test: add utils tests

pydantic/typing.py

@@ -302,7 +302,8 @@ def all_literal_values(type_: Type[Any]) -> Tuple[Any, ...]:
 
 def is_namedtuple(type_: Type[Any]) -> bool:
     """
-    Check if a given class is a `NamedTuple`
+    Check if a given class is a named tuple.
+    It can be either a `typing.NamedTuple` or `collections.namedtuple`
     """
     from .utils import lenient_issubclass
 
@@ -311,12 +312,12 @@ def is_namedtuple(type_: Type[Any]) -> bool:
 
 def is_typeddict(type_: Type[Any]) -> bool:
     """
-    Check if a given class is a `TypedDict`
+    Check if a given class is a typed dict (from `typing` or `typing_extensions`)
     In 3.10, there will be a public method (https://docs.python.org/3.10/library/typing.html#typing.is_typeddict)
     """
     from .utils import lenient_issubclass
 
-    return lenient_issubclass(type_, dict) and getattr(type_, '__annotations__', None)
+    return lenient_issubclass(type_, dict) and hasattr(type_, '__total__')
 
 
 test_type = NewType('test_type', str)

tests/test_typing.py

@@ -0,0 +1,55 @@
+from collections import namedtuple
+from typing import NamedTuple
+
+import pytest
+
+from pydantic.typing import is_namedtuple, is_typeddict
+
+try:
+    from typing import TypedDict as typing_TypedDict
+except ImportError:
+    typing_TypedDict = None
+
+try:
+    from typing_extensions import TypedDict as typing_extensions_TypedDict
+except ImportError:
+    typing_extensions_TypedDict = None
+
+
+try:
+    from mypy_extensions import TypedDict as mypy_extensions_TypedDict
+except ImportError:
+    mypy_extensions_TypedDict = None
+
+ALL_TYPEDDICT_KINDS = (typing_TypedDict, typing_extensions_TypedDict, mypy_extensions_TypedDict)
+
+
+def test_is_namedtuple():
+    class Employee(NamedTuple):
+        name: str
+        id: int = 3
+
+    assert is_namedtuple(namedtuple('Point', 'x y')) is True
+    assert is_namedtuple(Employee) is True
+    assert is_namedtuple(NamedTuple('Employee', [('name', str), ('id', int)])) is True
+
+    class SubTuple(tuple):
+        ...
+
+    assert is_namedtuple(SubTuple) is False
+
+
+@pytest.mark.parametrize('TypedDict', (t for t in ALL_TYPEDDICT_KINDS if t is not None))
+def test_is_typeddict_typing(TypedDict):
+    class Employee(TypedDict):
+        name: str
+        id: int
+
+    assert is_typeddict(Employee) is True
+    assert is_typeddict(TypedDict('Employee', {'name': str, 'id': int})) is True
+
+    class Other(dict):
+        name: str
+        id: int
+
+    assert is_typeddict(Other) is False