feature #12330 [Debug] DI controllable ErrorHandler::register() (nico…

…las-grekas)

This PR was merged into the 2.6-dev branch.

Discussion
----------

[Debug] DI controllable ErrorHandler::register()

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | yes
| Tests pass?   | yes
| Fixed tickets | #12327
| License       | MIT
| Doc PR        | -

This enhances the `ErrorHandler::register()` signature in a BC way, allowing greater control.

See https://github.com/symfony/symfony/pull/12330/files?w=1

Commits
-------

417f021 [Debug] DI controllable ErrorHandler::register()

src/Symfony/Bundle/FrameworkBundle/FrameworkBundle.php

@@ -47,7 +47,7 @@ class FrameworkBundle extends Bundle
 {
     public function boot()
     {
-        ErrorHandler::register($this->container->getParameter('debug.error_handler.throw_at'));
+        ErrorHandler::register(null, false)->throwAt($this->container->getParameter('debug.error_handler.throw_at'), true);
 
         if ($trustedProxies = $this->container->getParameter('kernel.trusted_proxies')) {
             Request::setTrustedProxies($trustedProxies);

src/Symfony/Component/Debug/ErrorHandler.php

@@ -110,29 +110,42 @@ class ErrorHandler
     /**
      * Registers the error handler.
      *
-     * @param int  $levels Levels to register to for throwing, 0 for none
-     * @param bool $throw  @deprecated argument, same as setting $levels to 0
+     * @param self|null|int $handler The handler to register, or @deprecated (since 2.6, to be removed in 3.0) bit field of thrown levels
+     * @param bool          $replace Whether to replace or not any existing handler
      *
-     * @return ErrorHandler The registered error handler
+     * @return self The registered error handler
      */
-    public static function register($levels = -1, $throw = true)
+    public static function register($handler = null, $replace = true)
     {
         if (null === self::$reservedMemory) {
             self::$reservedMemory = str_repeat('x', 10240);
             register_shutdown_function(__CLASS__.'::handleFatalError');
         }
 
-        $handler = new static();
-        $levels &= $handler->thrownErrors;
-        $prev = set_error_handler(array($handler, 'handleError'), $levels);
-        $prev = is_array($prev) ? $prev[0] : null;
-        if ($prev instanceof self) {
-            restore_error_handler();
-            $handler = $prev;
-        } else {
+        $levels = -1;
+
+        if ($handlerIsNew = !$handler instanceof self) {
+            // @deprecated polymorphism, to be removed in 3.0
+            if (null !== $handler) {
+                $levels = $replace ? $handler : 0;
+                $replace = true;
+            }
+            $handler = new static();
+        }
+
+        $prev = set_error_handler(array($handler, 'handleError'), $handler->thrownErrors | $handler->loggedErrors);
+
+        if ($handlerIsNew && is_array($prev) && $prev[0] instanceof self) {
+            $handler = $prev[0];
+            $replace = false;
+        }
+        if ($replace || !$prev) {
             $handler->setExceptionHandler(set_exception_handler(array($handler, 'handleException')));
+        } else {
+            restore_error_handler();
         }
-        $handler->throwAt($throw ? $levels : 0, true);
+
+        $handler->throwAt($levels & $handler->thrownErrors, true);
 
         return $handler;
     }

src/Symfony/Component/Debug/Tests/ErrorHandlerTest.php

@@ -52,12 +52,28 @@ public function testRegister()
 
         try {
             $this->assertInstanceOf('Symfony\Component\Debug\ErrorHandler', $handler);
+            $this->assertSame($handler, ErrorHandler::register());
+
+            $newHandler = new ErrorHandler();
+
+            $this->assertSame($newHandler, ErrorHandler::register($newHandler, false));
+            $h = set_error_handler('var_dump');
+            restore_error_handler();
+            $this->assertSame(array($handler, 'handleError'), $h);
 
             try {
-                $this->assertSame($handler, ErrorHandler::register());
-            } catch (\Exception $e) {
+                $this->assertSame($newHandler, ErrorHandler::register($newHandler, true));
+                $h = set_error_handler('var_dump');
                 restore_error_handler();
-                restore_exception_handler();
+                $this->assertSame(array($newHandler, 'handleError'), $h);
+            } catch (\Exception $e) {
+            }
+
+            restore_error_handler();
+            restore_exception_handler();
+
+            if (isset($e)) {
+                throw $e;
             }
         } catch (\Exception $e) {
         }
@@ -121,7 +137,9 @@ private static function triggerNotice($that)
     public function testConstruct()
     {
         try {
-            $this->assertEquals(3 | E_RECOVERABLE_ERROR | E_USER_ERROR, ErrorHandler::register(3)->throwAt(0));
+            $handler = ErrorHandler::register();
+            $handler->throwAt(3, true);
+            $this->assertEquals(3 | E_RECOVERABLE_ERROR | E_USER_ERROR, $handler->throwAt(0));
 
             restore_error_handler();
             restore_exception_handler();
@@ -175,19 +193,22 @@ public function testDefaultLogger()
     public function testHandleError()
     {
         try {
-            $handler = ErrorHandler::register(0);
+            $handler = ErrorHandler::register();
+            $handler->throwAt(0, true);
             $this->assertFalse($handler->handleError(0, 'foo', 'foo.php', 12, array()));
 
             restore_error_handler();
             restore_exception_handler();
 
-            $handler = ErrorHandler::register(3);
+            $handler = ErrorHandler::register();
+            $handler->throwAt(3, true);
             $this->assertFalse($handler->handleError(4, 'foo', 'foo.php', 12, array()));
 
             restore_error_handler();
             restore_exception_handler();
 
-            $handler = ErrorHandler::register(3);
+            $handler = ErrorHandler::register();
+            $handler->throwAt(3, true);
             try {
                 $handler->handleError(4, 'foo', 'foo.php', 12, array());
             } catch (\ErrorException $e) {
@@ -200,13 +221,15 @@ public function testHandleError()
             restore_error_handler();
             restore_exception_handler();
 
-            $handler = ErrorHandler::register(E_USER_DEPRECATED);
+            $handler = ErrorHandler::register();
+            $handler->throwAt(E_USER_DEPRECATED, true);
             $this->assertFalse($handler->handleError(E_USER_DEPRECATED, 'foo', 'foo.php', 12, array()));
 
             restore_error_handler();
             restore_exception_handler();
 
-            $handler = ErrorHandler::register(E_DEPRECATED);
+            $handler = ErrorHandler::register();
+            $handler->throwAt(E_DEPRECATED, true);
             $this->assertFalse($handler->handleError(E_DEPRECATED, 'foo', 'foo.php', 12, array()));
 
             restore_error_handler();
@@ -230,7 +253,7 @@ public function testHandleError()
                 ->will($this->returnCallback($warnArgCheck))
             ;
 
-            $handler = ErrorHandler::register(E_USER_DEPRECATED);
+            $handler = ErrorHandler::register();
             $handler->setDefaultLogger($logger, E_USER_DEPRECATED);
             $this->assertTrue($handler->handleError(E_USER_DEPRECATED, 'foo', 'foo.php', 12, array()));
 
@@ -252,7 +275,7 @@ public function testHandleError()
                 ->will($this->returnCallback($logArgCheck))
             ;
 
-            $handler = ErrorHandler::register(E_NOTICE);
+            $handler = ErrorHandler::register();
             $handler->setDefaultLogger($logger, E_NOTICE);
             $handler->screamAt(E_NOTICE);
             unset($undefVar);
@@ -357,7 +380,7 @@ public function testHandleFatalError()
         }
     }
 
-    public function testDeprecated()
+    public function testDeprecatedInterface()
     {
         try {
             $handler = ErrorHandler::register(0);