FIX: Show toggle button even when original content is displayed

assets/javascripts/discourse/components/show-original-content.gjs

@@ -11,10 +11,7 @@ const SHOW_ORIGINAL_COOKIE_EXPIRY = 30;
 
 export default class ShowOriginalContent extends Component {
   static shouldRender(args) {
-    return (
-      args.topic.is_translated ||
-      args.topic.postStream.posts.some(({ is_translated }) => is_translated)
-    );
+    return args.topic.show_translation_toggle;
   }
 
   @service router;

lib/discourse_translator/inline_translation.rb

@@ -22,41 +22,35 @@ def inject(plugin)
       # this prevents the need to load translations.
 
       plugin.register_modifier(:basic_post_serializer_cooked) do |cooked, serializer|
-        if !SiteSetting.experimental_inline_translation ||
-             serializer.object.locale_matches?(InlineTranslation.effective_locale) ||
-             serializer.scope&.request&.cookies&.key?(SHOW_ORIGINAL_COOKIE)
-          cooked
-        else
+        if show_translation?(serializer.object, serializer.scope)
           serializer.object.translation_for(InlineTranslation.effective_locale).presence
+        else
+          cooked
         end
       end
 
       plugin.register_modifier(:topic_serializer_fancy_title) do |fancy_title, serializer|
-        if !SiteSetting.experimental_inline_translation ||
-             serializer.object.locale_matches?(InlineTranslation.effective_locale) ||
-             serializer.scope&.request&.cookies&.key?(SHOW_ORIGINAL_COOKIE)
-          fancy_title
-        else
+        if show_translation?(serializer.object, serializer.scope)
           serializer
             .object
             .translation_for(InlineTranslation.effective_locale)
             .presence
             &.then { |t| Topic.fancy_title(t) }
+        else
+          fancy_title
         end
       end
 
       plugin.register_modifier(:topic_view_serializer_fancy_title) do |fancy_title, serializer|
-        if !SiteSetting.experimental_inline_translation ||
-             serializer.object.topic.locale_matches?(InlineTranslation.effective_locale) ||
-             serializer.scope&.request&.cookies&.key?(SHOW_ORIGINAL_COOKIE)
-          fancy_title
-        else
+        if show_translation?(serializer.object.topic, serializer.scope)
           serializer
             .object
             .topic
             .translation_for(InlineTranslation.effective_locale)
             .presence
             &.then { |t| Topic.fancy_title(t) }
+        else
+          fancy_title
         end
       end
 
@@ -73,10 +67,20 @@ def inject(plugin)
         end
       end
 
-      plugin.add_to_serializer(:topic_view, :is_translated) do
-        SiteSetting.experimental_inline_translation &&
+      plugin.add_to_serializer(:topic_view, :show_translation_toggle) do
+        return false if !SiteSetting.experimental_inline_translation
+        # either the topic or any of the posts has a translation
+        # also, check the locale first as it is cheaper than loading translation
+        (
           !object.topic.locale_matches?(InlineTranslation.effective_locale) &&
-          object.topic.translation_for(InlineTranslation.effective_locale).present?
+            object.topic.translation_for(InlineTranslation.effective_locale).present?
+        ) ||
+          (
+            object.posts.any? do |post|
+              !post.locale_matches?(InlineTranslation.effective_locale) &&
+                post.translation_for(InlineTranslation.effective_locale).present?
+            end
+          )
       end
 
       plugin.register_topic_preloader_associations(:content_locale) do
@@ -86,5 +90,11 @@ def inject(plugin)
         SiteSetting.translator_enabled && SiteSetting.experimental_inline_translation
       end
     end
+
+    def show_translation?(translatable, scope)
+      SiteSetting.experimental_inline_translation &&
+        !translatable.locale_matches?(InlineTranslation.effective_locale) &&
+        !scope&.request&.cookies&.key?(SHOW_ORIGINAL_COOKIE)
+    end
   end
 end

spec/serializers/topic_view_serializer_spec.rb

@@ -122,11 +122,11 @@
       before do
         topic.title = original_title
         SiteSetting.experimental_inline_translation = true
-        I18n.locale = "ja"
+        I18n.locale = "en"
       end
 
-      def serialize_topic(guardian_user: user, params: {})
-        env = { "action_dispatch.request.parameters" => params, "REQUEST_METHOD" => "GET" }
+      def serialize_topic(guardian_user: user, cookie: "")
+        env = create_request_env.merge("HTTP_COOKIE" => cookie)
         request = ActionDispatch::Request.new(env)
         guardian = Guardian.new(guardian_user, request)
         TopicViewSerializer.new(TopicView.new(topic), scope: guardian)
@@ -141,9 +141,11 @@ def serialize_topic(guardian_user: user, params: {})
 
       it "does not replace fancy_title with translation when show_original param is present" do
         topic.set_translation("ja", jap_title)
-        expect(serialize_topic(params: { "show" => "original" }).fancy_title).to eq(
-          topic.fancy_title,
-        )
+        expect(
+          serialize_topic(
+            cookie: DiscourseTranslator::InlineTranslation::SHOW_ORIGINAL_COOKIE,
+          ).fancy_title,
+        ).to eq(topic.fancy_title)
       end
 
       it "does not replace fancy_title with translation when no translation exists" do
@@ -159,15 +161,18 @@ def serialize_topic(guardian_user: user, params: {})
       end
 
       it "returns translated title in fancy_title when translation exists for current locale" do
+        I18n.locale = "ja"
         SiteSetting.automatic_translation_backfill_rate = 1
         SiteSetting.automatic_translation_target_languages = "ja"
         topic.set_translation("ja", jap_title)
         expect(serialize_topic.fancy_title).to eq("<h1>フス・ロ・ダ・ア</h1>")
       end
     end
 
-    describe "#is_translated" do
+    describe "#show_translation_toggle" do
       fab!(:user)
+      fab!(:post_1) { Fabricate(:post, topic:) }
+      fab!(:post_2) { Fabricate(:post, topic:) }
 
       before do
         SiteSetting.automatic_translation_backfill_rate = 1
@@ -184,15 +189,15 @@ def serialize_topic(guardian_user: user)
 
         SiteSetting.translator_enabled = false
         SiteSetting.experimental_inline_translation = false
-        expect(serialize_topic.is_translated).to eq(false)
+        expect(serialize_topic.show_translation_toggle).to eq(false)
 
         SiteSetting.translator_enabled = true
         SiteSetting.experimental_inline_translation = false
-        expect(serialize_topic.is_translated).to eq(false)
+        expect(serialize_topic.show_translation_toggle).to eq(false)
 
         SiteSetting.translator_enabled = true
         SiteSetting.experimental_inline_translation = true
-        expect(serialize_topic.is_translated).to eq(true)
+        expect(serialize_topic.show_translation_toggle).to eq(true)
       end
 
       it "returns true when there is translation for the topic" do
@@ -201,7 +206,7 @@ def serialize_topic(guardian_user: user)
         I18n.locale = "ja"
         topic.set_translation("ja", "こんにちは")
 
-        expect(serialize_topic.is_translated).to eq(true)
+        expect(serialize_topic.show_translation_toggle).to eq(true)
       end
     end
   end