Make `turbo does not succeed` example for in `RelationshipsController`

app/controllers/relationships_controller.rb

@@ -8,6 +8,8 @@ class RelationshipsController < ApplicationController
   turbo_stream_actions :create, :destroy
 
   def create
+    params.require :screen_name
+
     UseCase::Relationship::Create.call(
       source_user: current_user,
       target_user: ::User.find_by!(screen_name: params[:screen_name]),

spec/controllers/relationships_controller_spec.rb

@@ -4,6 +4,8 @@
 require "rails_helper"
 
 describe RelationshipsController, type: :controller do
+  render_views
+
   shared_examples_for "params is empty" do
     let(:params) { {} }
 

spec/shared_examples/error_raising.rb

@@ -14,10 +14,9 @@ RSpec.shared_examples_for "ajax does not succeed" do |part_of_error_message|
   end
 end
 
-RSpec.shared_examples_for "turbo does not succeed" do
+RSpec.shared_examples_for "turbo does not succeed" do |part_of_error_message|
   it "turbo does not succeed" do
     subject
-    # FIXME: for some reason, partials are not rendered, making the actual error message not accessible
-    expect(response.body).to include "turbo-stream action=\"append\" target=\"toasts\""
+    expect(response.body).to include(part_of_error_message)
   end
 end