Fix unrecognized NO_LOG option

Author: z4kn4fein

src/Log/LogLevel.php

@@ -31,6 +31,7 @@ public static function isValid($level): bool
             $level == self::ERROR ||
             $level == self::CRITICAL ||
             $level == self::ALERT ||
-            $level == self::EMERGENCY;
+            $level == self::EMERGENCY ||
+            $level == self::NO_LOG;
     }
 }

tests/LoggerTest.php

@@ -2,6 +2,8 @@
 
 namespace ConfigCat\Tests;
 
+use ConfigCat\ClientOptions;
+use ConfigCat\ConfigCatClient;
 use ConfigCat\Hooks;
 use ConfigCat\Log\InternalLogger;
 use ConfigCat\Log\LogLevel;
@@ -443,6 +445,50 @@ public function testLoggerNoLog()
         $logger->warning("");
     }
 
+    public function testClientNoLog()
+    {
+        $mockLogger = $this->getMockBuilder(LoggerInterface::class)->getMock();
+
+        $client = new ConfigCatClient("not-existing", [
+           ClientOptions::LOGGER => $mockLogger,
+           ClientOptions::LOG_LEVEL => LogLevel::NO_LOG
+        ]);
+
+        $mockLogger
+            ->expects(self::never())
+            ->method("emergency");
+
+        $mockLogger
+            ->expects(self::never())
+            ->method("alert");
+
+        $mockLogger
+            ->expects(self::never())
+            ->method("critical");
+
+        $mockLogger
+            ->expects(self::never())
+            ->method("error");
+
+        $mockLogger
+            ->expects(self::never())
+            ->method("warning");
+
+        $mockLogger
+            ->expects(self::never())
+            ->method("notice");
+
+        $mockLogger
+            ->expects(self::never())
+            ->method("info");
+
+        $mockLogger
+            ->expects(self::never())
+            ->method("debug");
+
+        $client->getValue("fake", false);
+    }
+
     public function testLoggerBypassesLogWhenExceptionIsIgnored()
     {
         $mockLogger = $this->getMockBuilder(LoggerInterface::class)->getMock();