Add AMS versions of the error responses in api/base_controller and cover not_found case with a unit test

app/controllers/api/base_controller.rb

@@ -30,5 +30,27 @@ module Api
     def requires_authentication?
       false
     end
+
+    def invalid_resource!(resource)
+      @resource = resource
+      render(json: { error: I18n.t(:invalid_resource, scope: "spree.api"),
+                     errors: @resource.errors },
+             status: :unprocessable_entity)
+    end
+
+    def invalid_api_key
+      render(json: { error: I18n.t(:invalid_api_key, key: api_key, scope: "spree.api") },
+             status: :unauthorized) && return
+    end
+
+    def unauthorized
+      render(json: { error: I18n.t(:unauthorized, scope: "spree.api") },
+             status: :unauthorized) && return
+    end
+
+    def not_found
+      render(json: { error: I18n.t(:resource_not_found, scope: "spree.api") },
+             status: :not_found) && return
+    end
   end
 end

spec/controllers/api/base_controller_spec.rb

@@ -50,10 +50,18 @@ describe Api::BaseController do
   it 'handles exceptions' do
     expect(subject).to receive(:authenticate_user).and_return(true)
     expect(subject).to receive(:index).and_raise(Exception.new("no joy"))
-    get :index, token: "fake_key"
+    get :index
     expect(json_response).to eq( "exception" => "no joy" )
   end
 
+  it 'handles record not found' do
+    expect(subject).to receive(:authenticate_user).and_return(true)
+    expect(subject).to receive(:index).and_raise(ActiveRecord::RecordNotFound.new)
+    get :index
+    expect(json_response).to eq( "error" => "The resource you were looking for could not be found." )
+    expect(response.status).to eq(404)
+  end
+
   it "maps symantec keys to nested_attributes keys" do
     klass = double(nested_attributes_options: { line_items: {},
                                                 bill_address: {} })