Elide port in example

p2p/http/example_test.go

@@ -7,6 +7,7 @@ import (
 	"log"
 	"net"
 	"net/http"
+	"regexp"
 	"strings"
 
 	"github.com/libp2p/go-libp2p"
@@ -126,6 +127,15 @@ func ExampleHost_overLibp2pStreams() {
 	// Output: Hello HTTP
 }
 
+var portRe = regexp.MustCompile(`/(tcp|udp)/(?P<port>\d+)/http`)
+
+// Given a multiaddr string, return the multiaddr with port filled in as <port>.
+// Useful for showing examples without hardcoding the port.
+func elidePort(addr string) string {
+	port := portRe.FindStringSubmatch(addr)[2]
+	return strings.Replace(addr, port, "<port>", 1)
+}
+
 func ExampleHost_Serve() {
 	server := libp2phttp.Host{
 		InsecureAllowHTTP: true, // For our example, we'll allow insecure HTTP
@@ -143,9 +153,9 @@ func ExampleHost_Serve() {
 	defer func() { <-serveDone }()
 	defer server.Close()
 
-	fmt.Println(server.Addrs())
+	fmt.Println(elidePort(server.Addrs()[0].String()))
 
-	// Output: [/ip4/127.0.0.1/tcp/50221/http]
+	// Output: /ip4/127.0.0.1/tcp/<port>/http
 }
 
 func ExampleHost_SetHTTPHandler() {