Now, it's time to see how to develop and test an Express application with what we have learned previously.

We will create a file-sharing application that allows users to upload files and password-protect them if they choose to. After uploading the files to the server, we will create a unique ID for that file, store the metadata along with the content (as a separate JSON file), and redirect the user to the file's information page. When trying to access a password-protected file, an HTTP basic authentication pop up will appear, and the user will have to only enter the password (no username in this case).

The package.json file, so far, will contain the following code:

{
  "name": "file-uploading-service",
  "version": "0.0.1",
  "private": true,
  "scripts": {
    "start": "node ./bin/www"
  },
  "dependencies": {
    "express": "~4.2.0",
    "static-favicon": "~1.0.0",
    "morgan": "~1.0.0",
    "cookie-parser": "~1.0.1",
    "body-parser...