Merge pull request #209 from jacebrowning/python-3.10

Preliminary Python 3.10 support

.python-version

@@ -1 +1 @@
-3.9.0
+3.10.0a6

datafiles/converters/__init__.py

@@ -1,4 +1,5 @@
 import dataclasses
+import inspect
 from enum import Enum
 from inspect import isclass
 from typing import Any, Dict, Mapping, Optional, Union
@@ -31,6 +32,18 @@ def register(cls: Union[type, str], converter: type):
 register(String.TYPE, String)
 
 
+def resolve(annotation, obj=None):
+    if isinstance(annotation, str):
+        log.debug(f"Attempting to eval {annotation!r} using {obj}")
+        annotation = annotation.replace('List', 'list').replace('Dict', 'list')
+        namespace = inspect.getmodule(obj).__dict__ if obj else None
+        try:
+            return eval(annotation, namespace)  # pylint: disable=eval-used
+        except NameError as e:
+            log.warn(f"Unable to eval: {e}")
+    return annotation
+
+
 @cached
 def map_type(cls, *, name: str = '', item_cls: Optional[type] = None):
     """Infer the converter type from a dataclass, type, or annotation."""
@@ -47,11 +60,13 @@ def map_type(cls, *, name: str = '', item_cls: Optional[type] = None):
     if dataclasses.is_dataclass(cls):
         converters = {}
         for field in dataclasses.fields(cls):
-            converters[field.name] = map_type(field.type, name=field.name)  # type: ignore
+            converters[field.name] = map_type(resolve(field.type), name=field.name)  # type: ignore
         converter = Dataclass.of_mappings(cls, converters)
         log.debug(f'Mapped {cls!r} to new converter: {converter}')
         return converter
 
+    cls = resolve(cls)
+
     if hasattr(cls, '__origin__'):
         converter = None
 

datafiles/mapper.py

@@ -12,7 +12,7 @@
 from cached_property import cached_property
 
 from . import config, formats, hooks
-from .converters import Converter, List, map_type
+from .converters import Converter, List, map_type, resolve
 from .types import Missing, Trilean
 from .utils import display, get_default_field_value, recursive_update, write
 
@@ -290,7 +290,7 @@ def create_mapper(obj, root=None) -> Mapper:
         for field in [field for field in dataclasses.fields(obj) if field.init]:
             self_name = f'self.{field.name}'
             if pattern is None or self_name not in pattern:
-                attrs[field.name] = map_type(field.type, name=field.name)  # type: ignore
+                attrs[field.name] = map_type(resolve(field.type, obj), name=field.name)  # type: ignore
 
     return Mapper(
         obj,

pyproject.toml

@@ -66,6 +66,7 @@ isort = "=5.5.1"
 
 # Linters
 mypy = "~0.790"
+typed_ast = "^1.4.3" # updated mypy dependency for Python 3.10
 pylint = "~2.7.4"
 pydocstyle = "*"
 

tests/__init__.py

@@ -1 +1,11 @@
 """Integration tests for the package."""
+
+import sys
+
+import pytest
+
+
+xfail_on_latest = pytest.mark.xfail(
+    sys.version_info >= (3, 10),
+    reason="Python 3.10+ cannot annotations for locally-defined types",
+)

tests/test_custom_converters_future.py

@@ -10,7 +10,6 @@
 from datafiles import datafile
 
 
-@pytest.mark.xfail(reason='https://github.com/jacebrowning/datafiles/issues/131')
 def test_optional_type(expect):
     @datafile("../tmp/sample.yml")
     class MyObject:

tests/test_generic_converters.py

@@ -5,7 +5,10 @@
 from datafiles import Missing, converters, datafile
 from datafiles.utils import dedent
 
+from . import xfail_on_latest
 
+
+@xfail_on_latest
 def test_generic_converters(expect):
     S = TypeVar("S")
     T = TypeVar("T")

tests/test_instantiation.py

@@ -8,6 +8,8 @@
 from datafiles import Missing, datafile
 from datafiles.utils import logbreak, write
 
+from . import xfail_on_latest
+
 
 @datafile('../tmp/sample.yml', manual=True)
 class SampleWithDefaults:
@@ -150,6 +152,7 @@ def when_file_exists(expect):
 
 
 def describe_missing_attributes():
+    @xfail_on_latest
     def when_dataclass(expect):
         @dataclass
         class Name:

tests/test_loading.py

@@ -9,6 +9,7 @@
 from datafiles import datafile
 from datafiles.utils import dedent, logbreak, read, write
 
+from . import xfail_on_latest
 from .samples import (
     Sample,
     SampleAsJSON,
@@ -249,6 +250,7 @@ def with_extra_attributes(sample, expect):
         expect(sample.nested.score) == 3.4
         expect(hasattr(sample.nested, 'extra')).is_(False)
 
+    @xfail_on_latest
     def with_multiple_levels(expect):
         @dataclass
         class Bottom:

tests/test_orm_usage.py

@@ -8,6 +8,8 @@
 from datafiles import datafile
 from datafiles.utils import logbreak, write
 
+from . import xfail_on_latest
+
 
 # This model is based on the example dataclass from:
 # https://docs.python.org/3/library/dataclasses.html
@@ -48,6 +50,7 @@ def test_multiple_instances_are_distinct(expect):
     }
 
 
+@xfail_on_latest
 def test_classes_can_share_a_nested_dataclass(expect):
     @datafile
     class Nested:
@@ -95,6 +98,7 @@ def test_partial_load_from_disk(expect):
     expect(items[0].quantity_on_hand) == 0
 
 
+@xfail_on_latest
 def test_missing_optional_fields_are_loaded(expect):
     @datafile
     class Name:

tests/test_profiling.py

@@ -6,6 +6,8 @@
 from datafiles import datafile
 from datafiles.utils import logbreak
 
+from . import xfail_on_latest
+
 
 def get_sample():
     @dataclass
@@ -29,16 +31,19 @@ class Sample:
     return Sample('profiling', Item(2, None), None, [Item(3, None)])
 
 
+@xfail_on_latest
 def test_init():
     get_sample()
 
 
+@xfail_on_latest
 def test_load():
     sample = get_sample()
     logbreak("Loading")
     sample.datafile.load()  # pylint: disable=no-member
 
 
+@xfail_on_latest
 def test_save():
     sample = get_sample()
     logbreak("Saving")

tests/test_saving.py

@@ -9,6 +9,7 @@
 from datafiles import datafile
 from datafiles.utils import dedent, logbreak, read, write
 
+from . import xfail_on_latest
 from .samples import (
     Sample,
     SampleWithCustomFields,
@@ -276,6 +277,7 @@ def with_nones(expect):
             """
         )
 
+    @xfail_on_latest
     def when_nested_dataclass_is_none(expect):
         @datafile
         class Name:

tests/test_setup.py

@@ -11,6 +11,8 @@
 import datafiles
 from datafiles import datafile
 
+from . import xfail_on_latest
+
 
 def describe_automatic():
     """Test creating a datafile using the decorator."""
@@ -76,6 +78,7 @@ class Sample:
 
             return Sample(1, Nested(name="b"), "a")
 
+        @xfail_on_latest
         def it_converts_attributes(expect, sample):
             expect(sample.datafile.data) == {
                 'name': "a",