DEV: Make service contracts immutable

We decided to make contracts immutable once their validations have run.
Indeed, it doesn’t make a lot of sense to modify a contract value
outside the contract itself.

If processing is needed, then it should happen inside the contract
itself.

plugins/chat/app/services/chat/create_message.rb

@@ -46,6 +46,16 @@ module Chat
 
       validates :chat_channel_id, presence: true
       validates :message, presence: true, if: -> { upload_ids.blank? }
+
+      after_validation do
+        next if message.blank?
+        self.message =
+          TextCleaner.clean(
+            message,
+            strip_whitespaces: options.strip_whitespaces,
+            strip_zero_width_spaces: true,
+          )
+      end
     end
     model :channel
     step :enforce_membership
@@ -57,7 +67,6 @@ module Chat
     policy :ensure_valid_thread_for_channel
     policy :ensure_thread_matches_parent
     model :uploads, optional: true
-    step :clean_message
     model :message_instance, :instantiate_message
     transaction do
       step :create_excerpt
@@ -134,14 +143,6 @@ module Chat
       guardian.user.uploads.where(id: params[:upload_ids])
     end
 
-    def clean_message(params:, options:)
-      params[:message] = TextCleaner.clean(
-        params[:message],
-        strip_whitespaces: options.strip_whitespaces,
-        strip_zero_width_spaces: true,
-      )
-    end
-
     def instantiate_message(channel:, guardian:, params:, uploads:, thread:, reply:, options:)
       channel.chat_messages.new(
         user: guardian.user,

plugins/chat/app/services/chat/search_chatable.rb

@@ -24,8 +24,9 @@ module Chat
       attribute :include_category_channels, :boolean, default: true
       attribute :include_direct_message_channels, :boolean, default: true
       attribute :excluded_memberships_channel_id, :integer
+
+      after_validation { self.term = term&.downcase&.strip&.gsub(/^[@#]+/, "") }
     end
-    step :clean_term
     model :memberships, optional: true
     model :users, optional: true
     model :groups, optional: true
@@ -34,10 +35,6 @@ module Chat
 
     private
 
-    def clean_term(params:)
-      params[:term] = params[:term]&.downcase&.strip&.gsub(/^[@#]+/, "")
-    end
-
     def fetch_memberships(guardian:)
       ::Chat::ChannelMembershipManager.all_for_user(guardian.user)
     end

plugins/chat/app/services/chat/update_message.rb

@@ -33,6 +33,16 @@ module Chat
 
       validates :message_id, presence: true
       validates :message, presence: true, if: -> { upload_ids.blank? }
+
+      after_validation do
+        next if message.blank?
+        self.message =
+          TextCleaner.clean(
+            message,
+            strip_whitespaces: options.strip_whitespaces,
+            strip_zero_width_spaces: true,
+          )
+      end
     end
     model :message
     model :uploads, optional: true
@@ -40,7 +50,6 @@ module Chat
     model :membership
     policy :can_modify_channel_message
     policy :can_modify_message
-    step :clean_message
     transaction do
       step :modify_message
       step :update_excerpt
@@ -90,14 +99,6 @@ module Chat
       guardian.can_edit_chat?(message)
     end
 
-    def clean_message(params:, options:)
-      params[:message] = TextCleaner.clean(
-        params[:message],
-        strip_zero_width_spaces: true,
-        strip_whitespaces: options.strip_whitespaces,
-      )
-    end
-
     def modify_message(params:, message:, guardian:, uploads:)
       message.message = params[:message]
       message.last_editor_id = guardian.user.id