struct: reflect slice elements to shadows when 'allowShadow' tag is presented (#196)

ini.go

@@ -36,7 +36,7 @@ const (
 
 	// Maximum allowed depth when recursively substituing variable names.
 	depthValues = 99
-	version     = "1.43.1"
+	version     = "1.44.0"
 )
 
 // Version returns current package version literal.

struct.go

@@ -349,14 +349,43 @@ func StrictMapTo(v, source interface{}, others ...interface{}) error {
 }
 
 // reflectSliceWithProperType does the opposite thing as setSliceWithProperType.
-func reflectSliceWithProperType(key *Key, field reflect.Value, delim string) error {
+func reflectSliceWithProperType(key *Key, field reflect.Value, delim string, allowShadow bool) error {
 	slice := field.Slice(0, field.Len())
 	if field.Len() == 0 {
 		return nil
 	}
+	sliceOf := field.Type().Elem().Kind()
+
+	if allowShadow {
+		var keyWithShadows *Key
+		for i := 0; i < field.Len(); i++ {
+			var val string
+			switch sliceOf {
+			case reflect.String:
+				val = slice.Index(i).String()
+			case reflect.Int, reflect.Int64:
+				val = fmt.Sprint(slice.Index(i).Int())
+			case reflect.Uint, reflect.Uint64:
+				val = fmt.Sprint(slice.Index(i).Uint())
+			case reflect.Float64:
+				val = fmt.Sprint(slice.Index(i).Float())
+			case reflectTime:
+				val = slice.Index(i).Interface().(time.Time).Format(time.RFC3339)
+			default:
+				return fmt.Errorf("unsupported type '[]%s'", sliceOf)
+			}
+
+			if i == 0 {
+				keyWithShadows = newKey(key.s, key.name, val)
+			} else {
+				keyWithShadows.AddShadow(val)
+			}
+		}
+		key = keyWithShadows
+		return nil
+	}
 
 	var buf bytes.Buffer
-	sliceOf := field.Type().Elem().Kind()
 	for i := 0; i < field.Len(); i++ {
 		switch sliceOf {
 		case reflect.String:
@@ -374,12 +403,12 @@ func reflectSliceWithProperType(key *Key, field reflect.Value, delim string) err
 		}
 		buf.WriteString(delim)
 	}
-	key.SetValue(buf.String()[:buf.Len()-1])
+	key.SetValue(buf.String()[:buf.Len()-len(delim)])
 	return nil
 }
 
 // reflectWithProperType does the opposite thing as setWithProperType.
-func reflectWithProperType(t reflect.Type, key *Key, field reflect.Value, delim string) error {
+func reflectWithProperType(t reflect.Type, key *Key, field reflect.Value, delim string, allowShadow bool) error {
 	switch t.Kind() {
 	case reflect.String:
 		key.SetValue(field.String())
@@ -394,7 +423,7 @@ func reflectWithProperType(t reflect.Type, key *Key, field reflect.Value, delim
 	case reflectTime:
 		key.SetValue(fmt.Sprint(field.Interface().(time.Time).Format(time.RFC3339)))
 	case reflect.Slice:
-		return reflectSliceWithProperType(key, field, delim)
+		return reflectSliceWithProperType(key, field, delim, allowShadow)
 	default:
 		return fmt.Errorf("unsupported type '%s'", t)
 	}
@@ -439,12 +468,12 @@ func (s *Section) reflectFrom(val reflect.Value) error {
 			continue
 		}
 
-		opts := strings.SplitN(tag, ",", 2)
-		if len(opts) == 2 && opts[1] == "omitempty" && isEmptyValue(field) {
+		rawName, omitEmpty, allowShadow := parseTagOptions(tag)
+		if omitEmpty && isEmptyValue(field) {
 			continue
 		}
 
-		fieldName := s.parseFieldName(tpField.Name, opts[0])
+		fieldName := s.parseFieldName(tpField.Name, rawName)
 		if len(fieldName) == 0 || !field.CanSet() {
 			continue
 		}
@@ -480,7 +509,7 @@ func (s *Section) reflectFrom(val reflect.Value) error {
 			key.Comment = tpField.Tag.Get("comment")
 		}
 
-		if err = reflectWithProperType(tpField.Type, key, field, parseDelim(tpField.Tag.Get("delim"))); err != nil {
+		if err = reflectWithProperType(tpField.Type, key, field, parseDelim(tpField.Tag.Get("delim")), allowShadow); err != nil {
 			return fmt.Errorf("error reflecting field (%s): %v", fieldName, err)
 		}
 

struct_test.go

@@ -375,6 +375,40 @@ omitempty  = 9
 	})
 }
 
+// Inspired by https://github.com/go-ini/ini/issues/196
+func TestMapToAndReflectFromStructWithShadows(t *testing.T) {
+	Convey("Map to struct and then reflect with shadows should generate original config content", t, func() {
+		type include struct {
+			Paths []string `ini:"path,omitempty,allowshadow"`
+		}
+
+		cfg, err := ini.LoadSources(ini.LoadOptions{
+			AllowShadows: true,
+		}, []byte(`
+[include]
+path = /tmp/gpm-profiles/test5.profile
+path = /tmp/gpm-profiles/test1.profile`))
+		So(err, ShouldBeNil)
+
+		sec := cfg.Section("include")
+		inc := new(include)
+		err = sec.MapTo(inc)
+		So(err, ShouldBeNil)
+
+		err = sec.ReflectFrom(inc)
+		So(err, ShouldBeNil)
+
+		var buf bytes.Buffer
+		_, err = cfg.WriteTo(&buf)
+		So(err, ShouldBeNil)
+		So(buf.String(), ShouldEqual, `[include]
+path = /tmp/gpm-profiles/test5.profile
+path = /tmp/gpm-profiles/test1.profile
+
+`)
+	})
+}
+
 type testMapper struct {
 	PackageName string
 }