Amend tests to always include all pagination keys

lib/active_model_serializers/adapter/json_api/pagination_links.rb

@@ -3,6 +3,7 @@ module ActiveModelSerializers
     class JsonApi < Base
       class PaginationLinks
         MissingSerializationContextError = Class.new(KeyError)
+        FIRST_PAGE = 1
 
         attr_reader :collection, :context
 
@@ -42,20 +43,36 @@ module ActiveModelSerializers
           url_for_page(1)
         end
 
+        def last_page_url
+          if collection.total_pages == 0
+            url_for_page(FIRST_PAGE)
+          else
+            url_for_page(collection.total_pages)
+          end
+        end
+
         def prev_page_url
-          return nil if collection.first_page?
-          url_for_page(collection.prev_page)
+          return nil if collection.current_page == FIRST_PAGE
+          url_for_page(collection.current_page - FIRST_PAGE)
         end
 
         def next_page_url
-          return nil if collection.last_page? || collection.out_of_range?
+          return nil if (collection.total_pages == 0 || collection.current_page == collection.total_pages)
           url_for_page(collection.next_page)
         end
 
         def url_for_page(number)
           params = query_parameters.dup
-          params[:page] = { page: per_page, number: number }
-          context.url_for(action: :index, params: params)
+          params[:page] = { size: per_page, number: number }
+          "#{url(adapter_options)}?#{params.to_query}"
+        end
+
+        def url(options = {})
+          @url ||= options.fetch(:links, {}).fetch(:self, nil) || request_url
+        end
+
+        def request_url
+          @request_url ||= context.request_url
         end
 
         def query_parameters