Incorporate the review comments.

lib/koala/api/graph_batch_api.rb

@@ -58,9 +58,10 @@ def execute(http_options = {})
             # when http_component is set we receive Koala::Http_service response object
             # from graph_call so this needs to be parsed
             # as generate_results method handles only JSON response
-            if http_options[:http_component]
-              response = JSON.load(response.body)
-              raise bad_response("Facebook returned an invalid body") unless response.is_a?(Array)
+            if http_options[:http_component] && http_options[:http_component] == :response
+              response = json_body(response.body)
+
+              raise bad_response('Facebook returned an invalid body') unless response.is_a?(Array)
             end
 
             batch_results += generate_results(response, batch)
@@ -131,10 +132,13 @@ def batch_args(calls_for_batch)
         JSON.dump calls
       end
 
-      def json_body(response)
-        # quirks_mode is needed because Facebook sometimes returns a raw true or false value --
-        # in Ruby 2.4 we can drop that.
-        JSON.parse(response.fetch("body"), quirks_mode: true)
+      def json_body(body)
+        return if body.nil?
+
+        JSON.parse(body)
+      rescue JSON::ParserError => e
+        Koala::Utils.logger.error("#{e.class}: #{e.message} while parsing #{body}")
+        nil
       end
 
       def desired_component(component:, response:, headers:)
@@ -146,11 +150,7 @@ def desired_component(component:, response:, headers:)
         # facebook returns the headers as an array of k/v pairs, but we want a regular hash
         when :headers then headers
         # (see note in regular api method about JSON parsing)
-        when :response
-          Koala::HTTPService::Response.new(
-              response["code"].to_i,
-              response["body"],
-              headers)
+        when :response then result
         else GraphCollection.evaluate(result, original_api)
         end
       end

spec/cases/graph_api_batch_spec.rb

@@ -401,27 +401,78 @@
           expect result[0].body == "{\"id\":\"1234\"}"
           expect result[0].headers == {"Content-Type"=>"text/javascript; charset=UTF-8"}
         end
-        
-        describe "if it errors" do
-          it "raises an APIError if the response is not 200" do
-            allow(Koala).to receive(:make_request).and_return(Koala::HTTPService::Response.new(500, "[]", {}))
+
+        describe 'if it errors' do
+          it 'raises an APIError if the response is not 200' do
+            allow(Koala).to receive(:make_request).and_return(Koala::HTTPService::Response.new(500, '[]', {}))
             expect {
-              Koala::Facebook::API.new("foo").batch {|batch_api| batch_api.get_object('me') }
+              Koala::Facebook::API.new('foo').batch { |batch_api| batch_api.get_object('me') }
             }.to raise_exception(Koala::Facebook::APIError)
           end
 
-          it "raises a BadFacebookResponse if the body is empty" do
-            allow(Koala).to receive(:make_request).and_return(Koala::HTTPService::Response.new(200, "", {}))
-            expect {
-              Koala::Facebook::API.new("foo").batch {|batch_api| batch_api.get_object('me') }
-            }.to raise_exception(Koala::Facebook::BadFacebookResponse)
-          end
-
-          it "raises a BadFacebookResponse if the body is non-empty, non-array" do
-            allow(Koala).to receive(:make_request).and_return(Koala::HTTPService::Response.new(200, "200", {}))
+          it 'raises a BadFacebookResponse if the body is empty' do
+            allow(Koala).to receive(:make_request).and_return(Koala::HTTPService::Response.new(200, '', {}))
             expect {
-              Koala::Facebook::API.new("foo").batch(http_component: :response) {|batch_api| batch_api.get_object('me') }
-            }.to raise_exception(Koala::Facebook::BadFacebookResponse, /Facebook returned an invalid body \[HTTP 200\]/)
+              Koala::Facebook::API.new('foo').batch { |batch_api| batch_api.get_object('me') }
+            }.to raise_exception(Koala::Facebook::BadFacebookResponse, /Facebook returned an empty body \[HTTP 200\]/)
+          end
+
+          describe 'handle invalid body errors' do
+            describe 'with http_component set to :response' do
+              it 'raises a BadFacebookResponse if the body is non-empty, non-array' do
+                allow(Koala).to receive(:make_request).and_return(Koala::HTTPService::Response.new(200, '200', {}))
+                expect {
+                  Koala::Facebook::API.new('foo').batch(http_component: :response) do |batch_api|
+                    batch_api.get_object('me')
+                  end
+                }.to raise_exception(Koala::Facebook::BadFacebookResponse, /Facebook returned an invalid body \[HTTP 200\]/)
+              end
+
+              it 'raises a BadFacebookResponse if the body is invalid JSON' do
+                allow(Koala).to receive(:make_request).and_return(Koala::HTTPService::Response.new(200, '{"\"id\":\1234\"}"}', {}))
+                expect {
+                  Koala::Facebook::API.new('foo').batch(http_component: :response) do |batch_api|
+                    batch_api.get_object('me')
+                  end
+                }.to raise_exception(Koala::Facebook::BadFacebookResponse, /Facebook returned an invalid body \[HTTP 200\]/)
+              end
+            end
+
+            describe 'with http_component set to :headers' do
+              it 'should not raise a BadFacebookResponse if the body is non-empty, non-array' do
+                allow(Koala).to receive(:make_request).and_return(Koala::HTTPService::Response.new(200, '200', {}))
+                expect {
+                  Koala::Facebook::API.new('foo').batch(http_component: :headers) { |batch_api| batch_api.get_object('me') }
+                }.not_to raise_exception(Koala::Facebook::BadFacebookResponse, /Facebook returned an invalid body \[HTTP 200\]/)
+              end
+
+              it 'should not raise a BadFacebookResponse if the body is invalid JSON' do
+                allow(Koala).to receive(:make_request).and_return(Koala::HTTPService::Response.new(200, '{"\"id\":\1234\"}"}', {}))
+                expect {
+                  Koala::Facebook::API.new('foo').batch(http_component: :headers) do |batch_api|
+                    batch_api.get_object('me')
+                  end
+                }.not_to raise_exception(Koala::Facebook::BadFacebookResponse, /Facebook returned an invalid body \[HTTP 200\]/)
+              end
+            end
+
+            describe 'with http_component set to :status' do
+              it 'should not raise a BadFacebookResponse if the body is non-empty, non-array' do
+                allow(Koala).to receive(:make_request).and_return(Koala::HTTPService::Response.new(200, '200', {}))
+                expect {
+                  Koala::Facebook::API.new('foo').batch(http_component: :status) { |batch_api| batch_api.get_object('me') }
+                }.not_to raise_exception(Koala::Facebook::BadFacebookResponse, /Facebook returned an invalid body \[HTTP 200\]/)
+              end
+
+              it 'should not raise a BadFacebookResponse if the body is invalid JSON' do
+                allow(Koala).to receive(:make_request).and_return(Koala::HTTPService::Response.new(200, '{"\"id\":\1234\"}"}', {}))
+                expect {
+                  Koala::Facebook::API.new('foo').batch(http_component: :status) do |batch_api|
+                    batch_api.get_object('me')
+                  end
+                }.not_to raise_exception(Koala::Facebook::BadFacebookResponse, /Facebook returned an invalid body \[HTTP 200\]/)
+              end
+            end
           end
 
           context "with error info" do