fix encoding of anchor and alias

encode.go

@@ -787,12 +787,11 @@ func (e *Encoder) encodeStruct(ctx context.Context, value reflect.Value, column
 		}
 		var key ast.MapKeyNode = e.encodeString(structField.RenderName, column)
 		switch {
-		case structField.AnchorName != "":
-			anchorNode, err := e.encodeAnchor(structField.AnchorName, value, fieldValue, column)
-			if err != nil {
-				return nil, err
+		case value.Type() == ast.AliasType:
+			if structField.IsInline {
+				// if both used alias and inline, output `<<: *alias`
+				key = ast.MergeKey(token.New("<<", "<<", e.pos(column)))
 			}
-			value = anchorNode
 		case structField.IsAutoAlias:
 			if fieldValue.Kind() != reflect.Ptr {
 				return nil, fmt.Errorf(
@@ -814,6 +813,12 @@ func (e *Encoder) encodeStruct(ctx context.Context, value reflect.Value, column
 				// if both used alias and inline, output `<<: *alias`
 				key = ast.MergeKey(token.New("<<", "<<", e.pos(column)))
 			}
+		case structField.AnchorName != "":
+			anchorNode, err := e.encodeAnchor(structField.AnchorName, value, fieldValue, column)
+			if err != nil {
+				return nil, err
+			}
+			value = anchorNode
 		case structField.AliasName != "":
 			aliasName := structField.AliasName
 			alias := ast.Alias(token.New("*", "*", e.pos(column)))

encode_test.go

@@ -1675,3 +1675,45 @@ func TestIssue174(t *testing.T) {
 		t.Fatalf("failed to encode: %q", got)
 	}
 }
+
+func TestIssue259(t *testing.T) {
+	type AnchorValue struct {
+		Foo uint64
+		Bar string
+	}
+
+	type Value struct {
+		Baz   string       `yaml:"baz"`
+		Value *AnchorValue `yaml:"value,anchor"`
+	}
+
+	type Schema struct {
+		Values []*Value
+	}
+
+	schema := Schema{}
+	anchorValue := AnchorValue{Foo: 3, Bar: "bar"}
+	schema.Values = []*Value{
+		{Baz: "xxx", Value: &anchorValue},
+		{Baz: "yyy", Value: &anchorValue},
+		{Baz: "zzz", Value: &anchorValue},
+	}
+	b, err := yaml.Marshal(schema)
+	if err != nil {
+		t.Fatal(err)
+	}
+	expected := `
+values:
+- baz: xxx
+  value: &value
+    foo: 3
+    bar: bar
+- baz: yyy
+  value: *value
+- baz: zzz
+  value: *value
+`
+	if strings.TrimPrefix(expected, "\n") != string(b) {
+		t.Fatalf("failed to encode: got = %s", string(b))
+	}
+}