I'm having an issue where update_attributes of a nested embeds_one relationship updates fields on the parent model instead of the child. This happens whether or not the "id" key is present in the home_team_attributes hash. There is no attr_accessible control on the GameTeam model.

I'm running mongoid 3.0.6, rails 3.1.3

snipped game model

class Game
include Mongoid::Document

embeds_one :home_team, :class_name => GameTeam.to_s
embeds_one :away_team, :class_name => GameTeam.to_s

accepts_nested_attributes_for :home_team, :away_team
attr_accessible :home_team_attributes, :away_team_attributes

...
end

test cases that reproduce the error:

context "when mass assigning home team name" do
it "should not update game name which isn't even a mongoid field" do
expect {
@game.update_attributes!( home_team_attributes:

{ name: "poopy" }

)
@game.reload
}.not_to change

{ @game.attributes['name'] }

end

it "should allow updating home team name" do
expect {
@game.update_attributes!( home_team_attributes:

{ name: "poopy" }

)
@game.reload
}.to change

{ @game.home_team.name }.to "poopy"
end

it "should allow updating home team name directly" do
expect { @game.home_team.update_attributes!( name: "poopy" ) @game.reload }.to change { @game.home_team.name }

.to "poopy"
end
end

rspec output:

Testing started at 2:20 PM ...

result should not have changed, but did change from nil to "poopy"
[[snip]]

result should have been changed to "poopy", but is now "Florida Gators"
[[snip]]

result should have been changed to "poopy", but is now "Florida Gators"
[[snip]]

3 examples, 3 failures, 0 passed

Finished in 0.156565 seconds

Process finished with exit code 1