SERVER-40839: Add tests for empty unprepared transactions

5 files changed, 80 insertions, 0 deletions

diff --git a/buildscripts/resmokeconfig/suites/sharded_causally_consistent_jscore_txns_passthrough.yml b/buildscripts/resmokeconfig/suites/sharded_causally_consistent_jscore_txns_passthrough.yml
index 64c70dcae67..6d3d50de224 100644
--- a/buildscripts/resmokeconfig/suites/sharded_causally_consistent_jscore_txns_passthrough.yml
+++ b/buildscripts/resmokeconfig/suites/sharded_causally_consistent_jscore_txns_passthrough.yml
@@ -41,6 +41,10 @@ selector:
   # attached to statements in a transaction beyond the first one.
   - jstests/core/txns/non_transactional_operations_on_session_with_transaction.js
 
+  # Empty commit/abort is currently allowed in mongos.
+  # TODO: SERVER-40885: unblacklist this.
+  - jstests/core/txns/empty_commit_abort.js
+
   exclude_with_any_tags:
   # Transactions are not allowed to operate on capped collections on shard servers.
   - requires_capped
diff --git a/buildscripts/resmokeconfig/suites/sharded_collections_causally_consistent_jscore_txns_passthrough.yml b/buildscripts/resmokeconfig/suites/sharded_collections_causally_consistent_jscore_txns_passthrough.yml
index 58a186ac39f..72b079cc5c9 100644
--- a/buildscripts/resmokeconfig/suites/sharded_collections_causally_consistent_jscore_txns_passthrough.yml
+++ b/buildscripts/resmokeconfig/suites/sharded_collections_causally_consistent_jscore_txns_passthrough.yml
@@ -40,6 +40,10 @@ selector:
   # attached to statements in a transaction beyond the first one.
   - jstests/core/txns/non_transactional_operations_on_session_with_transaction.js
 
+  # Empty commit/abort is currently allowed in mongos.
+  # TODO: SERVER-40885: unblacklist this.
+  - jstests/core/txns/empty_commit_abort.js
+
   exclude_with_any_tags:
   - assumes_against_mongod_not_mongos
   # Tests tagged with the following will fail because they assume collections are not sharded.
diff --git a/buildscripts/resmokeconfig/suites/sharded_jscore_txns.yml b/buildscripts/resmokeconfig/suites/sharded_jscore_txns.yml
index 44fd20dd3d0..e7af387796c 100644
--- a/buildscripts/resmokeconfig/suites/sharded_jscore_txns.yml
+++ b/buildscripts/resmokeconfig/suites/sharded_jscore_txns.yml
@@ -37,6 +37,10 @@ selector:
   # Uses hangAfterCollectionInserts failpoint not available on mongos.
   - jstests/core/txns/speculative_snapshot_includes_all_writes.js
 
+  # Empty commit/abort is currently allowed in mongos.
+  # TODO: SERVER-40885: unblacklist this.
+  - jstests/core/txns/empty_commit_abort.js
+
   exclude_with_any_tags:
   # Transactions are not allowed to operate on capped collections on shard servers.
   - requires_capped
diff --git a/buildscripts/resmokeconfig/suites/sharded_jscore_txns_sharded_collections.yml b/buildscripts/resmokeconfig/suites/sharded_jscore_txns_sharded_collections.yml
index 9f7b44b40c5..7e9914e833a 100644
--- a/buildscripts/resmokeconfig/suites/sharded_jscore_txns_sharded_collections.yml
+++ b/buildscripts/resmokeconfig/suites/sharded_jscore_txns_sharded_collections.yml
@@ -36,6 +36,10 @@ selector:
   # View tests aren't expected to work when collections are implicitly sharded.
   - jstests/core/txns/view_reads_in_transaction.js
 
+  # Empty commit/abort is currently allowed in mongos.
+  # TODO: SERVER-40885: unblacklist this.
+  - jstests/core/txns/empty_commit_abort.js
+
   exclude_with_any_tags:
   - assumes_against_mongod_not_mongos
   # Tests tagged with the following will fail because they assume collections are not sharded.
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());
+
+}());