error handling when extending flarum from extensions fails (#2740)

src/Extension/Exception/ExtensionBootError.php

@@ -0,0 +1,30 @@
+<?php
+
+/*
+ * This file is part of Flarum.
+ *
+ * For detailed copyright and license information, please view the
+ * LICENSE file that was distributed with this source code.
+ */
+
+namespace Flarum\Extension\Exception;
+
+use Exception;
+use Flarum\Extension\Extension;
+use Throwable;
+
+class ExtensionBootError extends Exception
+{
+    public $extension;
+    public $extender;
+
+    public function __construct(Extension $extension, $extender, Throwable $previous = null)
+    {
+        $this->extension = $extension;
+        $this->extender = $extender;
+
+        $extenderClass = get_class($extender);
+
+        parent::__construct("Experienced an error while booting extension: {$extension->getTitle()}.\n\nError occurred while applying an extender of type: $extenderClass.", null, $previous);
+    }
+}

src/Extension/Extension.php

@@ -11,6 +11,7 @@ namespace Flarum\Extension;
 
 use Flarum\Database\Migrator;
 use Flarum\Extend\LifecycleInterface;
+use Flarum\Extension\Exception\ExtensionBootError;
 use Illuminate\Contracts\Container\Container;
 use Illuminate\Contracts\Filesystem\Filesystem as FilesystemInterface;
 use Illuminate\Contracts\Support\Arrayable;
@@ -18,6 +19,7 @@ use Illuminate\Filesystem\Filesystem;
 use Illuminate\Support\Arr;
 use Illuminate\Support\Collection;
 use Illuminate\Support\Str;
+use Throwable;
 
 /**
  * @property string $name
@@ -50,7 +52,7 @@ class Extension implements Arrayable
 
     protected static function nameToId($name)
     {
-        list($vendor, $package) = explode('/', $name);
+        [$vendor, $package] = explode('/', $name);
         $package = str_replace(['flarum-ext-', 'flarum-'], '', $package);
 
         return "$vendor-$package";
@@ -131,7 +133,11 @@ class Extension implements Arrayable
     public function extend(Container $container)
     {
         foreach ($this->getExtenders() as $extender) {
-            $extender->extend($container, $this);
+            try {
+                $extender->extend($container, $this);
+            } catch (Throwable $e) {
+                throw new ExtensionBootError($this, $extender, $e);
+            }
         }
     }