Updated not-found image path handling to have better ux

Added test to cover.
Started refactoring some of the app error handling in
the process of this.

Fixes #2696

app/Exceptions/Handler.php

@@ -68,19 +68,6 @@ class Handler extends ExceptionHandler
             return redirect($e->redirectLocation);
         }
 
-        // Handle pretty exceptions which will show a friendly application-fitting page
-        // Which will include the basic message to point the user roughly to the cause.
-        if ($this->isExceptionType($e, PrettyException::class)  && !config('app.debug')) {
-            $message = $this->getOriginalMessage($e);
-            $code = ($e->getCode() === 0) ? 500 : $e->getCode();
-            return response()->view('errors/' . $code, ['message' => $message], $code);
-        }
-
-        // Handle 404 errors with a loaded session to enable showing user-specific information
-        if ($this->isExceptionType($e, NotFoundHttpException::class)) {
-            return \Route::respondWithRoute('fallback');
-        }
-
         return parent::render($request, $e);
     }
 

app/Exceptions/PrettyException.php

@@ -1,6 +1,44 @@
 <?php namespace BookStack\Exceptions;
 
-class PrettyException extends \Exception
-{
+use Exception;
+use Illuminate\Contracts\Support\Responsable;
+use Illuminate\Http\Request;
 
+class PrettyException extends Exception implements Responsable
+{
+    /**
+     * @var ?string
+     */
+    protected $subtitle = null;
+
+    /**
+     * @var ?string
+     */
+    protected $details = null;
+
+    /**
+     * Render a response for when this exception occurs.
+     * @param Request $request
+     */
+    public function toResponse($request)
+    {
+        $code = ($this->getCode() === 0) ? 500 : $this->getCode();
+        return response()->view('errors.' . $code, [
+            'message' => $this->getMessage(),
+            'subtitle' => $this->subtitle,
+            'details' => $this->details,
+        ], $code);
+    }
+
+    public function setSubtitle(string $subtitle): self
+    {
+        $this->subtitle = $subtitle;
+        return $this;
+    }
+
+    public function setDetails(string $details): self
+    {
+        $this->details = $details;
+        return $this;
+    }
 }

app/Http/Controllers/Images/ImageController.php

@@ -1,6 +1,7 @@
 <?php namespace BookStack\Http\Controllers\Images;
 
 use BookStack\Exceptions\ImageUploadException;
+use BookStack\Exceptions\NotFoundException;
 use BookStack\Http\Controllers\Controller;
 use BookStack\Uploads\Image;
 use BookStack\Uploads\ImageRepo;
@@ -27,12 +28,15 @@ class ImageController extends Controller
 
     /**
      * Provide an image file from storage.
+     * @throws NotFoundException
      */
     public function showImage(string $path)
     {
         $path = storage_path('uploads/images/' . $path);
         if (!file_exists($path)) {
-            abort(404);
+            throw (new NotFoundException(trans('errors.image_not_found')))
+                ->setSubtitle(trans('errors.image_not_found_subtitle'))
+                ->setDetails(trans('errors.image_not_found_details'));
         }
 
         return response()->file($path);