fix: better handling of zero values; no panic for generic types

context.go

@@ -239,13 +239,13 @@ func shallowStructToMap(v reflect.Value, result map[string]interface{}) {
 			if name == "-" {
 				continue
 			}
-			if len(parts) == 2 && parts[1] == "omitempty" && v.Field(i).IsZero() {
+			if len(parts) > 1 && parts[1] == "omitempty" {
 				vf := v.Field(i)
 				zero := vf.IsZero()
 				if vf.Kind() == reflect.Slice || vf.Kind() == reflect.Map {
 					// Special case: omit if they have no items in them to match the
 					// JSON encoder.
-					zero = vf.Len() > 0
+					zero = vf.Len() == 0
 				}
 				if zero {
 					continue

graphql_model.go

@@ -32,7 +32,9 @@ func getFields(typ reflect.Type) []reflect.StructField {
 		if newTyp.Kind() == reflect.Ptr {
 			newTyp = newTyp.Elem()
 		}
-		fields = append(fields, getFields(newTyp)...)
+		if newTyp.Kind() == reflect.Struct {
+			fields = append(fields, getFields(newTyp)...)
+		}
 	}
 
 	return fields

schema/schema.go

@@ -200,7 +200,9 @@ func getFields(typ reflect.Type) []reflect.StructField {
 		if newTyp.Kind() == reflect.Ptr {
 			newTyp = newTyp.Elem()
 		}
-		fields = append(fields, getFields(newTyp)...)
+		if newTyp.Kind() == reflect.Struct {
+			fields = append(fields, getFields(newTyp)...)
+		}
 	}
 
 	return fields
@@ -542,6 +544,8 @@ func GenerateWithMode(t reflect.Type, mode Mode, schema *Schema) (*Schema, error
 		return GenerateWithMode(t.Elem(), mode, schema)
 	case reflect.Interface:
 		// Interfaces can be any type.
+	case reflect.Uintptr, reflect.UnsafePointer, reflect.Func:
+		// Ignored...
 	default:
 		return nil, fmt.Errorf("unsupported type %s from %s", t.Kind(), t)
 	}