chore: add tests for examples

examples/echo/main_test.go

@@ -0,0 +1,58 @@
+package main
+
+import (
+	"context"
+	"log"
+	"testing"
+
+	"github.com/libp2p/go-libp2p/examples/testutils"
+)
+
+func TestMain(t *testing.T) {
+	var h testutils.LogHarness
+	h.Expect("listening for connections")
+	h.Expect("sender opening stream")
+	h.Expect("sender saying hello")
+	h.Expect("listener received new stream")
+	h.Expect("read: Hello, world!")
+	h.Expect(`read reply: "Hello, world!\n"`)
+
+	h.Run(t, func() {
+		// Create a context that will stop the hosts when the tests end
+		ctx, cancel := context.WithCancel(context.Background())
+		defer cancel()
+
+		// Get a tcp port for the listener
+		lport, err := testutils.FindFreePort(t, "", 5)
+		if err != nil {
+			log.Println(err)
+			return
+		}
+
+		// Get a tcp port for the sender
+		sport, err := testutils.FindFreePort(t, "", 5)
+		if err != nil {
+			log.Println(err)
+			return
+		}
+
+		// Make listener
+		lh, err := makeBasicHost(lport, true, 1)
+		if err != nil {
+			log.Println(err)
+			return
+		}
+
+		go runListener(ctx, lh, lport, true)
+
+		// Make sender
+		listenAddr := getHostAddress(lh)
+		sh, err := makeBasicHost(sport, true, 2)
+		if err != nil {
+			log.Println(err)
+			return
+		}
+
+		runSender(ctx, sh, listenAddr)
+	})
+}