Zeroes in decimal columns erroneously showing up in changeset

[dwwoelfel]

If I have a column with a zero value and I update that decimal column to zero again, paper trail creates a new version with changeset [0.0 => 0.0]

Example:

> m = MyModel.create(:my_decimal_column => 0)
> m.versions.last.changeset
=> {}
> m.update_attributes(:my_decimal_column => 0)
> m.versions.last.changeset
=> {"my_decimal_column"=>[0.0, 0.0]}

[rubennorte]

I'm watching the same behaviour in my code.

[batter]

I believe this is directly related to the serialization issue raised by pull #180, and I'm going to try to merge that in before the next release.

[TylerRick]

IIRC, ActiveRecord's type_cast code is separate from full-blown serializers, so #180 may not fix this, but maybe...

[batter]

Any chance one of you guys could provide a failing test? I attempted to write a failing test for this use case but wasn't able to do it.

[batter]

@dwwoelfel, @rubennorte - What version of rails were you using when you encountered this problem? I believe this issue has been fixed by a change in rails now. If you attempt to call update_attributes on a column, and values are passed in that are no different from what is currently stored on the model, then true gets returned, but a call to the database is not made.

I haven't done a complete thorough investigation, but I believe this change in behavior exists in rails >= 3.0. I tried to reproduce this issue using rails 3.0.2 and was unable to do so. This would lead me to believe that this bug shouldn't be encountered with PaperTrail >= 2.0.0, because those versions have a dependency on rails >= 3.

[batter]

Did some further investigation, with thanks to @TylerRick, looks like this issue should be addressed by ActiveRecord's TypeCasting code. This can be seen in ActiveRecord::ConnectionAdapters::Column. Unless someone can provide a failing test, it appears this one can be closed.

[kevintraver]

I just noticed this issue still exists. Specifically when using quotes:

> model.update_attributes(:my_decimal_column => '0.0')
> model.versions.last.changeset
=> { "my_decimal_column" => [0.0, 0.0] }

[batter]

@kevintraver - What versions of ActiveRecord and PaperTrail are you using?

[kevintraver]

paper_trail - 3.0.6
activerecord - 3.2.13

[batter]

@kevintraver - Looks like this may be expected behavior, see rails/rails#17537. At any rate, I'm fairly certain this is not an issue of PaperTrail doing something wrong.

[kevintraver]

Ok, thanks