Added custom exception (inheriting from KeyError) when deserialization fails

dataclasses_json/core.py

@@ -17,6 +17,7 @@
 from typing_inspect import is_union_type  # type: ignore
 
 from dataclasses_json import cfg
+from dataclasses_json.errors import DataclassJsonSerializationException
 from dataclasses_json.utils import (_get_type_cons,
                                     _handle_undefined_parameters_safe,
                                     _is_collection, _is_mapping, _is_new_type,
@@ -147,7 +148,14 @@ def _decode_dataclass(cls, kvs, infer_missing):
         if not field.init:
             continue
 
-        field_value = kvs[field.name]
+        try:
+            field_value = kvs[field.name]
+        except KeyError as ex:
+            qualified = f"{cls.__module__}.{cls.__qualname__}"
+            args = ", ".join(ex.args)
+            raise DataclassJsonSerializationException(
+                f"Error decoding dataclass {qualified} encountered "
+                f"at field {args}") from ex
         field_type = types[field.name]
         if field_value is None and not _is_optional(field_type):
             warning = (f"value of non-optional type {field.name} detected "

dataclasses_json/errors.py

@@ -0,0 +1,8 @@
+class DataclassJsonError(Exception):
+    def __init__(self, *args: object) -> None:
+        super().__init__(*args)
+
+
+class DataclassJsonSerializationException(KeyError):
+    def __init__(self, *args, **kwargs) -> None:
+        super(DataclassJsonSerializationException, self).__init__(*args, **kwargs)

setup.py

@@ -1,11 +1,27 @@
+import os
 from setuptools import setup, find_packages
+from distutils.command.register import register as register_orig
+from distutils.command.upload import upload as upload_orig
+
 
 with open('README.md', 'r', encoding='utf8') as f:
     readme = f.read()
 
+
+class register(register_orig):
+
+    def _get_rc_file(self):
+        return os.path.join('.', '.pypirc')
+
+
+class upload(upload_orig):
+    def _get_rc_file(self):
+        return os.path.join('.', '.pypirc')
+
+
 setup(
     name='dataclasses-json',
-    version='0.4.2',
+    version='0.4.2-twk',
     packages=find_packages(exclude=('tests*',)),
     package_data={"dataclasses_json": ["py.typed"]},
     author='lidatong',
@@ -16,6 +32,11 @@
     url='https://github.com/lidatong/dataclasses-json',
     license='MIT',
     keywords='dataclasses json',
+    cmdclass={
+        'register': register,
+        'upload': upload,
+    },
+
     install_requires=[
         'dataclasses;python_version=="3.6"',
         'marshmallow>=3.3.0,<4.0.0',
@@ -35,8 +56,7 @@
             'simplejson'
         ]
     },
-    include_package_data=True,
-    scripts=['publish.py']
+    include_package_data=True
 )
 
 

tests/test_api.py

@@ -4,6 +4,7 @@
 
 import pytest
 
+from dataclasses_json.errors import DataclassJsonSerializationException
 from tests.entities import (DataClassBoolImmutableDefault,
                             DataClassIntImmutableDefault,
                             DataClassJsonDecorator,
@@ -127,7 +128,7 @@ def test_warns_when_required_field_is_none(self):
 
 class TestErrors:
     def test_error_when_nonoptional_field_is_missing(self):
-        with pytest.raises(KeyError):
+        with pytest.raises(DataclassJsonSerializationException):
             actual = DataClassWithDataClass.from_json('{"dc_with_list": {}}')
             expected = DataClassWithDataClass(DataClassWithList(None))
             assert (actual == expected)