Add 2 passing and 1 failing Annotated test

tests/test_main.py

@@ -18,7 +18,8 @@
     root_validator,
     validator,
 )
-from pydantic.typing import Literal
+from pydantic.fields import Undefined
+from pydantic.typing import Annotated, Literal
 
 
 def test_success():
@@ -1374,3 +1375,25 @@ class M(BaseModel):
         a: int
 
     get_type_hints(M.__config__)
+
+
+@pytest.mark.parametrize(
+    ["value"],
+    [(Undefined,), (Field(default=5),), (Field(default=5, ge=0),)]
+)
+def test_annotated(value):
+    x_hint = Annotated[int, 5]
+
+    class M(BaseModel):
+        x: x_hint = value
+
+    assert M(x=5).x == 5
+
+    # get_type_hints doesn't recognize typing_extensions.Annotated, so will return the full
+    # annotation. 3.9 w/ stock Annotated will return the wrapped type by default, but return the
+    # full thing with the new include_extras flag.
+    if sys.version_info >= (3, 9):
+        assert get_type_hints(M)["x"] is int
+        assert get_type_hints(M, include_extras=True)["x"] == x_hint
+    else:
+        assert get_type_hints(M)["x"] == x_hint