INTPYTHON-602 Fix loading of embedded model fields that use database converters

Author: timgraham

django_mongodb_backend/fields/embedded_model.py

@@ -3,6 +3,7 @@
 from django.core import checks
 from django.core.exceptions import FieldDoesNotExist
 from django.db import models
+from django.db.models.expressions import Col
 from django.db.models.fields.related import lazy_related_operation
 from django.db.models.lookups import Transform
 
@@ -76,6 +77,15 @@ def _resolve_lookup(_, resolved_model):
     model = property(lambda self: self._model, _set_model)
 
     def from_db_value(self, value, expression, connection):
+        if value is None:
+            return None
+        if not isinstance(value, dict):
+            return value
+        for field in self.embedded_model._meta.fields:
+            expression = Col("", field)
+            converters = connection.ops.get_db_converters(expression)
+            for converter in converters:
+                value[field.attname] = converter(value[field.attname], expression, connection)
         return self.to_python(value)
 
     def to_python(self, value):

tests/model_fields_/models.py

@@ -104,6 +104,7 @@ class Data(EmbeddedModel):
     auto_now = models.DateTimeField(auto_now=True)
     auto_now_add = models.DateTimeField(auto_now_add=True)
     json_value = models.JSONField()
+    decimal = models.DecimalField(max_digits=9, decimal_places="2")
 
 
 class Address(EmbeddedModel):

tests/model_fields_/test_embedded_model.py

@@ -1,5 +1,6 @@
 import operator
 from datetime import timedelta
+from unittest import expectedFailure
 
 from django.core.exceptions import FieldDoesNotExist, ValidationError
 from django.db import models
@@ -93,7 +94,7 @@ def test_pre_save(self):
 class QueryingTests(TestCase):
     @classmethod
     def setUpTestData(cls):
-        cls.objs = [Holder.objects.create(data=Data(integer=x)) for x in range(6)]
+        cls.objs = [Holder.objects.create(data=Data(integer=x, decimal=f"{x}.5")) for x in range(6)]
 
     def test_exact(self):
         self.assertCountEqual(Holder.objects.filter(data__integer=3), [self.objs[3]])
@@ -113,6 +114,12 @@ def test_gte(self):
     def test_range(self):
         self.assertCountEqual(Holder.objects.filter(data__integer__range=(2, 4)), self.objs[2:5])
 
+    @expectedFailure
+    def test_exact_decimal(self):
+        # EmbeddedModelField lookups need to call
+        # DatabaseOperations.adapt__<foo>field_value().
+        self.assertCountEqual(Holder.objects.filter(data__decimal="3.5"), [self.objs[3]])
+
     def test_order_by_embedded_field(self):
         qs = Holder.objects.filter(data__integer__gt=3).order_by("-data__integer")
         self.assertSequenceEqual(qs, list(reversed(self.objs[4:])))