Deprecate SERVE_LATEST_DRAFT_PAGES setting

This commit deprecates the `SERVE_LATEST_DRAFT_PAGES` that allows for
arbitrary serving of draft Wagtail page content by primary key. This
functionality was added in 2017 in commit
e8902bd for a few pages and then
turned off for those pages in 2018 in commit
ae0156d. It hasn't been used since.

We now use wagtail-sharing to provide this functionality instead.

cfgov/cfgov/settings/base.py

@@ -642,15 +642,6 @@
     "ROBOTS_TXT_SEARCH_GOV_ONLY": [("environment is", "beta")],
 }
 
-# We want the ability to serve the latest drafts of some pages on beta
-# This value is read by v1.wagtail_hooks
-SERVE_LATEST_DRAFT_PAGES = []
-
-# To expose a previously-published page's latest draft version on beta,
-# add its primary key to the list below
-if DEPLOY_ENVIRONMENT == "beta":
-    SERVE_LATEST_DRAFT_PAGES = []
-
 # Email popup configuration. See v1.templatetags.email_popup.
 EMAIL_POPUP_URLS = {
     "debt": [

cfgov/v1/tests/test_wagtail_hooks.py

@@ -1,18 +1,12 @@
 from django.contrib.auth.models import Permission, User
 from django.core.exceptions import PermissionDenied
-from django.test import (
-    RequestFactory,
-    SimpleTestCase,
-    TestCase,
-    override_settings,
-)
+from django.test import RequestFactory, SimpleTestCase, TestCase
 from django.urls import reverse
 
 from wagtail import hooks
 from wagtail.admin.views.pages.bulk_actions.delete import DeleteBulkAction
 from wagtail.admin.views.pages.delete import delete
-from wagtail.models import Page, Site
-from wagtail.test.testapp.models import SimplePage
+from wagtail.models import Page
 from wagtail.test.utils import WagtailTestUtils
 from wagtail.whitelist import Whitelister as Allowlister
 
@@ -27,27 +21,6 @@
 )
 
 
-class TestServeLatestDraftPage(TestCase):
-    def setUp(self):
-        self.default_site = Site.objects.get(is_default_site=True)
-        self.page = SimplePage(title="live", slug="test", content="test")
-        self.default_site.root_page.add_child(instance=self.page)
-        self.page.title = "draft"
-        self.page.save_revision()
-
-    @override_settings(SERVE_LATEST_DRAFT_PAGES=[])
-    def test_not_serving_draft_serves_published_revision(self):
-        response = self.client.get("/test/")
-        self.assertContains(response, "live")
-        self.assertIsNone(response.get("Serving-Wagtail-Draft"))
-
-    def test_serving_draft_serves_latest_revision_and_adds_header(self):
-        with override_settings(SERVE_LATEST_DRAFT_PAGES=[self.page.pk]):
-            response = self.client.get("/test/")
-            self.assertContains(response, "draft")
-            self.assertEqual(response["Serving-Wagtail-Draft"], "1")
-
-
 class TestGetResourceTags(TestCase):
     def setUp(self):
         self.resource1 = Resource.objects.create(title="Test resource 1")

cfgov/v1/wagtail_hooks.py

@@ -179,15 +179,6 @@ def register_cdn_url():
     ]
 
 
-@hooks.register("before_serve_page")
-def serve_latest_draft_page(page, request, args, kwargs):
-    if page.pk in settings.SERVE_LATEST_DRAFT_PAGES:
-        latest_draft = page.get_latest_revision_as_object()
-        response = latest_draft.serve(request, *args, **kwargs)
-        response["Serving-Wagtail-Draft"] = "1"
-        return response
-
-
 @hooks.register("register_reports_menu_item")
 def register_page_metadata_report_menu_item():
     return MenuItem(