add user cant follow himself validation

spec/models/user_follow_spec.rb

@@ -0,0 +1,14 @@
+require 'rails_helper'
+
+RSpec.describe UserFollow, type: :model do
+  describe 'validations' do
+    context 'and user try to follow her-self' do
+      it 'raise error' do
+        user = create(:user)
+        user_follow = build(:user_follow, follower_id: user.id, followed_id: user.id)
+
+        expect(user_follow).to_not be_valid
+      end
+    end
+  end
+end