1 files changed, 98 insertions, 0 deletions
diff --git a/jstests/noPassthrough/preimages_can_be_inconsistent.js b/jstests/noPassthrough/preimages_can_be_inconsistent.js
new file mode 100644
index 00000000000..bf87f16e5cd
--- /dev/null
+++ b/jstests/noPassthrough/preimages_can_be_inconsistent.js
@@ -0,0 +1,98 @@
+/**
+ * Test that consistency checks for preimage work as expected. Consistency is defined by performing
+ * these steps:
+ *   * Fix a nsUUID to scan the preimage collection
+ *   * Obtain all preimage entries of the namespace by sorting in descending order of '_id.ts' and
+ *     '_id.applyIndexOps'.
+ *   * For each entry position and node:
+ *     * The entry exists in the node at that position and is equal across all nodes in that
+ *       position.
+ *     * The entry doesn't exist in the node at that position.
+ * @tags: [
+ *   requires_replication,
+ * ]
+ */
+
+(function() {
+"use strict";
+
+function getPreImage(collectionIndex, ts) {
+    return {
+        _id: {
+            nsUUID: UUID(`3b241101-e2bb-4255-8caf-4136c566a12${collectionIndex}`),
+            ts: new Timestamp(ts, 0),
+            applyOpsIndex: 0,
+        },
+        operationTime: ISODate("9000-01-01"),  // Put a date really far off into the future.
+    };
+}
+
+assert.doesNotThrow(() => {
+    const replSetTest = new ReplSetTest({name: "replSet", nodes: 2});
+    replSetTest.startSet();
+    replSetTest.initiate();
+
+    const primary = replSetTest.getPrimary();
+    const secondary = replSetTest.getSecondary();
+
+    const coll = primary.getDB("config")["system.preimages"];
+    const secondaryColl = secondary.getDB("config")["system.preimages"];
+
+    // Insert documents to the preimages collection. Ensure they are not replicated to secondaries.
+    coll.insert(getPreImage(1, 0));
+    coll.insert(getPreImage(1, 1));
+    coll.insert(getPreImage(2, 1));
+    coll.insert(getPreImage(3, 1));
+
+    assert.eq(coll.find({}).itcount(), 4);
+    assert.eq(secondaryColl.find({}).itcount(), 0);
+
+    // Now insert preimages in the old secondary.
+    replSetTest.stepUp(secondary);
+
+    const newPrimary = replSetTest.getPrimary();
+    const newColl = newPrimary.getDB("config")["system.preimages"];
+    newColl.insert(getPreImage(1, 1));
+    newColl.insert(getPreImage(2, 1));
+
+    // Verify that even if the data isn't consistent the test passes as consistency is defined as
+    // two nodes having entries equal or non-existent starting from the end.
+    replSetTest.stopSet();
+});
+
+const replSetTest = new ReplSetTest({name: "replSet", nodes: 2});
+replSetTest.startSet();
+replSetTest.initiate();
+
+const primary = replSetTest.getPrimary();
+const secondary = replSetTest.getSecondary();
+
+const coll = primary.getDB("config")["system.preimages"];
+const secondaryColl = secondary.getDB("config")["system.preimages"];
+
+// Insert a document to the preimage collection. Ensure it is not replicated to secondaries.
+coll.insert(getPreImage(1, 0));
+assert.eq(coll.find({}).itcount(), 1);
+assert.eq(secondaryColl.find({}).itcount(), 0);
+
+// Now insert another document to the secondary, this will cause an inconsistency error when we stop
+// the replica set.
+replSetTest.stepUp(secondary);
+
+const newPrimary = replSetTest.getPrimary();
+
+const newColl = newPrimary.getDB("config")["system.preimages"];
+newColl.insert(getPreImage(1, 1));
+
+// Verify that the two nodes are inconsistent.
+assert.throws(() => replSetTest.stopSet());
+
+try {
+    replSetTest.stopSet();
+} catch (e) {
+    // Verify that the inconsistency is the one we're looking for in preimages.
+    assert.eq(e.message.includes("Detected preimage entries that have different content"), true);
+}
+// Tear down the nodes now without checking for consistency.
+replSetTest.stopSet(undefined, undefined, {skipCheckDBHashes: true});
+})();