Fix testSeqNoCollision (elastic#52588)

Adjusts the assertion as we trim translog more eagerly since elastic#52556.

Relates elastic#52556
Closes elastic#52148

Author: dnhatn

server/src/test/java/org/elasticsearch/index/replication/IndexLevelReplicationTests.java

@@ -543,7 +543,10 @@ public void testRequestFailureReplication() throws Exception {
     }
 
     public void testSeqNoCollision() throws Exception {
-        try (ReplicationGroup shards = createGroup(2)) {
+        try (ReplicationGroup shards = createGroup(2, Settings.builder()
+            .put(IndexSettings.INDEX_SOFT_DELETES_SETTING.getKey(), true)
+            .put(IndexSettings.INDEX_TRANSLOG_RETENTION_AGE_SETTING.getKey(), "-1")
+            .put(IndexSettings.INDEX_TRANSLOG_RETENTION_SIZE_SETTING.getKey(), "-1").build())) {
             shards.startAll();
             int initDocs = shards.indexDocs(randomInt(10));
             List<IndexShard> replicas = shards.getReplicas();
@@ -570,19 +573,17 @@ public void testSeqNoCollision() throws Exception {
                 assertThat(snapshot.next(), nullValue());
                 assertThat(snapshot.skippedOperations(), equalTo(0));
             }
-            // Make sure that replica2 receives translog ops (eg. op2) from replica1
-            // and does not overwrite its stale operation (op1) as it is trimmed.
             logger.info("--> Promote replica1 as the primary");
             shards.promoteReplicaToPrimary(replica1).get(); // wait until resync completed.
             shards.index(new IndexRequest(index.getName(), "type", "d2").source("{}", XContentType.JSON));
             final Translog.Operation op2;
             try (Translog.Snapshot snapshot = getTranslog(replica2).newSnapshot()) {
-                assertThat(snapshot.totalOperations(), equalTo(initDocs + 2));
+                assertThat(snapshot.totalOperations(), equalTo(1));
                 op2 = snapshot.next();
                 assertThat(op2.seqNo(), equalTo(op1.seqNo()));
                 assertThat(op2.primaryTerm(), greaterThan(op1.primaryTerm()));
-                assertThat("Remaining of snapshot should contain init operations", snapshot, containsOperationsInAnyOrder(initOperations));
-                assertThat(snapshot.skippedOperations(), equalTo(1));
+                assertNull(snapshot.next());
+                assertThat(snapshot.skippedOperations(), equalTo(0));
             }
 
             // Make sure that peer-recovery transfers all but non-overridden operations.
@@ -591,8 +592,7 @@ public void testSeqNoCollision() throws Exception {
             shards.promoteReplicaToPrimary(replica2).get();
             logger.info("--> Recover replica3 from replica2");
             recoverReplica(replica3, replica2, true);
-            try (Translog.Snapshot snapshot = replica3.getHistoryOperations(
-                "test", replica3.indexSettings().isSoftDeleteEnabled() ? Engine.HistorySource.INDEX : Engine.HistorySource.TRANSLOG, 0)) {
+            try (Translog.Snapshot snapshot = replica3.newChangesSnapshot("test", 0, Long.MAX_VALUE, false)) {
                 assertThat(snapshot.totalOperations(), equalTo(initDocs + 1));
                 final List<Translog.Operation> expectedOps = new ArrayList<>(initOperations);
                 expectedOps.add(op2);