SERVER-40839: Add tests for empty unprepared transactions

1 files changed, 64 insertions, 0 deletions

diff --git a/jstests/core/txns/empty_commit_abort.js b/jstests/core/txns/empty_commit_abort.js
new file mode 100644
index 00000000000..0b65ffab94f
--- /dev/null
+++ b/jstests/core/txns/empty_commit_abort.js
@@ -0,0 +1,64 @@
+/**
+ * Tests transactions that commit/abort after no writes.
+ *
+ * @tags: [uses_transactions]
+ */
+(function() {
+    "use strict";
+
+    const dbName = "test";
+    const collName = "empty_commit_abort";
+    const testDB = db.getSiblingDB(dbName);
+    const testColl = testDB.getCollection(collName);
+
+    testColl.drop({writeConcern: {w: "majority"}});
+    assert.commandWorked(testDB.runCommand({create: collName, writeConcern: {w: "majority"}}));
+
+    const doc = {_id: 1, a: 1, b: 1};
+    assert.commandWorked(testColl.insert(doc));
+
+    const session = db.getMongo().startSession();
+    const sessionDB = session.getDatabase(dbName);
+    const sessionColl = sessionDB.getCollection(collName);
+
+    // ---- Test 1. No operations before commit ----
+    session.startTransaction();
+    assert.commandFailedWithCode(sessionDB.adminCommand({commitTransaction: 1}),
+                                 ErrorCodes.OperationNotSupportedInTransaction);
+    assert.commandFailedWithCode(session.abortTransaction_forTesting(),
+                                 ErrorCodes.NoSuchTransaction);
+
+    // ---- Test 2. No operations before abort ----
+    session.startTransaction();
+    assert.commandFailedWithCode(sessionDB.adminCommand({abortTransaction: 1}),
+                                 ErrorCodes.OperationNotSupportedInTransaction);
+    assert.commandFailedWithCode(session.abortTransaction_forTesting(),
+                                 ErrorCodes.NoSuchTransaction);
+
+    // ---- Test 3. Only reads before commit ----
+    session.startTransaction();
+    assert.eq(doc, sessionColl.findOne({a: 1}));
+    assert.commandWorked(session.commitTransaction_forTesting());
+
+    // ---- Test 4. Only reads before abort ----
+    session.startTransaction();
+    assert.eq(doc, sessionColl.findOne({a: 1}));
+    assert.commandWorked(session.abortTransaction_forTesting());
+
+    // ---- Test 5. Noop writes before commit ----
+    session.startTransaction();
+    let res = assert.commandWorked(sessionColl.update({a: 1}, {$set: {b: 1}}));
+    assert.eq(res.nMatched, 1, tojson(res));
+    assert.eq(res.nModified, 0, tojson(res));
+    assert.eq(res.nUpserted, 0, tojson(res));
+    assert.commandWorked(session.commitTransaction_forTesting());
+
+    // ---- Test 6. Noop writes before abort ----
+    session.startTransaction();
+    res = assert.commandWorked(sessionColl.update({a: 1}, {$set: {b: 1}}));
+    assert.eq(res.nMatched, 1, tojson(res));
+    assert.eq(res.nModified, 0, tojson(res));
+    assert.eq(res.nUpserted, 0, tojson(res));
+    assert.commandWorked(session.abortTransaction_forTesting());
+
+}());