Unify validation exception formatting. (#20173)

* Unify validation exception formatting.

This unifies all validation error formatting into the exception handler
and out of Form Request. “Don’t Flash” is typically a global concept
that always applies to a list of fields for all pages in the
applications, so seemed to make sense to specify in one place instead
of each form.

Total control of the Form Request error response can still be gained by
overriding failedValidation and throwing a HttpResponseException with
whatever response you want.

* Apply fixes from StyleCI (#20174)

* shorten method call

* remove old test

* Apply fixes from StyleCI (#20175)

src/Illuminate/Foundation/Exceptions/Handler.php

@@ -41,7 +41,7 @@ class Handler implements ExceptionHandlerContract
     protected $container;
 
     /**
-     * A list of the exception types that should not be reported.
+     * A list of the exception types that are not reported.
      *
      * @var array
      */
@@ -62,6 +62,16 @@ class Handler implements ExceptionHandlerContract
         \Illuminate\Validation\ValidationException::class,
     ];
 
+    /**
+     * A list of the inputs that are never flashed for validation exceptions.
+     *
+     * @var array
+     */
+    protected $dontFlash = [
+        'password',
+        'password_confirmation',
+    ];
+
     /**
      * Create a new exception handler instance.
      *
@@ -222,27 +232,28 @@ protected function convertValidationExceptionToResponse(ValidationException $e,
      */
     protected function invalid($request, ValidationException $exception)
     {
-        return redirect()->back()->withInput($request->except([
-            'password',
-            'password_confirmation',
-        ]))->withErrors(
-            $exception->validator->errors()->messages(),
-            $exception->errorBag
-        );
+        $url = $exception->redirectTo ?? url()->previous();
+
+        return redirect($url)
+                ->withInput($request->except($this->dontFlash))
+                ->withErrors(
+                    $exception->errors(),
+                    $exception->errorBag
+                );
     }
 
     /**
      * Convert a validation exception into a JSON response.
      *
      * @param  \Illuminate\Http\Request  $request
      * @param  \Illuminate\Validation\ValidationException  $exception
-     * @return \Illuminate\Http\Response
+     * @return \Illuminate\Http\JsonResponse
      */
     protected function invalidJson($request, ValidationException $exception)
     {
         return response()->json([
             'message' => $exception->getMessage(),
-            'errors' => $exception->validator->errors()->messages(),
+            'errors' => $exception->errors(),
         ], 422);
     }
 

src/Illuminate/Foundation/Http/FormRequest.php

@@ -3,7 +3,6 @@
 namespace Illuminate\Foundation\Http;
 
 use Illuminate\Http\Request;
-use Illuminate\Http\JsonResponse;
 use Illuminate\Routing\Redirector;
 use Illuminate\Contracts\Container\Container;
 use Illuminate\Contracts\Validation\Validator;
@@ -59,13 +58,6 @@ class FormRequest extends Request implements ValidatesWhenResolved
      */
     protected $errorBag = 'default';
 
-    /**
-     * The input keys that should not be flashed on redirect.
-     *
-     * @var array
-     */
-    protected $dontFlash = ['password', 'password_confirmation'];
-
     /**
      * Get the validator instance for the request.
      *
@@ -122,51 +114,9 @@ protected function validationData()
      */
     protected function failedValidation(Validator $validator)
     {
-        throw new ValidationException($validator, $this->response(
-            $this->formatErrors($validator)
-        ));
-    }
-
-    /**
-     * Get the proper failed validation response for the request.
-     *
-     * @param  array  $errors
-     * @return \Symfony\Component\HttpFoundation\Response
-     */
-    public function response(array $errors)
-    {
-        if ($this->expectsJson()) {
-            return $this->jsonResponse($errors);
-        }
-
-        return $this->redirector->to($this->getRedirectUrl())
-                        ->withInput($this->except($this->dontFlash))
-                        ->withErrors($errors, $this->errorBag);
-    }
-
-    /**
-     * Get the proper failed validation JSON response for the request.
-     *
-     * @param  array  $errors
-     * @return \Illuminate\Http\JsonResponse
-     */
-    public function jsonResponse(array $errors)
-    {
-        return new JsonResponse([
-            'message' => 'The given data was invalid.',
-            'errors' => $errors,
-        ], 422);
-    }
-
-    /**
-     * Format the errors from the given Validator instance.
-     *
-     * @param  \Illuminate\Contracts\Validation\Validator  $validator
-     * @return array
-     */
-    protected function formatErrors(Validator $validator)
-    {
-        return $validator->getMessageBag()->toArray();
+        throw (new ValidationException($validator))
+                    ->errorBag($this->errorBag)
+                    ->redirectTo($this->getRedirectUrl());
     }
 
     /**

src/Illuminate/Validation/ValidationException.php

@@ -27,6 +27,13 @@ class ValidationException extends Exception
      */
     public $errorBag;
 
+    /**
+     * The path the client should be redirected to.
+     *
+     * @var string
+     */
+    public $redirectTo;
+
     /**
      * Create a new exception instance.
      *
@@ -44,6 +51,42 @@ public function __construct($validator, $response = null, $errorBag = 'default')
         $this->validator = $validator;
     }
 
+    /**
+     * Get all of the validation error messages.
+     *
+     * @return array
+     */
+    public function errors()
+    {
+        return $this->validator->errors()->messages();
+    }
+
+    /**
+     * Set the error bag on the exception.
+     *
+     * @param  string  $errorBag
+     * @return $this
+     */
+    public function errorBag($errorBag)
+    {
+        $this->errorBag = $errorBag;
+
+        return $this;
+    }
+
+    /**
+     * Set the URL to redirect to on a validation error.
+     *
+     * @param  string  $url
+     * @return string
+     */
+    public function redirectTo($url)
+    {
+        $this->redirectTo = $url;
+
+        return $this;
+    }
+
     /**
      * Get the underlying response instance.
      *

tests/Foundation/FoundationFormRequestTest.php

@@ -10,7 +10,6 @@
 use Illuminate\Routing\UrlGenerator;
 use Illuminate\Http\RedirectResponse;
 use Illuminate\Foundation\Http\FormRequest;
-use Illuminate\Validation\ValidationException;
 use Illuminate\Contracts\Translation\Translator;
 use Illuminate\Validation\Factory as ValidationFactory;
 use Illuminate\Contracts\Validation\Factory as ValidationFactoryContract;
@@ -56,24 +55,6 @@ public function test_validate_method_throws_when_authorization_fails()
         $this->createRequest([], FoundationTestFormRequestForbiddenStub::class)->validate();
     }
 
-    public function test_redirect_response_is_properly_created_with_given_errors()
-    {
-        $request = $this->createRequest();
-
-        $this->mocks['redirect']->shouldReceive('withInput')->andReturnSelf();
-
-        $this->mocks['redirect']
-             ->shouldReceive('withErrors')
-             ->with(['name' => ['error']], 'default')
-             ->andReturnSelf();
-
-        $e = $this->catchException(ValidationException::class, function () use ($request) {
-            $request->validate();
-        });
-
-        $this->assertInstanceOf(RedirectResponse::class, $e->getResponse());
-    }
-
     public function test_prepare_for_validation_runs_before_validation()
     {
         $this->createRequest([], FoundationTestFormRequestHooks::class)->validate();