include_association with array parameter overwrites existing values

[dmolesUC]

Given either of the following:

amoeba do
  include_association :foo
  include_association :bar
  include_association :baz
end

amoeba do
  include_association [:foo, :bar, :baz]
end

@config[:includes] takes the value [:foo, :bar, :baz].

Given this form:

amoeba do
  include_association :foo
  include_association [:bar, :baz]
end

I would expect the same result, but instead the initial [:foo] gets overridden and the final value of@config[:includes] is just [:bar, :baz].

This is counterintuitive, to say the least.

(Not that you'd normally need to do this in the same file, but. We ran into it with an app that monkey-patches additional associations into a rails engine model. Including the app associations was clobbering the inclusion of the original engine associations.)

[dmolesUC]

A reasonably terse workaround:

amoeba do
  include_association :foo
  [:bar, :baz].each { |a| include_association a }
end

[dmolesUC]

I assume this is also an issue for exclude_association and for clone, given they all use push_value_to_array.

[davidguthu]

This is actually noted in the documentation as intended the way the DSL behaves.

[dmolesUC]

It's not at all obvious from the documentation that “original values” in

If you pass an array, your array will overwrite the original values

includes any previous calls to include_association, and even if documented, it's not at all obvious that such behavior is desirable.

[davidguthu]

I suppose the author came across a situation where he wanted to override prior settings without having to go through multiple singular calls to exclude_association? Agreed it's not the most intuitive.

[dmolesUC]

It's a long story, but the model is defined in one engine, then monkey-patched in another to add a bunch more relations, some of which need to be amoeba-duplicated.

[davidguthu]

Sounds like fun =P Did you end up using this gem despite the issues you had?

[dmolesUC]

A barrel of laughs. :) Yes, we used the [...].each { |a| include_association a } workaround I mentioned above.

[mattmenefee]

Pull request #67 added #include_associations and #exclude_associations (note that they're both plural) which seem to intend to be used when multiple associations are to be included or excluded. These new methods aren't documented in the Readme, but using them instead fixed the issue for me.