Empty Slice/Array throwing an compilation error and UnmarshalJSON is checking for all the attribute should be present

[shysudo]

We upgraded from version v7.3.1 to v10.2.1 facing following issues

1. When fields is empty slice(array) Code generation causing an compilation issue.
   {
   "type": "record",
   "name": "EquipmentDiscoveryStarted",
   "namespace": "io.leitstand.actor.events.controllers",
   "fields": []
   }

   `func (r EquipmentDiscoveryStarted) MarshalJSON() ([]byte, error) {
   var err error // (unused variable error)
   output := make(map[string]json.RawMessage)
   return json.Marshal(output)
   }

   func (r *EquipmentDiscoveryStarted) UnmarshalJSON(data []byte) error {
   var fields map[string]json.RawMessage
   if err := json.Unmarshal(data, &fields); err != nil {
   return err
   }

   var val json.RawMessage // (unused variable error)
   return nil
   }`

2. UnmashalJSON method is causing an issue for checking of all the attribute(struct) throwing error, if not provided value for it, all the attribute become mandatory.
   Example : `func (r *GfastPortReason) UnmarshalJSON(data []byte) error {
   var fields map[string]json.RawMessage
   if err := json.Unmarshal(data, &fields); err != nil {
   return err
   }

   var val json.RawMessage
   val = func() json.RawMessage {
   if v, ok := fields["reason"]; ok {
   return v
   }
   return nil
   }()

   if val != nil {
   if err := json.Unmarshal([]byte(val), &r.Reason); err != nil {
   return err
   }
   } else {
   return fmt.Errorf("no value specified for reason")
   }
   val = func() json.RawMessage {
   if v, ok := fields["description"]; ok {
   return v
   }
   return nil
   }()

   if val != nil {
   if err := json.Unmarshal([]byte(val), &r.Description); err != nil {
   return err
   }
   } else {
   return fmt.Errorf("no value specified for description")
   }
   return nil
   }`

[tanis2000]

Hey Gireesh, issue number one has been fixed in this PR (which has not yet been merged): #202