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.

doc/02-handlers-formatters-processors.md

@@ -113,6 +113,8 @@
    to the wrapped handler.
 - [_SamplingHandler_](../src/Monolog/Handler/SamplingHandler.php): Wraps around another handler and lets you sample records
    if you only want to store some of them.
+- [_NoopHandler_](../src/Monolog/Handler/NoopHandler.php): This handler handles anything by doing nothing. It does not stop
+  processing the rest of the stack. This can be used for testing, or to disable a handler when overriding a configuration.
 - [_NullHandler_](../src/Monolog/Handler/NullHandler.php): Any record it can handle will be thrown away. This can be used
   to put on top of an existing handler stack to disable it temporarily.
 - [_PsrHandler_](../src/Monolog/Handler/PsrHandler.php): Can be used to forward log records to an existing PSR-3 logger

src/Monolog/Handler/NoopHandler.php

@@ -0,0 +1,42 @@
+<?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\Logger;
+
+/**
+ * No-op
+ *
+ * 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.
+ *
+ * @author Roel Harbers <roelharbers@gmail.com>
+ */
+class NoopHandler extends Handler
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function isHandling(array $record): bool
+    {
+        return true;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function handle(array $record): bool
+    {
+        return false;
+    }
+}

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())
+        );
+    }
+}