Increase test and benchmark coverage

conn_test.go

@@ -169,6 +169,7 @@ func TestCloseBeforeSignal(t *testing.T) {
 	reader, pipewriter := io.Pipe()
 	defer pipewriter.Close()
 	defer reader.Close()
+	wg := sync.WaitGroup{}
 
 	bus, err := NewConn(rwc{Reader: reader, Writer: io.Discard})
 	if err != nil {
@@ -178,11 +179,13 @@ func TestCloseBeforeSignal(t *testing.T) {
 	ch := make(chan *Signal, 1)
 	bus.Signal(ch)
 
+	wg.Add(1)
 	go func() {
 		_, err := pipewriter.Write([]byte("REJECTED name\r\nOK myuuid\r\n"))
 		if err != nil {
 			t.Errorf("error writing to pipe: %v", err)
 		}
+		wg.Done()
 	}()
 
 	err = bus.Auth([]Auth{fakeAuth{}})
@@ -207,6 +210,7 @@ func TestCloseBeforeSignal(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+	wg.Wait()
 }
 
 func TestCloseChannelAfterRemoveSignal(t *testing.T) {

decoder_test.go

@@ -86,3 +86,118 @@ func TestSigByteSize(t *testing.T) {
 		}
 	}
 }
+
+func BenchmarkDecodeArrayEmptyStruct(b *testing.B) {
+	buf := bytes.NewBuffer(nil)
+	msg := &Message{
+		Type:  0x02,
+		Flags: 0x00,
+		Headers: map[HeaderField]Variant{
+			0x06: {
+				sig: Signature{
+					str: "s",
+				},
+				value: ":1.391",
+			},
+			0x05: {
+				sig: Signature{
+					str: "u",
+				},
+				value: uint32(2),
+			},
+			0x08: {
+				sig: Signature{
+					str: "g",
+				},
+				value: Signature{
+					str: "v",
+				},
+			},
+		},
+		Body: []interface{}{
+			Variant{
+				sig: Signature{
+					str: "(sa(iiay)ss)",
+				},
+				value: property{
+					IconName:    "iconname",
+					Pixmaps:     []pixmap{},
+					Title:       "title",
+					Description: "description",
+				},
+			},
+		},
+		serial: 0x00000003,
+	}
+	err := msg.EncodeTo(buf, binary.LittleEndian)
+	if err != nil {
+		b.Fatal(err)
+	}
+	data := buf.Bytes()
+	for i := 0; i < b.N; i++ {
+		buf.Reset()
+		buf.Write(data)
+		_, err = DecodeMessage(buf)
+		if err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+func BenchmarkDecodePropertyChanged(b *testing.B) {
+	intVal := int32(1)
+	buf := bytes.NewBuffer(nil)
+	msg := &Message{
+		Type:  TypeSignal,
+		Flags: 0x00,
+		Headers: map[HeaderField]Variant{
+			FieldSignature: {
+				sig: Signature{
+					str: "g",
+				},
+				value: Signature{
+					str: "sa{sv}as",
+				},
+			},
+			FieldInterface: {
+				sig: Signature{
+					str: "s",
+				},
+				value: "org.freedesktop.DBus.Properties",
+			},
+			FieldMember: {
+				sig: Signature{
+					str: "s",
+				},
+				value: "PropertiesChanged",
+			},
+			FieldPath: {
+				sig: Signature{
+					str: "o",
+				},
+				value: ObjectPath("/com/github/pboyd/Stress"),
+			},
+		},
+		Body: []interface{}{
+			"com.github.pboyd.Stress",
+			map[string]Variant{
+				"SomeInt": {sig: Signature{str: "i"}, value: &intVal},
+			},
+			[]string{},
+		},
+		serial: 0x000029f5,
+	}
+	err := msg.EncodeTo(buf, binary.LittleEndian)
+	if err != nil {
+		b.Fatal(err)
+	}
+	data := buf.Bytes()
+	for n := 0; n < b.N; n++ {
+		buf.Reset()
+		buf.Write(data)
+		_, err = DecodeMessage(buf)
+		if err != nil {
+			b.Fatal(err)
+		}
+	}
+}

encoder.go

@@ -35,6 +35,13 @@ func newEncoderAtOffset(out io.Writer, offset int, order binary.ByteOrder, fds [
 	return enc
 }
 
+func (enc *encoder) Reset(out io.Writer, order binary.ByteOrder, fds []int) {
+	enc.out = out
+	enc.order = order
+	enc.pos = 0
+	enc.fds = fds
+}
+
 // Aligns the next output to be on a multiple of n. Panics on write errors.
 func (enc *encoder) align(n int) {
 	pad := enc.padding(0, n)