I can't seem to get the npm module 'upper-case' to work properly

Question

I installed the npm module upper-case as following

npm install upper-case

Thereafter, I executed the following code in node.

let http = require('http');
let uc = require('upper-case');
http.createServer( (req, res) => {
  res.writeHead(200, {'Content-Type': 'text/html'});
  res.write(uc("Hello World!"));
  res.end();
}).listen(8080);

However, I can not get it to work. I get the following response.

TypeError: uc is not a function
    at Server.http.createServer (/.../foo.js:34:13)
    at Server.emit (events.js:189:13)
    at parserOnIncoming (_http_server.js:676:12)
    at HTTPParser.parserOnHeadersComplete (_http_common.js:109:17)

Why? What's going on!?

Answer 1

Really strange... But the following seems to work for some reason. I couldn't find this anywhere in the original npm module docs. Can anybody explain why this works?

let http = require('http');
let uc = require('upper-case');

http.createServer((req, res) => {
    res.writeHead(200, { 'Content-Type': 'text/html' });
    res.write(uc.upperCase("Hello World!"));
    res.end();
}).listen(8080);