From d46a3cab31afa8e49e35eb1c1bebff23609de21d Mon Sep 17 00:00:00 2001
From: Cohen Karnell <cohen@trialspark.com>
Date: Tue, 19 Nov 2019 10:43:23 -0500
Subject: [PATCH] Fix types and add test for concat

---
 sqlalchemy-stubs/sql/functions.pyi       |  2 +-
 test/test-data/sqlalchemy-functions.test | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/sqlalchemy-stubs/sql/functions.pyi b/sqlalchemy-stubs/sql/functions.pyi
index 6f5a5c3..ce3c584 100644
--- a/sqlalchemy-stubs/sql/functions.pyi
+++ b/sqlalchemy-stubs/sql/functions.pyi
@@ -112,7 +112,7 @@ class sum(ReturnTypeFromArgs[Any]): ...
 
 class now(GenericFunction[datetime]): ...
 
-class concat(GenericFunction[Text]): ...
+class concat(GenericFunction[Optional[Text]]): ...
 
 class char_length(GenericFunction[int]): ...
 
diff --git a/test/test-data/sqlalchemy-functions.test b/test/test-data/sqlalchemy-functions.test
index 90e7f46..3c321d0 100644
--- a/test/test-data/sqlalchemy-functions.test
+++ b/test/test-data/sqlalchemy-functions.test
@@ -16,3 +16,22 @@ users_table = Table(
 
 query = users_table.update().values(user=functions.concat(users_table.c.user, "@domain.com"))
 [out]
+
+[case testConcatFunctionNullableString]
+from sqlalchemy.sql import functions
+
+from sqlalchemy import Column, Table
+from sqlalchemy.types import Integer, String
+from sqlalchemy import MetaData
+
+metadata = MetaData()
+
+users_table = Table(
+    "users",
+    metadata,
+    Column("id", Integer, primary_key=True, autoincrement=True),
+    Column("user", String(42), unique=True, nullable=True),
+)
+
+query = users_table.update().values(user=functions.concat(users_table.c.user, "@domain.com"))
+[out]