feat: Add Multiaddr.AppendComponent

multiaddr.go

@@ -189,6 +189,18 @@ func (m Multiaddr) AsMultiaddr() Multiaddr {
 	return m
 }
 
+// AppendComponent is the same as using `append(m, *c)`, but with a safety check
+// for a nil Component.
+func (m Multiaddr) AppendComponent(cs ...*Component) Multiaddr {
+	for _, c := range cs {
+		if c == nil {
+			continue
+		}
+		m = append(m, *c)
+	}
+	return m
+}
+
 // Encapsulate wraps a given Multiaddr, returning the resulting joined Multiaddr
 func (m Multiaddr) Encapsulate(other asMultiaddr) Multiaddr {
 	return Join(m, other)

multiaddr_test.go

@@ -627,6 +627,17 @@ func assertValueForProto(t *testing.T, a Multiaddr, p int, exp string) {
 	}
 }
 
+func TestAppendComponent(t *testing.T) {
+	var m Multiaddr
+	res := m.AppendComponent(nil)
+	require.Equal(t, m, res)
+
+	c, err := NewComponent("ip4", "127.0.0.1")
+	require.NoError(t, err)
+	res = m.AppendComponent(c)
+	require.Equal(t, "/ip4/127.0.0.1", res.String())
+}
+
 func TestGetValue(t *testing.T) {
 	a := newMultiaddr(t, "/ip4/127.0.0.1/utp/tcp/5555/udp/1234/tls/utp/ipfs/QmbHVEEepCi7rn7VL7Exxpd2Ci9NNB6ifvqwhsrbRMgQFP")
 	assertValueForProto(t, a, P_IP4, "127.0.0.1")