Merge pull request #19 from heetch/custom-tag

Add custom tag

config.go

@@ -16,6 +16,11 @@ import (
 // Loader loads configuration keys from backends and stores them is a struct.
 type Loader struct {
 	backends []backend.Backend
+
+	// Tag specifies the tag name used to parse
+	// configuration keys and options.
+	// If empty, "config" is used.
+	Tag string
 }
 
 // NewLoader creates a Loader. If no backend is specified, the loader uses the environment.
@@ -64,7 +69,12 @@ func (l *Loader) parseStruct(ctx context.Context, ref *reflect.Value) error {
 			continue
 		}
 
-		tag := field.Tag.Get("config")
+		tagKey := l.Tag
+		if tagKey == "" {
+			tagKey = "config"
+		}
+
+		tag := field.Tag.Get(tagKey)
 		if tag == "-" {
 			continue
 		}

config_test.go

@@ -363,3 +363,26 @@ func TestTags(t *testing.T) {
 		assert.Equal(t, "", cfg.Key)
 	})
 }
+
+func TestCustomTag(t *testing.T) {
+	s := struct {
+		Name string `custom:"name"`
+		Age  int    `custom:"age"`
+	}{}
+
+	st := store{
+		"name": "name",
+		"age":  "10",
+	}
+
+	err := confita.NewLoader(st).Load(context.Background(), &s)
+	require.NoError(t, err)
+	require.Empty(t, &s)
+
+	l := confita.NewLoader(st)
+	l.Tag = "custom"
+	err = l.Load(context.Background(), &s)
+	require.NoError(t, err)
+	require.Equal(t, "name", s.Name)
+	require.Equal(t, 10, s.Age)
+}