Action not found in testing Ajax call

I have a route defined as :

change_area_backoffice_regions GET /backoffice/regions/
change_area(.:format) backoffice/regions#change_area

I am testing using the following functional test :

test “should list regions in another area” do
south_west = FactoryGirl.create(:area, name: "South West)
new_mexico = FactoryGirl.create(:region, area: south_west, code:

here is my call

xhr :get, :change_area => { :area => south_west[:id]}

sending the area[:id] as a parameter

assert_select "a", {:count => 1, :text => "New Mexico"}, "Wrong

name or more than one region element"

but I get a route error :
AbstractController::ActionNotFound: The action
‘{:change_area=>{:area=>20}}’ could not be found for
this action is defined , and the route is there , what’s wrong with y
test code ?

def change_area
@area = Area.find(params[:area])
@regions = @area.regions
render “backoffice/regions/change_area.js”

thanks for any feedback

[SOLVED] I re-read the error message, and it’s so obvious : The
action> ‘{:change_area=>{:area=>20}}’
I wrote a '=>" in place of a comma …
but it’s Sunday … I should clue my computer and go to the beach …