Fix background recache clearing tags

src/Http/Middleware/CacheTracker.php

@@ -10,9 +10,10 @@
 use Statamic\Contracts\Assets\Asset;
 use Statamic\Contracts\Entries\Entry;
 use Statamic\Contracts\Globals\Variables;
+use Statamic\Facades\StaticCache;
 use Statamic\Facades\URL;
 use Statamic\Forms;
-use Statamic\StaticCaching\Cacher;
+use Statamic\StaticCaching\RecacheToken;
 use Statamic\Structures\Nav;
 use Statamic\Structures\Page;
 use Statamic\Support\Str;
@@ -42,19 +43,16 @@ public function handle($request, Closure $next)
             return $next($request);
         }
 
-        $cacher = app(Cacher::class);
-
-        if ($cacher && $cacher->hasCachedPage($request)) {
-            return $next($request);
-        }
-
         $url = $this->url();
 
         if (Str::endsWith($url, '/')) {
             $url = substr($url, 0, -1);
         }
 
-        if (Tracker::has($url)) {
+        // A background-recache request re-renders a page that is still cached, so
+        // let it through even when the URL is already tracked - this is how the
+        // stored tags get refreshed when a page's content dependencies change.
+        if (! $this->isRecacheRequest($request) && Tracker::has($url)) {
             return $next($request);
         }
 
@@ -102,6 +100,15 @@ private function isEnabled($request)
         return $request->method() === 'GET' && ! Str::startsWith($request->path(), [config('statamic.routes.action', '!').'/', config('statamic.assets.image_manipulation.route')]);
     }
 
+    private function isRecacheRequest($request): bool
+    {
+        if (! $token = $request->input(StaticCache::recacheTokenParameter())) {
+            return false;
+        }
+
+        return StaticCache::checkRecacheToken($token);
+    }
+
     private function setupAdditionalTracking()
     {
         $pipelines = Tracker::getAdditionalTrackers();
@@ -206,6 +213,10 @@ private function setupTagHooks()
 
     private function url()
     {
-        return URL::makeAbsolute(class_exists(Livewire::class) ? Livewire::originalUrl() : URL::getCurrent());
+        $url = URL::makeAbsolute(class_exists(Livewire::class) ? Livewire::originalUrl() : URL::getCurrent());
+
+        // Strip the background-recache token so a recache request keys the same
+        // entry as the original page rather than creating an orphaned one.
+        return RecacheToken::removeFromUrl($url);
     }
 }

src/Tracker/Manager.php

@@ -76,20 +76,30 @@ public function invalidate(array $tags = [])
     {
         $storeData = $this->all();
 
+        // With background recaching the page is refreshed in place rather than
+        // deleted, and the recache request re-tracks the URL with fresh tags. We
+        // keep the existing entry so that if the recache job fails or is dropped
+        // the URL stays tracked and future saves will retry it, instead of being
+        // orphaned in the static cache with no tags.
+        $keepEntries = config('statamic.static_caching.background_recache', false);
+
         $urls = [];
         foreach ($storeData as $key => $data) {
-            $storeTags = $data['tags'];
-            $url = $data['url'];
+            if (! $this->tagsMatch($tags, $data['tags'])) {
+                continue;
+            }
 
-            if ($this->tagsMatch($tags, $storeTags)) {
-                $urls[] = $url;
+            $urls[] = $data['url'];
 
+            if (! $keepEntries) {
                 unset($storeData[$key]);
             }
         }
 
         if (! empty($urls)) {
-            $this->cacheStore()->forever($this->cacheKey, $storeData);
+            if (! $keepEntries) {
+                $this->cacheStore()->forever($this->cacheKey, $storeData);
+            }
 
             $this->invalidateUrls($urls);
         }

tests/Unit/TrackerTest.php

@@ -7,6 +7,7 @@
 use PHPUnit\Framework\Attributes\Test;
 use Statamic\Console\Commands\StaticWarmJob;
 use Statamic\Events\UrlInvalidated;
+use Statamic\Facades\StaticCache;
 use Thoughtco\StatamicCacheTracker\Events\ContentTracked;
 use Thoughtco\StatamicCacheTracker\Facades\Tracker;
 use Thoughtco\StatamicCacheTracker\Tests\TestCase;
@@ -244,6 +245,44 @@ public function it_queues_a_recache_job_instead_of_invalidating_when_background_
 
         Queue::assertPushed(StaticWarmJob::class);
         Event::assertNotDispatched(UrlInvalidated::class);
-        $this->assertCount(0, Tracker::all());
+
+        // The entry is retained so that if the recache job fails or is dropped
+        // the URL stays tracked and future saves will retry it, instead of being
+        // orphaned in the static cache with no tags.
+        $this->assertCount(1, Tracker::all());
+        $this->assertSame(['pages:home', 'collection:pages'], collect(Tracker::all())->first()['tags']);
+    }
+
+    #[Test]
+    public function it_refreshes_tags_for_an_already_tracked_url_on_a_recache_request()
+    {
+        $this->get('/');
+
+        $this->assertSame(['pages:home', 'collection:pages'], collect(Tracker::all())->first()['tags']);
+
+        Tracker::addAdditionalTracker(function ($tracker, $next) {
+            $tracker->addContentTag('fresh::tag');
+        });
+
+        $token = StaticCache::recacheTokenParameter().'='.StaticCache::recacheToken();
+
+        $this->get('/?'.$token);
+
+        $this->assertCount(1, Tracker::all());
+        $this->assertSame(['fresh::tag', 'pages:home', 'collection:pages'], collect(Tracker::all())->first()['tags']);
+    }
+
+    #[Test]
+    public function it_does_not_retrack_an_already_tracked_url_on_a_normal_request()
+    {
+        $this->get('/');
+
+        Tracker::addAdditionalTracker(function ($tracker, $next) {
+            $tracker->addContentTag('fresh::tag');
+        });
+
+        $this->get('/');
+
+        $this->assertSame(['pages:home', 'collection:pages'], collect(Tracker::all())->first()['tags']);
     }
 }

tests/__fixtures__/resources/views/nav-default.antlers.html

@@ -0,0 +1,3 @@
+{{ nav }}
+    {{ title }}
+{{ /nav }}

tests/__fixtures__/resources/views/nav-test.antlers.html

@@ -0,0 +1,3 @@
+{{ nav :handle="my_nav" }}
+    {{ title }}
+{{ /nav }}