DEV: Load theme objects typed setting metadata when routing to editor (#26354)

Why this change?

Previously, we were preloading the necessary metadata for
`adminCustomizeThemes.show.schema` route in the
`adminCustomizeThemes.show` route. This is wasteful because we're
loading data upfront when the objects setting editor may not be used.

This change also lays the ground work for a future commit where we need
to be shipping down additional metadata which may further add to the
payload.

spec/requests/admin/themes_controller_spec.rb

@@ -1313,4 +1313,83 @@ RSpec.describe Admin::ThemesController do
       delete "/admin/themes/bulk_destroy.json", params: { theme_ids: theme_ids }
     end
   end
+
+  describe "#objects_setting_metadata" do
+    fab!(:theme)
+
+    let(:theme_setting) do
+      yaml = File.read("#{Rails.root}/spec/fixtures/theme_settings/objects_settings.yaml")
+      field = theme.set_field(target: :settings, name: "yaml", value: yaml)
+      theme.save!
+      theme.settings
+    end
+
+    before { SiteSetting.experimental_objects_type_for_theme_settings = true }
+
+    it "returns 404 if user is not an admin" do
+      get "/admin/themes/#{theme.id}/objects_setting_metadata/objects_with_categories.json"
+
+      expect(response.status).to eq(404)
+
+      sign_in(user)
+
+      get "/admin/themes/#{theme.id}/objects_setting_metadata/objects_with_categories.json"
+
+      expect(response.status).to eq(404)
+
+      sign_in(moderator)
+
+      get "/admin/themes/#{theme.id}/objects_setting_metadata/objects_with_categories.json"
+
+      expect(response.status).to eq(404)
+    end
+
+    context "when user is an admin" do
+      before { sign_in(admin) }
+
+      it "returns 403 if `experimental_objects_type_for_theme_settings` site setting is not enabled" do
+        SiteSetting.experimental_objects_type_for_theme_settings = false
+
+        get "/admin/themes/#{theme.id}/objects_setting_metadata/objects_with_categories.json"
+
+        expect(response.status).to eq(403)
+      end
+
+      it "returns 400 if the `id` param is not the id of a valid theme" do
+        get "/admin/themes/some_invalid_id/objects_setting_metadata/objects_with_categories.json"
+
+        expect(response.status).to eq(400)
+      end
+
+      it "returns 400 if the `setting_name` param does not match a valid setting" do
+        get "/admin/themes/#{theme.id}/objects_setting_metadata/some_invalid_setting_name.json"
+
+        expect(response.status).to eq(400)
+      end
+
+      it "returns 200 with the right `property_descriptions` attributes" do
+        theme.set_field(
+          target: :translations,
+          name: "en",
+          value: File.read("#{Rails.root}/spec/fixtures/theme_locales/objects_settings/en.yaml"),
+        )
+
+        theme.save!
+
+        theme_setting
+
+        get "/admin/themes/#{theme.id}/objects_setting_metadata/objects_setting.json"
+
+        expect(response.status).to eq(200)
+
+        expect(response.parsed_body["property_descriptions"]).to eq(
+          {
+            "links.name" => "Name of the link",
+            "links.url" => "URL of the link",
+            "name" => "Section Name",
+          },
+        )
+      end
+    end
+  end
 end

spec/serializers/theme_objects_setting_metadata_serializer_spec.rb

@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+RSpec.describe ThemeObjectsSettingMetadataSerializer do
+  fab!(:theme)
+
+  let(:theme_setting) do
+    yaml = File.read("#{Rails.root}/spec/fixtures/theme_settings/objects_settings.yaml")
+    theme.set_field(target: :settings, name: "yaml", value: yaml)
+    theme.save!
+    theme.settings
+  end
+
+  before { SiteSetting.experimental_objects_type_for_theme_settings = true }
+
+  describe "#property_descriptions" do
+    let(:objects_setting_locale) do
+      theme.set_field(
+        target: :translations,
+        name: "en",
+        value: File.read("#{Rails.root}/spec/fixtures/theme_locales/objects_settings/en.yaml"),
+      )
+
+      theme.save!
+    end
+
+    it "should return a hash of the settings property descriptions" do
+      objects_setting_locale
+
+      payload = described_class.new(theme_setting[:objects_setting], root: false).as_json
+
+      expect(payload[:property_descriptions]).to eq(
+        {
+          "links.name" => "Name of the link",
+          "links.url" => "URL of the link",
+          "name" => "Section Name",
+        },
+      )
+    end
+  end
+end

spec/serializers/theme_settings_serializer_spec.rb

@@ -19,43 +19,4 @@ RSpec.describe ThemeSettingsSerializer do
       expect(payload[:theme_settings][:objects_schema][:name]).to eq("section")
     end
   end
-
-  describe "#objects_schema_property_descriptions" do
-    let(:objects_setting_locale) do
-      theme.set_field(
-        target: :translations,
-        name: "en",
-        value: File.read("#{Rails.root}/spec/fixtures/theme_locales/objects_settings/en.yaml"),
-      )
-
-      theme.save!
-    end
-
-    before { SiteSetting.experimental_objects_type_for_theme_settings = true }
-
-    it "should not include the attribute when theme setting is not typed objects" do
-      yaml = File.read("#{Rails.root}/spec/fixtures/theme_settings/valid_settings.yaml")
-      theme.set_field(target: :settings, name: "yaml", value: yaml)
-      theme.save!
-
-      payload = ThemeSettingsSerializer.new(theme.settings[:string_setting]).as_json
-
-      expect(payload[:theme_settings][:objects_schema_property_descriptions]).to be_nil
-    end
-
-    it "should include the attribute when theme setting is of typed objects" do
-      objects_setting_locale
-      objects_setting
-
-      payload = ThemeSettingsSerializer.new(objects_setting).as_json
-
-      expect(payload[:theme_settings][:objects_schema_property_descriptions]).to eq(
-        {
-          "links.name" => "Name of the link",
-          "links.url" => "URL of the link",
-          "name" => "Section Name",
-        },
-      )
-    end
-  end
 end

spec/system/admin_editing_objects_typed_theme_setting_spec.rb

@@ -78,12 +78,19 @@ RSpec.describe "Admin editing objects type theme setting", type: :system do
 
       expect(admin_customize_themes_page).to have_overridden_setting("objects_setting")
 
+      admin_objects_theme_setting_editor =
+        admin_customize_themes_page.click_edit_objects_theme_setting_button("objects_setting")
+
+      expect(admin_objects_theme_setting_editor).to have_setting_field("name", "some new name")
+
+      admin_objects_theme_setting_editor.back
+
       admin_customize_themes_page.reset_overridden_setting("objects_setting")
 
       admin_objects_theme_setting_editor =
         admin_customize_themes_page.click_edit_objects_theme_setting_button("objects_setting")
 
-      expect(admin_objects_theme_setting_editor).to have_setting_field("name", "some new name")
+      expect(admin_objects_theme_setting_editor).to have_setting_field("name", "section 1")
     end
 
     it "allows an admin to edit a theme setting of objects type via the settings editor" do

spec/system/page_objects/pages/admin_objects_theme_setting_editor.rb

@@ -35,6 +35,11 @@ module PageObjects
         self
       end
 
+      def back
+        find(".customize-themes-show-schema__back").click
+        self
+      end
+
       private
 
       def input_field(field_name)