instances of a Join Model should have their before_destroy callbacks called when destroyed through @instance.others.clear or @instance.update_attributes

with the following setup:

class Foo < ActiveRecord::Base

  has_many :bars, :through => :foo_bar_joins
  has_many :foo_bar_joins

end

class Bar < ActiveRecord::Base

  has_many :foos, :through => :foo_bar_joins
  has_many :foo_bar_joins
  
end

class FooBarJoin < ActiveRecord::Base

  belongs_to :foo
  belongs_to :bar
  
  before_destroy :i_am_called
  
  def i_am_called
    raise FooBarJoinBeforeDestroyCallbackIsCalled
  end
  
end

class FooBarJoinBeforeDestroyCallbackIsCalled < StandardError 
end

Then the following test should pass:

describe FooBarJoin do
  
  it "'s before_destroy callback should be called when it is called through Association's clear method" do
    foo = Foo.create
    bar = Bar.create
    foo.bars << bar
    #the next line should raise an error when it executes foobarjoin's before_destroy callback..
    foo.bars.clear.should raise_error(FooBarJoinBeforeDestroyCallbackIsCalled)
  end 
  
end

The before_destroy callback should also be called when foo.update_attributes removes instances of FooBarJoin

The above code is included as a rails app.