fix/conf_multi_layer_map (#4407)

Co-authored-by: aiden.ma <Aiden.ma@yijinin.com>

core/conf/config.go

@@ -189,7 +189,7 @@ func buildFieldsInfo(tp reflect.Type, fullName string) (*fieldInfo, error) {
 	switch tp.Kind() {
 	case reflect.Struct:
 		return buildStructFieldsInfo(tp, fullName)
-	case reflect.Array, reflect.Slice:
+	case reflect.Array, reflect.Slice, reflect.Map:
 		return buildFieldsInfo(mapping.Deref(tp.Elem()), fullName)
 	case reflect.Chan, reflect.Func:
 		return nil, fmt.Errorf("unsupported type: %s", tp.Kind())
@@ -332,6 +332,8 @@ func toLowerCaseKeyMap(m map[string]any, info *fieldInfo) map[string]any {
 			res[lk] = toLowerCaseInterface(v, ti)
 		} else if info.mapField != nil {
 			res[k] = toLowerCaseInterface(v, info.mapField)
+		} else if vv, ok := v.(map[string]any); ok {
+			res[k] = toLowerCaseKeyMap(vv, info)
 		} else {
 			res[k] = v
 		}

core/conf/config_test.go

@@ -1192,6 +1192,29 @@ Email = "bar"`)
 			assert.Len(t, c.Value, 2)
 		}
 	})
+
+	t.Run("multi layer map", func(t *testing.T) {
+		type Value struct {
+			User struct {
+				Name string
+			}
+		}
+
+		type Config struct {
+			Value map[string]map[string]Value
+		}
+
+		var input = []byte(`
+[Value.first.User1.User]
+Name = "foo"
+[Value.second.User2.User]
+Name = "bar"
+`)
+		var c Config
+		if assert.NoError(t, LoadFromTomlBytes(input, &c)) {
+			assert.Len(t, c.Value, 2)
+		}
+	})
 }
 
 func Test_getFullName(t *testing.T) {