Assign MembershipApplication#country_state

app/policies/membership_application_policy.rb

@@ -9,6 +9,7 @@ class MembershipApplicationPolicy < ApplicationPolicy
     %i[
       first_name last_name middle_name date_of_birth occupation email
       phone_number telegram_username organization_membership comment
+      country_state_id
     ]
   end
 end

app/views/membership_applications/new.html.erb

@@ -3,6 +3,7 @@
     <%= f.input :first_name %>
     <%= f.input :last_name %>
     <%= f.input :middle_name %>
+    <%= f.association :country_state, collection: CountryState.all %>
     <%= f.input :date_of_birth, start_year: Date.today.year - 150,
                                 end_year: Date.today.year %>
     <%= f.input :occupation %>

spec/requests/membership_applications/create_spec.rb

@@ -3,13 +3,22 @@
 require 'rails_helper'
 
 RSpec.describe 'POST /membership_applications' do
-  let :membership_application_attributes do
+  let :membership_application_plain_attributes do
     attributes_for :membership_application
   end
 
+  let :membership_application_all_attributes do
+    membership_application_plain_attributes.merge(
+      country_state_id: country_state&.id,
+    )
+  end
+
+  let(:country_state) { create :country_state }
+
   def make_request
-    post '/membership_applications',
-         params: { membership_application: membership_application_attributes }
+    post '/membership_applications', params: {
+      membership_application: membership_application_all_attributes,
+    }
   end
 
   specify do
@@ -26,7 +35,41 @@ RSpec.describe 'POST /membership_applications' do
 
     specify do
       expect(MembershipApplication.last).to \
-        have_attributes membership_application_attributes
+        have_attributes membership_application_plain_attributes
+    end
+
+    specify do
+      expect(MembershipApplication.last).to have_attributes(
+        country_state: country_state,
+      )
+    end
+  end
+
+  context 'when country state is not specified' do
+    let(:country_state) { nil }
+
+    specify do
+      expect { make_request }.to \
+        change(MembershipApplication, :count).from(0).to(1)
+    end
+
+    context 'after request' do
+      before { make_request }
+
+      specify do
+        expect(response).to redirect_to root_url
+      end
+
+      specify do
+        expect(MembershipApplication.last).to \
+          have_attributes membership_application_plain_attributes
+      end
+
+      specify do
+        expect(MembershipApplication.last).to have_attributes(
+          country_state: nil,
+        )
+      end
     end
   end
 end