FIX: Apply watched words to user fields

Currently we don’t apply watched words to custom user fields nor user
profile fields.
This led to users being able to use blocked words in their bio, location
or some custom user fields.

This patch addresses this issue by adding some validations so it’s not
possible anymore to save the User model or the UserProfile model if they
contain blocked words.

spec/models/user_spec.rb

@@ -1,9 +1,9 @@
 # frozen_string_literal: true
 
-describe User do
+RSpec.describe User do
   fab!(:group) { Fabricate(:group) }
 
-  let(:user) { Fabricate(:user, last_seen_at: 1.day.ago) }
+  subject(:user) { Fabricate(:user, last_seen_at: 1.day.ago) }
 
   def user_error_message(*keys)
     I18n.t(:"activerecord.errors.models.user.attributes.#{keys.join('.')}")
@@ -136,6 +136,29 @@ describe User do
         end
       end
     end
+
+    describe "#user_fields" do
+      fab!(:user_field) { Fabricate(:user_field) }
+      fab!(:watched_word) { Fabricate(:watched_word, word: "bad") }
+
+      before { user.set_user_field(user_field.id, value) }
+
+      context "when user fields contain watched words" do
+        let(:value) { "bad user field value" }
+
+        it "is not valid" do
+          user.valid?
+          expect(user.errors[:base].size).to eq(1)
+          expect(user.errors.messages[:base]).to include(/you can't post the word/)
+        end
+      end
+
+      context "when user fields do not contain watched words" do
+        let(:value) { "good user field value" }
+
+        it { is_expected.to be_valid }
+      end
+    end
   end
 
   describe '#count_by_signup_date' do