From d49d6b8f66feb07b4e184c79c5f6a3f68d8419da Mon Sep 17 00:00:00 2001
From: Todd Wolfson <todd@twolfson.com>
Date: Mon, 31 Oct 2022 16:02:46 -0700
Subject: [PATCH 1/4] Documented how to automatically update a timestamp via
 bulk_update

---
 docs/common_issues.rst | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/docs/common_issues.rst b/docs/common_issues.rst
index 3537b5061..669eab9bc 100644
--- a/docs/common_issues.rst
+++ b/docs/common_issues.rst
@@ -275,3 +275,33 @@ arguments using ``excluded_field_kwargs`` as follows:
         history = HistoricalRecords(
             excluded_field_kwargs={"organizer": set(["custom_argument"])}
         )
+
+
+Updated auto_now inside a bulk_update_with_history
+--------------------------------------------------
+
+If you are tracking update timestamps (e.g. ``updated_at``, ``modified_at``), these are only tracked when
+``Model.save()`` is called. As a result, ``bulk_update_with_history`` won't update them.
+
+As a convention, you can define a custom manager to update these timestamps automatically:
+
+.. code-block:: python
+
+    from django.utils import timezone
+
+    class UpdatedAtFriendlyQuerySet(models.QuerySet):
+        def bulk_update(self, objs, fields, *args, **kwargs):
+            timestamp = timezone.now()
+            for obj in objs:
+                assert hasattr(obj, "updated_at"), "Expected bulk_update object to have `updated_at`"
+                obj.updated_at = timestamp
+            assert "updated_at" not in fields, "Encountered unexpected scenario where we set `updated_at` via `bulk_update`"
+            new_fields = tuple(fields) + ("updated_at",)
+            super().bulk_update(objs, new_fields, *args, **kwargs)
+
+    class UpdatedAtFriendlyManager(models.manager.BaseManager.from_queryset(UpdatedAtFriendlyQuerySet)):
+        pass
+
+    class Poll(models.Model):
+        # This must be the first Manager declared in this class, otherwise it won't be detected as the `default_manager`
+        objects = UpdatedAtFriendlyManager()

From 855f3af0793f48812f824551f67f0cd10f794eea Mon Sep 17 00:00:00 2001
From: Todd Wolfson <todd@twolfson.com>
Date: Mon, 31 Oct 2022 16:02:53 -0700
Subject: [PATCH 2/4] Added missing example fields

---
 docs/common_issues.rst | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/docs/common_issues.rst b/docs/common_issues.rst
index 669eab9bc..13b9ee6b9 100644
--- a/docs/common_issues.rst
+++ b/docs/common_issues.rst
@@ -303,5 +303,8 @@ As a convention, you can define a custom manager to update these timestamps auto
         pass
 
     class Poll(models.Model):
+        created_at = models.DateTimeField(auto_now_add=True)
+        updated_at = models.DateTimeField(auto_now=True)
+
         # This must be the first Manager declared in this class, otherwise it won't be detected as the `default_manager`
         objects = UpdatedAtFriendlyManager()

From b3749f469e43eb4192ff1011c00ddc89e5588e54 Mon Sep 17 00:00:00 2001
From: Todd Wolfson <todd@twolfson.com>
Date: Mon, 31 Oct 2022 16:15:02 -0700
Subject: [PATCH 3/4] Added to CHANGES.rst

---
 CHANGES.rst | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGES.rst b/CHANGES.rst
index d4e51f023..3014fa39a 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -12,6 +12,7 @@ Unreleased
 - Added ``tracked_fields`` attribute to historical models (gh-1038)
 - Fixed ``KeyError`` when running ``clean_duplicate_history`` on models with ``excluded_fields`` (gh-1038)
 - Added support for Python 3.11 (gh-1053)
+- Documented ``auto_now`` solution for ``bulk_update_with_history`` (gh-1054)
 
 3.1.1 (2022-04-23)
 ------------------

From dd38fb0ae7734149fd0df8b8d815926e746d1330 Mon Sep 17 00:00:00 2001
From: Todd Wolfson <todd@twolfson.com>
Date: Tue, 1 Nov 2022 15:26:24 -0700
Subject: [PATCH 4/4] Corrected improper models.Manager reference

---
 docs/common_issues.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/docs/common_issues.rst b/docs/common_issues.rst
index 13b9ee6b9..eb3c2545f 100644
--- a/docs/common_issues.rst
+++ b/docs/common_issues.rst
@@ -299,7 +299,7 @@ As a convention, you can define a custom manager to update these timestamps auto
             new_fields = tuple(fields) + ("updated_at",)
             super().bulk_update(objs, new_fields, *args, **kwargs)
 
-    class UpdatedAtFriendlyManager(models.manager.BaseManager.from_queryset(UpdatedAtFriendlyQuerySet)):
+    class UpdatedAtFriendlyManager(models.Manager.from_queryset(UpdatedAtFriendlyQuerySet)):
         pass
 
     class Poll(models.Model):