Switch to cursor-based pagination with geared_pagination

Gemfile

@@ -14,3 +14,5 @@ gem 'selenium-webdriver'
 gem 'sqlite3'
 gem 'webdrivers', require: false
 gem 'yard'
+
+gem 'geared_pagination', '~> 1.1'

Gemfile.lock

@@ -6,7 +6,6 @@ PATH
       activejob (>= 6.0)
       activerecord (>= 6.0)
       job-iteration (~> 1.1)
-      pagy (~> 3.9)
       railties (>= 6.0)
 
 GEM
@@ -89,6 +88,9 @@ GEM
     concurrent-ruby (1.1.8)
     crass (1.0.6)
     erubi (1.10.0)
+    geared_pagination (1.1.0)
+      activesupport (>= 5.0)
+      addressable (>= 2.5.0)
     globalid (0.4.2)
       activesupport (>= 4.2.0)
     i18n (1.8.9)
@@ -112,7 +114,6 @@ GEM
     nokogiri (1.11.1)
       mini_portile2 (~> 2.5.0)
       racc (~> 1.4)
-    pagy (3.11.0)
     parallel (1.20.1)
     parser (2.7.2.0)
       ast (~> 2.4.1)
@@ -206,6 +207,7 @@ PLATFORMS
 
 DEPENDENCIES
   capybara
+  geared_pagination (~> 1.1)
   maintenance_tasks!
   mocha
   pry-byebug

app/controllers/maintenance_tasks/application_controller.rb

@@ -5,8 +5,6 @@ module MaintenanceTasks
   #
   # Can be extended to add different authentication and authorization code.
   class ApplicationController < ActionController::Base
-    include Pagy::Backend
-
     BULMA_CDN = 'https://cdn.jsdelivr.net'
 
     content_security_policy do |policy|

app/controllers/maintenance_tasks/tasks_controller.rb

@@ -20,7 +20,9 @@ def index
     def show
       @task = TaskData.find(params.fetch(:id))
       set_refresh if @task.last_run&.active?
-      @pagy, @previous_runs = pagy(@task.previous_runs)
+      set_page_and_extract_portion_from(@task.previous_runs,
+        ordered_by: { created_at: :desc })
+      set_paginated_headers
     end
 
     # Runs a given Task and redirects to the Task page.

app/helpers/maintenance_tasks/application_helper.rb

@@ -4,15 +4,19 @@ module MaintenanceTasks
   #
   # @api private
   module ApplicationHelper
-    include Pagy::Frontend
-
-    # Renders pagination for the page, if there is more than one page present.
-    #
-    # @param pagy [Pagy] the pagy instance containing pagination details,
-    #   including the number of pages the results are spread across.
-    # @return [String] the HTML to render for pagination.
-    def pagination(pagy)
-      raw(pagy_bulma_nav(pagy)) if pagy.pages > 1
+    # Renders pagination-related text showing the current page, total pages,
+    # and total number of records, if there is more than one page present.
+    # @param page [GearedPagination::Page] the page instance containing
+    #   pagination details.
+    # @param record_type [String] the type of the recordset.
+    # @return [String] the HTML to render with the helpful pagination text.
+    def pagination_text(page, record_type)
+      page_count = page.recordset.page_count
+      if page_count > 1
+        record_count = page.recordset.records_count
+        tag.span("Showing page #{page.number} of #{page_count} " \
+        "(#{record_count} total #{record_type.pluralize(record_count)})")
+      end
     end
 
     # Renders a time element with the given datetime, worded as relative to the

app/models/maintenance_tasks/task_data.rb

@@ -83,7 +83,7 @@ def code
     # @return [nil] if there are no Runs associated with the Task.
     def last_run
       return @last_run if defined?(@last_run)
-      @last_run = runs.first
+      @last_run = runs.last
     end
 
     # Returns the set of Run records associated with the Task previous to the
@@ -135,7 +135,7 @@ def csv_task?
     private
 
     def runs
-      Run.where(task_name: name).with_attached_csv.order(created_at: :desc)
+      Run.where(task_name: name).with_attached_csv
     end
   end
 end

app/views/maintenance_tasks/tasks/show.html.erb

@@ -41,12 +41,11 @@
   <pre><code><%= highlight_code(code) %></code></pre>
 <% end %>
 
-<% if @previous_runs.present? %>
+<% if @task.previous_runs.any? %>
   <hr/>
 
   <h4 class="title is-4">Previous Runs</h4>
-
-  <%= render @previous_runs %>
-
-  <%= pagination(@pagy) %>
+  <%= render @page.records %>
+  <%= pagination_text(@page, 'run')%>
+  <%= link_to "Next page", task_path(@task, page: @page.next_param) unless @page.last? %>
 <% end %>

config/initializers/geared_pagination.rb

@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+GearedPagination::Engine.config.after_initialize do
+  ActiveSupport.on_load(:action_controller) do
+    ActionController::Base.skip_after_action(:set_paginated_headers)
+  end
+end

lib/maintenance_tasks.rb

@@ -6,8 +6,6 @@
 
 require 'job-iteration'
 require 'maintenance_tasks/engine'
-require 'pagy'
-require 'pagy/extras/bulma'
 
 # Force the TaskJob class to load so we can verify upstream compatibility with
 # the JobIteration gem

maintenance_tasks.gemspec

@@ -26,6 +26,5 @@ Gem::Specification.new do |spec|
   spec.add_dependency('activejob', '>= 6.0')
   spec.add_dependency('activerecord', '>= 6.0')
   spec.add_dependency('job-iteration', '~> 1.1')
-  spec.add_dependency('pagy', '~> 3.9')
   spec.add_dependency('railties', '>= 6.0')
 end

test/helpers/maintenance_tasks/application_helper_test.rb

@@ -3,18 +3,23 @@
 
 module MaintenanceTasks
   class ApplicationHelperTest < ActionView::TestCase
-    setup { @pagy = mock }
+    setup { @page = mock }
 
-    test '#pagination returns nil if pages is less than or equal to 1' do
-      @pagy.expects(pages: 1)
-      expects(:pagy_bulma_nav).never
-      assert_nil pagination(@pagy)
+    test '#pagination_text returns nil if pages is less than or equal to 1' do
+      @page.stubs(recordset: mock(page_count: 1))
+      assert_nil pagination_text(@page, 'run')
     end
 
-    test '#pagination returns pagination element if pages is greater than 1' do
-      @pagy.expects(pages: 2)
-      expects(:pagy_bulma_nav).with(@pagy).returns('pagination')
-      assert_equal 'pagination', pagination(@pagy)
+    test '#pagination_text returns text with pagination info if pages is greater than 1' do
+      page_number = 1
+      total_pages = 2
+      records_count = 12
+      @page.stubs(
+        number: page_number,
+        recordset: mock(page_count: total_pages, records_count: records_count)
+      )
+      assert_equal '<span>Showing page 1 of 2 (12 total runs)</span>',
+        pagination_text(@page, 'run')
     end
 
     test '#time_ago returns a time element with the given datetime worded as relative to now and ISO 8601 UTC time in title attribute' do

test/models/maintenance_tasks/task_data_test.rb

@@ -80,8 +80,8 @@ class TaskDataTest < ActiveSupport::TestCase
       task_data = TaskData.find('Maintenance::UpdatePostsTask')
 
       assert_equal 2, task_data.previous_runs.count
-      assert_equal run_2, task_data.previous_runs.first
-      assert_equal run_1, task_data.previous_runs.last
+      assert_equal run_1, task_data.previous_runs.first
+      assert_equal run_2, task_data.previous_runs.last
     end
 
     test '#previous_runs is empty when there are no Runs for the Task' do