Merge pull request #50 from riannucci/master

Improve parent field support to allow types derived from *Key

entity.go

@@ -744,12 +744,13 @@ func (g *Goon) getStructKey(src interface{}) (key *datastore.Key, hasStringId bo
 					}
 				}
 			} else if tagValue == "parent" {
-				if vf.Type() == reflect.TypeOf(&datastore.Key{}) {
+				dskeyType := reflect.TypeOf(&datastore.Key{})
+				if vf.Type().ConvertibleTo(dskeyType) {
 					if parent != nil {
 						err = fmt.Errorf("goon: Only one field may be marked parent")
 						return
 					}
-					parent = vf.Interface().(*datastore.Key)
+					parent = vf.Convert(dskeyType).Interface().(*datastore.Key)
 				}
 			}
 		}
@@ -831,8 +832,10 @@ func (g *Goon) setStructKey(src interface{}, key *datastore.Key) error {
 				if parentSet {
 					return fmt.Errorf("goon: Only one field may be marked parent")
 				}
-				if vf.Type() == reflect.TypeOf(&datastore.Key{}) {
-					vf.Set(reflect.ValueOf(key.Parent()))
+				dskeyType := reflect.TypeOf(&datastore.Key{})
+				vfType := vf.Type()
+				if vfType.ConvertibleTo(dskeyType) {
+					vf.Set(reflect.ValueOf(key.Parent()).Convert(vfType))
 					parentSet = true
 				}
 			}

goon_test.go

@@ -2023,3 +2023,68 @@ func TestMultis(t *testing.T) {
 		}
 	}
 }
+
+type root struct {
+	Id   int64 `datastore:"-" goon:"id"`
+	Data int
+}
+
+type normalChild struct {
+	Id     int64          `datastore:"-" goon:"id"`
+	Parent *datastore.Key `datastore:"-" goon:"parent"`
+	Data   int
+}
+
+type coolKey *datastore.Key
+
+type derivedChild struct {
+	Id     int64   `datastore:"-" goon:"id"`
+	Parent coolKey `datastore:"-" goon:"parent"`
+	Data   int
+}
+
+func TestParents(t *testing.T) {
+	c, err := aetest.NewContext(nil)
+	if err != nil {
+		t.Fatalf("Could not start aetest - %v", err)
+	}
+	defer c.Close()
+	n := FromContext(c)
+
+	r := &root{1, 10}
+	rootKey, err := n.Put(r)
+	if err != nil {
+		t.Fatalf("couldn't Put(%+v)", r)
+	}
+
+	// Put exercises both get and set, since Id is uninitialized
+	nc := &normalChild{0, rootKey, 20}
+	nk, err := n.Put(nc)
+	if err != nil {
+		t.Fatalf("couldn't Put(%+v)", nc)
+	}
+	if nc.Parent == rootKey {
+		t.Fatalf("derived parent key pointer value didn't change")
+	}
+	if !(*datastore.Key)(nc.Parent).Equal(rootKey) {
+		t.Fatalf("parent of key not equal '%s' v '%s'! ", (*datastore.Key)(nc.Parent), rootKey)
+	}
+	if !nk.Parent().Equal(rootKey) {
+		t.Fatalf("parent of key not equal '%s' v '%s'! ", nk, rootKey)
+	}
+
+	dc := &derivedChild{0, (coolKey)(rootKey), 12}
+	dk, err := n.Put(dc)
+	if err != nil {
+		t.Fatalf("couldn't Put(%+v)", dc)
+	}
+	if dc.Parent == rootKey {
+		t.Fatalf("derived parent key pointer value didn't change")
+	}
+	if !(*datastore.Key)(dc.Parent).Equal(rootKey) {
+		t.Fatalf("parent of key not equal '%s' v '%s'! ", (*datastore.Key)(dc.Parent), rootKey)
+	}
+	if !dk.Parent().Equal(rootKey) {
+		t.Fatalf("parent of key not equal '%s' v '%s'! ", dk, rootKey)
+	}
+}