field: fix setting pointers. Closes ##16

field.go

@@ -63,29 +63,23 @@ func (f *Field) Kind() reflect.Kind {
 // settable (not addresable or not exported) or if the given value's type
 // doesn't match the fields type.
 func (f *Field) Set(val interface{}) error {
-	// needed to make the field settable
-	v := reflect.Indirect(f.value)
-
+	// we can't set unexported fields, so be sure this field is exported
 	if !f.IsExported() {
 		return errNotExported
 	}
 
 	// do we get here? not sure...
-	if !v.CanSet() {
+	if !f.value.CanSet() {
 		return errNotSettable
 	}
 
 	given := reflect.ValueOf(val)
 
-	if given.Kind() == reflect.Ptr {
-		given = given.Elem()
+	if f.value.Kind() != given.Kind() {
+		return fmt.Errorf("wrong kind. got: %s want: %s", given.Kind(), f.value.Kind())
 	}
 
-	if v.Kind() != given.Kind() {
-		return fmt.Errorf("wrong kind: %s want: %s", given.Kind(), v.Kind())
-	}
-
-	v.Set(given)
+	f.value.Set(given)
 	return nil
 }
 

field_test.go

@@ -11,12 +11,18 @@ type Foo struct {
 	B    int    `structs:"y"`
 	C    bool   `json:"c"`
 	d    string // not exported
+	E    *Baz
 	x    string `xml:"x"` // not exported, with tag
 	Y    []string
 	Z    map[string]interface{}
 	*Bar // embedded
 }
 
+type Baz struct {
+	A string
+	B int
+}
+
 type Bar struct {
 	E string
 	F int
@@ -35,6 +41,7 @@ func newStruct() *Struct {
 		A: "gopher",
 		C: true,
 		d: "small",
+		E: nil,
 		Y: []string{"example"},
 		Z: nil,
 	}
@@ -108,7 +115,22 @@ func TestField_Set(t *testing.T) {
 		t.Error(err)
 	}
 
-	// TODO: let's access a non addresable field, which should give an error
+	baz := &Baz{
+		A: "helloWorld",
+		B: 42,
+	}
+
+	f = s.Field("E")
+	err = f.Set(baz)
+	if err != nil {
+		t.Error(err)
+	}
+
+	ba := s.Field("E").Value().(*Baz)
+
+	if ba.A != "helloWorld" {
+		t.Errorf("could not set baz. Got: %s Want: helloWorld", ba.A)
+	}
 }
 
 func TestField(t *testing.T) {