Hook to get the page template that is in use on the admin page edit screen?

I would like to find out which page template is in use as I only want to enqueue some javascript if the page is using a certain template. Is this possible?

I’m not sure if this is for front end or back end, so I’m going to handle both.

BACK END

You can make use of get_current_screen() or the $pagenow global. Here are two examples which you can add in a plugin or in your functions.php to check the relevant info on an admin page

add_action( 'current_screen', function ( $current_screen )
{
    ?><pre><?php var_dump($current_screen); ?></pre><?php   

});

and

add_action( 'admin_head', function ()
{
    global $pagenow;

    ?><pre><?php var_dump($pagenow); ?></pre><?php  

});

Once you have the name of the specific admin page, you can do the following

add_action( 'admin_enqueue_scripts', function ( $hook ) 
{
    if ( 'some-page.php' === $hook ) {
        // Add your scripts
    }
});

FRONT END

As birgire pointed out, if you need to know this on front end, you can simply test this with is_page_template( 'some-template.php' )

add_action( 'wp_enqueue_scripts', function ()
{
    if ( is_page_template( 'some-template.php' ) ) {
        // Enqueue your script
    }
});