remcohaszing / axios-test-instance

Test NodeJS backends using Axios

Axios Test Instance

Test NodeJS backends using Axios

Table of Contents

• Installation
• Usage
• Examples
• See also
• License

Installation

npm install axios-test-instance

Usage

1. Create an Axios test instance by passing your app, which may be a Koa app, an Express app, or an HTTP request handler, to setTestApp in a beforeAll or beforeEach block.
2. Import request and use it in tests.

import { request, setTestApp } from 'axios-test-instance'

import { app } from './app.js'

beforeAll(async () => {
  await setTestApp(app)
})

The method above works with Jest, but it might not work with your testing framework. For this use case, a test instance can be created manually using createInstance.

import { createInstance } from 'axios-test-instance'

import { app } from './app.js'

let instance

beforeAll(async () => {
  instance = await createInstance(app)
})

afterAll(async () => {
  await instance.close()
})

Chances are you’re already using an Axios instance in your frontend. In this case, patchInstance can be used to patch this instance instead.

import { patchInstance } from 'axios-test-instance'

import { app } from './app.js'
import { request } from './request.js'

let instance

beforeAll(async () => {
  instance = await patchInstance(request, app)
})

afterAll(async () => {
  await instance.close()
})

Now requests made using this instance, will be redirected to the app under test.

Examples

For usages examples, have a look at our test cases:

• Koa example
• Express example
• Fastify example (See #2 for limitations)
• HTTP callback example
• End to end example

See also

• jest-axios-snapshot asserts axios responses using jest snapshots.

License

MIT © Remco Haszing

axios-test-instance's Issues

Support Fastify

We're currently migrating from express to fastify, would love to keep using this library!

https://www.fastify.io/

Avoid variadic `listen` with fastify 4

Using fastify@4 with this module prints

(node:76172) [FSTDEP011] FastifyDeprecation: Variadic listen method is deprecated. Please use ".listen(optionsObject)" instead. The variadic signature will be removed in `fastify@5`.
    at Object.emit (/Users/simen/repos/monorepo/node_modules/process-warning/index.js:52:13)
    at Object.listen (/Users/simen/repos/monorepo/node_modules/fastify/lib/server.js:31:16)
    at /Users/simen/repos/monorepo/node_modules/axios-test-instance/index.js:29:17
    at new Promise (<anonymous>)
    at startServer (/Users/simen/repos/monorepo/node_modules/axios-test-instance/index.js:28:16)
    at patchInstance (/Users/simen/repos/monorepo/node_modules/axios-test-instance/index.js:90:34)
    at createInstance (/Users/simen/repos/monorepo/node_modules/axios-test-instance/index.js:126:28)