DEV: Introduce plugin modifiers for post.cooked and topic.fancy_titles (#31261)

Related:
40fd82e2d1

This PR introduces three new plugin modifiers attached to 
- `basic_post_serializer.cooked`
- `basic_topic_serializer.fancy_title`
- `topic_view_serializer.fancy_title`

Implementation note: I had wanted to add them in the `Post` and `Topic`
models themselves, but they do not directly provide access to the
request's scope which is needed for the use case.

app/serializers/basic_post_serializer.rb

@@ -34,7 +34,9 @@ class BasicPostSerializer < ApplicationSerializer
         I18n.t("flagging.user_must_edit")
       end
     else
-      object.filter_quotes(@parent_post)
+      cooked = object.filter_quotes(@parent_post)
+      modified = DiscoursePluginRegistry.apply_modifier(:basic_post_serializer_cooked, cooked, self)
+      modified || cooked
     end
   end
 

app/serializers/basic_topic_serializer.rb

@@ -3,4 +3,10 @@
 # The most basic attributes of a topic that we need to create a link for it.
 class BasicTopicSerializer < ApplicationSerializer
   attributes :id, :title, :fancy_title, :slug, :posts_count
+
+  def fancy_title
+    f = object.fancy_title
+    modified = DiscoursePluginRegistry.apply_modifier(:topic_serializer_fancy_title, f, self)
+    modified || f
+  end
 end

app/serializers/topic_view_serializer.rb

@@ -317,4 +317,10 @@ class TopicViewSerializer < ApplicationSerializer
   def include_visibility_reason_id?
     object.topic.visibility_reason_id.present?
   end
+
+  def fancy_title
+    f = object.topic.fancy_title
+    modified = DiscoursePluginRegistry.apply_modifier(:topic_view_serializer_fancy_title, f, self)
+    modified || f
+  end
 end

spec/serializers/basic_post_serializer_spec.rb

@@ -3,7 +3,7 @@
 RSpec.describe BasicPostSerializer do
   describe "#name" do
     let(:user) { Fabricate.build(:user) }
-    let(:post) { Fabricate.build(:post, user: user) }
+    let(:post) { Fabricate.build(:post, user: user, cooked: "Hur dur I am a cooked raw") }
     let(:serializer) { BasicPostSerializer.new(post, scope: Guardian.new, root: false) }
     let(:json) { serializer.as_json }
 
@@ -16,5 +16,22 @@ RSpec.describe BasicPostSerializer do
       SiteSetting.enable_names = false
       expect(json[:name]).to be_blank
     end
+
+    describe "#cooked" do
+      it "returns the post's cooked" do
+        expect(json[:cooked]).to eq(post.cooked)
+      end
+
+      it "returns the modified cooked when register modified" do
+        plugin = Plugin::Instance.new
+        modifier = :basic_post_serializer_cooked
+        proc = Proc.new { "X" }
+        DiscoursePluginRegistry.register_modifier(plugin, modifier, &proc)
+
+        expect(json[:cooked]).to eq("X")
+      ensure
+        DiscoursePluginRegistry.unregister_modifier(plugin, modifier, &proc)
+      end
+    end
   end
 end

spec/serializers/basic_topic_serializer_spec.rb

@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+describe BasicTopicSerializer do
+  fab!(:topic) { Fabricate(:topic, title: "Hur dur this is a title") }
+
+  describe "#fancy_title" do
+    it "returns the fancy title" do
+      json = BasicTopicSerializer.new(topic).as_json
+
+      expect(json[:basic_topic][:fancy_title]).to eq(topic.title)
+    end
+
+    it "returns the fancy title with a modifier" do
+      plugin = Plugin::Instance.new
+      modifier = :topic_serializer_fancy_title
+      proc = Proc.new { "X" }
+      DiscoursePluginRegistry.register_modifier(plugin, modifier, &proc)
+      json = BasicTopicSerializer.new(topic).as_json
+
+      expect(json[:basic_topic][:fancy_title]).to eq("X")
+    ensure
+      DiscoursePluginRegistry.unregister_modifier(plugin, modifier, &proc)
+    end
+  end
+end

spec/serializers/topic_view_serializer_spec.rb

@@ -645,4 +645,25 @@ RSpec.describe TopicViewSerializer do
       expect(json[:topic_timer][:id]).to eq(topic_timer.id)
     end
   end
+
+  describe "#fancy_title" do
+    it "returns the fancy title" do
+      topic.update!(title: "Hur dur this is a title")
+      json = serialize_topic(topic, user)
+
+      expect(json[:fancy_title]).to eq("Hur dur this is a title")
+    end
+
+    it "returns the fancy title with a modifier" do
+      plugin = Plugin::Instance.new
+      modifier = :topic_view_serializer_fancy_title
+      proc = Proc.new { "X" }
+      DiscoursePluginRegistry.register_modifier(plugin, modifier, &proc)
+      json = serialize_topic(topic, user)
+
+      expect(json[:fancy_title]).to eq("X")
+    ensure
+      DiscoursePluginRegistry.unregister_modifier(plugin, modifier, &proc)
+    end
+  end
 end