Checking that we try hard enough to get peers from dns-discovery

Signed-off-by: Jiri Peinlich <jiri.peinlich@gmail.com>

ethereum/p2p/src/test/java/org/hyperledger/besu/ethereum/p2p/rlpx/RlpxAgentTest.java

@@ -711,6 +711,22 @@ public void connect_largeStreamOfPeers() {
     verify(agent, times(maxPeers)).connect(any(Peer.class));
   }
 
+  @Test
+  public void connect_largeStreamOfPeersFirstFewImpostors() {
+    final int maxPeers = 5;
+    final int impostorsCount = 5;
+    connectionInitializer.setAutoDisconnectCounter(impostorsCount);
+    final Stream<Peer> peerStream = Stream.generate(PeerTestHelper::createPeer).limit(20);
+
+    startAgentWithMaxPeers(maxPeers);
+    agent = spy(agent);
+    agent.connect(peerStream);
+
+    assertThat(agent.getConnectionCount()).isEqualTo(maxPeers);
+    // Check that stream was not fully iterated
+    verify(agent, times(maxPeers + impostorsCount)).connect(any(Peer.class));
+  }
+
   @Test
   public void disconnect() throws ExecutionException, InterruptedException {
     startAgent();

ethereum/p2p/src/test/java/org/hyperledger/besu/ethereum/p2p/rlpx/connections/MockConnectionInitializer.java

@@ -16,6 +16,7 @@
 
 import org.hyperledger.besu.ethereum.p2p.peers.Peer;
 import org.hyperledger.besu.ethereum.p2p.rlpx.ConnectCallback;
+import org.hyperledger.besu.ethereum.p2p.rlpx.wire.messages.DisconnectMessage;
 import org.hyperledger.besu.util.Subscribers;
 
 import java.net.InetSocketAddress;
@@ -32,6 +33,7 @@ public class MockConnectionInitializer implements ConnectionInitializer {
   private boolean autocompleteConnections = true;
   private final Map<Peer, CompletableFuture<PeerConnection>> incompleteConnections =
       new HashMap<>();
+  private int autoDisconnectCounter = 0;
 
   public MockConnectionInitializer(final PeerConnectionEventDispatcher eventDispatcher) {
     this.eventDispatcher = eventDispatcher;
@@ -72,6 +74,12 @@ public void subscribeIncomingConnect(final ConnectCallback callback) {
 
   @Override
   public CompletableFuture<PeerConnection> connect(final Peer peer) {
+    if (autoDisconnectCounter > 0) {
+      autoDisconnectCounter--;
+      MockPeerConnection mockPeerConnection = MockPeerConnection.create(peer, eventDispatcher);
+      mockPeerConnection.disconnect(DisconnectMessage.DisconnectReason.CLIENT_QUITTING);
+      return CompletableFuture.completedFuture(mockPeerConnection);
+    }
     if (autocompleteConnections) {
       return CompletableFuture.completedFuture(MockPeerConnection.create(peer, eventDispatcher));
     } else {
@@ -80,4 +88,8 @@ public CompletableFuture<PeerConnection> connect(final Peer peer) {
       return future;
     }
   }
+
+  public void setAutoDisconnectCounter(final int autoDisconnectCounter) {
+    this.autoDisconnectCounter = autoDisconnectCounter;
+  }
 }