on one of the attributes
> of an ActiveRecord class.
>
> In my test suite, I set the attribute from the same attribute in a
> record in the fixture. I then send invalid? to the object under test.
> invalid? returns _false_, and the .errors object for the record shows no
> errors.
>
> A :uniqueness constraint on another attribute does invalidate the
> record. All validations on other attributes behave as expected.
>
> I''ve done what I could to search the Rails docs, Google, Stack
Overflow,
> and this forum for similar problems, and found nothing.
>
> What''s wrong?
I didn''t take the time to dig through your test code thoroughly, but 
there are a few things you need to know about uniqueness validation on 
ActiveRecord? The primary issue is that uniqueness is not guaranteed. 
AFAIK there still exists a race condition that could cause duplicates to 
be allowed in the database. This is especially true when there are 
multiple instances of an app running. Or when records can be added 
outside of the application.

Again, AFAIK the ONLY way to guarantee uniqueness is by using a unique 
index on the column at the database level. Validation login in an ORM 
(like ActiveRecord IS NOT  sufficient). It is convenient to have because 
it''s easier to recover from a uniqueness violation, but it does not 
remove the necessity of having the unique constraint in the database.

A basic explanation of this can be found here:
http://guides.rubyonrails.org/active_record_validations_callbacks.html#uniqueness

I have a strong suspicion that your issue is related to this limitation.

-- 
Posted via http://www.ruby-forum.com/.

-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
For more options, visit https://groups.google.com/groups/opt_out.

On Tue, May 7, 2013 at 1:37 PM, Robert Walker
<lists-fsXkhYbjdPsEEoCn2XhGlw@public.gmane.org>
wrote:
> Fritz Anderson wrote in post #1108098:
>> ruby 2.0.0p0 (2013-02-24 revision 39474) [x86_64-darwin12.3.0]
>> Rails 3.2.13
>>
>> I have a validates ... :uniqueness constraint on one of the attributes
>> of an ActiveRecord class.
>>
>> In my test suite, I set the attribute from the same attribute in a
>> record in the fixture. I then send invalid? to the object under test.
>> invalid? returns _false_, and the .errors object for the record shows
no
>> errors.
>>
>> A :uniqueness constraint on another attribute does invalidate the
>> record. All validations on other attributes behave as expected.
>>
>> I''ve done what I could to search the Rails docs, Google, Stack
Overflow,
>> and this forum for similar problems, and found nothing.
>>
>> What''s wrong?
>
> I didn''t take the time to dig through your test code thoroughly,
but
> there are a few things you need to know about uniqueness validation on
> ActiveRecord? The primary issue is that uniqueness is not guaranteed.
> AFAIK there still exists a race condition that could cause duplicates to
> be allowed in the database. This is especially true when there are
> multiple instances of an app running. Or when records can be added
> outside of the application.
>
> Again, AFAIK the ONLY way to guarantee uniqueness is by using a unique
> index on the column at the database level. Validation login in an ORM
> (like ActiveRecord IS NOT  sufficient). It is convenient to have because
> it''s easier to recover from a uniqueness violation, but it does
not
> remove the necessity of having the unique constraint in the database.
>
> A basic explanation of this can be found here:
>
http://guides.rubyonrails.org/active_record_validations_callbacks.html#uniqueness
>
> I have a strong suspicion that your issue is related to this limitation.
>
In addition to the race condition Robert mentions, is that under test,
your database excursions might very well be wrapped in transactions
and not yet committed to the database. I suggest watching the log and
see if things are committed; unit tests generally should not rely on
the database to perform as such. Testing these sorts of things is more
an integration test where you are testing full paths back and forth.

-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
For more options, visit https://groups.google.com/groups/opt_out.

On Tuesday, May 7, 2013 4:12:21 PM UTC+1, Ruby-Forum.com User
wrote:
>
> ruby 2.0.0p0 (2013-02-24 revision 39474) [x86_64-darwin12.3.0] 
> Rails 3.2.13 
>
> I have a validates ... :uniqueness constraint on one of the attributes 
> of an ActiveRecord class. 
>
> In my test suite, I set the attribute from the same attribute in a 
> record in the fixture. I then send invalid? to the object under test. 
> invalid? returns _false_, and the .errors object for the record shows no 
> errors. 
>
> A :uniqueness constraint on another attribute does invalidate the 
> record. All validations on other attributes behave as expected. 
>
> I''ve done what I could to search the Rails docs, Google, Stack
Overflow,
> and this forum for similar problems, and found nothing. 
>
> What''s wrong? 
>
>
The object you''re trying to edit/save is still pointing to the same row
in
the database - it''s trying to update the existing row, not create a new
row
with the same tracking code

Fred
>
>
-- 
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To view this discussion on the web visit
https://groups.google.com/d/msg/rubyonrails-talk/-/GgdPE8DZM7sJ.
For more options, visit https://groups.google.com/groups/opt_out.