implement get_default coercion and handle deconstructing defaults appropriately, add test cases and fix misc type hinting issues closes #4

bckohan · bckohan · commit 309da698bc85 · 2022-08-12T12:54:17.000-07:00
diff --git a/django_enum/fields.py b/django_enum/fields.py
@@ -108,7 +108,16 @@ def __init__(
             kwargs.setdefault('choices', enum.choices if enum else [])
         super().__init__(*args, **kwargs)
 
-    def _try_coerce(self, value: Any, force: bool = False) -> Union[Choices, Any]:
+    def _try_coerce(
+            self,
+            value: Any,
+            force: bool = False
+    ) -> Union[Choices, Any]:
+        """
+        Attempt coercion of value to enumeration type instance, if unsuccessful
+        and non-strict, coercion to enum's primitive type will be done,
+        otherwise a ValueError is raised.
+        """
         if (
             (self.coerce or force)
             and self.enum is not None
@@ -133,15 +142,33 @@ def _try_coerce(self, value: Any, force: bool = False) -> Union[Choices, Any]:
 
     def deconstruct(self) -> Tuple[str, str, List, dict]:
         """
-        Preserve enum class for migrations. Strict is omitted because
-        reconstructed fields are *always* non-strict sense enum is null.
+        Preserve field migrations. Strict and coerce are omitted because
+        reconstructed fields are *always* non-strict and coerce is always
+        False.
+
+        .. warning::
+
+            Do not add enum to kwargs! It is important that migration files not
+            reference enum classes that might be removed from the code base in
+            the future as this would break older migration files! We simply use
+            the choices tuple, which is plain old data and entirely sufficient
+            to de/reconstruct our field.
 
         See deconstruct_
         """
         name, path, args, kwargs = super().deconstruct()
         if self.enum is not None:
             kwargs['choices'] = self.enum.choices
 
+        if 'default' in kwargs:
+            # ensure default in deconstructed fields is always the primitive
+            # value type
+            kwargs['default'] = getattr(
+                self.get_default(),
+                'value',
+                self.get_default()
+            )
+
         return name, path, args, kwargs
 
     def get_prep_value(self, value: Any) -> Any:
@@ -210,6 +237,15 @@ def to_python(self, value: Any) -> Union[Choices, Any]:
                 f"{self.enum.__name__ if self.enum else ''}."
             ) from err
 
+    def get_default(self) -> Any:
+        """Wrap get_default in an enum type coercion attempt"""
+        if self.has_default():
+            try:
+                return self.to_python(super().get_default())
+            except ValidationError:
+                return super().get_default()
+        return super().get_default()
+
     def validate(self, value: Any, model_instance: Model):
         """
         Validates the field as part of model clean routines. Runs super class
@@ -237,6 +273,9 @@ def validate(self, value: Any, model_instance: Model):
                 params={'value': value}
             ) from err
 
+    # def formfield(self, form_class=None, choices_form_class=None, **kwargs):
+    #    pass
+
 
 class EnumCharField(EnumMixin, CharField):
     """
@@ -302,7 +341,10 @@ class _EnumFieldMetaClass(type):
 
     SUPPORTED_PRIMITIVES = {int, str, float}
 
-    def __new__(mcs, enum: Choices) -> Field:  # pylint: disable=R0911
+    def __new__(  # pylint: disable=R0911
+            mcs,
+            enum: Type[Choices]
+    ) -> Type[EnumMixin]:
         """
         Construct a new Django Field class given the Enumeration class. The
         correct Django field class to inherit from is determined based on the
@@ -347,7 +389,7 @@ def EnumField(  # pylint: disable=C0103
         enum: Type[Choices],
         *field_args,
         **field_kwargs
-) -> Field:
+) -> EnumMixin:
     """
     *This is a function, not a type*. Some syntactic sugar that wraps the enum
     field metaclass so that we can cleanly create enums like so:
diff --git a/django_enum/filters.py b/django_enum/filters.py
@@ -4,7 +4,6 @@
 
 from django.db.models import Field as ModelField
 from django.forms.fields import Field as FormField
-from django_enum.fields import EnumMixin
 from django_enum.forms import EnumChoiceField
 
 try:
@@ -56,7 +55,7 @@ def filter_for_lookup(
                 lookup_type: str
         ) -> Tuple[Type[Filter], dict]:
             """For EnumFields use the EnumFilter class by default"""
-            if isinstance(field, EnumMixin) and getattr(field, 'enum', None):
+            if hasattr(field, 'enum') and hasattr(field.enum, 'choices'):
                 return EnumFilter, {'enum': field.enum}
             return super().filter_for_lookup(field, lookup_type)
 
diff --git a/django_enum/forms.py b/django_enum/forms.py
@@ -120,7 +120,6 @@ def _coerce(self, value: Any) -> Union[Choices, Any]:
             one of our empty_values, or the value itself if this is a
             non-strict field and the value is of a matching primitive type
         """
-
         if value in self.empty_values:
             return self.empty_value
         if (
diff --git a/django_enum/tests/djenum/migrations/0001_initial.py b/django_enum/tests/djenum/migrations/0001_initial.py
@@ -1,4 +1,4 @@
-# Generated by Django 3.2.14 on 2022-08-09 23:57
+# Generated by Django 3.2.15 on 2022-08-12 04:26
 
 import django_enum.fields
 from django.db import migrations, models
@@ -31,7 +31,7 @@ class Migration(migrations.Migration):
                 ('char_field', models.CharField(blank=True, default='A', max_length=1)),
                 ('dj_int_enum', django_enum.fields.EnumPositiveSmallIntegerField(choices=[(1, 'One'), (2, 'Two'), (3, 'Three')], default=1)),
                 ('dj_text_enum', django_enum.fields.EnumCharField(choices=[('A', 'Label A'), ('B', 'Label B'), ('C', 'Label C')], default='A', max_length=1)),
-                ('non_strict_int', django_enum.fields.EnumPositiveSmallIntegerField(blank=True, choices=[(0, 'Value 1'), (2, 'Value 2'), (32767, 'Value 32767')], default=None, null=True)),
+                ('non_strict_int', django_enum.fields.EnumPositiveSmallIntegerField(blank=True, choices=[(0, 'Value 1'), (2, 'Value 2'), (32767, 'Value 32767')], default=5, null=True)),
                 ('non_strict_text', django_enum.fields.EnumCharField(blank=True, choices=[('V1', 'Value1'), ('V22', 'Value2'), ('V333', 'Value3'), ('D', 'Default')], default='', max_length=12)),
                 ('no_coerce', django_enum.fields.EnumPositiveSmallIntegerField(blank=True, choices=[(0, 'Value 1'), (2, 'Value 2'), (32767, 'Value 32767')], default=None, null=True)),
             ],
diff --git a/django_enum/tests/djenum/models.py b/django_enum/tests/djenum/models.py
@@ -20,11 +20,11 @@ class EnumTester(models.Model):
     small_pos_int = EnumField(SmallPosIntEnum, null=True, default=None, db_index=True, blank=True)
     small_int = EnumField(SmallIntEnum, null=False, default=SmallIntEnum.VAL3, db_index=True, blank=True)
 
-    pos_int = EnumField(PosIntEnum, default=PosIntEnum.VAL3, db_index=True, blank=True)
+    pos_int = EnumField(PosIntEnum, default=2147483647, db_index=True, blank=True)
     int = EnumField(IntEnum, null=True, db_index=True, blank=True)
 
     big_pos_int = EnumField(BigPosIntEnum, null=True, default=None, db_index=True, blank=True)
-    big_int = EnumField(BigIntEnum, default=BigIntEnum.VAL0, db_index=True, blank=True)
+    big_int = EnumField(BigIntEnum, default=-2147483649, db_index=True, blank=True)
 
     constant = EnumField(Constants, null=True, default=None, db_index=True, blank=True)
 
@@ -67,14 +67,14 @@ class EnumTester(models.Model):
     ################################################
 
     dj_int_enum = EnumField(DJIntEnum, default=DJIntEnum.ONE)
-    dj_text_enum = EnumField(DJTextEnum, default=DJTextEnum.A)
+    dj_text_enum = EnumField(DJTextEnum, default='A')
 
     # Non-strict
     non_strict_int = EnumField(
         SmallPosIntEnum,
         strict=False,
         null=True,
-        default=None,
+        default=5,
         blank=True
     )
 
diff --git a/django_enum/tests/edit_tests/edits/_7.py b/django_enum/tests/edit_tests/edits/_7.py
@@ -0,0 +1,22 @@
+from django.db import models
+from django_enum import EnumField, TextChoices
+from enum_properties import s
+
+
+class MigrationTester(models.Model):
+
+    class IntEnum(models.TextChoices):
+        A = 'A', 'One'
+        B = 'B', 'Two',
+        C = 'C', 'Three'
+
+    class Color(TextChoices, s('rgb'), s('hex', case_fold=True)):
+        RED = 'R', 'Red', (1, 0, 0), 'ff0000'
+        GREEN = 'G', 'Green', (0, 1, 0), '00ff00'
+        BLUE = 'B', 'Blue', (0, 0, 1), '0000ff'
+        BLACK = 'K', 'Black', (0, 0, 0), '000000'
+
+    int_enum = EnumField(IntEnum, null=True, default=None)
+
+    # set default
+    color = EnumField(Color, default='000000')
diff --git a/django_enum/tests/edit_tests/edits/_8.py b/django_enum/tests/edit_tests/edits/_8.py
@@ -0,0 +1,24 @@
+from django.db import models
+from django_enum import EnumField, TextChoices
+from enum_properties import s
+
+
+class MigrationTester(models.Model):
+
+    class IntEnum(models.TextChoices):
+        A = 'A', 'One'
+        B = 'B', 'Two',
+        C = 'C', 'Three'
+
+    class Color(TextChoices, s('rgb'), s('hex', case_fold=True)):
+        RED = 'R', 'Red', (1, 0, 0), 'ff0000'
+        GREEN = 'G', 'Green', (0, 1, 0), '00ff00'
+
+        # change meaning of default indirectly
+        BLUE = 'B', 'Blue', (0, 0, 1), '000000'
+        BLACK = 'K', 'Black', (0, 0, 0), '0000ff'
+
+    int_enum = EnumField(IntEnum, null=True, default=None)
+
+    # default value unchanged
+    color = EnumField(Color, default='000000')
diff --git a/django_enum/tests/enum_prop/migrations/0001_initial.py b/django_enum/tests/enum_prop/migrations/0001_initial.py
@@ -1,4 +1,4 @@
-# Generated by Django 3.2.14 on 2022-08-09 23:57
+# Generated by Django 3.2.15 on 2022-08-12 04:26
 
 import django_enum.fields
 from django.db import migrations, models
@@ -31,7 +31,7 @@ class Migration(migrations.Migration):
                 ('char_field', models.CharField(blank=True, default='A', max_length=1)),
                 ('dj_int_enum', django_enum.fields.EnumPositiveSmallIntegerField(choices=[(1, 'One'), (2, 'Two'), (3, 'Three')], default=1)),
                 ('dj_text_enum', django_enum.fields.EnumCharField(choices=[('A', 'Label A'), ('B', 'Label B'), ('C', 'Label C')], default='A', max_length=1)),
-                ('non_strict_int', django_enum.fields.EnumPositiveSmallIntegerField(blank=True, choices=[(0, 'Value 1'), (2, 'Value 2'), (32767, 'Value 32767')], default=None, null=True)),
+                ('non_strict_int', django_enum.fields.EnumPositiveSmallIntegerField(blank=True, choices=[(0, 'Value 1'), (2, 'Value 2'), (32767, 'Value 32767')], default=5, null=True)),
                 ('non_strict_text', django_enum.fields.EnumCharField(blank=True, choices=[('V1', 'Value1'), ('V22', 'Value2'), ('V333', 'Value3'), ('D', 'Default')], default='', max_length=12)),
                 ('no_coerce', django_enum.fields.EnumPositiveSmallIntegerField(blank=True, choices=[(0, 'Value 1'), (2, 'Value 2'), (32767, 'Value 32767')], default=None, null=True)),
             ],
diff --git a/django_enum/tests/enum_prop/models.py b/django_enum/tests/enum_prop/models.py
@@ -20,13 +20,13 @@
     class EnumTester(models.Model):
 
         small_pos_int = EnumField(SmallPosIntEnum, null=True, default=None, db_index=True, blank=True)
-        small_int = EnumField(SmallIntEnum, null=False, default=SmallIntEnum.VAL3, db_index=True, blank=True)
+        small_int = EnumField(SmallIntEnum, null=False, default='Value 32767', db_index=True, blank=True)
 
-        pos_int = EnumField(PosIntEnum, default=PosIntEnum.VAL3, db_index=True, blank=True)
+        pos_int = EnumField(PosIntEnum, default=2147483647, db_index=True, blank=True)
         int = EnumField(IntEnum, null=True, db_index=True, blank=True)
 
         big_pos_int = EnumField(BigPosIntEnum, null=True, default=None, db_index=True, blank=True)
-        big_int = EnumField(BigIntEnum, default=BigIntEnum.VAL0, db_index=True, blank=True)
+        big_int = EnumField(BigIntEnum, default=BigPosIntEnum.VAL0, db_index=True, blank=True)
 
         constant = EnumField(Constants, null=True, default=None, db_index=True, blank=True)
 
@@ -76,7 +76,7 @@ class EnumTester(models.Model):
             SmallPosIntEnum,
             strict=False,
             null=True,
-            default=None,
+            default=5,
             blank=True
         )
         non_strict_text = EnumField(
diff --git a/django_enum/tests/tests.py b/django_enum/tests/tests.py
