Allow the creation of guests associated to no group

app/controllers/guests_controller.rb

@@ -5,7 +5,7 @@ require 'csv'
 class GuestsController < ApplicationController
   def index
     render json: Guest.all.includes(:group)
-                      .joins(:group)
+                      .left_joins(:group)
                       .order('groups.name' => :asc, name: :asc)
                       .as_json(only: %i[id name status], include: { group: { only: %i[id name] } })
   end

app/models/guest.rb

@@ -25,7 +25,7 @@
 #
 class Guest < ApplicationRecord
   acts_as_tenant :wedding
-  belongs_to :group
+  belongs_to :group, optional: true
 
   enum :status, {
     considered: 0,

spec/models/guest_spec.rb

@@ -16,7 +16,7 @@ RSpec.describe Guest, type: :model do
     end
   end
 
-  it { should belong_to(:group) }
+  it { should belong_to(:group).optional }
 
   describe 'scopes' do
     describe '.potential' do

spec/requests/guests_spec.rb

@@ -41,7 +41,7 @@ RSpec.describe 'guests', type: :request do
         properties: {
           guest: {
             type: :object,
-            required: %i[name group_id status],
+            required: %i[name status],
             properties: {
               name: { type: :string },
               group_id: { type: :string, format: :uuid },
@@ -70,6 +70,7 @@ RSpec.describe 'guests', type: :request do
         properties: {
           guest: {
             type: :object,
+            required: %i[name status],
             properties: {
               name: { type: :string },
               group_id: { type: :string, format: :uuid },