Request ID for tracing 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' to import the framework.

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

2fill in blank

medium

Complete the code to add a middleware that assigns a unique request ID.

Express

app.use((req, res, next) => {
  req.id = [1]();
  next();
});

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

Aconsole.log

BDate.now

Cuuid.v4

DMath.random

Attempts:

3 left

💡 Hint

Common Mistakes

Using Date.now or Math.random which are not guaranteed unique.

Using uuid.v4() generates a unique request ID for tracing.

3fill in blank

hard

Fix the error in the code to correctly import the UUID v4 function.

Express

const { [1] } = require('uuid');

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Auuidv4

Bv4

Cuuid

DuuidV4

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'uuidv4' or 'uuidV4' which are not exported names.

The correct import syntax is const { v4 } = require('uuid');.

4fill in blank

hard

Fill both blanks to log the request ID and method in the middleware.

Express

app.use((req, res, next) => {
  console.log('Request ID:', req.[1], 'Method:', req.[2]);
  next();
});

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

Aid

Bmethod

Curl

Dbody

Attempts:

3 left

💡 Hint

Common Mistakes

Using req.url or req.body instead of req.method.

Request ID is stored in req.id and HTTP method in req.method.

5fill in blank

hard

Fill all three blanks to create a middleware that adds a request ID header and logs it.

Express

app.use((req, res, next) => {
  const id = [1]();
  req.[2] = id;
  res.setHeader('[3]', id);
  next();
});

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

Av4

Bid

CX-Request-ID

Duuid

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong header name or not assigning the ID to req.id.

The middleware generates a UUID with v4(), assigns it to req.id, and sets the X-Request-ID header.