Merge struct fields in Unmarshal (#284)

* add test for unexported field preservation
* merge struct values instead of replacing them
* use struct merging on nested value structs
* unmarshalling merges nested struct pointers when non-nil
This commit is contained in:
Roberth Kulbin
2019-07-25 08:06:17 +01:00
committed by Thomas Pelletier
parent dba45d427f
commit 84da2c4a25
2 changed files with 143 additions and 16 deletions
+38 -16
View File
@@ -526,7 +526,9 @@ func (d *Decoder) unmarshal(v interface{}) error {
return errors.New("only a pointer to struct or map can be unmarshaled from TOML")
}
sval, err := d.valueFromTree(elem, d.tval)
vv := reflect.ValueOf(v).Elem()
sval, err := d.valueFromTree(elem, d.tval, &vv)
if err != nil {
return err
}
@@ -534,15 +536,21 @@ func (d *Decoder) unmarshal(v interface{}) error {
return nil
}
// Convert toml tree to marshal struct or map, using marshal type
func (d *Decoder) valueFromTree(mtype reflect.Type, tval *Tree) (reflect.Value, error) {
// Convert toml tree to marshal struct or map, using marshal type. When mval1
// is non-nil, merge fields into the given value instead of allocating a new one.
func (d *Decoder) valueFromTree(mtype reflect.Type, tval *Tree, mval1 *reflect.Value) (reflect.Value, error) {
if mtype.Kind() == reflect.Ptr {
return d.unwrapPointer(mtype, tval)
return d.unwrapPointer(mtype, tval, mval1)
}
var mval reflect.Value
switch mtype.Kind() {
case reflect.Struct:
mval = reflect.New(mtype).Elem()
if mval1 != nil {
mval = *mval1
} else {
mval = reflect.New(mtype).Elem()
}
for i := 0; i < mtype.NumField(); i++ {
mtypef := mtype.Field(i)
an := annotation{tag: d.tagName}
@@ -563,7 +571,8 @@ func (d *Decoder) valueFromTree(mtype reflect.Type, tval *Tree) (reflect.Value,
continue
}
val := tval.Get(key)
mvalf, err := d.valueFromToml(mtypef.Type, val)
fval := mval.Field(i)
mvalf, err := d.valueFromToml(mtypef.Type, val, &fval)
if err != nil {
return mval, formatError(err, tval.GetPosition(key))
}
@@ -607,7 +616,7 @@ func (d *Decoder) valueFromTree(mtype reflect.Type, tval *Tree) (reflect.Value,
// save the old behavior above and try to check anonymous structs
if !found && opts.defaultValue == "" && mtypef.Anonymous && mtypef.Type.Kind() == reflect.Struct {
v, err := d.valueFromTree(mtypef.Type, tval)
v, err := d.valueFromTree(mtypef.Type, tval, nil)
if err != nil {
return v, err
}
@@ -620,7 +629,7 @@ func (d *Decoder) valueFromTree(mtype reflect.Type, tval *Tree) (reflect.Value,
for _, key := range tval.Keys() {
// TODO: path splits key
val := tval.GetPath([]string{key})
mvalf, err := d.valueFromToml(mtype.Elem(), val)
mvalf, err := d.valueFromToml(mtype.Elem(), val, nil)
if err != nil {
return mval, formatError(err, tval.GetPosition(key))
}
@@ -634,7 +643,7 @@ func (d *Decoder) valueFromTree(mtype reflect.Type, tval *Tree) (reflect.Value,
func (d *Decoder) valueFromTreeSlice(mtype reflect.Type, tval []*Tree) (reflect.Value, error) {
mval := reflect.MakeSlice(mtype, len(tval), len(tval))
for i := 0; i < len(tval); i++ {
val, err := d.valueFromTree(mtype.Elem(), tval[i])
val, err := d.valueFromTree(mtype.Elem(), tval[i], nil)
if err != nil {
return mval, err
}
@@ -647,7 +656,7 @@ func (d *Decoder) valueFromTreeSlice(mtype reflect.Type, tval []*Tree) (reflect.
func (d *Decoder) valueFromOtherSlice(mtype reflect.Type, tval []interface{}) (reflect.Value, error) {
mval := reflect.MakeSlice(mtype, len(tval), len(tval))
for i := 0; i < len(tval); i++ {
val, err := d.valueFromToml(mtype.Elem(), tval[i])
val, err := d.valueFromToml(mtype.Elem(), tval[i], nil)
if err != nil {
return mval, err
}
@@ -656,16 +665,22 @@ func (d *Decoder) valueFromOtherSlice(mtype reflect.Type, tval []interface{}) (r
return mval, nil
}
// Convert toml value to marshal value, using marshal type
func (d *Decoder) valueFromToml(mtype reflect.Type, tval interface{}) (reflect.Value, error) {
// Convert toml value to marshal value, using marshal type. When mval1 is non-nil
// and the given type is a struct value, merge fields into it.
func (d *Decoder) valueFromToml(mtype reflect.Type, tval interface{}, mval1 *reflect.Value) (reflect.Value, error) {
if mtype.Kind() == reflect.Ptr {
return d.unwrapPointer(mtype, tval)
return d.unwrapPointer(mtype, tval, mval1)
}
switch t := tval.(type) {
case *Tree:
var mval11 *reflect.Value
if mtype.Kind() == reflect.Struct {
mval11 = mval1
}
if isTree(mtype) {
return d.valueFromTree(mtype, t)
return d.valueFromTree(mtype, t, mval11)
}
return reflect.ValueOf(nil), fmt.Errorf("Can't convert %v(%T) to a tree", tval, tval)
case []*Tree:
@@ -743,8 +758,15 @@ func (d *Decoder) valueFromToml(mtype reflect.Type, tval interface{}) (reflect.V
}
}
func (d *Decoder) unwrapPointer(mtype reflect.Type, tval interface{}) (reflect.Value, error) {
val, err := d.valueFromToml(mtype.Elem(), tval)
func (d *Decoder) unwrapPointer(mtype reflect.Type, tval interface{}, mval1 *reflect.Value) (reflect.Value, error) {
var melem *reflect.Value
if mval1 != nil && !mval1.IsNil() && mtype.Elem().Kind() == reflect.Struct {
elem := mval1.Elem()
melem = &elem
}
val, err := d.valueFromToml(mtype.Elem(), tval, melem)
if err != nil {
return reflect.ValueOf(nil), err
}