Schema validation in Express - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the schema validation library.

Express

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

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Abody-parser

Bexpress

Cmongoose

Djoi

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'express' instead of 'joi'.

Trying to import 'mongoose' which is for databases.

We use joi to define and validate schemas in Express apps.

2fill in blank

medium

Complete the code to define a schema for a user with a required string name.

Express

const schema = Joi.object({ name: Joi.[1]().required() });

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Astring

Bnumber

Cboolean

Darray

Attempts:

3 left

💡 Hint

Common Mistakes

Using number() for a name.

Using array() which is for lists.

The string() method defines a string type in Joi schemas.

3fill in blank

hard

Fix the error in the validation call to check the request body.

Express

const { error } = schema.[1](req.body);

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Avalidate

Btest

Ccheck

DvalidateBody

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-existent methods like validateBody or check.

Confusing with test which is not a Joi method.

The correct method to validate data with Joi is validate().

4fill in blank

hard

Fill both blanks to create middleware that validates the request body and sends an error if invalid.

Express

function validateUser(req, res, next) {
  const { error } = schema.[1](req.body);
  if (error) return res.status([2]).send(error.details[0].message);
  next();
}

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Avalidate

B400

C500

Dcheck

Attempts:

3 left

💡 Hint

Common Mistakes

Using status 500 which means server error, not client error.

Using a wrong method like 'check' instead of 'validate'.

Use validate to check the data and send status 400 for bad requests.

5fill in blank

hard

Fill all three blanks to define a schema with a required string 'username', an optional number 'age', and validate an object.

Express

const schema = Joi.object({
  username: Joi.[1]().required(),
  age: Joi.[2](),
});

const { error } = schema.[3]({ username: 'Alice', age: 30 });

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

Astring

Bnumber

Cvalidate

Dboolean

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up data types like using boolean for age.

Forgetting to call 'validate' to check the data.

Use string() for username, number() for age, and validate() to check the object.