PhpBrew\Extension\ExtensionFactory::lookup PHP Method

    public static function lookup($packageName, array $lookupDirectories = array(), $fallback = true)
    {
        if ($fallback) {
            // Always push the PHP source directory to the end of the list for the fallback.
            $lookupDirectories[] = Config::getBuildDir() . '/' . Config::getCurrentPhpName() . '/ext';
        }
        foreach ($lookupDirectories as $lookupDir) {
            if (!file_exists($lookupDir)) {
                continue;
            }
            $extensionDir = $lookupDir . DIRECTORY_SEPARATOR . $packageName;
            if ($ext = self::createFromDirectory($packageName, $extensionDir)) {
                return $ext;
            }
        }
        return new Extension($packageName);
    }

 /**
  * @dataProvider packageNameProvider
  */
 public function testInstallPackages($extensionName, $extensionVersion = 'latest')
 {
     $logger = new Logger();
     $logger->setDebug();
     $manager = new ExtensionManager($logger);
     $peclProvider = new PeclProvider();
     $downloader = new ExtensionDownloader($logger, new OptionResult());
     $peclProvider->setPackageName($extensionName);
     $downloader->download($peclProvider, $extensionVersion);
     $ext = ExtensionFactory::lookup($extensionName);
     $this->assertNotNull($ext);
     $manager->installExtension($ext, array());
 }