SERVER-32144 Remove test coverage for replication protocol version 0

This reverts commit c5a4250a649ab0afb4ecdf227d4a0400f9e68786.

11 files changed, 105 insertions, 1176 deletions

diff --git a/src/mongo/bson/oid_test.cpp b/src/mongo/bson/oid_test.cpp
index 7a0e6d6773d..8be156ae41d 100644
--- a/src/mongo/bson/oid_test.cpp
+++ b/src/mongo/bson/oid_test.cpp
@@ -149,4 +149,16 @@ TEST(Basic, FromStringToString) {
     std::string fromStr("541b1a00e8a23afa832b218e");
     ASSERT_EQUALS(OID(fromStr).toString(), fromStr);
 }
+
+TEST(Basic, FromTerm) {
+    auto term = 7;
+    auto oid = OID::fromTerm(term);
+
+    auto oidStr = oid.toString();
+    auto oidHead = oidStr.substr(0, 8);
+    auto oidTail = oidStr.substr(oidStr.length() - 1);
+
+    ASSERT_EQUALS("7fffffff", oidHead);
+    ASSERT_EQUALS(term, std::stoi(oidTail));
+}
 }
diff --git a/src/mongo/db/repl/SConscript b/src/mongo/db/repl/SConscript
index 6200fb4b39a..064d3244740 100644
--- a/src/mongo/db/repl/SConscript
+++ b/src/mongo/db/repl/SConscript
@@ -917,12 +917,6 @@ env.CppUnitTest(
     ],
 )
 
-env.CppUnitTest('replication_coordinator_impl_elect_test',
-                'replication_coordinator_impl_elect_test.cpp',
-                LIBDEPS=[
-                    'repl_coordinator_test_fixture',
-                ])
-
 env.CppUnitTest('replication_coordinator_impl_elect_v1_test',
                 'replication_coordinator_impl_elect_v1_test.cpp',
                 LIBDEPS=['repl_coordinator_test_fixture'])
@@ -931,10 +925,6 @@ env.CppUnitTest('replication_coordinator_impl_heartbeat_v1_test',
                 'replication_coordinator_impl_heartbeat_v1_test.cpp',
                 LIBDEPS=['repl_coordinator_test_fixture'])
 
-env.CppUnitTest('replication_coordinator_impl_heartbeat_test',
-                'replication_coordinator_impl_heartbeat_test.cpp',
-                LIBDEPS=['repl_coordinator_test_fixture'])
-
 env.CppUnitTest('replication_coordinator_impl_reconfig_test',
                 'replication_coordinator_impl_reconfig_test.cpp',
                 LIBDEPS=['repl_coordinator_test_fixture'])
diff --git a/src/mongo/db/repl/oplog_fetcher_test.cpp b/src/mongo/db/repl/oplog_fetcher_test.cpp
index 352298b195a..354377f2912 100644
--- a/src/mongo/db/repl/oplog_fetcher_test.cpp
+++ b/src/mongo/db/repl/oplog_fetcher_test.cpp
@@ -88,7 +88,7 @@ protected:
      * Tests handling of two batches of operations returned from query.
      * Returns getMore request.
      */
-    RemoteCommandRequest testTwoBatchHandling(bool isV1ElectionProtocol);
+    RemoteCommandRequest testTwoBatchHandling();
 
     OpTime remoteNewerOpTime;
     OpTime staleOpTime;
@@ -137,13 +137,11 @@ BSONObj OplogFetcherTest::makeOplogQueryMetadataObject(OpTime lastAppliedOpTime,
 HostAndPort source("localhost:12345");
 NamespaceString nss("local.oplog.rs");
 
-ReplSetConfig _createConfig(bool isV1ElectionProtocol) {
+ReplSetConfig _createConfig() {
     BSONObjBuilder bob;
     bob.append("_id", "myset");
     bob.append("version", 1);
-    if (isV1ElectionProtocol) {
-        bob.append("protocolVersion", 1);
-    }
+    bob.append("protocolVersion", 1);
     {
         BSONArrayBuilder membersBob(bob.subarrayStart("members"));
         BSONObjBuilder(membersBob.subobjStart())
@@ -168,7 +166,7 @@ std::unique_ptr<ShutdownState> OplogFetcherTest::processSingleBatch(RemoteComman
                               lastFetched,
                               source,
                               nss,
-                              _createConfig(true),
+                              _createConfig(),
                               0,
                               rbid,
                               requireFresherSyncSource,
@@ -224,7 +222,7 @@ std::unique_ptr<OplogFetcher> OplogFetcherTest::makeOplogFetcher(ReplSetConfig c
 TEST_F(
     OplogFetcherTest,
     FindQueryContainsTermAndStartTimestampIfGetCurrentTermAndLastCommittedOpTimeReturnsValidTerm) {
-    auto cmdObj = makeOplogFetcher(_createConfig(true))->getFindQuery_forTest();
+    auto cmdObj = makeOplogFetcher(_createConfig())->getFindQuery_forTest();
     ASSERT_EQUALS(mongo::BSONType::Object, cmdObj["filter"].type());
     ASSERT_BSONOBJ_EQ(BSON("ts" << BSON("$gte" << lastFetched.opTime.getTimestamp())),
                       cmdObj["filter"].Obj());
@@ -235,7 +233,7 @@ TEST_F(
 TEST_F(OplogFetcherTest,
        FindQueryDoesNotContainTermIfGetCurrentTermAndLastCommittedOpTimeReturnsUninitializedTerm) {
     dataReplicatorExternalState->currentTerm = OpTime::kUninitializedTerm;
-    auto cmdObj = makeOplogFetcher(_createConfig(true))->getFindQuery_forTest();
+    auto cmdObj = makeOplogFetcher(_createConfig())->getFindQuery_forTest();
     ASSERT_EQUALS(mongo::BSONType::Object, cmdObj["filter"].type());
     ASSERT_BSONOBJ_EQ(BSON("ts" << BSON("$gte" << lastFetched.opTime.getTimestamp())),
                       cmdObj["filter"].Obj());
@@ -244,39 +242,29 @@ TEST_F(OplogFetcherTest,
 }
 
 TEST_F(OplogFetcherTest, MetadataObjectContainsMetadataFieldsUnderProtocolVersion1) {
-    auto metadataObj = makeOplogFetcher(_createConfig(true))->getMetadataObject_forTest();
+    auto metadataObj = makeOplogFetcher(_createConfig())->getMetadataObject_forTest();
     ASSERT_EQUALS(3, metadataObj.nFields());
     ASSERT_EQUALS(1, metadataObj[rpc::kReplSetMetadataFieldName].numberInt());
     ASSERT_EQUALS(1, metadataObj[rpc::kOplogQueryMetadataFieldName].numberInt());
 }
 
-TEST_F(OplogFetcherTest, MetadataObjectIsEmptyUnderProtocolVersion0) {
-    auto metadataObj = makeOplogFetcher(_createConfig(false))->getMetadataObject_forTest();
-    ASSERT_BSONOBJ_EQ(ReadPreferenceSetting::secondaryPreferredMetadata(), metadataObj);
-}
-
 TEST_F(OplogFetcherTest, AwaitDataTimeoutShouldEqualHalfElectionTimeoutUnderProtocolVersion1) {
-    auto config = _createConfig(true);
+    auto config = _createConfig();
     auto timeout = makeOplogFetcher(config)->getAwaitDataTimeout_forTest();
     ASSERT_EQUALS(config.getElectionTimeoutPeriod() / 2, timeout);
 }
 
-TEST_F(OplogFetcherTest, AwaitDataTimeoutShouldBeAConstantUnderProtocolVersion0) {
-    auto timeout = makeOplogFetcher(_createConfig(false))->getAwaitDataTimeout_forTest();
-    ASSERT_EQUALS(OplogFetcher::kDefaultProtocolZeroAwaitDataTimeout, timeout);
-}
-
 TEST_F(OplogFetcherTest, FindQueryHasNoReadconcernIfTermNotLastFetched) {
     auto uninitializedTerm = OpTime::kUninitializedTerm;
     ASSERT_NOT_EQUALS(dataReplicatorExternalState->currentTerm, uninitializedTerm);
     dataReplicatorExternalState->currentTerm++;
-    auto cmdObj = makeOplogFetcher(_createConfig(true))->getFindQuery_forTest();
+    auto cmdObj = makeOplogFetcher(_createConfig())->getFindQuery_forTest();
     ASSERT_FALSE(cmdObj.hasField("readConcern"));
 }
 
 TEST_F(OplogFetcherTest, FindQueryHasNoReadconcernIfTermUninitialized) {
     dataReplicatorExternalState->currentTerm = OpTime::kUninitializedTerm;
-    auto cmdObj = makeOplogFetcher(_createConfig(true))->getFindQuery_forTest();
+    auto cmdObj = makeOplogFetcher(_createConfig())->getFindQuery_forTest();
     ASSERT_FALSE(cmdObj.hasField("readConcern"));
 }
 
@@ -696,18 +684,14 @@ TEST_F(OplogFetcherTest,
     ASSERT_FALSE(dataReplicatorExternalState->syncSourceHasSyncSource);
 }
 
-RemoteCommandRequest OplogFetcherTest::testTwoBatchHandling(bool isV1ElectionProtocol) {
+RemoteCommandRequest OplogFetcherTest::testTwoBatchHandling() {
     ShutdownState shutdownState;
 
-    if (!isV1ElectionProtocol) {
-        dataReplicatorExternalState->currentTerm = OpTime::kUninitializedTerm;
-    }
-
     OplogFetcher oplogFetcher(&getExecutor(),
                               lastFetched,
                               source,
                               nss,
-                              _createConfig(isV1ElectionProtocol),
+                              _createConfig(),
                               0,
                               rbid,
                               true,
@@ -757,20 +741,13 @@ RemoteCommandRequest OplogFetcherTest::testTwoBatchHandling(bool isV1ElectionPro
 TEST_F(
     OplogFetcherTest,
     NoDataAvailableAfterFirstTwoBatchesShouldCauseTheOplogFetcherToShutDownWithSuccessfulStatus) {
-    auto request = testTwoBatchHandling(true);
+    auto request = testTwoBatchHandling();
     ASSERT_EQUALS(dataReplicatorExternalState->currentTerm, request.cmdObj["term"].numberLong());
     ASSERT_EQUALS(dataReplicatorExternalState->lastCommittedOpTime,
                   unittest::assertGet(OpTime::parseFromOplogEntry(
                       request.cmdObj["lastKnownCommittedOpTime"].Obj())));
 }
 
-TEST_F(OplogFetcherTest,
-       GetMoreRequestUnderProtocolVersionZeroDoesNotIncludeTermOrLastKnownCommittedOpTime) {
-    auto request = testTwoBatchHandling(false);
-    ASSERT_FALSE(request.cmdObj.hasField("term"));
-    ASSERT_FALSE(request.cmdObj.hasField("lastKnownCommittedOpTime"));
-}
-
 TEST_F(OplogFetcherTest, ValidateDocumentsReturnsNoSuchKeyIfTimestampIsNotFoundInAnyDocument) {
     auto firstEntry = makeNoopOplogEntry(Seconds(123), 100);
     auto secondEntry = BSON("o" << BSON("msg"
diff --git a/src/mongo/db/repl/repl_set_config_test.cpp b/src/mongo/db/repl/repl_set_config_test.cpp
index 9a9731d89f8..07f303c7016 100644
--- a/src/mongo/db/repl/repl_set_config_test.cpp
+++ b/src/mongo/db/repl/repl_set_config_test.cpp
@@ -1685,32 +1685,7 @@ TEST(ReplSetConfig, GetCatchUpTakeoverDelayDefault) {
 }
 
 TEST(ReplSetConfig, ConfirmDefaultValuesOfAndAbilityToSetWriteConcernMajorityJournalDefault) {
-    // PV0, should default to false.
     ReplSetConfig config;
-    ASSERT_OK(config.initialize(BSON("_id"
-                                     << "rs0"
-                                     << "version"
-                                     << 1
-                                     << "members"
-                                     << BSON_ARRAY(BSON("_id" << 0 << "host"
-                                                              << "localhost:12345")))));
-    ASSERT_OK(config.validate());
-    ASSERT_FALSE(config.getWriteConcernMajorityShouldJournal());
-    ASSERT_FALSE(config.toBSON().hasField("writeConcernMajorityJournalDefault"));
-
-    // Should be able to set it true in PV0.
-    ASSERT_OK(config.initialize(BSON("_id"
-                                     << "rs0"
-                                     << "version"
-                                     << 1
-                                     << "members"
-                                     << BSON_ARRAY(BSON("_id" << 0 << "host"
-                                                              << "localhost:12345"))
-                                     << "writeConcernMajorityJournalDefault"
-                                     << true)));
-    ASSERT_OK(config.validate());
-    ASSERT_TRUE(config.getWriteConcernMajorityShouldJournal());
-    ASSERT_TRUE(config.toBSON().hasField("writeConcernMajorityJournalDefault"));
 
     // PV1, should default to true.
     ASSERT_OK(config.initialize(BSON("_id"
diff --git a/src/mongo/db/repl/replication_consistency_markers_impl_test.cpp b/src/mongo/db/repl/replication_consistency_markers_impl_test.cpp
index c45a4114ce7..1e586e28f65 100644
--- a/src/mongo/db/repl/replication_consistency_markers_impl_test.cpp
+++ b/src/mongo/db/repl/replication_consistency_markers_impl_test.cpp
@@ -291,53 +291,4 @@ TEST_F(ReplicationConsistencyMarkersTest, ReplicationConsistencyMarkers) {
     ASSERT_FALSE(recoveryUnit->waitUntilDurableCalled);
 }
 
-TEST_F(ReplicationConsistencyMarkersTest, SetMinValidOnPVChange) {
-    auto minValidNss = makeNamespace(_agent, "minValid");
-    auto oplogTruncateAfterPointNss = makeNamespace(_agent, "oplogTruncateAfterPoint");
-    auto checkpointTimestampNss = makeNamespace(_agent, "checkpointTimestamp");
-
-    ReplicationConsistencyMarkersImpl consistencyMarkers(
-        getStorageInterface(), minValidNss, oplogTruncateAfterPointNss, checkpointTimestampNss);
-    auto opCtx = getOperationContext();
-    ASSERT(consistencyMarkers.createInternalCollections(opCtx).isOK());
-    consistencyMarkers.initializeMinValidDocument(opCtx);
-
-    auto advanceAndCheckMinValidOpTime = [&](OpTime advanceTo, OpTime expected) {
-        consistencyMarkers.setMinValidToAtLeast(opCtx, advanceTo);
-        ASSERT_EQUALS(expected, consistencyMarkers.getMinValid(opCtx));
-    };
-
-    // Set minValid in PV 1.
-    OpTime startOpTime({Seconds(20), 0}, 1LL);
-    advanceAndCheckMinValidOpTime(startOpTime, startOpTime);
-
-    // In rollback, minValid is when the date becomes consistent and never goes back.
-    OpTime rollbackOpTime({Seconds(10), 0}, 1LL);
-    advanceAndCheckMinValidOpTime(rollbackOpTime, startOpTime);
-
-    // Writes arrive, so minValid advances.
-    OpTime opTime1({Seconds(30), 0}, 1LL);
-    advanceAndCheckMinValidOpTime(opTime1, opTime1);
-
-    // A new term starts and oplog diverges, so the timestamp is lower.
-    OpTime newTermOpTime({Seconds(20), 0}, 2LL);
-    advanceAndCheckMinValidOpTime(newTermOpTime, newTermOpTime);
-
-    // We should never advance minValid to a lower term, but verify it never goes back even if the
-    // timestamp is higher.
-    OpTime invalidOpTime({Seconds(80), 0}, 1LL);
-    advanceAndCheckMinValidOpTime(invalidOpTime, newTermOpTime);
-
-    // PV downgrade to PV0
-    OpTime downgradeOpTime({Seconds(50), 0}, -1LL);
-    advanceAndCheckMinValidOpTime(downgradeOpTime, downgradeOpTime);
-
-    // Writes arrive in PV0.
-    OpTime opTime2({Seconds(60), 0}, -1LL);
-    advanceAndCheckMinValidOpTime(opTime2, opTime2);
-
-    // PV upgrade again.
-    OpTime upgradeOpTime({Seconds(70), 0}, 0LL);
-    advanceAndCheckMinValidOpTime(upgradeOpTime, upgradeOpTime);
-}
 }  // namespace
diff --git a/src/mongo/db/repl/replication_coordinator_impl_elect_test.cpp b/src/mongo/db/repl/replication_coordinator_impl_elect_test.cpp
deleted file mode 100644
index b7b871cd89f..00000000000
--- a/src/mongo/db/repl/replication_coordinator_impl_elect_test.cpp
+++ /dev/null
@@ -1,651 +0,0 @@
-/**
- *    Copyright (C) 2014 MongoDB Inc.
- *
- *    This program is free software: you can redistribute it and/or  modify
- *    it under the terms of the GNU Affero General Public License, version 3,
- *    as published by the Free Software Foundation.
- *
- *    This program is distributed in the hope that it will be useful,
- *    but WITHOUT ANY WARRANTY; without even the implied warranty of
- *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *    GNU Affero General Public License for more details.
- *
- *    You should have received a copy of the GNU Affero General Public License
- *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
- *    As a special exception, the copyright holders give permission to link the
- *    code of portions of this program with the OpenSSL library under certain
- *    conditions as described in each individual source file and distribute
- *    linked combinations including the program with the OpenSSL library. You
- *    must comply with the GNU Affero General Public License in all respects for
- *    all of the code used other than as permitted herein. If you modify file(s)
- *    with this exception, you may extend this exception to your version of the
- *    file(s), but you are not obligated to do so. If you do not wish to do so,
- *    delete this exception statement from your version. If you delete this
- *    exception statement from all source files in the program, then also delete
- *    it in the license file.
- */
-
-#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kReplication
-
-#include "mongo/platform/basic.h"
-
-#include "mongo/db/jsobj.h"
-#include "mongo/db/operation_context_noop.h"
-#include "mongo/db/repl/is_master_response.h"
-#include "mongo/db/repl/repl_set_config.h"
-#include "mongo/db/repl/repl_set_heartbeat_args.h"
-#include "mongo/db/repl/repl_set_heartbeat_response.h"
-#include "mongo/db/repl/replication_coordinator_external_state_mock.h"
-#include "mongo/db/repl/replication_coordinator_impl.h"
-#include "mongo/db/repl/replication_coordinator_test_fixture.h"
-#include "mongo/db/repl/topology_coordinator.h"
-#include "mongo/executor/network_interface_mock.h"
-#include "mongo/unittest/unittest.h"
-#include "mongo/util/fail_point_service.h"
-#include "mongo/util/log.h"
-
-namespace mongo {
-namespace repl {
-namespace {
-
-using executor::NetworkInterfaceMock;
-using executor::RemoteCommandRequest;
-using executor::RemoteCommandResponse;
-
-class ReplCoordElectTest : public ReplCoordTest {
-protected:
-    void assertStartSuccess(const BSONObj& configDoc, const HostAndPort& selfHost);
-    void simulateFreshEnoughForElectability();
-};
-
-void ReplCoordElectTest::assertStartSuccess(const BSONObj& configDoc, const HostAndPort& selfHost) {
-    ReplCoordTest::assertStartSuccess(addProtocolVersion(configDoc, 0), selfHost);
-}
-
-void ReplCoordElectTest::simulateFreshEnoughForElectability() {
-    ReplicationCoordinatorImpl* replCoord = getReplCoord();
-    ReplSetConfig rsConfig = replCoord->getReplicaSetConfig_forTest();
-    NetworkInterfaceMock* net = getNet();
-    net->enterNetwork();
-    for (int i = 0; i < rsConfig.getNumMembers() - 1; ++i) {
-        const NetworkInterfaceMock::NetworkOperationIterator noi = net->getNextReadyRequest();
-        const RemoteCommandRequest& request = noi->getRequest();
-        log() << request.target.toString() << " processing " << request.cmdObj;
-        if (request.cmdObj.firstElement().fieldNameStringData() == "replSetFresh") {
-            net->scheduleResponse(
-                noi,
-                net->now(),
-                makeResponseStatus(BSON("ok" << 1 << "fresher" << false << "opTime"
-                                             << Date_t::fromMillisSinceEpoch(Timestamp(0, 0).asLL())
-                                             << "veto"
-                                             << false)));
-        } else {
-            error() << "Black holing unexpected request to " << request.target << ": "
-                    << request.cmdObj;
-            net->blackHole(noi);
-        }
-        net->runReadyNetworkOperations();
-    }
-    net->exitNetwork();
-}
-
-TEST_F(ReplCoordElectTest, StartElectionDoesNotStartAnElectionWhenNodeHasNoOplogEntries) {
-    logger::globalLogDomain()->setMinimumLoggedSeverity(logger::LogSeverity::Debug(3));
-    // Election never starts because we haven't set a lastOpTimeApplied value yet, via a
-    // heartbeat.
-    startCapturingLogMessages();
-    assertStartSuccess(BSON("_id"
-                            << "mySet"
-                            << "version"
-                            << 1
-                            << "members"
-                            << BSON_ARRAY(BSON("_id" << 1 << "host"
-                                                     << "node1:12345")
-                                          << BSON("_id" << 2 << "host"
-                                                        << "node2:12345"))),
-                       HostAndPort("node1", 12345));
-    ASSERT_OK(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
-    simulateEnoughHeartbeatsForAllNodesUp();
-    stopCapturingLogMessages();
-    ASSERT_EQUALS(1, countLogLinesContaining("node has no applied oplog entries"));
-}
-
-/**
- * This test checks that an election can happen when only one node is up, and it has the
- * vote(s) to win.
- */
-TEST_F(ReplCoordElectTest, ElectionSucceedsWhenNodeIsTheOnlyElectableNode) {
-    assertStartSuccess(BSON("_id"
-                            << "mySet"
-                            << "version"
-                            << 1
-                            << "members"
-                            << BSON_ARRAY(BSON("_id" << 1 << "host"
-                                                     << "node1:12345")
-                                          << BSON("_id" << 2 << "host"
-                                                        << "node2:12345"
-                                                        << "votes"
-                                                        << 0
-                                                        << "hidden"
-                                                        << true
-                                                        << "priority"
-                                                        << 0))),
-                       HostAndPort("node1", 12345));
-
-    ASSERT_OK(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
-    // Fake OpTime from initiate, or a write op.
-    getExternalState()->setLastOpTime(OpTime{{0, 0}, -1});
-
-    ASSERT(getReplCoord()->getMemberState().secondary())
-        << getReplCoord()->getMemberState().toString();
-
-    getReplCoord()->setMyLastAppliedOpTime(OpTime(Timestamp(10, 0), -1));
-
-    NetworkInterfaceMock* net = getNet();
-    net->enterNetwork();
-    const NetworkInterfaceMock::NetworkOperationIterator noi = net->getNextReadyRequest();
-    // blackhole heartbeat
-    net->scheduleResponse(
-        noi, net->now(), executor::RemoteCommandResponse(ErrorCodes::OperationFailed, "timeout"));
-    net->runReadyNetworkOperations();
-    // blackhole freshness
-    const NetworkInterfaceMock::NetworkOperationIterator noi2 = net->getNextReadyRequest();
-    net->scheduleResponse(
-        noi2, net->now(), executor::RemoteCommandResponse(ErrorCodes::OperationFailed, "timeout"));
-    net->runReadyNetworkOperations();
-    net->exitNetwork();
-
-    ASSERT(getReplCoord()->getMemberState().primary())
-        << getReplCoord()->getMemberState().toString();
-    ASSERT(getReplCoord()->getApplierState() == ReplicationCoordinator::ApplierState::Draining);
-
-    const auto opCtxPtr = makeOperationContext();
-    auto& opCtx = *opCtxPtr;
-
-    // Since we're still in drain mode, expect that we report ismaster: false, issecondary:true.
-    IsMasterResponse imResponse;
-    getReplCoord()->fillIsMasterForReplSet(&imResponse);
-    ASSERT_FALSE(imResponse.isMaster()) << imResponse.toBSON().toString();
-    ASSERT_TRUE(imResponse.isSecondary()) << imResponse.toBSON().toString();
-    getReplCoord()->signalDrainComplete(&opCtx, getReplCoord()->getTerm());
-    getReplCoord()->fillIsMasterForReplSet(&imResponse);
-    ASSERT_TRUE(imResponse.isMaster()) << imResponse.toBSON().toString();
-    ASSERT_FALSE(imResponse.isSecondary()) << imResponse.toBSON().toString();
-}
-
-TEST_F(ReplCoordElectTest, ElectionSucceedsWhenNodeIsTheOnlyNode) {
-    startCapturingLogMessages();
-    assertStartSuccess(BSON("_id"
-                            << "mySet"
-                            << "version"
-                            << 1
-                            << "members"
-                            << BSON_ARRAY(BSON("_id" << 1 << "host"
-                                                     << "node1:12345"))),
-                       HostAndPort("node1", 12345));
-
-    ASSERT_OK(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
-
-    // Fake OpTime from initiate, or a write op.
-    getExternalState()->setLastOpTime(OpTime{{0, 0}, -1});
-
-    ASSERT(getReplCoord()->getMemberState().primary())
-        << getReplCoord()->getMemberState().toString();
-    ASSERT(getReplCoord()->getApplierState() == ReplicationCoordinator::ApplierState::Draining);
-
-    const auto opCtxPtr = makeOperationContext();
-    auto& opCtx = *opCtxPtr;
-
-    // Since we're still in drain mode, expect that we report ismaster: false, issecondary:true.
-    IsMasterResponse imResponse;
-    getReplCoord()->fillIsMasterForReplSet(&imResponse);
-    ASSERT_FALSE(imResponse.isMaster()) << imResponse.toBSON().toString();
-    ASSERT_TRUE(imResponse.isSecondary()) << imResponse.toBSON().toString();
-    getReplCoord()->signalDrainComplete(&opCtx, getReplCoord()->getTerm());
-    getReplCoord()->fillIsMasterForReplSet(&imResponse);
-    ASSERT_TRUE(imResponse.isMaster()) << imResponse.toBSON().toString();
-    ASSERT_FALSE(imResponse.isSecondary()) << imResponse.toBSON().toString();
-}
-
-TEST_F(ReplCoordElectTest, ElectionSucceedsWhenAllNodesVoteYea) {
-    BSONObj configObj = BSON("_id"
-                             << "mySet"
-                             << "version"
-                             << 1
-                             << "members"
-                             << BSON_ARRAY(BSON("_id" << 1 << "host"
-                                                      << "node1:12345")
-                                           << BSON("_id" << 2 << "host"
-                                                         << "node2:12345")
-                                           << BSON("_id" << 3 << "host"
-                                                         << "node3:12345")));
-    assertStartSuccess(configObj, HostAndPort("node1", 12345));
-    OperationContextNoop opCtx;
-    getReplCoord()->setMyLastAppliedOpTime(OpTime{{100, 1}, -1});
-    getExternalState()->setLastOpTime(OpTime{{100, 1}, -1});
-
-    ASSERT_OK(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
-    startCapturingLogMessages();
-    simulateSuccessfulElection();
-    stopCapturingLogMessages();
-    ASSERT_EQUALS(1, countLogLinesContaining("election succeeded"));
-}
-
-TEST_F(ReplCoordElectTest, ElectionFailsWhenOneNodeVotesNay) {
-    // one responds with -10000 votes, and one doesn't respond, and we are not elected
-    startCapturingLogMessages();
-    BSONObj configObj = BSON("_id"
-                             << "mySet"
-                             << "version"
-                             << 1
-                             << "members"
-                             << BSON_ARRAY(BSON("_id" << 1 << "host"
-                                                      << "node1:12345")
-                                           << BSON("_id" << 2 << "host"
-                                                         << "node2:12345")
-                                           << BSON("_id" << 3 << "host"
-                                                         << "node3:12345")));
-    assertStartSuccess(configObj, HostAndPort("node1", 12345));
-    ReplSetConfig config = assertMakeRSConfig(configObj);
-
-    OperationContextNoop opCtx;
-    OpTime time1(Timestamp(100, 1), 0);
-    getReplCoord()->setMyLastAppliedOpTime(time1);
-    ASSERT_OK(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
-
-    simulateEnoughHeartbeatsForAllNodesUp();
-    simulateFreshEnoughForElectability();
-    NetworkInterfaceMock* net = getNet();
-    net->enterNetwork();
-    while (net->hasReadyRequests()) {
-        const NetworkInterfaceMock::NetworkOperationIterator noi = net->getNextReadyRequest();
-        const RemoteCommandRequest& request = noi->getRequest();
-        log() << request.target.toString() << " processing " << request.cmdObj;
-        if (request.target != HostAndPort("node2", 12345)) {
-            net->blackHole(noi);
-        } else if (request.cmdObj.firstElement().fieldNameStringData() != "replSetElect") {
-            net->blackHole(noi);
-        } else {
-            net->scheduleResponse(
-                noi,
-                net->now(),
-                makeResponseStatus(BSON("ok" << 1 << "vote" << -10000 << "round" << OID())));
-        }
-        net->runReadyNetworkOperations();
-    }
-    net->exitNetwork();
-    stopCapturingLogMessages();
-    ASSERT_EQUALS(1, countLogLinesContaining("couldn't elect self, only received -9999 votes"));
-}
-
-TEST_F(ReplCoordElectTest, VotesWithStringValuesAreNotCountedAsYeas) {
-    // one responds with a bad 'vote' field, and one doesn't respond, and we are not elected
-    startCapturingLogMessages();
-    BSONObj configObj = BSON("_id"
-                             << "mySet"
-                             << "version"
-                             << 1
-                             << "members"
-                             << BSON_ARRAY(BSON("_id" << 1 << "host"
-                                                      << "node1:12345")
-                                           << BSON("_id" << 2 << "host"
-                                                         << "node2:12345")
-                                           << BSON("_id" << 3 << "host"
-                                                         << "node3:12345")));
-    assertStartSuccess(configObj, HostAndPort("node1", 12345));
-    ReplSetConfig config = assertMakeRSConfig(configObj);
-
-    OperationContextNoop opCtx;
-    OpTime time1(Timestamp(100, 1), 0);
-    getReplCoord()->setMyLastAppliedOpTime(time1);
-    ASSERT_OK(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
-
-    simulateEnoughHeartbeatsForAllNodesUp();
-    simulateFreshEnoughForElectability();
-    NetworkInterfaceMock* net = getNet();
-    net->enterNetwork();
-    while (net->hasReadyRequests()) {
-        const NetworkInterfaceMock::NetworkOperationIterator noi = net->getNextReadyRequest();
-        const RemoteCommandRequest& request = noi->getRequest();
-        log() << request.target.toString() << " processing " << request.cmdObj;
-        if (request.target != HostAndPort("node2", 12345)) {
-            net->blackHole(noi);
-        } else if (request.cmdObj.firstElement().fieldNameStringData() != "replSetElect") {
-            net->blackHole(noi);
-        } else {
-            net->scheduleResponse(noi,
-                                  net->now(),
-                                  makeResponseStatus(BSON("ok" << 1 << "vote"
-                                                               << "yea"
-                                                               << "round"
-                                                               << OID())));
-        }
-        net->runReadyNetworkOperations();
-    }
-    net->exitNetwork();
-    stopCapturingLogMessages();
-    ASSERT_EQUALS(1,
-                  countLogLinesContaining("wrong type for vote argument in replSetElect command"));
-}
-
-TEST_F(ReplCoordElectTest, TransitionToRollbackFailsWhenElectionInProgress) {
-    BSONObj configObj = BSON("_id"
-                             << "mySet"
-                             << "version"
-                             << 1
-                             << "members"
-                             << BSON_ARRAY(BSON("_id" << 1 << "host"
-                                                      << "node1:12345")
-                                           << BSON("_id" << 2 << "host"
-                                                         << "node2:12345")
-                                           << BSON("_id" << 3 << "host"
-                                                         << "node3:12345")));
-    assertStartSuccess(configObj, HostAndPort("node1", 12345));
-    ReplSetConfig config = assertMakeRSConfig(configObj);
-
-    OperationContextNoop opCtx;
-    OpTime time1(Timestamp(100, 1), 0);
-    getReplCoord()->setMyLastAppliedOpTime(time1);
-    ASSERT_OK(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
-
-    simulateEnoughHeartbeatsForAllNodesUp();
-    simulateFreshEnoughForElectability();
-
-    ASSERT_EQUALS(ErrorCodes::ElectionInProgress,
-                  getReplCoord()->setFollowerMode(MemberState::RS_ROLLBACK));
-
-    ASSERT_FALSE(getReplCoord()->getMemberState().rollback());
-
-    // We do not need to respond to any pending network operations because setFollowerMode() will
-    // cancel the freshness checker and election command runner.
-}
-
-TEST_F(ReplCoordElectTest, NodeWillNotStandForElectionDuringHeartbeatReconfig) {
-    // start up, receive reconfig via heartbeat while at the same time, become candidate.
-    // candidate state should be cleared.
-    OperationContextNoop opCtx;
-    assertStartSuccess(BSON("_id"
-                            << "mySet"
-                            << "version"
-                            << 2
-                            << "members"
-                            << BSON_ARRAY(BSON("_id" << 1 << "host"
-                                                     << "node1:12345")
-                                          << BSON("_id" << 2 << "host"
-                                                        << "node2:12345")
-                                          << BSON("_id" << 3 << "host"
-                                                        << "node3:12345")
-                                          << BSON("_id" << 4 << "host"
-                                                        << "node4:12345")
-                                          << BSON("_id" << 5 << "host"
-                                                        << "node5:12345"))),
-                       HostAndPort("node1", 12345));
-    ASSERT_OK(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
-    getReplCoord()->setMyLastAppliedOpTime(OpTime(Timestamp(100, 0), 0));
-
-    getGlobalFailPointRegistry()
-        ->getFailPoint("blockHeartbeatReconfigFinish")
-        ->setMode(FailPoint::alwaysOn);
-
-    // hb reconfig
-    NetworkInterfaceMock* net = getNet();
-    net->enterNetwork();
-    ReplSetHeartbeatResponse hbResp2;
-    ReplSetConfig config;
-    config
-        .initialize(BSON("_id"
-                         << "mySet"
-                         << "version"
-                         << 3
-                         << "members"
-                         << BSON_ARRAY(BSON("_id" << 1 << "host"
-                                                  << "node1:12345")
-                                       << BSON("_id" << 2 << "host"
-                                                     << "node2:12345"))))
-        .transitional_ignore();
-    hbResp2.setConfig(config);
-    hbResp2.setConfigVersion(3);
-    hbResp2.setSetName("mySet");
-    hbResp2.setState(MemberState::RS_SECONDARY);
-    BSONObjBuilder respObj2;
-    respObj2 << "ok" << 1;
-    hbResp2.addToBSON(&respObj2, false);
-    net->runUntil(net->now() + Seconds(10));  // run until we've sent a heartbeat request
-    const NetworkInterfaceMock::NetworkOperationIterator noi2 = net->getNextReadyRequest();
-    net->scheduleResponse(noi2, net->now(), makeResponseStatus(respObj2.obj()));
-    net->runReadyNetworkOperations();
-    getNet()->exitNetwork();
-
-    // prepare candidacy
-    BSONObjBuilder result;
-    ReplicationCoordinator::ReplSetReconfigArgs args;
-    args.force = false;
-    args.newConfigObj = config.toBSON();
-    ASSERT_EQUALS(ErrorCodes::ConfigurationInProgress,
-                  getReplCoord()->processReplSetReconfig(&opCtx, args, &result));
-
-    logger::globalLogDomain()->setMinimumLoggedSeverity(logger::LogSeverity::Debug(2));
-    startCapturingLogMessages();
-
-    // receive sufficient heartbeats to trigger an election
-    ReplicationCoordinatorImpl* replCoord = getReplCoord();
-    ReplSetConfig rsConfig = replCoord->getReplicaSetConfig_forTest();
-    net->enterNetwork();
-    for (int i = 0; i < 2; ++i) {
-        const NetworkInterfaceMock::NetworkOperationIterator noi = net->getNextReadyRequest();
-        const RemoteCommandRequest& request = noi->getRequest();
-        log() << request.target.toString() << " processing " << request.cmdObj;
-        ReplSetHeartbeatArgs hbArgs;
-        if (hbArgs.initialize(request.cmdObj).isOK()) {
-            ReplSetHeartbeatResponse hbResp;
-            hbResp.setSetName(rsConfig.getReplSetName());
-            hbResp.setState(MemberState::RS_SECONDARY);
-            hbResp.setConfigVersion(rsConfig.getConfigVersion());
-            BSONObjBuilder respObj;
-            respObj << "ok" << 1;
-            hbResp.addToBSON(&respObj, false);
-            net->scheduleResponse(noi, net->now(), makeResponseStatus(respObj.obj()));
-        } else {
-            error() << "Black holing unexpected request to " << request.target << ": "
-                    << request.cmdObj;
-            net->blackHole(noi);
-        }
-        net->runReadyNetworkOperations();
-    }
-
-    stopCapturingLogMessages();
-    // ensure node does not stand for election
-    ASSERT_EQUALS(1,
-                  countLogLinesContaining("Not standing for election; processing "
-                                          "a configuration change"));
-    getGlobalFailPointRegistry()
-        ->getFailPoint("blockHeartbeatReconfigFinish")
-        ->setMode(FailPoint::off);
-}
-
-TEST_F(ReplCoordElectTest, StepsDownRemoteIfNodeHasHigherPriorityThanCurrentPrimary) {
-    BSONObj configObj = BSON("_id"
-                             << "mySet"
-                             << "version"
-                             << 1
-                             << "members"
-                             << BSON_ARRAY(BSON("_id" << 1 << "host"
-                                                      << "node1:12345"
-                                                      << "priority"
-                                                      << 2)
-                                           << BSON("_id" << 2 << "host"
-                                                         << "node2:12345")
-                                           << BSON("_id" << 3 << "host"
-                                                         << "node3:12345")));
-    assertStartSuccess(configObj, HostAndPort("node1", 12345));
-    ReplSetConfig config = assertMakeRSConfig(configObj);
-
-    auto replCoord = getReplCoord();
-
-    OperationContextNoop opCtx;
-    OpTime time1(Timestamp(100, 1), 0);
-    getReplCoord()->setMyLastAppliedOpTime(time1);
-    ASSERT_OK(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
-
-    auto net = getNet();
-    net->enterNetwork();
-    while (net->hasReadyRequests()) {
-        auto noi = net->getNextReadyRequest();
-        auto&& request = noi->getRequest();
-        log() << request.target << " processing " << request.cmdObj;
-        ASSERT_EQUALS("replSetHeartbeat", request.cmdObj.firstElement().fieldNameStringData());
-        ReplSetHeartbeatArgs hbArgs;
-        if (hbArgs.initialize(request.cmdObj).isOK()) {
-            ReplSetHeartbeatResponse hbResp;
-            Date_t responseDate = net->now();
-            hbResp.setSetName(config.getReplSetName());
-            if (request.target == HostAndPort("node2", 12345)) {
-                hbResp.setState(MemberState::RS_PRIMARY);
-            } else {
-                hbResp.setState(MemberState::RS_SECONDARY);
-                responseDate += Milliseconds{1};
-            }
-            hbResp.setConfigVersion(config.getConfigVersion());
-            auto response = makeResponseStatus(hbResp.toBSON(replCoord->isV1ElectionProtocol()));
-            net->scheduleResponse(noi, responseDate, response);
-        } else {
-            error() << "Black holing unexpected request to " << request.target << ": "
-                    << request.cmdObj;
-            net->blackHole(noi);
-        }
-    }
-    const auto afterHeartbeatsProcessed = net->now() + Milliseconds{1};
-    net->runUntil(afterHeartbeatsProcessed);
-    ASSERT_EQ(afterHeartbeatsProcessed, net->now());
-
-    ASSERT_TRUE(net->hasReadyRequests());
-    auto noi = net->getNextReadyRequest();
-    auto&& request = noi->getRequest();
-    log() << request.target << " processing " << request.cmdObj;
-    ASSERT_EQUALS("replSetStepDown", request.cmdObj.firstElement().fieldNameStringData());
-    ASSERT_EQUALS(1LL, request.cmdObj["secondaryCatchUpPeriodSecs"].safeNumberLong());
-    auto target = request.target;
-    ASSERT_EQUALS(HostAndPort("node2", 12345), target);
-    auto response = makeResponseStatus(BSON("ok" << 1));
-    net->scheduleResponse(noi, net->now(), response);
-    logger::globalLogDomain()->setMinimumLoggedSeverity(logger::LogSeverity::Debug(1));
-    startCapturingLogMessages();
-    net->runReadyNetworkOperations();
-    stopCapturingLogMessages();
-    logger::globalLogDomain()->setMinimumLoggedSeverity(logger::LogSeverity::Log());
-    net->exitNetwork();
-    ASSERT_EQUALS(1,
-                  countLogLinesContaining(str::stream() << "stepdown of primary("
-                                                        << target.toString()
-                                                        << ") succeeded"));
-}
-
-TEST_F(ReplCoordElectTest, NodeCancelsElectionUponReceivingANewConfigDuringFreshnessCheckingPhase) {
-    // Start up and become electable.
-    assertStartSuccess(BSON("_id"
-                            << "mySet"
-                            << "version"
-                            << 2
-                            << "members"
-                            << BSON_ARRAY(BSON("_id" << 1 << "host"
-                                                     << "node1:12345")
-                                          << BSON("_id" << 3 << "host"
-                                                        << "node3:12345")
-                                          << BSON("_id" << 2 << "host"
-                                                        << "node2:12345"))
-                            << "settings"
-                            << BSON("heartbeatIntervalMillis" << 100)),
-                       HostAndPort("node1", 12345));
-    ASSERT_OK(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
-    getReplCoord()->setMyLastAppliedOpTime(OpTime(Timestamp(100, 0), 0));
-    getReplCoord()->setMyLastDurableOpTime(OpTime(Timestamp(100, 0), 0));
-    simulateEnoughHeartbeatsForAllNodesUp();
-    simulateFreshEnoughForElectability();
-    ASSERT(TopologyCoordinator::Role::kCandidate == getTopoCoord().getRole());
-
-    // Advance to freshness checker request phase.
-    NetworkInterfaceMock* net = getNet();
-    net->enterNetwork();
-    while (TopologyCoordinator::Role::kCandidate != getTopoCoord().getRole()) {
-        net->runUntil(net->now() + Seconds(1));
-        if (!net->hasReadyRequests()) {
-            continue;
-        }
-        net->blackHole(net->getNextReadyRequest());
-    }
-    net->exitNetwork();
-    ASSERT(TopologyCoordinator::Role::kCandidate == getTopoCoord().getRole());
-
-    // Submit a reconfig and confirm it cancels the election.
-    ReplicationCoordinatorImpl::ReplSetReconfigArgs config = {
-        BSON("_id"
-             << "mySet"
-             << "version"
-             << 4
-             << "members"
-             << BSON_ARRAY(BSON("_id" << 1 << "host"
-                                      << "node1:12345")
-                           << BSON("_id" << 2 << "host"
-                                         << "node2:12345"))),
-        true};
-
-    BSONObjBuilder result;
-    const auto opCtx = makeOperationContext();
-    ASSERT_OK(getReplCoord()->processReplSetReconfig(opCtx.get(), config, &result));
-    // Wait until election cancels.
-    net->enterNetwork();
-    net->runReadyNetworkOperations();
-    net->exitNetwork();
-    ASSERT(TopologyCoordinator::Role::kFollower == getTopoCoord().getRole());
-}
-
-TEST_F(ReplCoordElectTest, NodeCancelsElectionUponReceivingANewConfigDuringElectionPhase) {
-    // Start up and become electable.
-    assertStartSuccess(BSON("_id"
-                            << "mySet"
-                            << "version"
-                            << 2
-                            << "members"
-                            << BSON_ARRAY(BSON("_id" << 1 << "host"
-                                                     << "node1:12345")
-                                          << BSON("_id" << 3 << "host"
-                                                        << "node3:12345")
-                                          << BSON("_id" << 2 << "host"
-                                                        << "node2:12345"))
-                            << "settings"
-                            << BSON("heartbeatIntervalMillis" << 100)),
-                       HostAndPort("node1", 12345));
-    ASSERT_OK(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
-    getReplCoord()->setMyLastAppliedOpTime(OpTime(Timestamp(100, 0), 0));
-    getReplCoord()->setMyLastDurableOpTime(OpTime(Timestamp(100, 0), 0));
-    simulateEnoughHeartbeatsForAllNodesUp();
-    simulateFreshEnoughForElectability();
-    ASSERT(TopologyCoordinator::Role::kCandidate == getTopoCoord().getRole());
-
-    // Submit a reconfig and confirm it cancels the election.
-    ReplicationCoordinatorImpl::ReplSetReconfigArgs config = {
-        BSON("_id"
-             << "mySet"
-             << "version"
-             << 4
-             << "members"
-             << BSON_ARRAY(BSON("_id" << 1 << "host"
-                                      << "node1:12345")
-                           << BSON("_id" << 2 << "host"
-                                         << "node2:12345"))),
-        true};
-
-    BSONObjBuilder result;
-    const auto opCtx = makeOperationContext();
-    ASSERT_OK(getReplCoord()->processReplSetReconfig(opCtx.get(), config, &result));
-    // Wait until election cancels.
-    getNet()->enterNetwork();
-    getNet()->runReadyNetworkOperations();
-    getNet()->exitNetwork();
-    ASSERT(TopologyCoordinator::Role::kFollower == getTopoCoord().getRole());
-}
-
-}  // namespace
-}  // namespace repl
-}  // namespace mongo
diff --git a/src/mongo/db/repl/replication_coordinator_impl_heartbeat_test.cpp b/src/mongo/db/repl/replication_coordinator_impl_heartbeat_test.cpp
deleted file mode 100644
index 55140bb9a23..00000000000
--- a/src/mongo/db/repl/replication_coordinator_impl_heartbeat_test.cpp
+++ /dev/null
@@ -1,275 +0,0 @@
-/**
- *    Copyright (C) 2014 MongoDB Inc.
- *
- *    This program is free software: you can redistribute it and/or  modify
- *    it under the terms of the GNU Affero General Public License, version 3,
- *    as published by the Free Software Foundation.
- *
- *    This program is distributed in the hope that it will be useful,
- *    but WITHOUT ANY WARRANTY; without even the implied warranty of
- *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *    GNU Affero General Public License for more details.
- *
- *    You should have received a copy of the GNU Affero General Public License
- *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
- *    As a special exception, the copyright holders give permission to link the
- *    code of portions of this program with the OpenSSL library under certain
- *    conditions as described in each individual source file and distribute
- *    linked combinations including the program with the OpenSSL library. You
- *    must comply with the GNU Affero General Public License in all respects for
- *    all of the code used other than as permitted herein. If you modify file(s)
- *    with this exception, you may extend this exception to your version of the
- *    file(s), but you are not obligated to do so. If you do not wish to do so,
- *    delete this exception statement from your version. If you delete this
- *    exception statement from all source files in the program, then also delete
- *    it in the license file.
- */
-
-#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kReplication
-
-#include "mongo/platform/basic.h"
-
-#include "mongo/db/jsobj.h"
-#include "mongo/db/operation_context_noop.h"
-#include "mongo/db/repl/repl_set_config.h"
-#include "mongo/db/repl/repl_set_heartbeat_args.h"
-#include "mongo/db/repl/repl_set_heartbeat_args_v1.h"
-#include "mongo/db/repl/repl_set_heartbeat_response.h"
-#include "mongo/db/repl/replication_coordinator_external_state_mock.h"
-#include "mongo/db/repl/replication_coordinator_impl.h"
-#include "mongo/db/repl/replication_coordinator_test_fixture.h"
-#include "mongo/db/repl/topology_coordinator.h"
-#include "mongo/executor/network_interface_mock.h"
-#include "mongo/unittest/unittest.h"
-#include "mongo/util/log.h"
-
-namespace mongo {
-namespace repl {
-namespace {
-
-using executor::NetworkInterfaceMock;
-using executor::RemoteCommandRequest;
-using executor::RemoteCommandResponse;
-
-class ReplCoordHBTest : public ReplCoordTest {
-protected:
-    void assertStartSuccess(const BSONObj& configDoc, const HostAndPort& selfHost);
-    void assertMemberState(MemberState expected, std::string msg = "");
-    ReplSetHeartbeatResponse receiveHeartbeatFrom(const ReplSetConfig& rsConfig,
-                                                  int sourceId,
-                                                  const HostAndPort& source);
-};
-
-void ReplCoordHBTest::assertStartSuccess(const BSONObj& configDoc, const HostAndPort& selfHost) {
-    ReplCoordTest::assertStartSuccess(addProtocolVersion(configDoc, 0), selfHost);
-}
-
-void ReplCoordHBTest::assertMemberState(const MemberState expected, std::string msg) {
-    const MemberState actual = getReplCoord()->getMemberState();
-    ASSERT(expected == actual) << "Expected coordinator to report state " << expected.toString()
-                               << " but found " << actual.toString() << " - " << msg;
-}
-
-ReplSetHeartbeatResponse ReplCoordHBTest::receiveHeartbeatFrom(const ReplSetConfig& rsConfig,
-                                                               int sourceId,
-                                                               const HostAndPort& source) {
-    ReplSetHeartbeatArgs hbArgs;
-    hbArgs.setProtocolVersion(1);
-    hbArgs.setConfigVersion(rsConfig.getConfigVersion());
-    hbArgs.setSetName(rsConfig.getReplSetName());
-    hbArgs.setSenderHost(source);
-    hbArgs.setSenderId(sourceId);
-    ASSERT(hbArgs.isInitialized());
-
-    ReplSetHeartbeatResponse response;
-    ASSERT_OK(getReplCoord()->processHeartbeat(hbArgs, &response));
-    return response;
-}
-
-TEST_F(ReplCoordHBTest, NodeJoinsExistingReplSetWhenReceivingAConfigContainingTheNodeViaHeartbeat) {
-    logger::globalLogDomain()->setMinimumLoggedSeverity(logger::LogSeverity::Debug(3));
-    ReplSetConfig rsConfig = assertMakeRSConfigV0(BSON("_id"
-                                                       << "mySet"
-                                                       << "version"
-                                                       << 3
-                                                       << "members"
-                                                       << BSON_ARRAY(BSON("_id" << 1 << "host"
-                                                                                << "h1:1")
-                                                                     << BSON("_id" << 2 << "host"
-                                                                                   << "h2:1")
-                                                                     << BSON("_id" << 3 << "host"
-                                                                                   << "h3:1"))));
-    init("mySet");
-    addSelf(HostAndPort("h2", 1));
-    const Date_t startDate = getNet()->now();
-    start();
-    enterNetwork();
-    assertMemberState(MemberState::RS_STARTUP);
-    NetworkInterfaceMock* net = getNet();
-    ASSERT_FALSE(net->hasReadyRequests());
-    exitNetwork();
-    receiveHeartbeatFrom(rsConfig, 1, HostAndPort("h1", 1));
-
-    enterNetwork();
-    NetworkInterfaceMock::NetworkOperationIterator noi = net->getNextReadyRequest();
-    const RemoteCommandRequest& request = noi->getRequest();
-    ASSERT_EQUALS(HostAndPort("h1", 1), request.target);
-    ReplSetHeartbeatArgsV1 hbArgs;
-    ASSERT_OK(hbArgs.initialize(request.cmdObj));
-    ASSERT_EQUALS("mySet", hbArgs.getSetName());
-    ASSERT_EQUALS(-2, hbArgs.getConfigVersion());
-    ReplSetHeartbeatResponse hbResp;
-    hbResp.setSetName("mySet");
-    hbResp.setState(MemberState::RS_PRIMARY);
-    hbResp.noteReplSet();
-    hbResp.setConfigVersion(rsConfig.getConfigVersion());
-    hbResp.setConfig(rsConfig);
-    BSONObjBuilder responseBuilder;
-    responseBuilder << "ok" << 1;
-    hbResp.addToBSON(&responseBuilder, false);
-    net->scheduleResponse(
-        noi, startDate + Milliseconds(200), makeResponseStatus(responseBuilder.obj()));
-    assertRunUntil(startDate + Milliseconds(200));
-
-    // Because the new config is stored using an out-of-band thread, we need to perform some
-    // extra synchronization to let the executor finish the heartbeat reconfig.  We know that
-    // after the out-of-band thread completes, it schedules new heartbeats.  We assume that no
-    // other network operations get scheduled during or before the reconfig, though this may
-    // cease to be true in the future.
-    noi = net->getNextReadyRequest();
-
-    assertMemberState(MemberState::RS_STARTUP2);
-    OperationContextNoop opCtx;
-    ReplSetConfig storedConfig;
-    ASSERT_OK(storedConfig.initialize(
-        unittest::assertGet(getExternalState()->loadLocalConfigDocument(&opCtx))));
-    ASSERT_OK(storedConfig.validate());
-    ASSERT_EQUALS(3, storedConfig.getConfigVersion());
-    ASSERT_EQUALS(3, storedConfig.getNumMembers());
-    exitNetwork();
-}
-
-TEST_F(ReplCoordHBTest,
-       NodeDoesNotJoinExistingReplSetWhenReceivingAConfigNotContainingTheNodeViaHeartbeat) {
-    // Tests that a node in RS_STARTUP will not transition to RS_REMOVED if it receives a
-    // configuration that does not contain it.
-    logger::globalLogDomain()->setMinimumLoggedSeverity(logger::LogSeverity::Debug(3));
-    ReplSetConfig rsConfig = assertMakeRSConfigV0(BSON("_id"
-                                                       << "mySet"
-                                                       << "version"
-                                                       << 3
-                                                       << "members"
-                                                       << BSON_ARRAY(BSON("_id" << 1 << "host"
-                                                                                << "h1:1")
-                                                                     << BSON("_id" << 2 << "host"
-                                                                                   << "h2:1")
-                                                                     << BSON("_id" << 3 << "host"
-                                                                                   << "h3:1"))));
-    init("mySet");
-    addSelf(HostAndPort("h4", 1));
-    const Date_t startDate = getNet()->now();
-    start();
-    enterNetwork();
-    assertMemberState(MemberState::RS_STARTUP, "1");
-    NetworkInterfaceMock* net = getNet();
-    ASSERT_FALSE(net->hasReadyRequests());
-    exitNetwork();
-    receiveHeartbeatFrom(rsConfig, 1, HostAndPort("h1", 1));
-
-    enterNetwork();
-    NetworkInterfaceMock::NetworkOperationIterator noi = net->getNextReadyRequest();
-    const RemoteCommandRequest& request = noi->getRequest();
-    ASSERT_EQUALS(HostAndPort("h1", 1), request.target);
-    ReplSetHeartbeatArgsV1 hbArgs;
-    ASSERT_OK(hbArgs.initialize(request.cmdObj));
-    ASSERT_EQUALS("mySet", hbArgs.getSetName());
-    ASSERT_EQUALS(-2, hbArgs.getConfigVersion());
-    ReplSetHeartbeatResponse hbResp;
-    hbResp.setSetName("mySet");
-    hbResp.setState(MemberState::RS_PRIMARY);
-    hbResp.noteReplSet();
-    hbResp.setConfigVersion(rsConfig.getConfigVersion());
-    hbResp.setConfig(rsConfig);
-    BSONObjBuilder responseBuilder;
-    responseBuilder << "ok" << 1;
-    hbResp.addToBSON(&responseBuilder, false);
-    net->scheduleResponse(
-        noi, startDate + Milliseconds(200), makeResponseStatus(responseBuilder.obj()));
-    assertRunUntil(startDate + Milliseconds(2200));
-
-    // Because the new config is stored using an out-of-band thread, we need to perform some
-    // extra synchronization to let the executor finish the heartbeat reconfig.  We know that
-    // after the out-of-band thread completes, it schedules new heartbeats.  We assume that no
-    // other network operations get scheduled during or before the reconfig, though this may
-    // cease to be true in the future.
-    noi = net->getNextReadyRequest();
-
-    assertMemberState(MemberState::RS_STARTUP, "2");
-    OperationContextNoop opCtx;
-
-    StatusWith<BSONObj> loadedConfig(getExternalState()->loadLocalConfigDocument(&opCtx));
-    ASSERT_NOT_OK(loadedConfig.getStatus()) << loadedConfig.getValue();
-    exitNetwork();
-}
-
-TEST_F(ReplCoordHBTest, NodeReturnsNotYetInitializedInResponseToAHeartbeatReceivedPriorToAConfig) {
-    // ensure that if we've yet to receive an initial config, we return NotYetInitialized
-    init("mySet");
-    ReplSetHeartbeatArgs hbArgs;
-    hbArgs.setProtocolVersion(1);
-    hbArgs.setConfigVersion(3);
-    hbArgs.setSetName("mySet");
-    hbArgs.setSenderHost(HostAndPort("h1:1"));
-    hbArgs.setSenderId(1);
-    ASSERT(hbArgs.isInitialized());
-
-    ReplSetHeartbeatResponse response;
-    Status status = getReplCoord()->processHeartbeat(hbArgs, &response);
-    ASSERT_EQUALS(ErrorCodes::NotYetInitialized, status.code());
-}
-
-TEST_F(ReplCoordHBTest,
-       NodeChangesToRecoveringStateWhenAllNodesRespondToHeartbeatsWithUnauthorized) {
-    // Tests that a node that only has auth error heartbeats is recovering
-    logger::globalLogDomain()->setMinimumLoggedSeverity(logger::LogSeverity::Debug(3));
-    assertStartSuccess(BSON("_id"
-                            << "mySet"
-                            << "version"
-                            << 1
-                            << "members"
-                            << BSON_ARRAY(BSON("_id" << 1 << "host"
-                                                     << "node1:12345")
-                                          << BSON("_id" << 2 << "host"
-                                                        << "node2:12345"))),
-                       HostAndPort("node1", 12345));
-    ASSERT_OK(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
-
-    // process heartbeat
-    enterNetwork();
-    const NetworkInterfaceMock::NetworkOperationIterator noi = getNet()->getNextReadyRequest();
-    const RemoteCommandRequest& request = noi->getRequest();
-    log() << request.target.toString() << " processing " << request.cmdObj;
-    getNet()->scheduleResponse(noi,
-                               getNet()->now(),
-                               makeResponseStatus(BSON("ok" << 0.0 << "errmsg"
-                                                            << "unauth'd"
-                                                            << "code"
-                                                            << ErrorCodes::Unauthorized)));
-
-    if (request.target != HostAndPort("node2", 12345) &&
-        request.cmdObj.firstElement().fieldNameStringData() != "replSetHeartbeat") {
-        error() << "Black holing unexpected request to " << request.target << ": "
-                << request.cmdObj;
-        getNet()->blackHole(noi);
-    }
-    getNet()->runReadyNetworkOperations();
-    exitNetwork();
-
-    ASSERT_TRUE(getTopoCoord().getMemberState().recovering());
-    assertMemberState(MemberState::RS_RECOVERING, "0");
-}
-
-}  // namespace
-}  // namespace repl
-}  // namespace mongo
diff --git a/src/mongo/db/repl/replication_coordinator_impl_test.cpp b/src/mongo/db/repl/replication_coordinator_impl_test.cpp
index f374290ec8f..c981c0af10f 100644
--- a/src/mongo/db/repl/replication_coordinator_impl_test.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl_test.cpp
@@ -1409,6 +1409,71 @@ TEST_F(ReplCoordTest, NodeReturnsBadValueWhenUpdateTermIsRunAgainstANonReplNode)
     ASSERT_EQUALS(ErrorCodes::BadValue, getReplCoord()->updateTerm(opCtx.get(), 0).code());
 }
 
+TEST_F(ReplCoordTest, ElectionIdTracksTermInPV1) {
+    init("mySet/test1:1234,test2:1234,test3:1234");
+
+    assertStartSuccess(BSON("_id"
+                            << "mySet"
+                            << "version"
+                            << 1
+                            << "members"
+                            << BSON_ARRAY(BSON("_id" << 0 << "host"
+                                                     << "test1:1234")
+                                          << BSON("_id" << 1 << "host"
+                                                        << "test2:1234")
+                                          << BSON("_id" << 2 << "host"
+                                                        << "test3:1234"))
+                            << "protocolVersion"
+                            << 1),
+                       HostAndPort("test1", 1234));
+    getReplCoord()->setMyLastAppliedOpTime(OpTime(Timestamp(100, 1), 0));
+    getReplCoord()->setMyLastDurableOpTime(OpTime(Timestamp(100, 1), 0));
+    ASSERT_OK(getReplCoord()->setFollowerMode(MemberState::RS_SECONDARY));
+    ASSERT_TRUE(getReplCoord()->getMemberState().secondary());
+
+    // No election has taken place yet.
+    {
+        auto term = getTopoCoord().getTerm();
+        auto electionId = getTopoCoord().getElectionId();
+
+        ASSERT_EQUALS(0, term);
+        ASSERT_FALSE(electionId.isSet());
+    }
+
+    simulateSuccessfulV1Election();
+
+    ASSERT_TRUE(getReplCoord()->getMemberState().primary());
+
+    // Check that the electionId is set properly after the election.
+    {
+        auto term = getTopoCoord().getTerm();
+        auto electionId = getTopoCoord().getElectionId();
+
+        ASSERT_EQUALS(1, term);
+        ASSERT_EQUALS(OID::fromTerm(term), electionId);
+    }
+
+    const auto opCtx = makeOperationContext();
+    auto status = getReplCoord()->stepDown(opCtx.get(), true, Milliseconds(0), Milliseconds(1000));
+
+    ASSERT_OK(status);
+    ASSERT_TRUE(getReplCoord()->getMemberState().secondary());
+
+    simulateSuccessfulV1ElectionWithoutExitingDrainMode(
+        getReplCoord()->getElectionTimeout_forTest());
+
+    ASSERT_TRUE(getReplCoord()->getMemberState().primary());
+
+    // Check that the electionId is again properly set after the new election.
+    {
+        auto term = getTopoCoord().getTerm();
+        auto electionId = getTopoCoord().getElectionId();
+
+        ASSERT_EQUALS(2, term);
+        ASSERT_EQUALS(OID::fromTerm(term), electionId);
+    }
+}
+
 TEST_F(ReplCoordTest, NodeChangesTermAndStepsDownWhenAndOnlyWhenUpdateTermSuppliesAHigherTerm) {
     init("mySet/test1:1234,test2:1234,test3:1234");
 
@@ -4410,32 +4475,6 @@ TEST_F(ReplCoordTest,
                                replCoord->getElectionTimeout_forTest());
 }
 
-TEST_F(ReplCoordTest, DoNotScheduleElectionWhenCancelAndRescheduleElectionTimeoutIsRunInPV0) {
-    assertStartSuccess(BSON("_id"
-                            << "mySet"
-                            << "protocolVersion"
-                            << 0
-                            << "version"
-                            << 2
-                            << "members"
-                            << BSON_ARRAY(BSON("host"
-                                               << "node1:12345"
-                                               << "_id"
-                                               << 0)
-                                          << BSON("host"
-                                                  << "node2:12345"
-                                                  << "_id"
-                                                  << 1))),
-                       HostAndPort("node1", 12345));
-    ReplicationCoordinatorImpl* replCoord = getReplCoord();
-    ASSERT_OK(replCoord->setFollowerMode(MemberState::RS_SECONDARY));
-
-    getReplCoord()->cancelAndRescheduleElectionTimeout();
-
-    auto electionTimeoutWhen = replCoord->getElectionTimeout_forTest();
-    ASSERT_EQUALS(Date_t(), electionTimeoutWhen);
-}
-
 TEST_F(ReplCoordTest, DoNotScheduleElectionWhenCancelAndRescheduleElectionTimeoutIsRunInRollback) {
     assertStartSuccess(BSON("_id"
                             << "mySet"
diff --git a/src/mongo/db/repl/replication_coordinator_test_fixture.cpp b/src/mongo/db/repl/replication_coordinator_test_fixture.cpp
index c2278a72e9a..a7ce2561f57 100644
--- a/src/mongo/db/repl/replication_coordinator_test_fixture.cpp
+++ b/src/mongo/db/repl/replication_coordinator_test_fixture.cpp
@@ -72,10 +72,6 @@ ReplSetConfig ReplCoordTest::assertMakeRSConfig(const BSONObj& configBson) {
     return config;
 }
 
-ReplSetConfig ReplCoordTest::assertMakeRSConfigV0(const BSONObj& configBson) {
-    return assertMakeRSConfig(addProtocolVersion(configBson, 0));
-}
-
 BSONObj ReplCoordTest::addProtocolVersion(const BSONObj& configDoc, int protocolVersion) {
     BSONObjBuilder builder;
     builder << "protocolVersion" << protocolVersion;
@@ -238,8 +234,7 @@ void ReplCoordTest::simulateEnoughHeartbeatsForAllNodesUp() {
         log() << request.target.toString() << " processing " << request.cmdObj;
         ReplSetHeartbeatArgsV1 hbArgs;
         ReplSetHeartbeatArgs hbArgsPV0;
-        if (hbArgs.initialize(request.cmdObj).isOK() ||
-            hbArgsPV0.initialize(request.cmdObj).isOK()) {
+        if (hbArgs.initialize(request.cmdObj).isOK()) {
             ReplSetHeartbeatResponse hbResp;
             hbResp.setSetName(rsConfig.getReplSetName());
             hbResp.setState(MemberState::RS_SECONDARY);
@@ -393,68 +388,6 @@ void ReplCoordTest::simulateSuccessfulV1ElectionAt(Date_t electionTime) {
     ASSERT(replCoord->getMemberState().primary()) << replCoord->getMemberState().toString();
 }
 
-void ReplCoordTest::simulateSuccessfulElection() {
-    ReplicationCoordinatorImpl* replCoord = getReplCoord();
-    NetworkInterfaceMock* net = getNet();
-    ReplSetConfig rsConfig = replCoord->getReplicaSetConfig_forTest();
-    ASSERT(replCoord->getMemberState().secondary()) << replCoord->getMemberState().toString();
-    bool hasReadyRequests = true;
-    // Process requests until we're primary and consume the heartbeats for the notification
-    // of election win.
-    while (!replCoord->getMemberState().primary() || hasReadyRequests) {
-        log() << "Waiting on network in state " << replCoord->getMemberState();
-        getNet()->enterNetwork();
-        const NetworkInterfaceMock::NetworkOperationIterator noi = net->getNextReadyRequest();
-        const RemoteCommandRequest& request = noi->getRequest();
-        log() << request.target.toString() << " processing " << request.cmdObj;
-        ReplSetHeartbeatArgs hbArgs;
-        if (hbArgs.initialize(request.cmdObj).isOK()) {
-            ReplSetHeartbeatResponse hbResp;
-            hbResp.setSetName(rsConfig.getReplSetName());
-            hbResp.setState(MemberState::RS_SECONDARY);
-            hbResp.setConfigVersion(rsConfig.getConfigVersion());
-            BSONObjBuilder respObj;
-            respObj << "ok" << 1;
-            hbResp.addToBSON(&respObj, false);
-            net->scheduleResponse(noi, net->now(), makeResponseStatus(respObj.obj()));
-        } else if (request.cmdObj.firstElement().fieldNameStringData() == "replSetFresh") {
-            net->scheduleResponse(
-                noi,
-                net->now(),
-                makeResponseStatus(BSON(
-                    "ok" << 1 << "fresher" << false << "opTime" << Date_t() << "veto" << false)));
-        } else if (request.cmdObj.firstElement().fieldNameStringData() == "replSetElect") {
-            net->scheduleResponse(noi,
-                                  net->now(),
-                                  makeResponseStatus(BSON("ok" << 1 << "vote" << 1 << "round"
-                                                               << request.cmdObj["round"].OID())));
-        } else {
-            error() << "Black holing unexpected request to " << request.target << ": "
-                    << request.cmdObj;
-            net->blackHole(noi);
-        }
-        net->runReadyNetworkOperations();
-        hasReadyRequests = net->hasReadyRequests();
-        getNet()->exitNetwork();
-    }
-    ASSERT(replCoord->getApplierState() == ReplicationCoordinator::ApplierState::Draining);
-    ASSERT(replCoord->getMemberState().primary()) << replCoord->getMemberState().toString();
-
-    IsMasterResponse imResponse;
-    replCoord->fillIsMasterForReplSet(&imResponse);
-    ASSERT_FALSE(imResponse.isMaster()) << imResponse.toBSON().toString();
-    ASSERT_TRUE(imResponse.isSecondary()) << imResponse.toBSON().toString();
-    {
-        auto opCtx = makeOperationContext();
-        replCoord->signalDrainComplete(opCtx.get(), replCoord->getTerm());
-    }
-    replCoord->fillIsMasterForReplSet(&imResponse);
-    ASSERT_TRUE(imResponse.isMaster()) << imResponse.toBSON().toString();
-    ASSERT_FALSE(imResponse.isSecondary()) << imResponse.toBSON().toString();
-
-    ASSERT(replCoord->getMemberState().primary()) << replCoord->getMemberState().toString();
-}
-
 void ReplCoordTest::signalDrainComplete(OperationContext* opCtx) {
     getExternalState()->setFirstOpTimeOfMyTerm(OpTime(Timestamp(1, 1), getReplCoord()->getTerm()));
     getReplCoord()->signalDrainComplete(opCtx, getReplCoord()->getTerm());
diff --git a/src/mongo/db/repl/replication_coordinator_test_fixture.h b/src/mongo/db/repl/replication_coordinator_test_fixture.h
index 15b0027b32f..67f30ceeff9 100644
--- a/src/mongo/db/repl/replication_coordinator_test_fixture.h
+++ b/src/mongo/db/repl/replication_coordinator_test_fixture.h
@@ -74,7 +74,6 @@ public:
      * Constructs a ReplSetConfig from the given BSON, or raises a test failure exception.
      */
     static ReplSetConfig assertMakeRSConfig(const BSONObj& configBSON);
-    static ReplSetConfig assertMakeRSConfigV0(const BSONObj& configBson);
 
     /**
      * Adds { protocolVersion: 0 or 1 } to the config.
@@ -225,7 +224,6 @@ protected:
      *
      * Behavior is unspecified if node does not have a clean config, is not in SECONDARY, etc.
      */
-    void simulateSuccessfulElection();
     void simulateSuccessfulV1Election();
 
     /**
diff --git a/src/mongo/shell/utils.js b/src/mongo/shell/utils.js
index c07aebac8d7..6d130491b29 100644
--- a/src/mongo/shell/utils.js
+++ b/src/mongo/shell/utils.js
@@ -1405,49 +1405,29 @@ rs.debug.getLastOpWritten = function(server) {
 };
 
 /**
- * Compares OpTimes. Returns -1 if ot1 is 'earlier' than ot2, 1 if 'later' and 0 if equal.
- *
- * Note: Since Protocol Version 1 was introduced for replication, 'OpTimes'
- * can come in two different formats. This function will throw an error when the OpTime
- * passed do not have the same protocol version.
- *
- * OpTime Formats:
- * PV0: Timestamp
- * PV1: {ts:Timestamp, t:NumberLong}
+ * Compares OpTimes in the format {ts:Timestamp, t:NumberLong}.
+ * Returns -1 if ot1 is 'earlier' than ot2, 1 if 'later' and 0 if equal.
  */
 rs.compareOpTimes = function(ot1, ot2) {
-    function _isOpTimeV1(opTime) {
-        return (opTime.hasOwnProperty("ts") && opTime.hasOwnProperty("t"));
-    }
-    function _isEmptyOpTime(opTime) {
-        return (opTime.ts.getTime() == 0 && opTime.ts.getInc() == 0 && opTime.t == -1);
-    }
 
-    // Make sure both OpTimes have a timestamp and a term.
-    var ot1 = _isOpTimeV1(ot1) ? ot1 : {ts: ot1, t: NumberLong(-1)};
-    var ot2 = _isOpTimeV1(ot2) ? ot2 : {ts: ot2, t: NumberLong(-1)};
+    function _isValidOptime(opTime) {
+        let timestampIsValid = (opTime.hasOwnProperty("ts") && (opTime.ts !== Timestamp(0, 0)));
+        let termIsValid = (opTime.hasOwnProperty("t") && (opTime.t != -1));
 
-    if (_isEmptyOpTime(ot1) || _isEmptyOpTime(ot2)) {
-        throw Error("cannot do comparison with empty OpTime, received: " + tojson(ot1) + " and " +
-                    tojson(ot2));
+        return timestampIsValid && termIsValid;
     }
 
-    if ((ot1.t == -1 && ot2.t != -1) || (ot1.t != -1 && ot2.t == -1)) {
-        throw Error("cannot compare OpTimes between different protocol versions, received: " +
-                    tojson(ot1) + " and " + tojson(ot2));
+    if (!_isValidOptime(ot1) || !_isValidOptime(ot2)) {
+        throw Error("invalid optimes, received: " + tojson(ot1) + " and " + tojson(ot2));
     }
 
-    if (!friendlyEqual(ot1.t, ot2.t)) {
-        if (ot1.t < ot2.t) {
-            return -1;
-        } else {
-            return 1;
-        }
+    if (ot1.t > ot2.t) {
+        return 1;
+    } else if (ot1.t < ot2.t) {
+        return -1;
+    } else {
+        return timestampCmp(ot1.ts, ot2.ts);
     }
-    // else equal terms, so proceed to compare timestamp component.
-
-    // Otherwise, choose the OpTime with the lower timestamp.
-    return timestampCmp(ot1.ts, ot2.ts);
 };
 
 help = shellHelper.help = function(x) {