Make serializer fields import explicit (#4628)

rest_framework/serializers.py

@@ -12,18 +12,27 @@ response content is handled by parsers and renderers.
 """
 from __future__ import unicode_literals
 
+import copy
+import inspect
 import traceback
+from collections import OrderedDict
 
+from django.core.exceptions import ValidationError as DjangoValidationError
+from django.core.exceptions import ImproperlyConfigured
 from django.db import models
 from django.db.models import DurationField as ModelDurationField
 from django.db.models.fields import Field as DjangoModelField
 from django.db.models.fields import FieldDoesNotExist
+from django.utils import six, timezone
 from django.utils.functional import cached_property
 from django.utils.translation import ugettext_lazy as _
 
 from rest_framework.compat import JSONField as ModelJSONField
 from rest_framework.compat import postgres_fields, set_many, unicode_to_repr
-from rest_framework.utils import model_meta
+from rest_framework.exceptions import ErrorDetail, ValidationError
+from rest_framework.fields import get_error_detail, set_value
+from rest_framework.settings import api_settings
+from rest_framework.utils import html, model_meta, representation
 from rest_framework.utils.field_mapping import (
     ClassLookupDict, get_field_kwargs, get_nested_relation_kwargs,
     get_relation_kwargs, get_url_kwargs
@@ -42,9 +51,23 @@ from rest_framework.validators import (
 #
 # This helps keep the separation between model fields, form fields, and
 # serializer fields more explicit.
+from rest_framework.fields import (  # NOQA # isort:skip
+    BooleanField, CharField, ChoiceField, DateField, DateTimeField, DecimalField,
+    DictField, DurationField, EmailField, Field, FileField, FilePathField, FloatField,
+    HiddenField, IPAddressField, ImageField, IntegerField, JSONField, ListField,
+    ModelField, MultipleChoiceField, NullBooleanField, ReadOnlyField, RegexField,
+    SerializerMethodField, SlugField, TimeField, URLField, UUIDField,
+)
+from rest_framework.relations import (  # NOQA # isort:skip
+    HyperlinkedIdentityField, HyperlinkedRelatedField, ManyRelatedField,
+    PrimaryKeyRelatedField, RelatedField, SlugRelatedField, StringRelatedField,
+)
 
-from rest_framework.fields import *  # NOQA # isort:skip
-from rest_framework.relations import *  # NOQA # isort:skip
+# Non-field imports, but public API
+from rest_framework.fields import (  # NOQA # isort:skip
+    CreateOnlyDefault, CurrentUserDefault, SkipField, empty
+)
+from rest_framework.relations import Hyperlink, PKOnlyObject  # NOQA # isort:skip
 
 # We assume that 'validators' are intended for the child serializer,
 # rather than the parent serializer.

tests/test_serializer.py

 # coding: utf-8
 from __future__ import unicode_literals
 
+import inspect
 import pickle
 import re
 
 import pytest
 
-from rest_framework import serializers
+from rest_framework import fields, relations, serializers
 from rest_framework.compat import unicode_repr
+from rest_framework.fields import Field
 
 from .utils import MockObject
 
 
+# Test serializer fields imports.
+# -------------------------------
+
+class TestFieldImports:
+    def is_field(self, name, value):
+        return (
+            isinstance(value, type) and
+            issubclass(value, Field) and
+            not name.startswith('_')
+        )
+
+    def test_fields(self):
+        msg = "Expected `fields.%s` to be imported in `serializers`"
+        field_classes = [
+            key for key, value
+            in inspect.getmembers(fields)
+            if self.is_field(key, value)
+        ]
+
+        # sanity check
+        assert 'Field' in field_classes
+        assert 'BooleanField' in field_classes
+
+        for field in field_classes:
+            assert hasattr(serializers, field), msg % field
+
+    def test_relations(self):
+        msg = "Expected `relations.%s` to be imported in `serializers`"
+        field_classes = [
+            key for key, value
+            in inspect.getmembers(relations)
+            if self.is_field(key, value)
+        ]
+
+        # sanity check
+        assert 'RelatedField' in field_classes
+
+        for field in field_classes:
+            assert hasattr(serializers, field), msg % field
+
+
 # Tests for core functionality.
 # -----------------------------