Merge pull request #269 from jacebrowning/handle-typeddict

Fix exception when TypedDict is used

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Release Notes
 
+## 1.4.1 (2022-07-28)
+
+- Fixed exception when `TypedDict` is used, but schema is not yet supported.
+
 ## 1.4 (2022-06-03)
 
 - Added support for accessing `Dict` keys as attributes.

datafiles/converters/__init__.py

@@ -164,4 +164,10 @@ def map_type(cls, *, name: str = "", item_cls: Optional[type] = None):
     if issubclass(cls, Enum):
         return Enumeration.of_type(cls)
 
+    if issubclass(cls, dict):
+        log.warn("Schema enforcement not possible with 'TypedDict' annotation")
+        key = map_type(str)
+        value = Any
+        return Dictionary.of_mapping(key, value)
+
     raise TypeError(f"Could not map type: {cls}")

datafiles/converters/containers.py

@@ -129,7 +129,10 @@ class Dictionary(Converter):
 
     @classmethod
     def of_mapping(cls, key: type, value: type):
-        name = f"{key.__name__}{value.__name__}Dict"
+        try:
+            name = f"{key.__name__}{value.__name__}Dict"
+        except AttributeError:  # Python < 3.10
+            name = "UntypedDict"
         bases = (cls,)
         return type(name, bases, {})
 
@@ -151,7 +154,7 @@ def to_python_value(cls, deserialized_data, *, target_object):
 
     @classmethod
     def to_preserialization_data(cls, python_value, *, default_to_skip=None):
-        data = dict(python_value)
+        data = dict(python_value) if python_value else {}
 
         if data == default_to_skip:
             data.clear()

datafiles/tests/__init__.py

@@ -8,3 +8,8 @@
     sys.version_info < (3, 10),
     reason="Union types (PEP 604) are not available in Python 3.9 and earlier",
 )
+
+xfail_without_type_names = pytest.mark.xfail(
+    sys.version_info < (3, 10),
+    reason="Types lack a __name__ in Python 3.9 and earlier",
+)

datafiles/tests/test_converters.py

@@ -6,10 +6,11 @@
 
 import pytest
 from ruamel.yaml.scalarstring import LiteralScalarString
+from typing_extensions import TypedDict
 
 from datafiles import converters, settings
 
-from . import xfail_without_pep_604
+from . import xfail_without_pep_604, xfail_without_type_names
 
 
 @dataclass
@@ -24,6 +25,11 @@ class MyNestedDataclass:
     dc: MyDataclass
 
 
+class MyTypedDict(TypedDict):
+    title: str
+    salary: int
+
+
 class MyNonDataclass:
     pass
 
@@ -45,6 +51,7 @@ class Color(Enum):
 StringSet = converters.Set.of_type(converters.String)
 MyDataclassConverter = converters.map_type(MyDataclass)
 MyDataclassConverterList = converters.map_type(List[MyDataclass])
+MyTypedDictConverter = converters.map_type(MyTypedDict)
 
 
 def describe_map_type():
@@ -88,6 +95,11 @@ def it_requires_dict_annotations_to_have_types(expect):
         with expect.raises(TypeError, "Types are required with 'Dict' annotation"):
             converters.map_type(Dict)
 
+    @xfail_without_type_names
+    def it_handles_typed_dict_annotations(expect):
+        converter = converters.map_type(MyTypedDict)
+        expect(converter.__name__) == "StringAnyDict"
+
     def it_handles_abstract_mapping_types(expect):
         converter = converters.map_type(Mapping[str, int])
         expect(converter.__name__) == "StringIntegerDict"
@@ -211,6 +223,9 @@ def when_immutable(expect, converter, data, value):
                 (MyDataclassConverter, MyDataclass(42), MyDataclass(foobar=42)),
                 (MyDataclassConverterList, None, []),
                 (MyDataclassConverterList, 42, [MyDataclass(foobar=0)]),
+                (MyTypedDictConverter, None, {}),
+                (MyTypedDictConverter, {}, {}),
+                (MyTypedDictConverter, {"a": 1}, {"a": 1}),
             ],
         )
         def when_mutable(expect, converter, data, value):
@@ -293,6 +308,10 @@ def describe_to_preserialization_data():
                 (StringList, [123, True, False], ["123", "True", "False"]),
                 (StringList, [], [None]),
                 (StringList, None, [None]),
+                # Dicts
+                (MyTypedDictConverter, None, {}),
+                (MyTypedDictConverter, {}, {}),
+                (MyTypedDictConverter, {"a": 1}, {"a": 1}),
                 # Sets
                 (StringSet, "ab", ["ab"]),
                 (StringSet, ("b", 1, "A"), ["b", "1", "A"]),

pyproject.toml

@@ -1,7 +1,7 @@
 [tool.poetry]
 
 name = "datafiles"
-version = "1.4"
+version = "1.4.1"
 description = "File-based ORM for dataclasses."
 
 license = "MIT"
@@ -56,7 +56,7 @@ classproperties = "^0.2"
 minilog = "^2.1"
 
 # Typing
-typing-extensions = "^3.7"
+typing-extensions = "^3.7" # remove this when Python 3.7 support is dropped
 
 [tool.poetry.dev-dependencies]