Add a test to verify MAX_SUBSCRIBED_TOPICS constant (#9163)

networking/eth2/src/main/java/tech/pegasys/teku/networking/eth2/gossip/topics/Eth2GossipTopicFilter.java

@@ -31,8 +31,9 @@
 
 public class Eth2GossipTopicFilter implements GossipTopicFilter {
   private static final Logger LOG = LogManager.getLogger();
-  private final Supplier<Set<String>> relevantTopics;
+
   private final Spec spec;
+  private final Supplier<Set<String>> relevantTopics;
 
   public Eth2GossipTopicFilter(
       final RecentChainData recentChainData, final GossipEncoding gossipEncoding, final Spec spec) {

networking/eth2/src/main/java/tech/pegasys/teku/networking/eth2/gossip/topics/GossipSubValidationUtil.java

@@ -20,16 +20,10 @@ public class GossipSubValidationUtil {
 
   public static ValidationResult fromInternalValidationResult(
       final InternalValidationResult result) {
-    switch (result.code()) {
-      case ACCEPT:
-        return ValidationResult.Valid;
-      case SAVE_FOR_FUTURE:
-      case IGNORE:
-        return ValidationResult.Ignore;
-      case REJECT:
-        return ValidationResult.Invalid;
-      default:
-        throw new IllegalArgumentException("Unexpected internal validation result: " + result);
-    }
+    return switch (result.code()) {
+      case ACCEPT -> ValidationResult.Valid;
+      case SAVE_FOR_FUTURE, IGNORE -> ValidationResult.Ignore;
+      case REJECT -> ValidationResult.Invalid;
+    };
   }
 }

networking/eth2/src/main/java/tech/pegasys/teku/networking/eth2/gossip/topics/topichandlers/Eth2TopicHandler.java

@@ -60,7 +60,7 @@ public class Eth2TopicHandler<MessageT extends SszData> implements TopicHandler
   private final String topic;
   final TimeProvider timeProvider;
 
-  // every  slot of mainnet config
+  // every slot of mainnet config
   private final Throttler<Logger> loggerThrottler = new Throttler<>(LOG, UInt64.valueOf(12));
 
   public Eth2TopicHandler(

networking/eth2/src/test/java/tech/pegasys/teku/networking/eth2/gossip/topics/GossipTopicsTest.java

@@ -16,9 +16,18 @@
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 
+import java.util.Comparator;
+import org.apache.tuweni.bytes.Bytes32;
 import org.junit.jupiter.api.Test;
 import tech.pegasys.teku.infrastructure.bytes.Bytes4;
 import tech.pegasys.teku.networking.eth2.gossip.encoding.GossipEncoding;
+import tech.pegasys.teku.networking.p2p.libp2p.gossip.LibP2PGossipNetworkBuilder;
+import tech.pegasys.teku.spec.Spec;
+import tech.pegasys.teku.spec.SpecMilestone;
+import tech.pegasys.teku.spec.TestSpecFactory;
+import tech.pegasys.teku.spec.datastructures.state.Fork;
+import tech.pegasys.teku.storage.storageSystem.InMemoryStorageSystemBuilder;
+import tech.pegasys.teku.storage.storageSystem.StorageSystem;
 
 public class GossipTopicsTest {
   private final GossipEncoding gossipEncoding = GossipEncoding.SSZ_SNAPPY;
@@ -44,4 +53,35 @@ public void extractForkDigest_invalid() {
     assertThatThrownBy(() -> GossipTopics.extractForkDigest(topic))
         .isInstanceOf(IllegalArgumentException.class);
   }
+
+  @Test
+  public void maxSubscribedTopicsConstantIsLargeEnough() {
+    final SpecMilestone latestMilestone = SpecMilestone.values()[SpecMilestone.values().length - 1];
+    final Spec spec = TestSpecFactory.createMainnet(latestMilestone);
+
+    final StorageSystem storageSystem = InMemoryStorageSystemBuilder.buildDefault(spec);
+    storageSystem.chainUpdater().initializeGenesis();
+    final Bytes32 genesisValidatorsRoot =
+        storageSystem.recentChainData().getGenesisData().orElseThrow().getGenesisValidatorsRoot();
+
+    // sum of all topics for highest fork + (fork-1) + (fork-2)
+    int exactMaxSubscribedTopics =
+        SpecMilestone.getMilestonesUpTo(latestMilestone).stream()
+            .sorted(Comparator.reverseOrder())
+            .limit(3)
+            .mapToInt(
+                milestone -> {
+                  final Fork fork = spec.getForkSchedule().getFork(milestone);
+                  final Bytes4 forkDigest =
+                      spec.forMilestone(milestone)
+                          .miscHelpers()
+                          .computeForkDigest(fork.getCurrentVersion(), genesisValidatorsRoot);
+                  return GossipTopics.getAllTopics(gossipEncoding, forkDigest, spec, milestone)
+                      .size();
+                })
+            .sum();
+
+    assertThat(exactMaxSubscribedTopics)
+        .isLessThanOrEqualTo(LibP2PGossipNetworkBuilder.MAX_SUBSCRIBED_TOPICS);
+  }
 }

networking/p2p/src/main/java/tech/pegasys/teku/networking/p2p/libp2p/gossip/LibP2PGossipNetworkBuilder.java

@@ -19,6 +19,7 @@
 import static tech.pegasys.teku.networking.p2p.libp2p.gossip.LibP2PGossipNetwork.NULL_SEQNO_GENERATOR;
 import static tech.pegasys.teku.networking.p2p.libp2p.gossip.LibP2PGossipNetwork.STRICT_FIELDS_VALIDATOR;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
 import io.libp2p.core.pubsub.PubsubApi;
 import io.libp2p.core.pubsub.PubsubApiKt;
@@ -56,7 +57,7 @@
 public class LibP2PGossipNetworkBuilder {
 
   // Enough to subscribe to three forks simultaneously so testnets can fork in subsequent epochs
-  public static final int MAX_SUBSCRIBED_TOPICS = 250;
+  @VisibleForTesting public static final int MAX_SUBSCRIBED_TOPICS = 250;
 
   public static LibP2PGossipNetworkBuilder create() {
     return new LibP2PGossipNetworkBuilder();