Always display self, first, last pagination links

Author: mecampbellsoup

lib/active_model_serializers/adapter/json_api/pagination_links.rb

@@ -35,19 +35,21 @@ def as_json
         private
 
         def pages_from
-          return {} if collection.total_pages <= FIRST_PAGE
-
           {}.tap do |pages|
-            pages[:self] = collection.current_page
+            pages[:self]  = collection.current_page
+            pages[:first] = FIRST_PAGE
+            pages[:last]  = collection.total_pages
 
-            unless collection.current_page == FIRST_PAGE
-              pages[:first] = FIRST_PAGE
-              pages[:prev]  = collection.current_page - FIRST_PAGE
-            end
+            if collection.total_pages > 0
+              unless collection.current_page == FIRST_PAGE
+                pages[:prev] = collection.current_page - FIRST_PAGE
+              end
 
-            unless collection.current_page == collection.total_pages
-              pages[:next] = collection.current_page + FIRST_PAGE
-              pages[:last] = collection.total_pages
+              unless collection.current_page == collection.total_pages
+                pages[:next] = collection.current_page + FIRST_PAGE
+              end
+            else
+              pages[:last] = FIRST_PAGE
             end
           end
         end

test/adapter/json_api/pagination_links_test.rb

@@ -54,6 +54,14 @@ def data
           }
         end
 
+        def empty_collection_links
+          {
+            self: "#{URI}?page%5Bnumber%5D=1&page%5Bsize%5D=2",
+            first: "#{URI}?page%5Bnumber%5D=1&page%5Bsize%5D=2",
+            last: "#{URI}?page%5Bnumber%5D=1&page%5Bsize%5D=2"
+          }
+        end
+
         def links
           {
             links: {
@@ -71,6 +79,7 @@ def last_page_links
             links: {
               self: "#{URI}?page%5Bnumber%5D=3&page%5Bsize%5D=2",
               first: "#{URI}?page%5Bnumber%5D=1&page%5Bsize%5D=2",
+              last: "#{URI}?page%5Bnumber%5D=3&page%5Bsize%5D=2",
               prev: "#{URI}?page%5Bnumber%5D=2&page%5Bsize%5D=2"
             }
           }
@@ -111,7 +120,7 @@ def expected_response_with_last_page_pagination_links
         def expected_response_with_no_data_pagination_links
           {}.tap do |hash|
             hash[:data] = []
-            hash[:links] = {}
+            hash.merge! links: empty_collection_links
           end
         end