Fix Carbon::$toStringFormat error when using Carbon 3 (#195)

Author: duncanmcclean

src/Generator.php

@@ -8,8 +8,10 @@
 use Illuminate\Filesystem\Filesystem;
 use Illuminate\Routing\Router;
 use Illuminate\Support\Arr;
+use Illuminate\Support\Facades\Date;
 use League\Flysystem\Filesystem as Flysystem;
 use League\Flysystem\Local\LocalFilesystemAdapter;
+use ReflectionClass;
 use Statamic\Contracts\Imaging\UrlBuilder;
 use Statamic\Facades\Blink;
 use Statamic\Facades\Collection;
@@ -266,8 +268,7 @@ protected function makeContentGenerationClosures($pages, $request)
                 $errors = [];
 
                 foreach ($pages as $page) {
-                    // There is no getter method, so use reflection.
-                    $oldCarbonFormat = (new \ReflectionClass(Carbon::class))->getStaticPropertyValue('toStringFormat');
+                    $oldCarbonFormat = $this->getToStringFormat();
 
                     if ($this->shouldSetCarbonFormat($page)) {
                         Carbon::setToStringFormat(Statamic::dateFormat());
@@ -481,4 +482,29 @@ protected function shouldRejectPage($page, $outputError = false)
 
         return $excluded;
     }
+
+    /**
+     * This method is used to get the current toStringFormat for Carbon, in order for us
+     * to restore it later. There's no getter for it, so we need to use reflection.
+     *
+     * @throws \ReflectionException
+     */
+    protected function getToStringFormat(): ?string
+    {
+        $reflection = new ReflectionClass($date = Date::now());
+
+        // Carbon 2.x
+        if ($reflection->hasProperty('toStringFormat')) {
+            $format = $reflection->getProperty('toStringFormat');
+            $format->setAccessible(true);
+
+            return $format->getValue();
+        }
+
+        // Carbon 3.x
+        $factory = $reflection->getMethod('getFactory');
+        $factory->setAccessible(true);
+
+        return Arr::get($factory->invoke($date)->getSettings(), 'toStringFormat');
+    }
 }