Backtracking association proxy chained methods

Maybe you'd like to test if the patch in #1960 Make named_scopes remember the current scope when defined fixes this problem? Haven't had the time to test your diff there.

Thanks for the suggestion Diego, but when I apply your patch, my test attached above still fails, and a new test fails ( test_named_scope(DefaultScopingTest) ).

I don't think the issue I'm dealing with has is specific to named scopes but instead to associations proxies in general.

In fact, the same problem occurs with named scopes and class methods, but it's the basically the inverse of #1960 Make named_scopes remember the current scope when defined (I thought they were dups at first, sorry for the confusion). Class methods called through association proxies and named scopes are both evaluated within the context of a with_scope. Adding

named_scope :having_author_id, lambda { |author_id| {:conditions => ['`categorizations`.author_id = ?', author_id]} }

to Categorization and then doing

count_without_class_method = authors(:david).categorizations.find(:all).select {|cz| cz.category.categorizations.size > 1 }.size
    count_with_class_method = Categorization.having_author_id(authors(:david).id).that_have_siblings_with_common_category_parent.size
    assert_equal(count_without_class_method,count_with_class_method)

gives the same result as accessing it through the association_collection.

Either way, to get the result you want, just put the cz.category.categorizations.size within an exclusive scope:

def that_have_siblings_with_common_category_parent
  find(:all).select {|cz| with_exclusive_scope {cz.category.categorizations.size > 1} }
end

With this, the test passes.

Thanks Ryan, that's good to know. But I wonder if that should be considered the "correct" way to do that, or is that a hack/workaround/band-aid? I'm inclined to think it's a hack and we'd be better off solving the underlying problem (though, I don't know what that would be, yet). However, I'd rather be proven wrong before I waste any time trying to "fix" something that nobody else wants fixed. ;-)