Installations

npm install @mswjs/http-middleware

Developer Guide

BETA

Typescript

No

Module System

CommonJS

Min. Node Version

>=18

Node Version

18.20.5

NPM Version

10.8.2 Score

69.5

Supply Chain

89.7

Quality

81.8

Maintenance

100

Vulnerability

99.3

License

Pull Requests

Open

0

Total

25

Closed

2

Merged

23

Issues

Open

5

Total

26

Closed

21

Releases

13

v0.10.3

Published on 12 Jan 2025

v0.10.2

Published on 25 Oct 2024

v0.10.1

Published on 24 Apr 2024

v0.10.0

Published on 05 Apr 2024

v0.9.2

Published on 26 Nov 2023

v0.9.1

Published on 07 Nov 2023

View all 13 releases

Contributors

15

View all 15 contributors

Languages

2

TypeScript

JavaScript

TypeScript (95.43%)

JavaScript (4.57%)

Developer

mswjs

Download Statistics

Total Downloads

1,941,128

Last Day

4,536

Last Week

22,581

Last Month

114,001

Last Year

1,131,802

GitHub Statistics

115 Stars

60 Commits

13 Forks

4 Watching

1 Branches

15 Contributors

Bundle Size

585.56 kB

Minified

233.72 kB

Minified + Gzipped

Bundlephobia

Maintainers

1

Package Meta Information

Latest Version

0.10.3

Package Id

@mswjs/http-middleware@0.10.3

Unpacked Size

10.20 kB

Size

3.73 kB

File Count

8

NPM Version

10.8.2

Node Version

18.20.5

Publised On

12 Jan 2025

Total Downloads

Cumulative downloads

Total Downloads

1,941,128

Last day

-18.1%

4,536

Compared to previous day

Last week

-26.2%

22,581

Compared to previous week

Last month

-3.4%

114,001

Compared to previous month

Last year

111.8%

1,131,802

Compared to previous year

Daily Downloads

Weekly Downloads

Monthly Downloads

Yearly Downloads

Dependencies

2

express strict-event-emitter

Peer Dependencies

1

msw

Dev Dependencies

16

@open-draft/test-server @ossjs/release @types/express @types/node @typescript-eslint/eslint-plugin @typescript-eslint/parser eslint eslint-config-prettier eslint-plugin-prettier husky lint-staged msw prettier rimraf typescript vitest

Versions

`@mswjs/http-middleware`

Spawn an Express server from your Mock Service Worker request handlers or apply them to an existing server using a middleware.

When to use this?

You should always prefer Mock Service Worker for API mocking because it can meet most of your requirements without having to spawn and maintain an actual HTTP server. Please refer to the Getting started tutorial to integrate next-generation API mocking into your application.

There are, however, use cases when this extension can be applicable:

If you wish to curl your mock definitions locally;
When prototyping a Node.js backend implementation;
When integrating API mocking in a complex application architecture (i.e. for dockerized applications).

Getting started

Install

1$ npm install @mswjs/http-middleware

Declare request handlers

1// src/mocks/handlers.js
2import { http, graphql, HttpResponse } from 'msw'
3
4export const handlers = [
5  http.post('/user', () => {
6    return HttpResponse.json({ firstName: 'John' })
7  }),
8  graphql.query('GetUser', () => {
9    return HttpResponse.json({
10      data: {
11        user: {
12          firstName: 'John',
13        },
14      },
15    })
16  }),
17]

Learn more about writing request handlers.

Integration

Option 1: Standalone server

1import { createServer } from '@mswjs/http-middleware'
2import { handlers } from './handlers'
3
4const httpServer = createServer(...handlers)
5
6httpServer.listen(9090)

Option 2: Middleware

1import { createMiddleware } from '@mswjs/http-middleware'
2import app from './app'
3import { handlers } from './handlers'
4
5app.use(createMiddleware(...handlers))

API

`createServer(...handlers: RequestHandler[])`

Establishes a standalone Express server that uses the given request handlers to process all incoming requests.

1import { http, HttpResponse } from 'msw'
2import { createServer } from '@mswjs/http-middleware'
3
4const httpServer = createServer(
5  http.get('/user', () => {
6    return HttpResponse.json({ firstName: 'John' })
7  }),
8)
9
10httpServer.listen(9090)

Making a GET http://localhost:9090/user request returns the following response:

1200 OK
2Content-Type: application/json
3
4{
5  "firstName": "John"
6}

`createMiddleware(...handlers: RequestHandler[])`

Creates an Express middleware function that uses the given request handlers to process all incoming requests.

1import { http, HttpResponse } from 'msw'
2import { createMiddleware } from '@mswjs/http-middleware'
3
4const app = express()
5
6app.use(
7  createMiddleware(
8    http.get('/user', () => {
9      return HttpResponse.json({ firstName: 'John' })
10    }),
11  ),
12)
13
14app.use(9090)

Mentions

David Idol, original implementation.

No vulnerabilities found.

10

Dangerous-Workflow

Determines if the project's GitHub Action workflows avoid dangerous patterns.

10

Binary-Artifacts

Determines if the project has generated executable (binary) artifacts in the source repository.

3

Code-Review

Determines if the project requires human code review before pull requests (aka merge requests) are merged.

2

Maintained

Determines if the project is "actively maintained".

0

Pinned-Dependencies

Determines if the project has declared and pinned the dependencies of its build process.

0

Token-Permissions

Determines if the project's workflows follow the principle of least privilege.

0

CII-Best-Practices

Determines if the project has an OpenSSF (formerly CII) Best Practices Badge.

0

Fuzzing

Determines if the project uses fuzzing.

0

License

Determines if the project has defined a license.

0

Security-Policy

Determines if the project has published a security policy.

0

SAST

Determines if the project uses static code analysis.

0

Vulnerabilities

Determines if the project has open, known unfixed vulnerabilities.

Score

2.9

/10

Last Scanned on 2025-01-27

The Open Source Security Foundation is a cross-industry collaboration to improve the security of open source software (OSS). The Scorecard provides security health metrics for open source projects.

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