app/controllers/collaborations_controller.rb
class CollaborationsController < ApplicationController
def destroy
@collaboration = Collaboration.find(params[:id])
@project = @collaboration.project
if authorize_action_for @project
@collaboration.delete
redirect_to project_path(@project), notice: "Collaboration deleted"
else
redirect_to project_path(@project), notice: "You cannot delete this collaboration"
end
end
end