Support new 'X | None' union syntax in field types

Author: dmach

osc/util/models.py

@@ -39,6 +39,15 @@ def get_origin(typ):
 else:
     from typing import get_origin
 
+
+# types.UnionType was added in Python 3.10
+if sys.version_info < (3, 10):
+    class UnionType:
+        pass
+else:
+    from types import UnionType
+
+
 import urllib3.response
 
 from . import xml
@@ -165,7 +174,7 @@ def inner_type(self):
     @property
     def is_optional(self):
         origin_type = get_origin(self.type) or self.type
-        return origin_type == Union and len(self.type.__args__) == 2 and type(None) in self.type.__args__
+        return origin_type in (Union, UnionType) and type(None) in self.type.__args__
 
     @property
     def is_model(self):
@@ -193,7 +202,7 @@ def validate_type(self, value, expected_types=None):
             origin_type = get_origin(expected_type) or expected_type
 
             # unwrap Union
-            if origin_type == Union:
+            if origin_type in (Union, UnionType):
                 if value is None and type(None) in expected_type.__args__:
                     valid_type = True
                     continue

tests/test_models.py

@@ -1,3 +1,4 @@
+import sys
 import unittest
 from typing import Set
 
@@ -24,6 +25,16 @@ def test_bool(self):
 
 
 class Test(unittest.TestCase):
+    @unittest.skipIf(sys.version_info[:2] < (3, 10), "added in python 3.10")
+    def test_union_or(self):
+        class TestModel(BaseModel):
+            text: str | None = Field()
+
+        m = TestModel()
+        self.assertEqual(m.dict(), {"text": None})
+
+        self.assertRaises(TypeError, setattr, m.text, 123)
+
     def test_dict(self):
         class TestSubmodel(BaseModel):
             text: str = Field(default="default")