add completion execution guarantees to firestore write ops (#481)

1 files changed, 3 insertions, 2 deletions

diff --git a/Firestore/Source/Public/FIRFirestore.h b/Firestore/Source/Public/FIRFirestore.h
index 0935917..91a96a5 100644
--- a/Firestore/Source/Public/FIRFirestore.h
+++ b/Firestore/Source/Public/FIRFirestore.h
@@ -115,10 +115,11 @@ NS_SWIFT_NAME(Firestore)
  * and collections. Unlike other firestore access, data accessed with the transaction will not
  * reflect local changes that have not been committed. For this reason, it is required that all
  * reads are performed before any writes. Transactions must be performed while online. Otherwise,
- * reads will fail, and the final commit will fail.
+ * reads will fail, the final commit will fail, and the completion block will return an error.
  *
  * @param updateBlock The block to execute within the transaction context.
- * @param completion The block to call with the result or error of the transaction.
+ * @param completion The block to call with the result or error of the transaction. This
+ *     block will run even if the client is offline, unless the process is killed.
  */
 - (void)runTransactionWithBlock:(id _Nullable (^)(FIRTransaction *, NSError **))updateBlock
                      completion:(void (^)(id _Nullable result, NSError *_Nullable error))completion;