How to stub after_create callback save! in model? - ruby-on-rails

Question

I receive following error:
Output:
1) LabelsController#create label is new creates a new label
Failure/Error: post :create, attributes[:label], format: :json
NoMethodError:
undefined method `save!' for nil:NilClass
# ./app/models/labeling.rb:17:in `update_target'
In Labeling model:
after_create :update_target
def update_target
self.target.save!
end
Test:
require 'spec_helper'
describe LabelsController do
before(:each) do
controller.stub(:current_user).and_return(mock_model(User))
stub_request(:any, "www.example.com").to_return(status: 200)
end
describe "#create" do
context "label is new" do
it "creates a new label" do
attributes = {
label: {
name: "test",
labeling: {
target_type: "Link", target_id: 1
}
}
}
response.status.should == 200
post :create, attributes[:label], format: :json
end
end
end
end
Labeling controller:
def create
label = Label.find_by_name(params[:name])
labeling = label.labelings.build do |lb|
lb.user_id = current_user.id
lb.target_type = params[:labeling][:target_type]
lb.target_id = params[:labeling][:target_id]
end
if labeling.save
render json: {
name: label.name,
id: label.id,
labeling: {
id: labeling.id
}
}
end
end

Answer 1

By the looks of it you don't have a Target with ID 1 on the database, so where you refer to self.target the returned value is nil.
What I'd do in your case is first create a target and then pass its id to the attributes hash:
target = Traget.create!
attributes = {
label: {
name: "test",
labeling: {
target_type: "Link", target_id: target.id
}
}
}
This way you don't need to stub anything.
If you really must stub the method you can use RSpecs any_instance method:
Labeling.any_instance.stub(:update_target).and_return(true)