SERVER-45987 Ensure apply op entries for deletes in multi-document transactions only include the document key

1 files changed, 124 insertions, 0 deletions

diff --git a/jstests/change_streams/delete_in_txn_produces_correct_doc_key.js b/jstests/change_streams/delete_in_txn_produces_correct_doc_key.js
new file mode 100644
index 00000000000..32cf184faf1
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+++ b/jstests/change_streams/delete_in_txn_produces_correct_doc_key.js
@@ -0,0 +1,124 @@
+// Tests that 'delete' events within a multi-document transaction do not include the full document
+// in the 'documentKey' field. Exercises the fix for SERVER-45987.
+// @tags: [
+//  uses_transactions,
+//  multiversion_incompatible,
+//  assumes_against_mongod_not_mongos
+//  ]
+
+(function() {
+"use strict";
+
+load("jstests/libs/collection_drop_recreate.js");  // For assert[Drop|Create]Collection.
+load("jstests/libs/change_stream_util.js");        // For ChangeStreamTest.
+
+const collName = "delete_in_txn_produces_correct_doc_key";
+
+/**
+ * Test function which is used to test three types of delete-related commands, deleteOne(),
+ * deleteMany() and findAndModify(). Ensure only documentKey instead of a full document
+ * will be logged on entries for deletes in multi-document transactions, and also ensure that
+ * we can resume the change stream from these delete events.
+ */
+function testDeleteInMultiDocTxn({collName, deleteCommand, expectedChanges}) {
+    // Initialize the collection.
+    const coll = assertDropAndRecreateCollection(db, collName);
+
+    // Enable the 'recordPreImages' flag on the collection. This allows us to verify that the full
+    // document is not written to the 'documentKey' field even when we know it is available to the
+    // oplog writer during the delete operation.
+    assert.commandWorked(db.runCommand({collMod: collName, recordPreImages: true}));
+
+    assert.commandWorked(coll.insertMany([
+        {_id: 1, a: 0, fullDoc: "It's a full document!"},
+        {_id: 2, a: 0},
+        {_id: 3, a: 0},
+        {_id: 4, a: 1}
+    ]));
+
+    // Open a change stream on the test collection.
+    const cst = new ChangeStreamTest(db);
+    let cursor = cst.startWatchingChanges({pipeline: [{$changeStream: {}}], collection: coll});
+
+    // Start a transaction in which to perform the delete operation(s).
+    const session = db.getMongo().startSession();
+    const sessionDb = session.getDatabase(db.getName());
+    const sessionColl = sessionDb[collName];
+    session.startTransaction();
+
+    // Run the given 'deleteCommand' function to perform the delete(s).
+    deleteCommand(sessionColl);
+
+    // Commit the transaction so that the events become visible to the change stream.
+    assert.commandWorked(session.commitTransaction_forTesting());
+
+    // Verify that the stream returns the expected sequence of changes.
+    const changes = cst.assertNextChangesEqual({cursor: cursor, expectedChanges: expectedChanges});
+
+    // Test the change stream can be resumed after a delete event from within the transaction.
+    cursor = cst.startWatchingChanges({
+        pipeline: [{$changeStream: {resumeAfter: changes[changes.length - 1]._id}}],
+        collection: coll
+    });
+    assert.commandWorked(coll.insert({_id: 5}));
+    assert.docEq(cst.getOneChange(cursor).documentKey, {_id: 5});
+
+    cst.cleanUp();
+}
+
+jsTestLog("Testing deleteOne() in a transaction.");
+testDeleteInMultiDocTxn({
+    collName: collName,
+    deleteCommand: function(sessionColl) {
+        assert.commandWorked(sessionColl.deleteOne({_id: 1}));
+    },
+    expectedChanges: [
+        {
+            documentKey: {_id: 1},
+            ns: {db: db.getName(), coll: collName},
+            operationType: "delete",
+        },
+    ],
+});
+
+jsTestLog("Testing deleteMany() in a transaction.");
+testDeleteInMultiDocTxn({
+    collName: collName,
+    deleteCommand: function(sessionColl) {
+        assert.commandWorked(sessionColl.deleteMany({a: 0, _id: {$gt: 0}}));
+    },
+    expectedChanges: [
+        {
+            documentKey: {_id: 1},
+            ns: {db: db.getName(), coll: collName},
+            operationType: "delete",
+        },
+        {
+            documentKey: {_id: 2},
+            ns: {db: db.getName(), coll: collName},
+            operationType: "delete",
+        },
+        {
+            documentKey: {_id: 3},
+            ns: {db: db.getName(), coll: collName},
+            operationType: "delete",
+        },
+    ],
+});
+
+// Note that findAndModify will delete only the *first* matching document.
+jsTestLog("Testing findAndModify() in a transaction.");
+testDeleteInMultiDocTxn({
+    collName: collName,
+    deleteCommand: function(sessionColl) {
+        sessionColl.findAndModify({query: {a: 0}, sort: {_id: 1}, remove: true});
+    },
+    expectedChanges: [
+        {
+            documentKey: {_id: 1},
+            ns: {db: db.getName(), coll: collName},
+            operationType: "delete",
+        },
+    ],
+});
+}());