Added the NoopHandler.

This handler handles anything, but does nothing, and does not stop bubbling to the rest of the stack.

This can be used for testing, or to disable a handler when overriding a configuration without influencing the rest of the stack.

tests/Monolog/Handler/NoopHandlerTest.php

@@ -0,0 +1,59 @@
+<?php declare(strict_types=1);
+
+/*
+ * This file is part of the Monolog package.
+ *
+ * (c) Roel Harbers <roelharbers@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Monolog\Handler;
+
+use Monolog\Test\TestCase;
+use Monolog\Logger;
+
+/**
+ * @covers Monolog\Handler\NoopHandler::handle
+ */
+class NoopHandlerTest extends TestCase
+{
+    /**
+     * @dataProvider logLevelsProvider
+     */
+    public function testIsHandling($level)
+    {
+        $handler = new NoopHandler();
+        $this->assertTrue($handler->isHandling($this->getRecord($level)));
+    }
+
+    public function isHandleProvider()
+    {
+        return array_map(
+            function ($level) {
+                return [$level];
+            },
+            array_values(Logger::getLevels())
+        );
+    }
+
+    /**
+     * @dataProvider logLevelsProvider
+     */
+    public function testHandle($level)
+    {
+        $handler = new NoopHandler();
+        $this->assertFalse($handler->handle($this->getRecord($level)));
+    }
+
+    public function logLevelsProvider()
+    {
+        return array_map(
+            function ($level) {
+                return [$level];
+            },
+            array_values(Logger::getLevels())
+        );
+    }
+}