Validation error response formatting in Express - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to send a JSON error response with status 400.

Express

res.status(400).json({ error: [1] });

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

A"Invalid input"

BInvalid input

C400

Derror

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting quotes around the error message string.

Passing a number instead of a string as the error message.

The error message must be a string inside quotes to be valid JSON.

2fill in blank

medium

Complete the code to extract validation errors from the request and send them in the response.

Express

const errors = req.validationErrors();
if (errors) {
  return res.status(422).json({ errors: [1] });
}

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

Areq.errors

Berror

Cerrors

DvalidationErrors

Attempts:

3 left

💡 Hint

Common Mistakes

Using a wrong variable name that does not exist.

Sending a single error instead of the whole errors array.

The variable errors holds the validation errors and should be sent in the response.

3fill in blank

hard

Fix the error in the code to properly format the validation error response.

Express

res.status(400).json({ message: [1] });

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

Aerror

B"Validation failed"

Cerrors.array()

Derrors

Attempts:

3 left

💡 Hint

Common Mistakes

Passing an array where a string is expected.

Using a variable that is not defined.

The message key should have a string describing the error, not the errors array.

4fill in blank

hard

Fill both blanks to send a detailed validation error response with status and errors array.

Express

res.status([1]).json({ status: [2], errors: errors.array() });

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

A422

B400

Attempts:

3 left

💡 Hint

Common Mistakes

Using 400 instead of 422 for validation errors.

Mismatch between HTTP status and JSON status field.

The HTTP status code 422 means Unprocessable Entity, suitable for validation errors.

5fill in blank

hard

Fill all three blanks to create a middleware that checks validation results and sends errors if any.

Express

const { validationResult } = require('express-validator');

function validate(req, res, next) {
  const errors = validationResult(req);
  if (!errors.isEmpty()) {
    return res.status([1]).json({
      [2]: [3]
    });
  }
  next();
}

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

A400

Berrors

Cerrors.array()

D422

Attempts:

3 left

💡 Hint

Common Mistakes

Using status 400 instead of 422.

Sending the errors object directly instead of errors.array().

Use status 422 for validation errors, and send the errors array under the key 'errors'.