DEV: Change category type to categories type for theme object schema (#26339)

Why this change?

This is a follow-up to 86b2e3aa3e.

Basically, we want to allow people to select more than 1 category as well.

What does this change do?

1. Change `type: category` to `type: categories` and support `min` and `max`
   validations for `type: categories`.

2. Fix the `<SchemaThemeSetting::Types::Categories>` component to support the
   `min` and `max` validations and switch it to use the `<CategorySelector>` component
   instead of the `<CategoryChooser>` component which only supports selecting one category.

spec/serializers/theme_objects_setting_metadata_serializer_spec.rb

@@ -37,4 +37,58 @@ RSpec.describe ThemeObjectsSettingMetadataSerializer do
       )
     end
   end
+
+  describe "#categories" do
+    fab!(:category_1) { Fabricate(:category) }
+    fab!(:category_2) { Fabricate(:category) }
+    fab!(:category_3) { Fabricate(:private_category, group: Fabricate(:group)) }
+    fab!(:admin)
+
+    it "should return a hash of serialized categories" do
+      theme_setting[:objects_with_categories].value = [
+        {
+          "category_ids" => [category_1.id, category_2.id],
+          "child_categories" => [{ "category_ids" => [category_3.id] }],
+        },
+      ]
+
+      scope = Guardian.new
+
+      payload =
+        described_class.new(theme_setting[:objects_with_categories], scope:, root: false).as_json
+
+      categories = payload[:categories]
+
+      expect(categories.keys).to contain_exactly(category_1.id, category_2.id)
+
+      expect(categories[category_1.id]).to eq(
+        BasicCategorySerializer.new(category_1, scope:, root: false).as_json,
+      )
+
+      expect(categories[category_2.id]).to eq(
+        BasicCategorySerializer.new(category_2, scope:, root: false).as_json,
+      )
+
+      scope = Guardian.new(admin)
+
+      payload =
+        described_class.new(theme_setting[:objects_with_categories], scope:, root: false).as_json
+
+      categories = payload[:categories]
+
+      expect(categories.keys).to contain_exactly(category_1.id, category_2.id, category_3.id)
+
+      expect(categories[category_1.id]).to eq(
+        BasicCategorySerializer.new(category_1, scope:, root: false).as_json,
+      )
+
+      expect(categories[category_2.id]).to eq(
+        BasicCategorySerializer.new(category_2, scope:, root: false).as_json,
+      )
+
+      expect(categories[category_3.id]).to eq(
+        BasicCategorySerializer.new(category_3, scope:, root: false).as_json,
+      )
+    end
+  end
 end

spec/serializers/theme_settings_serializer_spec.rb

@@ -3,18 +3,18 @@
 RSpec.describe ThemeSettingsSerializer do
   fab!(:theme)
 
-  let(:objects_setting) do
+  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[:objects_setting]
+    theme.settings
   end
 
-  describe "#objects_schema" do
-    before { SiteSetting.experimental_objects_type_for_theme_settings = true }
+  before { SiteSetting.experimental_objects_type_for_theme_settings = true }
 
+  describe "#objects_schema" do
     it "should include the attribute when theme setting is typed objects" do
-      payload = ThemeSettingsSerializer.new(objects_setting).as_json
+      payload = ThemeSettingsSerializer.new(theme_setting[:objects_setting]).as_json
 
       expect(payload[:theme_settings][:objects_schema][:name]).to eq("section")
     end