refactor: Obtain the JSON from the response rather than the call

Author: kgilpin

lib/appmap/handler.rb

@@ -5,6 +5,7 @@
 module AppMap
   # Specific hook handler classes and general related utilities.
   module Handler
+    TEMPLATE_RENDER_FORMAT = 'appmap.handler.template.return_value_format'
     TEMPLATE_RENDER_VALUE = 'appmap.handler.template.return_value'
 
     # Try to find handler module with a given name.

lib/appmap/handler/rails/render_handler.rb

@@ -6,12 +6,23 @@ module Rails
       class RenderHandler < AppMap::Handler::Function
         def handle_call(receiver, args)
           options, _ = args
+          # TODO: :file, :xml
+          # https://guides.rubyonrails.org/v5.1/layouts_and_rendering.html
           if options[:json]
-            Thread.current[TEMPLATE_RENDER_VALUE] = options[:json]
+            Thread.current[TEMPLATE_RENDER_FORMAT] = :json
           end
 
           super
         end
+
+        def handle_return(call_event_id, elapsed, return_value, exception)
+          if Thread.current[TEMPLATE_RENDER_FORMAT] == :json
+            Thread.current[TEMPLATE_RENDER_VALUE] = JSON.parse(return_value) rescue nil
+          end
+          Thread.current[TEMPLATE_RENDER_FORMAT] = nil
+
+          super
+        end
       end
     end
   end

lib/appmap/handler/rails/request_handler.rb

@@ -47,7 +47,7 @@ def to_h
                     value: self.class.display_string(val),
                     object_id: val.__id__,
                   }.tap do |message|
-                    AppMap::Event::MethodEvent.add_schema message, val, always: true
+                    AppMap::Event::MethodEvent.add_schema message, val
                   end
                 end
               end

spec/rails_recording_spec.rb

@@ -55,7 +55,7 @@ def rails_versions
                   'status_code' => 201,
                   'headers' => hash_including('Content-Type' => 'application/json; charset=utf-8'),
                 ),
-                'return_value' => hash_including('class' => 'User', 'object_id' => Integer, 'properties' => include({'name' => 'login', 'class' => 'String'})),
+                'return_value' => hash_including('class' => 'Hash', 'object_id' => Integer, 'properties' => include({'name' => 'login', 'class' => 'String'})),
               )
             )
           end