Modernize sal-akka-raft tests

[controller.git] / opendaylight / md-sal / sal-akka-raft / src / test / java / org / opendaylight / controller / cluster / raft / behaviors / FollowerTest.java

diff --git a/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/behaviors/FollowerTest.java b/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/behaviors/FollowerTest.java
index a51134676a16ff81477eae2a5f092b54f684ff8b..8006d5a6ac906ed6a11598b59f5c6aba6269f109 100644 (file)
--- a/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/behaviors/FollowerTest.java
+++ b/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/behaviors/FollowerTest.java
@@ -7,6 +7,7 @@
  */
 package org.opendaylight.controller.cluster.raft.behaviors;
 
+import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
@@ -25,21 +26,15 @@ import akka.protobuf.ByteString;
 import akka.testkit.TestActorRef;
 import akka.testkit.javadsl.TestKit;
 import com.google.common.base.Stopwatch;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableMap;
 import com.google.common.io.ByteSource;
 import com.google.common.util.concurrent.Uninterruptibles;
 import java.io.OutputStream;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Optional;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
 import org.junit.After;
-import org.junit.Assert;
 import org.junit.Test;
 import org.opendaylight.controller.cluster.raft.DefaultConfigParamsImpl;
 import org.opendaylight.controller.cluster.raft.MockRaftActor;
@@ -157,7 +152,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
 
         Uninterruptibles.sleepUninterruptibly(context.getConfigParams()
                 .getElectionTimeOutInterval().toMillis() - 100, TimeUnit.MILLISECONDS);
-        follower.handleMessage(leaderActor, new AppendEntries(1, "leader", -1, -1, Collections.emptyList(),
+        follower.handleMessage(leaderActor, new AppendEntries(1, "leader", -1, -1, List.of(),
                 -1, -1, (short) 1));
 
         Uninterruptibles.sleepUninterruptibly(130, TimeUnit.MILLISECONDS);
@@ -166,7 +161,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
 
         Uninterruptibles.sleepUninterruptibly(context.getConfigParams()
                 .getElectionTimeOutInterval().toMillis() - 150, TimeUnit.MILLISECONDS);
-        follower.handleMessage(leaderActor, new AppendEntries(1, "leader", -1, -1, Collections.emptyList(),
+        follower.handleMessage(leaderActor, new AppendEntries(1, "leader", -1, -1, List.of(),
                 -1, -1, (short) 1));
 
         Uninterruptibles.sleepUninterruptibly(200, TimeUnit.MILLISECONDS);
@@ -221,10 +216,9 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         context.getReplicatedLog().append(newReplicatedLogEntry(1,100, "bar"));
         context.getReplicatedLog().setSnapshotIndex(99);
 
-        List<ReplicatedLogEntry> entries = Arrays.asList(
-                newReplicatedLogEntry(2, 101, "foo"));
+        List<ReplicatedLogEntry> entries = List.of(newReplicatedLogEntry(2, 101, "foo"));
 
-        Assert.assertEquals(1, context.getReplicatedLog().size());
+        assertEquals(1, context.getReplicatedLog().size());
 
         // The new commitIndex is 101
         AppendEntries appendEntries = new AppendEntries(2, "leader-1", 100, 1, entries, 101, 100, (short)0);
@@ -246,8 +240,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
 
         MockRaftActorContext context = createActorContext();
 
-        List<ReplicatedLogEntry> entries = Arrays.asList(
-                newReplicatedLogEntry(2, 101, "foo"));
+        List<ReplicatedLogEntry> entries = List.of(newReplicatedLogEntry(2, 101, "foo"));
 
         // The new commitIndex is 101
         AppendEntries appendEntries = new AppendEntries(2, "leader-1", -1, -1, entries, 101, 100, (short) 0);
@@ -272,8 +265,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         context.getReplicatedLog().append(newReplicatedLogEntry(1, 100, "bar"));
         context.getReplicatedLog().setSnapshotIndex(99);
 
-        List<ReplicatedLogEntry> entries = Arrays.asList(
-                newReplicatedLogEntry(2, 101, "foo"));
+        List<ReplicatedLogEntry> entries = List.of(newReplicatedLogEntry(2, 101, "foo"));
 
         // The new commitIndex is 101
         AppendEntries appendEntries = new AppendEntries(2, "leader-1", -1, -1, entries, 101, 100, (short) 0);
@@ -297,8 +289,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         context.getReplicatedLog().clear(0,2);
         context.getReplicatedLog().setSnapshotIndex(100);
 
-        List<ReplicatedLogEntry> entries = Arrays.asList(
-                newReplicatedLogEntry(2, 101, "foo"));
+        List<ReplicatedLogEntry> entries = List.of(newReplicatedLogEntry(2, 101, "foo"));
 
         // The new commitIndex is 101
         AppendEntries appendEntries = new AppendEntries(2, "leader-1", -1, -1, entries, 101, 100, (short) 0);
@@ -323,8 +314,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         context.getReplicatedLog().clear(0,2);
         context.getReplicatedLog().setSnapshotIndex(100);
 
-        List<ReplicatedLogEntry> entries = Arrays.asList(
-                newReplicatedLogEntry(2, 105, "foo"));
+        List<ReplicatedLogEntry> entries = List.of(newReplicatedLogEntry(2, 105, "foo"));
 
         // The new commitIndex is 101
         AppendEntries appendEntries = new AppendEntries(2, "leader-1", -1, -1, entries, 105, 100, (short) 0);
@@ -346,8 +336,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
 
         MockRaftActorContext context = createActorContext();
 
-        List<ReplicatedLogEntry> entries = Arrays.asList(
-                newReplicatedLogEntry(2, 101, "foo"));
+        List<ReplicatedLogEntry> entries = List.of(newReplicatedLogEntry(2, 101, "foo"));
 
         // The new commitIndex is 101
         AppendEntries appendEntries = new AppendEntries(2, "leader-1", 100, 1, entries, 101, 100, (short)0);
@@ -367,7 +356,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         context.setCommitIndex(101);
         setLastLogEntry(context, 1, 101, new MockRaftActorContext.MockPayload(""));
 
-        entries = Arrays.asList(newReplicatedLogEntry(2, 101, "foo"));
+        entries = List.of(newReplicatedLogEntry(2, 101, "foo"));
 
         // The new commitIndex is 101
         appendEntries = new AppendEntries(2, "leader-1", 101, 1, entries, 102, 101, (short)0);
@@ -394,8 +383,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
 
         MockRaftActorContext context = createActorContext();
 
-        List<ReplicatedLogEntry> entries = Arrays.asList(
-                newReplicatedLogEntry(2, 101, "foo"));
+        List<ReplicatedLogEntry> entries = List.of(newReplicatedLogEntry(2, 101, "foo"));
 
         // The new commitIndex is 101
         AppendEntries appendEntries = new AppendEntries(2, "leader-1", 100, 1, entries, 101, 100, (short)0);
@@ -415,8 +403,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         setLastLogEntry(context, 1, 100,
                 new MockRaftActorContext.MockPayload(""));
 
-        entries = Arrays.asList(
-                newReplicatedLogEntry(2, 101, "foo"));
+        entries = List.of(newReplicatedLogEntry(2, 101, "foo"));
 
         // leader-2 is becoming the leader now and it says the commitIndex is 45
         appendEntries = new AppendEntries(2, "leader-2", 45, 1, entries, 46, 100, (short)0);
@@ -434,8 +421,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
 
         MockRaftActorContext context = createActorContext();
 
-        List<ReplicatedLogEntry> entries = Arrays.asList(
-                newReplicatedLogEntry(2, 101, "foo"));
+        List<ReplicatedLogEntry> entries = List.of(newReplicatedLogEntry(2, 101, "foo"));
 
         // The new commitIndex is 101
         AppendEntries appendEntries = new AppendEntries(2, "leader-1", 100, 1, entries, 101, 100, (short)0);
@@ -456,8 +442,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         setLastLogEntry(context, 1, 101,
                 new MockRaftActorContext.MockPayload(""));
 
-        entries = Arrays.asList(
-                newReplicatedLogEntry(2, 101, "foo"));
+        entries = List.of(newReplicatedLogEntry(2, 101, "foo"));
 
         // The new commitIndex is 101
         appendEntries = new AppendEntries(2, "leader-1", 101, 1, entries, 102, 101, (short)0);
@@ -474,8 +459,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         setLastLogEntry(context, 1, 100,
                 new MockRaftActorContext.MockPayload(""));
 
-        entries = Arrays.asList(
-                newReplicatedLogEntry(2, 101, "foo"));
+        entries = List.of(newReplicatedLogEntry(2, 101, "foo"));
 
         // leader-2 is becoming the leader now and it says the commitIndex is 45
         appendEntries = new AppendEntries(2, "leader-2", 45, 1, entries, 46, 100, (short)0);
@@ -504,8 +488,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
                 new MockRaftActorContext.MockPayload(""));
         context.getReplicatedLog().setSnapshotIndex(99);
 
-        List<ReplicatedLogEntry> entries = Arrays.<ReplicatedLogEntry>asList(
-                newReplicatedLogEntry(2, 101, "foo"));
+        List<ReplicatedLogEntry> entries = List.of(newReplicatedLogEntry(2, 101, "foo"));
 
         // The new commitIndex is 101
         AppendEntries appendEntries = new AppendEntries(2, "leader-1", 100, 1, entries, 101, 100, (short)0);
@@ -527,13 +510,13 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
 
         MockRaftActorContext context = createActorContext();
 
-        AppendEntries appendEntries = new AppendEntries(2, "leader", 0, 2, Collections.emptyList(), 101, -1, (short)0);
+        AppendEntries appendEntries = new AppendEntries(2, "leader", 0, 2, List.of(), 101, -1, (short)0);
 
         follower = createBehavior(context);
 
         RaftActorBehavior newBehavior = follower.handleMessage(leaderActor, appendEntries);
 
-        Assert.assertSame(follower, newBehavior);
+        assertSame(follower, newBehavior);
 
         AppendEntriesReply reply = MessageCollectorActor.expectFirstMatching(leaderActor,
                 AppendEntriesReply.class);
@@ -550,13 +533,13 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         context.getReplicatedLog().setSnapshotIndex(4);
         context.getReplicatedLog().setSnapshotTerm(3);
 
-        AppendEntries appendEntries = new AppendEntries(3, "leader", 1, 3, Collections.emptyList(), 8, -1, (short)0);
+        AppendEntries appendEntries = new AppendEntries(3, "leader", 1, 3, List.of(), 8, -1, (short)0);
 
         follower = createBehavior(context);
 
         RaftActorBehavior newBehavior = follower.handleMessage(leaderActor, appendEntries);
 
-        Assert.assertSame(follower, newBehavior);
+        assertSame(follower, newBehavior);
 
         AppendEntriesReply reply = MessageCollectorActor.expectFirstMatching(leaderActor, AppendEntriesReply.class);
 
@@ -587,9 +570,8 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         context.setReplicatedLog(log);
 
         // Prepare the entries to be sent with AppendEntries
-        List<ReplicatedLogEntry> entries = new ArrayList<>();
-        entries.add(newReplicatedLogEntry(1, 3, "three"));
-        entries.add(newReplicatedLogEntry(1, 4, "four"));
+        List<ReplicatedLogEntry> entries = List.of(
+            newReplicatedLogEntry(1, 3, "three"), newReplicatedLogEntry(1, 4, "four"));
 
         // Send appendEntries with the same term as was set on the receiver
         // before the new behavior was created (1 in this case)
@@ -603,7 +585,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
 
         RaftActorBehavior newBehavior = follower.handleMessage(leaderActor, appendEntries);
 
-        Assert.assertSame(follower, newBehavior);
+        assertSame(follower, newBehavior);
 
         assertEquals("Next index", 5, log.last().getIndex() + 1);
         assertEquals("Entry 3", entries.get(0), log.get(3));
@@ -639,9 +621,8 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         context.setReplicatedLog(log);
 
         // Prepare the entries to be sent with AppendEntries
-        List<ReplicatedLogEntry> entries = new ArrayList<>();
-        entries.add(newReplicatedLogEntry(2, 2, "two-1"));
-        entries.add(newReplicatedLogEntry(2, 3, "three"));
+        List<ReplicatedLogEntry> entries = List.of(
+            newReplicatedLogEntry(2, 2, "two-1"), newReplicatedLogEntry(2, 3, "three"));
 
         // Send appendEntries with the same term as was set on the receiver
         // before the new behavior was created (1 in this case)
@@ -653,7 +634,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
 
         RaftActorBehavior newBehavior = follower.handleMessage(leaderActor, appendEntries);
 
-        Assert.assertSame(follower, newBehavior);
+        assertSame(follower, newBehavior);
 
         // The entry at index 2 will be found out-of-sync with the leader
         // and will be removed
@@ -690,9 +671,8 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         context.setReplicatedLog(log);
 
         // Prepare the entries to be sent with AppendEntries
-        List<ReplicatedLogEntry> entries = new ArrayList<>();
-        entries.add(newReplicatedLogEntry(2, 2, "two-1"));
-        entries.add(newReplicatedLogEntry(2, 3, "three"));
+        List<ReplicatedLogEntry> entries = List.of(
+            newReplicatedLogEntry(2, 2, "two-1"), newReplicatedLogEntry(2, 3, "three"));
 
         // Send appendEntries with the same term as was set on the receiver
         // before the new behavior was created (1 in this case)
@@ -705,7 +685,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
 
         RaftActorBehavior newBehavior = follower.handleMessage(leaderActor, appendEntries);
 
-        Assert.assertSame(follower, newBehavior);
+        assertSame(follower, newBehavior);
 
         expectAndVerifyAppendEntriesReply(2, false, context.getId(), 1, 2, true);
     }
@@ -725,8 +705,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         context.setReplicatedLog(log);
 
         // Prepare the entries to be sent with AppendEntries
-        List<ReplicatedLogEntry> entries = new ArrayList<>();
-        entries.add(newReplicatedLogEntry(1, 4, "four"));
+        List<ReplicatedLogEntry> entries = List.of(newReplicatedLogEntry(1, 4, "four"));
 
         AppendEntries appendEntries = new AppendEntries(1, "leader", 3, 1, entries, 4, -1, (short)0);
 
@@ -734,7 +713,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
 
         RaftActorBehavior newBehavior = follower.handleMessage(leaderActor, appendEntries);
 
-        Assert.assertSame(follower, newBehavior);
+        assertSame(follower, newBehavior);
 
         expectAndVerifyAppendEntriesReply(1, false, context.getId(), 1, 2);
     }
@@ -755,7 +734,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         context.setReplicatedLog(log);
 
         // Send the last entry again.
-        List<ReplicatedLogEntry> entries = Arrays.asList(newReplicatedLogEntry(1, 1, "one"));
+        List<ReplicatedLogEntry> entries = List.of(newReplicatedLogEntry(1, 1, "one"));
 
         follower = createBehavior(context);
 
@@ -768,7 +747,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
 
         // Send the last entry again and also a new one.
 
-        entries = Arrays.asList(newReplicatedLogEntry(1, 1, "one"), newReplicatedLogEntry(1, 2, "two"));
+        entries = List.of(newReplicatedLogEntry(1, 1, "one"), newReplicatedLogEntry(1, 2, "two"));
 
         MessageCollectorActor.clearMessages(leaderActor);
         follower.handleMessage(leaderActor, new AppendEntries(1, "leader", 0, 1, entries, 2, -1, (short)0));
@@ -796,8 +775,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         context.setReplicatedLog(log);
 
         // Prepare the entries to be sent with AppendEntries
-        List<ReplicatedLogEntry> entries = new ArrayList<>();
-        entries.add(newReplicatedLogEntry(1, 4, "four"));
+        List<ReplicatedLogEntry> entries = List.of(newReplicatedLogEntry(1, 4, "four"));
 
         AppendEntries appendEntries = new AppendEntries(1, "leader", 3, 1, entries, 4, 3, (short)0);
 
@@ -805,7 +783,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
 
         RaftActorBehavior newBehavior = follower.handleMessage(leaderActor, appendEntries);
 
-        Assert.assertSame(follower, newBehavior);
+        assertSame(follower, newBehavior);
 
         expectAndVerifyAppendEntriesReply(1, true, context.getId(), 1, 4);
     }
@@ -853,7 +831,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
                 snapshot.getLastAppliedIndex());
         assertEquals("getLastTerm", lastInstallSnapshot.getLastIncludedTerm(), snapshot.getLastTerm());
         assertEquals("getState type", ByteState.class, snapshot.getState().getClass());
-        Assert.assertArrayEquals("getState", bsSnapshot.toByteArray(), ((ByteState)snapshot.getState()).getBytes());
+        assertArrayEquals("getState", bsSnapshot.toByteArray(), ((ByteState)snapshot.getState()).getBytes());
         assertEquals("getElectionTerm", 1, snapshot.getElectionTerm());
         assertEquals("getElectionVotedFor", "leader", snapshot.getElectionVotedFor());
         applySnapshot.getCallback().onSuccess();
@@ -907,7 +885,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
 
         // Send an append entry
         AppendEntries appendEntries = new AppendEntries(1, "leader", 1, 1,
-                Arrays.asList(newReplicatedLogEntry(2, 1, "3")), 2, -1, (short)1);
+                List.of(newReplicatedLogEntry(2, 1, "3")), 2, -1, (short)1);
 
         follower.handleMessage(leaderActor, appendEntries);
 
@@ -950,7 +928,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
 
         // Send appendEntries with a new term and leader.
         AppendEntries appendEntries = new AppendEntries(2, "new-leader", 1, 1,
-                Arrays.asList(newReplicatedLogEntry(2, 2, "3")), 2, -1, (short)1);
+                List.of(newReplicatedLogEntry(2, 2, "3")), 2, -1, (short)1);
 
         follower.handleMessage(leaderActor, appendEntries);
 
@@ -1004,8 +982,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         setLastLogEntry(context, 1, 101,
                 new MockRaftActorContext.MockPayload(""));
 
-        List<ReplicatedLogEntry> entries = Arrays.asList(
-                newReplicatedLogEntry(2, 101, "foo"));
+        List<ReplicatedLogEntry> entries = List.of(newReplicatedLogEntry(2, 101, "foo"));
 
         // The new commitIndex is 101
         AppendEntries appendEntries = new AppendEntries(2, "leader", 101, 1, entries, 102, 101, (short)0);
@@ -1081,7 +1058,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
     @Test
     public void testFollowerSchedulesElectionIfNonVoting() {
         MockRaftActorContext context = createActorContext();
-        context.updatePeerIds(new ServerConfigurationPayload(Arrays.asList(new ServerInfo(context.getId(), false))));
+        context.updatePeerIds(new ServerConfigurationPayload(List.of(new ServerInfo(context.getId(), false))));
         ((DefaultConfigParamsImpl)context.getConfigParams()).setHeartBeatInterval(
                 FiniteDuration.apply(100, TimeUnit.MILLISECONDS));
         ((DefaultConfigParamsImpl)context.getConfigParams()).setElectionTimeoutFactor(1);
@@ -1132,7 +1109,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         final AtomicReference<MockRaftActor> followerRaftActor = new AtomicReference<>();
         RaftActorSnapshotCohort snapshotCohort = newRaftActorSnapshotCohort(followerRaftActor);
         Builder builder = MockRaftActor.builder().persistent(Optional.of(true)).id(id)
-                .peerAddresses(ImmutableMap.of("leader", "")).config(config).snapshotCohort(snapshotCohort);
+                .peerAddresses(Map.of("leader", "")).config(config).snapshotCohort(snapshotCohort);
         TestActorRef<MockRaftActor> followerActorRef = actorFactory.createTestActor(builder.props()
                 .withDispatcher(Dispatchers.DefaultDispatcherId()), id);
         followerRaftActor.set(followerActorRef.underlyingActor());
@@ -1142,7 +1119,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         InMemoryJournal.addDeleteMessagesCompleteLatch(id);
         InMemoryJournal.addWriteMessagesCompleteLatch(id, 1, ApplyJournalEntries.class);
 
-        List<ReplicatedLogEntry> entries = Arrays.asList(
+        List<ReplicatedLogEntry> entries = List.of(
                 newReplicatedLogEntry(1, 0, "one"), newReplicatedLogEntry(1, 1, "two"));
 
         AppendEntries appendEntries = new AppendEntries(1, "leader", -1, -1, entries, 1, -1, (short)0);
@@ -1169,7 +1146,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         assertEquals("Snapshot getLastAppliedIndex", 1, snapshot.getLastAppliedIndex());
         assertEquals("Snapshot getLastTerm", 1, snapshot.getLastTerm());
         assertEquals("Snapshot getLastIndex", 1, snapshot.getLastIndex());
-        assertEquals("Snapshot state", ImmutableList.of(entries.get(0).getData(), entries.get(1).getData()),
+        assertEquals("Snapshot state", List.of(entries.get(0).getData(), entries.get(1).getData()),
                 MockRaftActor.fromState(snapshot.getState()));
     }
 
@@ -1187,7 +1164,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         final AtomicReference<MockRaftActor> followerRaftActor = new AtomicReference<>();
         RaftActorSnapshotCohort snapshotCohort = newRaftActorSnapshotCohort(followerRaftActor);
         Builder builder = MockRaftActor.builder().persistent(Optional.of(true)).id(id)
-                .peerAddresses(ImmutableMap.of("leader", "")).config(config).snapshotCohort(snapshotCohort);
+                .peerAddresses(Map.of("leader", "")).config(config).snapshotCohort(snapshotCohort);
         TestActorRef<MockRaftActor> followerActorRef = actorFactory.createTestActor(builder.props()
                 .withDispatcher(Dispatchers.DefaultDispatcherId()), id);
         followerRaftActor.set(followerActorRef.underlyingActor());
@@ -1197,7 +1174,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         InMemoryJournal.addDeleteMessagesCompleteLatch(id);
         InMemoryJournal.addWriteMessagesCompleteLatch(id, 1, ApplyJournalEntries.class);
 
-        List<ReplicatedLogEntry> entries = Arrays.asList(
+        List<ReplicatedLogEntry> entries = List.of(
                 newReplicatedLogEntry(1, 0, "one"), newReplicatedLogEntry(1, 1, "two"),
                 newReplicatedLogEntry(1, 2, "three"));
 
@@ -1225,7 +1202,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         assertEquals("Snapshot getLastAppliedIndex", 2, snapshot.getLastAppliedIndex());
         assertEquals("Snapshot getLastTerm", 1, snapshot.getLastTerm());
         assertEquals("Snapshot getLastIndex", 2, snapshot.getLastIndex());
-        assertEquals("Snapshot state", ImmutableList.of(entries.get(0).getData(), entries.get(1).getData(),
+        assertEquals("Snapshot state", List.of(entries.get(0).getData(), entries.get(1).getData(),
                 entries.get(2).getData()), MockRaftActor.fromState(snapshot.getState()));
 
         assertEquals("Journal size", 0, followerRaftActor.get().getReplicatedLog().size());
@@ -1244,7 +1221,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         assertEquals("Last index", 2, followerRaftActor.get().getReplicatedLog().lastIndex());
         assertEquals("Last applied index", 2, followerRaftActor.get().getRaftActorContext().getLastApplied());
         assertEquals("Commit index", 2, followerRaftActor.get().getRaftActorContext().getCommitIndex());
-        assertEquals("State", ImmutableList.of(entries.get(0).getData(), entries.get(1).getData(),
+        assertEquals("State", List.of(entries.get(0).getData(), entries.get(1).getData(),
                 entries.get(2).getData()), followerRaftActor.get().getState());
     }
 
@@ -1262,7 +1239,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         final AtomicReference<MockRaftActor> followerRaftActor = new AtomicReference<>();
         RaftActorSnapshotCohort snapshotCohort = newRaftActorSnapshotCohort(followerRaftActor);
         Builder builder = MockRaftActor.builder().persistent(Optional.of(true)).id(id)
-                .peerAddresses(ImmutableMap.of("leader", "")).config(config).snapshotCohort(snapshotCohort);
+                .peerAddresses(Map.of("leader", "")).config(config).snapshotCohort(snapshotCohort);
         TestActorRef<MockRaftActor> followerActorRef = actorFactory.createTestActor(builder.props()
                 .withDispatcher(Dispatchers.DefaultDispatcherId()), id);
         followerRaftActor.set(followerActorRef.underlyingActor());
@@ -1272,7 +1249,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         InMemoryJournal.addDeleteMessagesCompleteLatch(id);
         InMemoryJournal.addWriteMessagesCompleteLatch(id, 1, ApplyJournalEntries.class);
 
-        List<ReplicatedLogEntry> entries = Arrays.asList(
+        List<ReplicatedLogEntry> entries = List.of(
                 newReplicatedLogEntry(1, 0, "one"), newReplicatedLogEntry(1, 1, "two"),
                 newReplicatedLogEntry(1, 2, "three"));
 
@@ -1302,7 +1279,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         assertEquals("Snapshot getLastAppliedIndex", 0, snapshot.getLastAppliedIndex());
         assertEquals("Snapshot getLastTerm", 1, snapshot.getLastTerm());
         assertEquals("Snapshot getLastIndex", 2, snapshot.getLastIndex());
-        assertEquals("Snapshot state", ImmutableList.of(entries.get(0).getData()),
+        assertEquals("Snapshot state", List.of(entries.get(0).getData()),
                 MockRaftActor.fromState(snapshot.getState()));
     }
 
@@ -1318,7 +1295,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         follower = createBehavior(context);
 
         follower.handleMessage(leaderActor,
-                new AppendEntries(1, "leader", -1, -1, Collections.emptyList(), -1, -1, (short)0));
+                new AppendEntries(1, "leader", -1, -1, List.of(), -1, -1, (short)0));
 
         AppendEntriesReply reply = MessageCollectorActor.expectFirstMatching(leaderActor, AppendEntriesReply.class);
         assertTrue(reply.isNeedsLeaderAddress());
@@ -1327,7 +1304,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         PeerAddressResolver mockResolver = mock(PeerAddressResolver.class);
         ((DefaultConfigParamsImpl)context.getConfigParams()).setPeerAddressResolver(mockResolver);
 
-        follower.handleMessage(leaderActor, new AppendEntries(1, "leader", -1, -1, Collections.emptyList(), -1, -1,
+        follower.handleMessage(leaderActor, new AppendEntries(1, "leader", -1, -1, List.of(), -1, -1,
                 (short)0, RaftVersions.CURRENT_VERSION, leaderActor.path().toString()));
 
         reply = MessageCollectorActor.expectFirstMatching(leaderActor, AppendEntriesReply.class);
@@ -1370,10 +1347,8 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
         int size = chunkSize;
         if (chunkSize > snapshotLength) {
             size = snapshotLength;
-        } else {
-            if (start + chunkSize > snapshotLength) {
-                size = snapshotLength - start;
-            }
+        } else if (start + chunkSize > snapshotLength) {
+            size = snapshotLength - start;
         }
 
         byte[] nextChunk = new byte[size];
@@ -1410,12 +1385,7 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest<Follower> {
     }
 
     private ByteString createSnapshot() {
-        HashMap<String, String> followerSnapshot = new HashMap<>();
-        followerSnapshot.put("1", "A");
-        followerSnapshot.put("2", "B");
-        followerSnapshot.put("3", "C");
-
-        return toByteString(followerSnapshot);
+        return toByteString(Map.of("1", "A", "2", "B", "3", "C"));
     }
 
     @Override