1 files changed, 35 insertions, 0 deletions
diff --git a/jstests/replsets/rslib.js b/jstests/replsets/rslib.js
index 209ed8172e1..4af2e49bbf0 100644
--- a/jstests/replsets/rslib.js
+++ b/jstests/replsets/rslib.js
@@ -14,6 +14,7 @@ var reInitiateWithoutThrowingOnAbortedMember;
 var awaitRSClientHosts;
 var getLastOpTime;
 var setLogVerbosity;
+var stopReplicationAndEnforceNewPrimaryToCatchUp;
 
 (function() {
 "use strict";
@@ -453,4 +454,38 @@ setLogVerbosity = function(nodes, logVerbosity) {
         assert.commandWorked(node.adminCommand(verbosity));
     });
 };
+
+/**
+ * Stop replication on secondaries, do writes and step up the node that was passed in.
+ *
+ * The old primary has extra writes that are not replicated to the other nodes yet,
+ * but the new primary steps up, getting the vote from the the third node "voter".
+ */
+stopReplicationAndEnforceNewPrimaryToCatchUp = function(rst, node) {
+    // Write documents that cannot be replicated to secondaries in time.
+    const oldSecondaries = rst.getSecondaries();
+    const oldPrimary = rst.getPrimary();
+
+    stopServerReplication(oldSecondaries);
+    for (let i = 0; i < 3; i++) {
+        assert.commandWorked(oldPrimary.getDB("test").foo.insert({x: i}));
+    }
+
+    const latestOpOnOldPrimary = getLatestOp(oldPrimary);
+
+    // New primary wins immediately, but needs to catch up.
+    const newPrimary = rst.stepUpNoAwaitReplication(node);
+    const latestOpOnNewPrimary = getLatestOp(newPrimary);
+    // Check this node is not writable.
+    assert.eq(newPrimary.getDB("test").isMaster().ismaster, false);
+
+    return {
+        oldSecondaries: oldSecondaries,
+        oldPrimary: oldPrimary,
+        newPrimary: newPrimary,
+        voter: oldSecondaries[1],
+        latestOpOnOldPrimary: latestOpOnOldPrimary,
+        latestOpOnNewPrimary: latestOpOnNewPrimary
+    };
+};
 }());