add-special-handling

CHANGELOG.md

@@ -10,6 +10,8 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 ### Added
 
 - Support converting unmarshalled configurations to `interface{}`.
+Defaults to `map[string]interface{}` for now if the source has nested values and
+the destination is just an `interface{}`.
 
 ## [1.3.0] - 2024-08-26
 

internal/convert/converter.go

@@ -92,9 +92,7 @@ func (c Converter) convert(name string, from any, toVal reflect.Value) error { /
 	case toVal.Kind() == reflect.Struct:
 		return c.convertStruct(name, fromVal, toVal)
 	case toVal.Kind() == reflect.Interface: // Right after all other checks.
-		toVal.Set(fromVal)
-
-		return nil
+		return c.convertInterface(name, fromVal, toVal)
 	default:
 		// If it reached here then it weren't able to convert it.
 		return fmt.Errorf("%s: unsupported type: %s", name, toVal.Kind()) //nolint:err113
@@ -554,6 +552,55 @@ func (c Converter) convertStruct(name string, fromVal, toVal reflect.Value) erro
 	}
 }
 
+func (c Converter) convertInterface(name string, fromVal, toVal reflect.Value) error {
+	switch fromVal.Kind() {
+	case reflect.Map:
+		if fromVal.IsNil() {
+			toVal.SetZero()
+
+			return nil
+		}
+
+		if toVal.IsNil() {
+			toVal.Set(reflect.MakeMapWithSize(fromVal.Type(), fromVal.Len()))
+		}
+
+		fromKeyType := fromVal.Type().Key()
+		fromValueType := fromVal.Type().Elem()
+		errs := make([]error, 0, fromVal.Len())
+		for _, fromKeyVal := range fromVal.MapKeys() {
+			fieldName := name + "[" + fromKeyVal.String() + "]"
+
+			fromValueVal := fromVal.MapIndex(fromKeyVal)
+			toValueVal := reflect.New(fromValueType)
+			key, value := maps.Unpack(fromValueVal.Interface())
+			if err := c.convert(fieldName, value, pointer(toValueVal)); err != nil {
+				errs = append(errs, err)
+
+				continue
+			}
+
+			if key == "" {
+				key = fromKeyVal.String()
+			}
+			toKeyVal := reflect.New(fromKeyType)
+			if err := c.convert(fieldName, key, pointer(toKeyVal)); err != nil {
+				errs = append(errs, err)
+
+				continue
+			}
+
+			toVal.Elem().SetMapIndex(reflect.Indirect(toKeyVal), reflect.Indirect(toValueVal))
+		}
+
+		return errors.Join(errs...)
+	default:
+		toVal.Set(fromVal)
+
+		return nil
+	}
+}
+
 func pointer(val reflect.Value) reflect.Value {
 	if val.Kind() == reflect.Pointer {
 		if val.IsNil() {

internal/convert/converter_test.go

@@ -974,6 +974,21 @@ func TestConverter(t *testing.T) { //nolint:maintidx
 				Key2: "value2",
 			}),
 		},
+		{
+			description: "packed KV and field to interface{}",
+			from: map[string]interface{}{
+				"key1": maps.KeyValue{
+					Key:   "key1",
+					Value: "value1",
+				},
+				"key2": "value2",
+			},
+			to: pointer(any(nil)),
+			expected: pointer(any(map[string]interface{}{
+				"key1": "value1",
+				"key2": "value2",
+			})),
+		},
 		{
 			description: "slice to interface",
 			from:        []int{1, 2, 3},