feat(pagination): return meta page_count for paged paginators

Author: utilityboy

lib/jsonapi/operation.rb

@@ -57,6 +57,10 @@ def apply
         options[:record_count] = record_count
       end
 
+      if JSONAPI.configuration.top_level_meta_include_page_count
+        options[:page_count] = page_count
+      end
+
       return JSONAPI::ResourcesOperationResult.new(:ok,
                                                    resource_records,
                                                    options)
@@ -153,6 +157,12 @@ def record_count
       @_record_count ||= records.count(:all)
     end
 
+    def page_count
+      if @paginator.is_a?(PagedPaginator)
+        @_page_count ||= @paginator.calculate_page_count(record_count)
+      end
+    end
+
     def source_resource
       @_source_resource ||= @source_klass.find_by_key(@source_id, context: @context)
     end
@@ -176,6 +186,7 @@ def options
       opts = {}
       opts.merge!(pagination_params: pagination_params) if JSONAPI.configuration.top_level_links_include_pagination
       opts.merge!(record_count: record_count) if JSONAPI.configuration.top_level_meta_include_record_count
+      opts.merge!(page_count: page_count) if JSONAPI.configuration.top_level_meta_include_page_count
       opts
     end
 

lib/jsonapi/operation_result.rb

@@ -32,12 +32,13 @@ def initialize(code, resource, options = {})
   end
 
   class ResourcesOperationResult < OperationResult
-    attr_accessor :resources, :pagination_params, :record_count
+    attr_accessor :resources, :pagination_params, :record_count, :page_count
 
     def initialize(code, resources, options = {})
       @resources = resources
       @pagination_params = options.fetch(:pagination_params, {})
       @record_count = options[:record_count]
+      @page_count = options[:page_count]
       super(code, options)
     end
   end

test/integration/requests/request_test.rb

@@ -442,6 +442,22 @@ def test_filter_related_resources
     JSONAPI.configuration.top_level_meta_include_record_count = false
   end
 
+  def test_page_count_meta
+    Api::V2::BookCommentResource.paginator :paged
+    JSONAPI.configuration.top_level_meta_include_record_count = true
+    JSONAPI.configuration.top_level_meta_include_page_count = true
+    get '/api/v2/books/1/book_comments'
+    assert_equal 26, json_response['meta']['record_count']
+    # based on default page size
+    assert_equal 3, json_response['meta']['page_count']
+    get '/api/v2/books/1/book_comments?page[size]=5'
+    assert_equal 26, json_response['meta']['record_count']
+    assert_equal 6, json_response['meta']['page_count']
+  ensure
+    JSONAPI.configuration.top_level_meta_include_record_count = false
+    JSONAPI.configuration.top_level_meta_include_page_count = false
+  end
+
   def test_pagination_related_resources_without_related
     Api::V2::BookResource.paginator :offset
     Api::V2::BookCommentResource.paginator :offset