From ee54398a9f38abfda4d05a33a994258168fae876 Mon Sep 17 00:00:00 2001
From: Tony McDonald <anthony.mcdonald@digital.cabinet-office.gov.uk>
Date: Mon, 15 Jun 2026 12:00:53 +0100
Subject: [PATCH] Fall back to draft content store for unpublished document
 collection links

Adding a not-yet-published GOV.UK URL to a document collection group
failed with "Url must reference a GOV.UK page", because the link
validation only queries the live content store, which holds published
content only.

Fall back to the draft content store when the live content store returns
a 404, so unpublished URLs resolve again. The live store is still queried
first, preserving locale-agnostic lookups (e.g. Welsh pages), and the
draft store handles drafts in any locale.

Add Services.draft_content_store, authenticated with a dedicated
DRAFT_CONTENT_STORE_BEARER_TOKEN, as the draft content store serves
non-public content and requires a Signon bearer token.
---
 .../govuk_url.rb                              |  9 +++++++-
 lib/services.rb                               |  7 +++++++
 .../govuk_url_test.rb                         | 21 ++++++++++++++++++-
 3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/app/models/document_collection_non_whitehall_link/govuk_url.rb b/app/models/document_collection_non_whitehall_link/govuk_url.rb
index 011cfdebd0a..13bd46fc25b 100644
--- a/app/models/document_collection_non_whitehall_link/govuk_url.rb
+++ b/app/models/document_collection_non_whitehall_link/govuk_url.rb
@@ -41,7 +41,7 @@ def content_id
   def content_item_from_content_store
     path = parsed_url.path
 
-    item = Services.content_store.content_item(path).to_h
+    item = content_item_for(path)
 
     if item["base_path"] != path && item["document_type"] != "guide"
       raise GdsApi::HTTPNotFound, 404
@@ -51,4 +51,11 @@ def content_item_from_content_store
   rescue GdsApi::ContentStore::ItemNotFound
     raise GdsApi::HTTPNotFound, 404
   end
+
+  def content_item_for(path)
+    Services.content_store.content_item(path).to_h
+  rescue GdsApi::ContentStore::ItemNotFound
+    # Fall back to the draft content store for unpublished content
+    Services.draft_content_store.content_item(path).to_h
+  end
 end
diff --git a/lib/services.rb b/lib/services.rb
index 08e899db84d..10ce79cc87b 100644
--- a/lib/services.rb
+++ b/lib/services.rb
@@ -16,6 +16,13 @@ def self.content_store
     @content_store ||= GdsApi::ContentStore.new(Plek.find("content-store"))
   end
 
+  def self.draft_content_store
+    @draft_content_store ||= GdsApi::ContentStore.new(
+      Plek.find("draft-content-store"),
+      bearer_token: ENV.fetch("DRAFT_CONTENT_STORE_BEARER_TOKEN", "example"),
+    )
+  end
+
   def self.asset_manager
     @asset_manager ||= GdsApi::AssetManager.new(
       Plek.find("asset-manager"),
diff --git a/test/unit/app/models/document_collection_non_whitehall_link/govuk_url_test.rb b/test/unit/app/models/document_collection_non_whitehall_link/govuk_url_test.rb
index 463f8d92d59..8726848c63e 100644
--- a/test/unit/app/models/document_collection_non_whitehall_link/govuk_url_test.rb
+++ b/test/unit/app/models/document_collection_non_whitehall_link/govuk_url_test.rb
@@ -98,8 +98,27 @@ class DocumentCollectionNonWhitehallLink::GovukUrlTest < ActiveSupport::TestCase
     assert url.valid?
   end
 
-  test "should be invalid when content store returns a 404" do
+  test "should be valid for an unpublished URL found only in the draft content store" do
+    draft_content_id = SecureRandom.uuid
+    Services.content_store.stubs(:content_item).with("/unpublished").raises(GdsApi::ContentStore::ItemNotFound.new(404))
+    Services.draft_content_store.stubs(:content_item).with("/unpublished").returns(
+      "content_id" => draft_content_id,
+      "title" => "Unpublished",
+      "base_path" => "/unpublished",
+      "publishing_app" => "whitehall",
+    )
+
+    url = DocumentCollectionNonWhitehallLink::GovukUrl.new(
+      url: "https://www.gov.uk/unpublished",
+      document_collection_group: build(:document_collection_group),
+    )
+
+    assert url.valid?
+  end
+
+  test "should be invalid when neither content store has the path" do
     Services.content_store.stubs(:content_item).raises(GdsApi::ContentStore::ItemNotFound.new(404))
+    Services.draft_content_store.stubs(:content_item).raises(GdsApi::ContentStore::ItemNotFound.new(404))
 
     url = DocumentCollectionNonWhitehallLink::GovukUrl.new(
       url: "https://www.gov.uk/test",