Use custom copiers declared in Config

copystructure.go

@@ -88,6 +88,7 @@ func (c Config) Copy(v interface{}) (interface{}, error) {
  if c.Copiers == nil {
  c.Copiers = Copiers
  }
+ w.copiers = c.Copiers
 
  err := reflectwalk.Walk(v, w)
  if err != nil {
@@ -116,6 +117,7 @@ func ifaceKey(pointers, depth int) uint64 {
 type walker struct {
  Result interface{}
 
+ copiers map[reflect.Type]CopierFunc
  depth int
  ignoreDepth int
  vals []reflect.Value
@@ -379,7 +381,7 @@ func (w *walker) Struct(s reflect.Value) error {
  w.lock(s)
 
  var v reflect.Value
- if c, ok := Copiers[s.Type()]; ok {
+ if c, ok := w.copiers[s.Type()]; ok {
  // We have a Copier for this struct, so we use that copier to
  // get the copy, and we ignore anything deeper than this.
  w.ignoreDepth = w.depth

copystructure_test.go

@@ -1153,3 +1153,37 @@ func TestCopy_timeDoublePointer(t *testing.T) {
  t.Fatalf("\n%#v\n\n%#v", v, result)
  }
 }
+
+type nestedValue struct {
+ v string
+}
+
+func TestCopy_customCopierConfig(t *testing.T) {
+ type T struct {
+ Val *nestedValue
+ }
+
+ v := &T{
+ Val: &nestedValue{v: "original"},
+ }
+
+ cfg := Config{
+ Copiers: map[reflect.Type]CopierFunc{
+ reflect.TypeOf(nestedValue{}): customCopier,
+ },
+ }
+ result, err := cfg.Copy(v)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ copiedVal := result.(*T)
+
+ if !reflect.DeepEqual(v.Val.v, copiedVal.Val.v) {
+ t.Fatalf("\nexpected: %#v\ngiven: %#v", v.Val.v, copiedVal.Val.v)
+ }
+}
+
+func customCopier(v interface{}) (interface{}, error) {
+ return v.(nestedValue), nil
+}