DEV: Change HashtagAutocompleteService to use DiscoursePluginRegistry (#19491)

Follow up to a review in #18937, this commit changes the HashtagAutocompleteService to no longer use class variables to register hashtag data sources or types in context priority order. This is to address multisite concerns, where one site could e.g. have chat disabled and another might not. The filtered plugin registers I added will not be included if the plugin is disabled.

plugins/chat/lib/chat_channel_hashtag_data_source.rb

@@ -5,6 +5,10 @@ class Chat::ChatChannelHashtagDataSource
     "comment"
   end
 
+  def self.type
+    "channel"
+  end
+
   def self.channel_to_hashtag_item(guardian, channel)
     HashtagAutocompleteService::HashtagItem.new.tap do |item|
       item.text = channel.title

plugins/chat/plugin.rb

@@ -730,11 +730,11 @@ after_initialize do
   register_about_stat_group("chat_users") { Chat::Statistics.about_users }
 
   # Make sure to update spec/system/hashtag_autocomplete_spec.rb when changing this.
-  register_hashtag_data_source("channel", Chat::ChatChannelHashtagDataSource)
-  register_hashtag_type_in_context("channel", "chat-composer", 200)
-  register_hashtag_type_in_context("category", "chat-composer", 100)
-  register_hashtag_type_in_context("tag", "chat-composer", 50)
-  register_hashtag_type_in_context("channel", "topic-composer", 10)
+  register_hashtag_data_source(Chat::ChatChannelHashtagDataSource)
+  register_hashtag_type_priority_for_context("channel", "chat-composer", 200)
+  register_hashtag_type_priority_for_context("category", "chat-composer", 100)
+  register_hashtag_type_priority_for_context("tag", "chat-composer", 50)
+  register_hashtag_type_priority_for_context("channel", "topic-composer", 10)
 
   Site.markdown_additional_options["chat"] = {
     limited_pretty_text_features: ChatMessage::MARKDOWN_FEATURES,

plugins/chat/spec/models/chat_message_spec.rb

@@ -5,18 +5,6 @@ require "rails_helper"
 describe ChatMessage do
   fab!(:message) { Fabricate(:chat_message, message: "hey friend, what's up?!") }
 
-  # TODO (martin) Remove this after https://github.com/discourse/discourse/pull/19491 is merged
-  def register_hashtag_contexts
-    # This is annoying, but we need to reset the hashtag data sources inbetween
-    # tests, and since this is normally done in plugin.rb with the plugin API
-    # there is not an easier way to do this.
-    HashtagAutocompleteService.register_data_source("channel", Chat::ChatChannelHashtagDataSource)
-    HashtagAutocompleteService.register_type_in_context("channel", "chat-composer", 200)
-    HashtagAutocompleteService.register_type_in_context("category", "chat-composer", 100)
-    HashtagAutocompleteService.register_type_in_context("tag", "chat-composer", 50)
-    HashtagAutocompleteService.register_type_in_context("channel", "topic-composer", 10)
-  end
-
   describe ".cook" do
     it "does not support HTML tags" do
       cooked = ChatMessage.cook("<h1>test</h1>")
@@ -258,7 +246,7 @@ describe ChatMessage do
     end
 
     it "supports hashtag-autocomplete plugin" do
-      register_hashtag_contexts
+      SiteSetting.chat_enabled = true
       SiteSetting.enable_experimental_hashtag_autocomplete = true
 
       category = Fabricate(:category)
@@ -521,7 +509,7 @@ describe ChatMessage do
       fab!(:secure_category) { Fabricate(:private_category, group: group) }
 
       before do
-        register_hashtag_contexts
+        SiteSetting.chat_enabled = true
         SiteSetting.enable_experimental_hashtag_autocomplete = true
         SiteSetting.suppress_secured_categories_from_admin = true
       end

plugins/chat/spec/system/hashtag_autocomplete_spec.rb

@@ -19,15 +19,6 @@ describe "Using #hashtag autocompletion to search for and lookup channels",
   before do
     SiteSetting.enable_experimental_hashtag_autocomplete = true
 
-    # This is annoying, but we need to reset the hashtag data sources inbetween
-    # tests, and since this is normally done in plugin.rb with the plugin API
-    # there is not an easier way to do this.
-    HashtagAutocompleteService.register_data_source("channel", Chat::ChatChannelHashtagDataSource)
-    HashtagAutocompleteService.register_type_in_context("channel", "chat-composer", 200)
-    HashtagAutocompleteService.register_type_in_context("category", "chat-composer", 100)
-    HashtagAutocompleteService.register_type_in_context("tag", "chat-composer", 50)
-    HashtagAutocompleteService.register_type_in_context("channel", "topic-composer", 10)
-
     chat_system_bootstrap(user, [channel1, channel2])
     sign_in(user)
   end