UX: Show parent category name for category hashtags (#31188)

This commit changes the display of category hashtag
autocomplete to show the parent category name in this
format:

* Parent Name > Child Name

This helps further distinguish categories in the autocomplete
where there may be multiple different parent categories with
the same name child category, e.g. if every category has an
Announcements subcategory.

app/services/category_hashtag_data_source.rb

@@ -18,7 +18,14 @@ class CategoryHashtagDataSource
 
   def self.category_to_hashtag_item(category)
     HashtagAutocompleteService::HashtagItem.new.tap do |item|
-      item.text = category.name
+      item.text =
+        (
+          if category.parent_category
+            "#{category.parent_category.name} > #{category.name}"
+          else
+            category.name
+          end
+        )
       item.slug = category.slug
       item.description = category.description_text
       item.icon = icon

spec/services/category_hashtag_data_source_spec.rb

@@ -1,15 +1,23 @@
 # frozen_string_literal: true
 
 RSpec.describe CategoryHashtagDataSource do
-  fab!(:parent_category) { Fabricate(:category, slug: "fun", topic_count: 2) }
+  fab!(:parent_category) { Fabricate(:category, name: "Silly Land", slug: "fun", topic_count: 2) }
   fab!(:category1) do
-    Fabricate(:category, slug: "random", topic_count: 12, parent_category: parent_category)
+    Fabricate(
+      :category,
+      name: "Random",
+      slug: "random",
+      topic_count: 12,
+      parent_category: parent_category,
+    )
   end
   fab!(:category2) { Fabricate(:category, name: "Book Section", slug: "books", topic_count: 566) }
-  fab!(:category3) { Fabricate(:category, slug: "movies", topic_count: 245) }
+  fab!(:category3) { Fabricate(:category, name: "Kino Korner", slug: "movies", topic_count: 245) }
   fab!(:group)
-  fab!(:category4) { Fabricate(:private_category, slug: "secret", group: group, topic_count: 40) }
+  fab!(:category4) do
-  fab!(:category5) { Fabricate(:category, slug: "casual", topic_count: 99) }
+    Fabricate(:private_category, name: "Nunya", slug: "secret", group: group, topic_count: 40)
+  end
+  fab!(:category5) { Fabricate(:category, name: "Chillzone", slug: "casual", topic_count: 99) }
   fab!(:user)
   let(:guardian) { Guardian.new(user) }
   let(:uncategorized_category) { Category.find(SiteSetting.uncategorized_category_id) }
@@ -55,6 +63,16 @@ RSpec.describe CategoryHashtagDataSource do
       expect(described_class.lookup(Guardian.new(user), ["secret"]).first).not_to eq(nil)
     end
 
+    it "formats the category text for a category without a parent" do
+      result = described_class.lookup(guardian, ["movies"]).first
+      expect(result.text).to eq("Kino Korner")
+    end
+
+    it "formats the category text for a category with a parent" do
+      result = described_class.lookup(guardian, ["fun:random"]).first
+      expect(result.text).to eq("Silly Land > Random")
+    end
+
     context "with sub-sub-categories" do
       before { SiteSetting.max_category_nesting = 3 }
 
@@ -94,6 +112,15 @@ RSpec.describe CategoryHashtagDataSource do
         result = described_class.lookup(guardian, ["child:grandchild"])
         expect(result.map(&:relative_url)).to eq([parent2_child_grandchild.url])
       end
+
+      it "formats the category text for sub-sub-categories" do
+        parent = Fabricate(:category, slug: "parent", name: "Parent")
+        child = Fabricate(:category, slug: "child", parent_category_id: parent.id, name: "Child")
+        grandchild =
+          Fabricate(:category, slug: "grandchild", parent_category_id: child.id, name: "Grandchild")
+        result = described_class.lookup(guardian, ["child:grandchild"])
+        expect(result.last.text).to eq("Child > Grandchild")
+      end
     end
   end
 
@@ -102,6 +129,7 @@ RSpec.describe CategoryHashtagDataSource do
       result = described_class.search(guardian, "mov", 5).first
       expect(result.ref).to eq("movies")
       expect(result.slug).to eq("movies")
+      expect(result.text).to eq("Kino Korner")
     end
 
     it "finds categories by partial slug" do
@@ -121,6 +149,11 @@ RSpec.describe CategoryHashtagDataSource do
       expect(result.ref).to eq("fun:random")
       expect(result.slug).to eq("random")
     end
+
+    it "formats the text correctly for a parent:child category that is found" do
+      result = described_class.search(guardian, "random", 5).first
+      expect(result.text).to eq("Silly Land > Random")
+    end
   end
 
   describe "#search_without_term" do

spec/services/hashtag_autocomplete_service_spec.rb

@@ -212,8 +212,8 @@ RSpec.describe HashtagAutocompleteService do
 
       expect(service.search("book", %w[category tag]).map(&:ref)).to eq(
         [
-          "book-reviews:book", # category exact match on slug, name sorted
           "book-library:book",
+          "book-reviews:book", # category exact match on slug, name sorted
           "book-library", # category starts with match on slug, name sorted
           "book-reviews",
           "bookmania", # tag starts with match on slug, name sorted
@@ -226,8 +226,8 @@ RSpec.describe HashtagAutocompleteService do
       )
       expect(service.search("book", %w[category tag]).map(&:text)).to eq(
         [
-          "Good Books",
+          "Book Library > Horror",
-          "Horror",
+          "Book Reviews > Good Books",
           "Book Library",
           "Book Reviews",
           "bookmania",