src/Composer/Installer/LibraryInstaller.php
protected function getPackageBasePath(PackageInterface $package)
    {
        $installPath = $this->getInstallPath($package);
        $targetDir = $package->getTargetDir();

        if ($targetDir) {
            return preg_replace('{/*'.str_replace('/', '/+', preg_quote($targetDir)).'/?$}', '', $installPath);
        }

        return $installPath;
    }
protected function getPackageBasePath(PackageInterface $package)
    {
        $installPath = $this->getInstallPath($package);
        $targetDir = $package->getTargetDir();

        if ($targetDir) {
            return preg_replace('{/*'.str_replace('/', '/+', preg_quote($targetDir)).'/?$}', '', $installPath);
        }

        return $installPath;
    }
protected function getPackageBasePath ( PackageInterface $ package ) { $ installPath = $ this -> getInstallPath ( $ package ) ; $ targetDir = $ package -> getTargetDir ( ) ; if ( $ targetDir ) { return preg_replace ( '{/*' . str_replace ( '/' , '/+' , preg_quote ( $ targetDir ) ) . '/?$}' , '' , $ installPath ) ; } return $ installPath ; }
Returns the base path of the package without target-dir path

It is used for BC as getInstallPath tends to be overridden by
installer plugins but not getPackageBasePath

@param  PackageInterface $package
@return string
Returns the base path of the package without target - dir path