#508 add hasLogger method to Monolog\Registry

src/Monolog/Registry.php

@@ -63,6 +63,21 @@ class Registry
         self::$loggers[$name] = $logger;
     }
 
+    /**
+     * Checks if such logging channel exists by name or instance
+     *
+     * @param string|Logger $logger Name or logger instance
+     */
+    public static function hasLogger($logger)
+    {
+        if ($logger instanceof Logger) {
+            $index = array_search($logger, self::$loggers, true);
+            return false !== $index;
+        } else {
+            return isset(self::$loggers[$logger]);
+        }
+    }
+
     /**
      * Removes instance from registry by name or instance
      *

tests/Monolog/RegistryTest.php

@@ -0,0 +1,64 @@
+<?php
+
+/*
+ * This file is part of the Monolog package.
+ *
+ * (c) Jordi Boggiano <j.boggiano@seld.be>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Monolog;
+
+use Monolog\Logger;
+use Monolog\Registry;
+
+class RegistryTest extends \PHPUnit_Framework_TestCase
+{
+    protected function setUp()
+    {
+        Registry::clear();
+    }
+
+    /**
+     * @dataProvider hasLoggerProvider
+     * @covers Monolog\Registry::hasLogger
+     */
+    public function testHasLogger(array $loggersToAdd, array $loggersToCheck, array $expectedResult)
+    {
+        foreach ($loggersToAdd as $loggerToAdd) {
+            Registry::addLogger($loggerToAdd);
+        }
+        foreach ($loggersToCheck as $index => $loggerToCheck) {
+            $this->assertSame($expectedResult[$index], Registry::hasLogger($loggerToCheck));
+        }
+    }
+
+    public function hasLoggerProvider()
+    {
+        $logger1 = new Logger('test1');
+        $logger2 = new Logger('test2');
+        $logger3 = new Logger('test3');
+        return array(
+            // only instances
+            array(
+                array($logger1),
+                array($logger1, $logger2),
+                array(true, false),
+            ),
+            // only names
+            array(
+                array($logger1),
+                array('test1', 'test2'),
+                array(true, false),
+            ),
+            // mixed case
+            array(
+                array($logger1, $logger2),
+                array('test1', $logger2, 'test3', $logger3),
+                array(true, true, false, false),
+            ),
+        );
+    }
+}