server_test: wait for OnClose in TestClientEOF.

In the test for client Call failing with ErrClosed on a closed
server, wait for the client's OnClose handler to get triggered
to make sure closing the socket had properly been administered
on the client's side. Otherwise trying a new Call() might fail
with some other error than ErrClosed, for instance ENOTCONN.

Signed-off-by: Krisztian Litkey <[email protected]>

server_test.go

@@ -339,7 +339,12 @@ func TestClientEOF(t *testing.T) {
 		server          = mustServer(t)(NewServer())
 		addr, listener  = newTestListener(t)
 		errs            = make(chan error, 1)
-		client, cleanup = newTestClient(t, addr)
+		onCloseCh       = make(chan struct{})
+		client, cleanup = newTestClient(t, addr,
+			WithOnClose(func() {
+				onCloseCh <- struct{}{}
+			}),
+		)
 	)
 	defer cleanup()
 	defer listener.Close()
@@ -363,6 +368,8 @@ func TestClientEOF(t *testing.T) {
 		t.Fatal(err)
 	}
 
+	<-onCloseCh
+
 	// server shutdown, but we still make a call.
 	if err := client.Call(ctx, serviceName, "Test", tp, tp); err == nil {
 		t.Fatalf("expected error when calling against shutdown server")