DynamoDB: transact_write_items() should return failing item (#5482)

getmoto · Sep 17, 2022 · e230750 · e230750
1 parent 5739db4
commit e230750
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Showing 3 changed files with 12 additions and 8 deletions.
diff --git a/moto/dynamodb/exceptions.py b/moto/dynamodb/exceptions.py
@@ -207,14 +207,14 @@ class TransactionCanceledException(DynamodbException):
 
     def __init__(self, errors):
         msg = self.cancel_reason_msg.format(
-            ", ".join([str(code) for code, _ in errors])
+            ", ".join([str(code) for code, _, _ in errors])
         )
         super().__init__(
             error_type=TransactionCanceledException.error_type, message=msg
         )
         reasons = [
-            {"Code": code, "Message": message} if code else {"Code": "None"}
-            for code, message in errors
+            {"Code": code, "Message": message, **item} if code else {"Code": "None"}
+            for code, message, item in errors
         ]
         self.description = json.dumps(
             {

diff --git a/moto/dynamodb/models/__init__.py b/moto/dynamodb/models/__init__.py
@@ -1654,7 +1654,7 @@ def check_unicity(table_name, key):
                 raise MultipleTransactionsException()
             target_items.add(item)
 
-        errors = []
+        errors = []  # [(Code, Message, Item), ..]
         for item in transact_items:
             try:
                 if "ConditionCheck" in item:
@@ -1738,14 +1738,14 @@ def check_unicity(table_name, key):
                     )
                 else:
                     raise ValueError
-                errors.append((None, None))
+                errors.append((None, None, None))
             except MultipleTransactionsException:
                 # Rollback to the original state, and reraise the error
                 self.tables = original_table_state
                 raise MultipleTransactionsException()
             except Exception as e:  # noqa: E722 Do not use bare except
-                errors.append((type(e).__name__, e.message))
-        if set(errors) != set([(None, None)]):
+                errors.append((type(e).__name__, e.message, item))
+        if any([code is not None for code, _, _ in errors]):
             # Rollback to the original state, and reraise the errors
             self.tables = original_table_state
             raise TransactionCanceledException(errors)

diff --git a/tests/test_dynamodb/test_dynamodb.py b/tests/test_dynamodb/test_dynamodb.py
@@ -3882,7 +3882,11 @@ def test_transact_write_items_put_conditional_expressions():
     reasons = ex.value.response["CancellationReasons"]
     reasons.should.have.length_of(5)
     reasons.should.contain(
-        {"Code": "ConditionalCheckFailed", "Message": "The conditional request failed"}
+        {
+            "Code": "ConditionalCheckFailed",
+            "Message": "The conditional request failed",
+            "Item": {"id": {"S": "foo2"}, "foo": {"S": "bar"}},
+        }
     )
     reasons.should.contain({"Code": "None"})
     ex.value.response["ResponseMetadata"]["HTTPStatusCode"].should.equal(400)