change MakeConnectedSwitches to not connect to itself

and a test for it

p2p/switch.go

@@ -509,8 +509,10 @@ func MakeConnectedSwitches(cfg *cfg.P2PConfig, n int, initSwitch func(int, *Swit
 		panic(err)
 	}
 
-	for i := 1; i < n; i++ {
+	for i := 0; i < n; i++ {
-		connect(switches, 0, i)
+		for j := i + 1; j < n; j++ {
+			connect(switches, i, j)
+		}
 	}
 
 	return switches

p2p/switch_test.go

@@ -286,6 +286,21 @@ func TestSwitchReconnectsToPersistentPeer(t *testing.T) {
 	assert.False(peer.IsRunning())
 }
 
+func TestSwitchFullConnectivity(t *testing.T) {
+	switches := MakeConnectedSwitches(config, 3, initSwitchFunc, Connect2Switches)
+	defer func() {
+		for _, sw := range switches {
+			sw.Stop()
+		}
+	}()
+
+	for i, sw := range switches {
+		if sw.Peers().Size() != 2 {
+			t.Fatalf("Expected each switch to be connected to 2 other, but %d switch only connected to %d", sw.Peers().Size(), i)
+		}
+	}
+}
+
 func BenchmarkSwitches(b *testing.B) {
 	b.StopTimer()