File type validation in Express - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the Express module.

Express

const express = require('[1]');

Drag options to blanks, or click blank then click option'

Aexpress

Bhttp

Cfs

Dpath

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'http' instead of 'express'.

Forgetting to put the module name in quotes.

The Express module is imported using require('express').

2fill in blank

medium

Complete the code to use multer middleware for file uploads.

Express

const multer = require('[1]');

Drag options to blanks, or click blank then click option'

Aexpress

Bcors

Cbody-parser

Dmulter

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'body-parser' which does not handle file uploads.

Using 'express' instead of 'multer'.

Multer is the middleware used for handling file uploads in Express.

3fill in blank

hard

Fix the error in the file filter function to only accept PNG files.

Express

const fileFilter = (req, file, cb) => {
  if (file.mimetype === '[1]') {
    cb(null, true);
  } else {
    cb(null, false);
  }
};

Drag options to blanks, or click blank then click option'

Aimage/png

Bapplication/pdf

Cimage/jpeg

Dtext/plain

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'image/jpeg' which is for JPEG images.

Using 'application/pdf' which is for PDF files.

The MIME type for PNG images is image/png. This filter allows only PNG files.

4fill in blank

hard

Fill both blanks to configure multer with a file size limit and file filter.

Express

const upload = multer({
  limits: { fileSize: [1] },
  fileFilter: [2]
});

Drag options to blanks, or click blank then click option'

A1024 * 1024

BfileFilter

C5000

Dtrue

Attempts:

3 left

💡 Hint

Common Mistakes

Setting fileSize to 5000 which is too small.

Passing 'true' instead of the fileFilter function.

The file size limit is set to 1MB (1024 * 1024 bytes). The fileFilter function is passed as the fileFilter option.

5fill in blank

hard

Fill all three blanks to create an Express route that uses multer to upload a single file named 'avatar'.

Express

app.post('/upload', [1].single('[2]'), (req, res) => {
  if (!req.file) {
    return res.status(400).send('[3]');
  }
  res.send('File uploaded successfully');
});

Drag options to blanks, or click blank then click option'

Aupload

Bavatar

CNo file uploaded

Dexpress

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'express' instead of the multer instance.

Using a wrong field name other than 'avatar'.

Not handling the case when no file is uploaded.

The multer instance is named upload. The single file field is named 'avatar'. The error message is 'No file uploaded'.