From 73127535694b251d5cd53ab5ced94611bcc12bca Mon Sep 17 00:00:00 2001
From: Anton Khorev <tony29@yandex.ru>
Date: Mon, 23 Jun 2025 19:21:29 +0300
Subject: [PATCH] Split long version lists into 3 parts, with middle list
 scrollable

---
 app/helpers/numbered_pagination_helper.rb     | 36 +++++++++++++++----
 .../numbered_pagination_helper_test.rb        | 18 ++++++++++
 2 files changed, 47 insertions(+), 7 deletions(-)

diff --git a/app/helpers/numbered_pagination_helper.rb b/app/helpers/numbered_pagination_helper.rb
index 5e3e20f27..5495be67f 100644
--- a/app/helpers/numbered_pagination_helper.rb
+++ b/app/helpers/numbered_pagination_helper.rb
@@ -2,13 +2,35 @@ module NumberedPaginationHelper
   def element_versions_pagination(top_version, active_version: 0, &)
     lists = []
 
-    lists << tag.ul(:class => [
-                      "pagination pagination-sm",
-                      "overflow-x-scroll pb-3", # horizontal scrollbar with reserved space below
-                      "pt-1" # space reserved for focus outlines
-                    ]) do
-      (1..top_version).each do |v|
-        concat element_versions_pagination_item(v, **yield(v), :active => v == active_version)
+    if top_version <= 5
+      lists << tag.ul(:class => "pagination pagination-sm mt-1") do
+        (1..top_version).each do |v|
+          concat element_versions_pagination_item(v, **yield(v), :active => v == active_version)
+        end
+      end
+    else
+      start_list_versions = 1..1
+      end_list_versions = top_version..top_version
+      middle_list_versions = (start_list_versions.last + 1)..(end_list_versions.first - 1)
+
+      lists << tag.ul(:class => "pagination pagination-sm mt-1") do
+        start_list_versions.each do |v|
+          concat element_versions_pagination_item(v, **yield(v), :active => v == active_version)
+        end
+      end
+      lists << tag.ul(:class => [
+                        "pagination pagination-sm",
+                        "overflow-x-scroll pb-3", # horizontal scrollbar with reserved space below
+                        "pt-1" # space reserved for focus outlines
+                      ]) do
+        middle_list_versions.each do |v|
+          concat element_versions_pagination_item(v, **yield(v), :active => v == active_version)
+        end
+      end
+      lists << tag.ul(:class => "pagination pagination-sm mt-1") do
+        end_list_versions.each do |v|
+          concat element_versions_pagination_item(v, **yield(v), :active => v == active_version)
+        end
       end
     end
 
diff --git a/test/helpers/numbered_pagination_helper_test.rb b/test/helpers/numbered_pagination_helper_test.rb
index 87e2df520..377e5a38f 100644
--- a/test/helpers/numbered_pagination_helper_test.rb
+++ b/test/helpers/numbered_pagination_helper_test.rb
@@ -23,6 +23,24 @@ class NumberedPaginationHelperTest < ActionView::TestCase
     end
   end
 
+  def test_element_versions_pagination6
+    pagination = element_versions_pagination(6) { |v| sample_item_data v }
+    pagination_dom = Rails::Dom::Testing.html_document_fragment.parse(pagination)
+    assert_dom pagination_dom, "ul", :count => 3 do |lists|
+      assert_dom lists[0], "> li", 1 do
+        check_version_link sample_item_data(1)
+      end
+      assert_dom lists[1], "> li", 4 do |items|
+        items.each_with_index do |item, i|
+          check_version_link item, sample_item_data(i + 2)
+        end
+      end
+      assert_dom lists[2], "> li", 1 do
+        check_version_link sample_item_data(6)
+      end
+    end
+  end
+
   private
 
   def sample_item_data(version)
-- 
2.39.5