fix:filter caching for unhashable types (#135)

* add test for unhashable obj filter caching

* hash instances by id() instead of the object itself

* changelog and bumpversion

Author: dshafer

.bumpversion.cfg

@@ -1,5 +1,5 @@
 [bumpversion]
-current_version = 0.31.1
+current_version = 0.31.2
 
 [bumpversion:file:pyproject.toml]
 

CHANGELOG.md

@@ -4,7 +4,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-# [0.31.1 = 2023-09-11]
+# [0.31.2 = 2023-09-11]
 - [PR 134](https://github.com/salesforce/django-declarative-apis/pull/134) Make filter caching work for all datatypes
 - [PR 131](https://github.com/salesforce/django-declarative-apis/pull/131) Support non-utf8 request body
 

django_declarative_apis/machinery/filtering.py

@@ -97,7 +97,7 @@ def _get_callable_field_value_with_cache(inst, field_name, model_cache, field_ty
     else:
         # not a foreign key.  Cache it by (inst, field_name) - it won't be a cache hit on another instance, but
         # will be cached if this same inst is returned later in the response
-        cache_key = (inst, field_name)
+        cache_key = (id(inst), field_name)
 
     if cache_key in model_cache:
         logger.debug("ev=model_cache, status=hit, key=%s", cache_key)

docs/source/conf.py

@@ -74,7 +74,7 @@
 # built documents.
 
 # The full version, including alpha/beta/rc tags.
-release = '0.31.1'  # set by bumpversion
+release = '0.31.2'  # set by bumpversion
 
 # The short X.Y version.
 version = release.rsplit('.', 1)[0]

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "django-declarative-apis"
-version = "0.31.1"  # set by bumpversion
+version = "0.31.2"  # set by bumpversion
 description = "Simple, readable, declarative APIs for Django"
 readme = "README.md"
 dependencies = [

tests/filters.py

@@ -5,7 +5,7 @@
 # For full license text, see the LICENSE file in the repo root or https://opensource.org/licenses/BSD-3-Clause
 #
 
-from django_declarative_apis.machinery.filtering import ALWAYS, expandable
+from django_declarative_apis.machinery.filtering import ALWAYS, NEVER, expandable
 
 from . import models
 
@@ -50,6 +50,12 @@
     models.InefficientBranchA: {"leaf": lambda inst: inst.leaf},
     models.InefficientBranchB: {"leaf": lambda inst: inst.leaf},
     models.InefficientRoot: {"branch_a": ALWAYS, "branch_b": ALWAYS},
+    models.InefficientPydanticRoot: {
+        "default_factory": NEVER,
+        "__len__": NEVER,
+        "branch_a": lambda inst: inst.branch_a,
+        "branch_b": lambda inst: inst.branch_b,
+    },
 }
 
 RENAMED_EXPANDABLE_MODEL_FIELDS = {

tests/machinery/test_base.py

@@ -761,6 +761,27 @@ def _mark_as_fake_relation(self, field):
         field.is_fake_relation = True
 
 
+class FilterCachingUnhashableTestCase(django.test.TestCase):
+    def setUp(self):
+        leaf = models.InefficientLeaf.objects.create(id=1)
+        branch_a = models.InefficientBranchA.objects.create(id=1, leaf=leaf)
+        branch_b = models.InefficientBranchB.objects.create(id=1, leaf=leaf)
+        self.root = models.InefficientPydanticRoot(
+            id=4, branch_a=branch_a, branch_b=branch_b
+        )
+
+    def test_filtering_accepts_nonhashable_root_item(self):
+        with override_settings(
+            DDA_FILTER_MODEL_CACHING_ENABLED=True, DDA_FILTER_CACHE_DEBUG_LOG=True
+        ):
+            try:
+                filtering.apply_filters_to_object(
+                    self.root, filters.INEFFICIENT_FUNCTION_FILTERS
+                )
+            except TypeError:
+                self.fail("should be able to use filter caching on pydantic objects")
+
+
 class ResourceUpdateEndpointDefinitionTestCase(
     testutils.RequestCreatorMixin, django.test.TestCase
 ):

tests/models.py

@@ -4,7 +4,7 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # For full license text, see the LICENSE file in the repo root or https://opensource.org/licenses/BSD-3-Clause
 #
-
+import pydantic
 from django.db import models
 
 
@@ -73,6 +73,12 @@ class InefficientRoot(models.Model):
     branch_b = models.ForeignKey(InefficientBranchB, on_delete=models.CASCADE)
 
 
+class InefficientPydanticRoot(pydantic.BaseModel, arbitrary_types_allowed=True):
+    id: int = None
+    branch_a: InefficientBranchA = None
+    branch_b: InefficientBranchB = None
+
+
 try:
     import dirtyfields