fix(connecteventmanager): add test to confirm sync Connected() call flow

bitswap/network/connecteventmanager_test.go

@@ -18,7 +18,8 @@ type mockConnEvent struct {
 
 type mockConnListener struct {
 	sync.Mutex
-	events []mockConnEvent
+	events          []mockConnEvent
+	peerConnectedCb func(p peer.ID)
 }
 
 func newMockConnListener() *mockConnListener {
@@ -29,6 +30,9 @@ func (cl *mockConnListener) PeerConnected(p peer.ID) {
 	cl.Lock()
 	defer cl.Unlock()
 	cl.events = append(cl.events, mockConnEvent{connected: true, peer: p})
+	if cl.peerConnectedCb != nil {
+		cl.peerConnectedCb(p)
+	}
 }
 
 func (cl *mockConnListener) PeerDisconnected(p peer.ID) {
@@ -173,3 +177,51 @@ func TestConnectEventManagerDisconnectAfterMarkUnresponsive(t *testing.T) {
 	require.Empty(t, cem.peers) // all disconnected
 	require.Equal(t, expectedEvents, connListener.events)
 }
+
+func TestConnectEventManagerConnectFlowSynchronous(t *testing.T) {
+	connListener := newMockConnListener()
+	actionsCh := make(chan string)
+	connListener.peerConnectedCb = func(p peer.ID) {
+		actionsCh <- "PeerConnected:" + p.String()
+		time.Sleep(time.Millisecond * 50)
+	}
+
+	peers := testutil.GeneratePeers(2)
+	cem := newConnectEventManager(connListener)
+	cem.Start()
+	t.Cleanup(cem.Stop)
+
+	go func() {
+		actionsCh <- "Connected:" + peers[0].String()
+		cem.Connected(peers[0])
+		actionsCh <- "Done:" + peers[0].String()
+		actionsCh <- "Connected:" + peers[1].String()
+		cem.Connected(peers[1])
+		actionsCh <- "Done:" + peers[1].String()
+		close(actionsCh)
+	}()
+
+	// We expect Done to be sent _after_ PeerConnected, which demonstrates the
+	// call to Connected() blocks until PeerConnected() returns.
+	gotActions := make([]string, 0, 3)
+	for event := range actionsCh {
+		gotActions = append(gotActions, event)
+	}
+	expectedActions := []string{
+		"Connected:" + peers[0].String(),
+		"PeerConnected:" + peers[0].String(),
+		"Done:" + peers[0].String(),
+		"Connected:" + peers[1].String(),
+		"PeerConnected:" + peers[1].String(),
+		"Done:" + peers[1].String(),
+	}
+	require.Equal(t, expectedActions, gotActions)
+
+	// Flush the event queue.
+	wait(t, cem)
+	expectedEvents := []mockConnEvent{
+		{peer: peers[0], connected: true},
+		{peer: peers[1], connected: true},
+	}
+	require.Equal(t, expectedEvents, connListener.events)
+}