Restrictions: For this exercise you must use an Express$-$server. You cannot use Express' static

middleware or any other third$-$party middleware.

Create a server that answers to calls to any url of the form $/$public$/$somefile$.$ext $($where somefile.ext is

a filename put in by the user, for example the regularly used "deer.jpg$")$ by either:

If the requested url is for a jpg: Send an image to the browser from a folder $"./$public$"$

In all other cases: Triggers a download at the browser so that the requested file from the

$"./$public$"-$folder can be saved to the user's system.

You are asked to do this in two different ways. First: Deliberately not use the root option of

res.sendFile and res.download. Second: By using the root option. For both cases try to download the

actual JS$-$file that contains the code of your server by moving outside of the $"./$public$"$ folder!

Provide the URL$-$string that makes this possible $($when not using the root$-$option in your code$)$ as a

comment.

Hint: To trick your server to go outside the $"./$public$"$ folder you need to lookup how some special

characters are URL$-$encoded, particularly useful will be the encodings for the dot $"."$ and the slash

$"/".$