Use all next/previous link params

lib/shopify_api/collection_pagination.rb

@@ -1,46 +1,46 @@
+require 'pry'
 module ShopifyAPI
   module CollectionPagination
 
     def next_page?
-      next_page_info.present?
+      next_url_params.present?
     end
 
     def previous_page?
-      previous_page_info.present?
+      previous_url_params.present?
     end
 
     def fetch_next_page
-      fetch_page(next_page_info)
+      fetch_page(next_url_params)
     end
 
     def fetch_previous_page
-      fetch_page(previous_page_info)
+      fetch_page(previous_url_params)
     end
 
     private
 
     AVAILABLE_IN_VERSION = ShopifyAPI::ApiVersion::Unstable.new
 
-    def fetch_page(page_info)
-      return [] unless page_info
+    def fetch_page(url_params)
+      return [] unless url_params.present?
 
-      resource_class.where(original_params.merge(page_info: page_info))
+      resource_class.where(url_params)
     end
 
-    def previous_page_info
-      @previous_page_info ||= extract_page_info(pagination_link_headers.previous_link)
+    def previous_url_params
+      @previous_url_params ||= extract_url_params(pagination_link_headers.previous_link)
     end
 
-    def next_page_info
-      @next_page_info ||= extract_page_info(pagination_link_headers.next_link)
+    def next_url_params
+      @next_url_params ||= extract_url_params(pagination_link_headers.next_link)
     end
 
-    def extract_page_info(link_header)
+    def extract_url_params(link_header)
       raise NotImplementedError unless ShopifyAPI::Base.api_version >= AVAILABLE_IN_VERSION
 
       return nil unless link_header.present?
-
-      CGI.parse(link_header.url.query).dig("page_info", 0)
+      Rack::Utils.parse_nested_query(link_header.url.query)
     end
 
     def pagination_link_headers

test/pagination_test.rb

@@ -9,14 +9,12 @@ def setup
     @next_page_info = "eyJkaXJlY3Rpb24iOiJuZXh0IiwibGFzdF9pZCI6NDQwMDg5NDIzLCJsYXN0X3ZhbHVlIjoiNDQwMDg5NDIzIn0%3D"
     @previous_page_info = "eyJsYXN0X2lkIjoxMDg4MjgzMDksImxhc3RfdmFsdWUiOiIxMDg4MjgzMDkiLCJkaXJlY3Rpb24iOiJuZXh0In0%3D"
 
-    @next_link_header = "<https://this-is-my-test-shop.myshopify.com/admin/api/unstable/orders.json?page_info=#{@next_page_info}>; rel=\"next\""
-    @previous_link_header = "<https://this-is-my-test-shop.myshopify.com/admin/api/unstable/orders.json?page_info=#{@previous_page_info}>; rel=\"previous\""
+    @next_link_header = "<https://this-is-my-test-shop.myshopify.com/admin/api/unstable/orders.json?page_info=#{@next_page_info}>; rel=\"next\">"
+    @previous_link_header = "<https://this-is-my-test-shop.myshopify.com/admin/api/unstable/orders.json?page_info=#{@previous_page_info}>; rel=\"previous\">"
   end
 
-  test "navigates using next and previous link headers" do
-    link_header =
-      "<https://this-is-my-test-shop.myshopify.com/admin/api/unstable/orders.json?page_info=#{@previous_page_info}>; rel=\"previous\",\
-      <https://this-is-my-test-shop.myshopify.com/admin/api/unstable/orders.json?page_info=#{@next_page_info}>; rel=\"next\""
+  test "navigates using next and previous link headers with no original params" do
+    link_header ="#{@previous_link_header}, #{@next_link_header}"
 
     fake 'orders', :method => :get, :status => 200, api_version: @version, :body => load_fixture('orders'), :link => link_header
     orders = ShopifyAPI::Order.all
@@ -28,7 +26,6 @@ def setup
       status: 200,
       body: load_fixture('orders')
     )
-
     next_page = orders.fetch_next_page
     assert_equal 450789469, next_page.first.id
 
@@ -44,24 +41,26 @@ def setup
     assert_equal 1122334455, previous_page.first.id
   end
 
-  test "retains previous querystring parameters" do
+  test "uses all passed in querystring parameters" do
+    params = "page_info=#{@next_page_info}&limit=50&fields=#{CGI.escape('id,created_at')}"
+    @next_link_header = "<https://this-is-my-test-shop.myshopify.com/admin/api/unstable/orders.json?#{params}>; rel=\"next\">"
     fake(
       'orders',
       method: :get,
       status: 200,
       api_version: @version,
-      url: "https://this-is-my-test-shop.myshopify.com/admin/api/unstable/orders.json?fields=id%2Cupdated_at",
+      url: "https://this-is-my-test-shop.myshopify.com/admin/api/unstable/orders.json?fields=id%2Cupdated_at&limit=100",
       body: load_fixture('orders'),
       link: @next_link_header
     )
-    orders = ShopifyAPI::Order.where(fields: 'id,updated_at')
+    orders = ShopifyAPI::Order.where(fields: 'id,updated_at', limit: 100)
 
     fake(
       'orders',
       method: :get,
       status: 200,
       api_version: @version,
-      url: "https://this-is-my-test-shop.myshopify.com/admin/api/unstable/orders.json?fields=id%2Cupdated_at&page_info=#{@next_page_info}",
+      url: "https://this-is-my-test-shop.myshopify.com/admin/api/unstable/orders.json?fields=id%2Ccreated_at&limit=50&page_info=#{@next_page_info}",
       body: load_fixture('orders')
     )
     next_page = orders.fetch_next_page