From 465ee7792ff48905088efdf3df6f718081b5e244 Mon Sep 17 00:00:00 2001
From: Eugen Rochko <eugen@zeonfederated.com>
Date: Thu, 7 Apr 2022 18:06:15 +0200
Subject: [PATCH] Fix pagination header on empty trends responses in REST API
 (#17986)

---
 app/controllers/api/v1/trends/links_controller.rb    | 6 +++++-
 app/controllers/api/v1/trends/statuses_controller.rb | 6 +++++-
 app/controllers/api/v1/trends/tags_controller.rb     | 6 +++++-
 app/models/trends/query.rb                           | 2 +-
 4 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/app/controllers/api/v1/trends/links_controller.rb b/app/controllers/api/v1/trends/links_controller.rb
index b1cde5a4b..2385fe438 100644
--- a/app/controllers/api/v1/trends/links_controller.rb
+++ b/app/controllers/api/v1/trends/links_controller.rb
@@ -36,13 +36,17 @@ class Api::V1::Trends::LinksController < Api::BaseController
   end
 
   def next_path
-    api_v1_trends_links_url pagination_params(offset: offset_param + limit_param(DEFAULT_LINKS_LIMIT))
+    api_v1_trends_links_url pagination_params(offset: offset_param + limit_param(DEFAULT_LINKS_LIMIT)) if records_continue?
   end
 
   def prev_path
     api_v1_trends_links_url pagination_params(offset: offset_param - limit_param(DEFAULT_LINKS_LIMIT)) if offset_param > limit_param(DEFAULT_LINKS_LIMIT)
   end
 
+  def records_continue?
+    @links.size == limit_param(DEFAULT_LINKS_LIMIT)
+  end
+
   def offset_param
     params[:offset].to_i
   end
diff --git a/app/controllers/api/v1/trends/statuses_controller.rb b/app/controllers/api/v1/trends/statuses_controller.rb
index 4977803fb..1f2fff582 100644
--- a/app/controllers/api/v1/trends/statuses_controller.rb
+++ b/app/controllers/api/v1/trends/statuses_controller.rb
@@ -36,7 +36,7 @@ class Api::V1::Trends::StatusesController < Api::BaseController
   end
 
   def next_path
-    api_v1_trends_statuses_url pagination_params(offset: offset_param + limit_param(DEFAULT_STATUSES_LIMIT))
+    api_v1_trends_statuses_url pagination_params(offset: offset_param + limit_param(DEFAULT_STATUSES_LIMIT)) if records_continue?
   end
 
   def prev_path
@@ -46,4 +46,8 @@ class Api::V1::Trends::StatusesController < Api::BaseController
   def offset_param
     params[:offset].to_i
   end
+
+  def records_continue?
+    @statuses.size == limit_param(DEFAULT_STATUSES_LIMIT)
+  end
 end
diff --git a/app/controllers/api/v1/trends/tags_controller.rb b/app/controllers/api/v1/trends/tags_controller.rb
index 329ef5ae7..38003f599 100644
--- a/app/controllers/api/v1/trends/tags_controller.rb
+++ b/app/controllers/api/v1/trends/tags_controller.rb
@@ -32,7 +32,7 @@ class Api::V1::Trends::TagsController < Api::BaseController
   end
 
   def next_path
-    api_v1_trends_tags_url pagination_params(offset: offset_param + limit_param(DEFAULT_TAGS_LIMIT))
+    api_v1_trends_tags_url pagination_params(offset: offset_param + limit_param(DEFAULT_TAGS_LIMIT)) if records_continue?
   end
 
   def prev_path
@@ -42,4 +42,8 @@ class Api::V1::Trends::TagsController < Api::BaseController
   def offset_param
     params[:offset].to_i
   end
+
+  def records_continue?
+    @tags.size == limit_param(DEFAULT_TAGS_LIMIT)
+  end
 end
diff --git a/app/models/trends/query.rb b/app/models/trends/query.rb
index 231b65228..f19df162f 100644
--- a/app/models/trends/query.rb
+++ b/app/models/trends/query.rb
@@ -59,7 +59,7 @@ class Trends::Query
     @records
   end
 
-  delegate :each, :empty?, :first, :last, to: :records
+  delegate :each, :empty?, :first, :last, :size, to: :records
 
   def to_ary
     records.dup