RESTful mock server using axios.
GET
/POST
/PUT
/DELETE
API endpoint in a few lines.Using npm:
$ npm install axios
$ npm install axios-mock-server --save-dev
Using Yarn:
$ yarn add axios
$ yarn add axios-mock-server --dev
Introducing the simplest use of axios-mock-server.
First, create a mocks
directory to store the files you want to mock up.
$ mkdir mocks
Next, create an API endpoint file in the mocks
directory.
Let's define a mock API that retrieves basic user information with a GET
request.
Create a mocks/users
directory and create a _userId.js
file.
$ mkdir mocks/users
$ touch mocks/users/_userId.js
# If Windows (Command Prompt)
> mkdir mocks\users
> echo. > mocks\users\_userId.js
Add the following to the mocks/users/_userId.js
file.
// file: 'mocks/users/_userId.js'
const users = [{ id: 0, name: 'foo' }, { id: 1, name: 'bar' }]
module.exports = {
get({ values }) {
return [200, users.find(user => user.id === values.userId)]
}
}
The routing of axios-mock-server is automatically generated according to the tree structure of JavaScript and TypeScript files in the mocks
directory in the same way as the routing of Nuxt.js.
Reference: Routing - Nuxt.js
In other words, the mocks/users/_userId.js
file can define an endpoint using dynamic routing as the path of /users/:userId
.
axios-mock-server needs to build and generate the necessary files for routing before running.
$ node_modules/.bin/axios-mock-server
# If Windows (Command Prompt)
> node_modules\.bin\axios-mock-server
If the build is successful, the $mock.js
file is generated in themocks
directory.
$ cat mocks/\$mock.js
/* eslint-disable */
module.exports = (client) => require('axios-mock-server')([
{
path: '/users/_userId',
methods: require('./users/_userId')
}
], client)
# If Windows (Command Prompt)
> type mocks\$mock.js
Finally, import the mocks/$mock.js
file generated by index.js
file etc. and pass it to the argument of axios-mock-server.
axios-mock-server will mock up all axios communications by default.
// file: 'index.js'
const axios = require('axios')
const mock = require('./mocks/$mock.js')
mock()
axios.get('https://example.com/users/1').then(({ data }) => {
console.log(data)
})
If you run the index.js
file, you will see that { id: 1, name: 'bar' }
is returned.
$ node index.js
{ id: 1, name: 'bar' }
axios-mock-server can be used to mock up browser usage, data persistence and multipart/form-data
format communication.
It is also easy to link with Nuxt.js (@nuxtjs/axios).
See examples for source code.
WIP
const users = [{ id: 0, name: 'foo' }, { id: 1, name: 'bar' }]
/**
* Type definitions for variables passed as arguments in requests
* @typedef { Object } MockMethodParams
* @property { import('axios').AxiosRequestConfig } config axios request settings
* @property {{ [key: string]: string | number }} values Dynamic value of the requested URL (underscore part of the path)
* @property {{ [key: string]: any }} params The value of the query parameter for the requested URL
* @property { any } data Request data sent by POST etc.
*/
/**
* Type definition when response is returned as an object
* @typedef { Object } MockResponseObject
* @property { number } status HTTP response status code
* @property { any? } data Response data
* @property {{ [key: string]: any }?} headers Response header
*/
/**
* Response type definition
* @typedef { [number, any?, { [key: string]: any }?] | MockResponseObject } MockResponse
*/
export default {
/**
* All methods such as GET and POST have the same type
* @param { MockMethodParams }
* @returns { MockResponse }
*/
get({ values }) {
return [200, users.find(user => user.id === values.userId)]
},
/**
* You can also return a response asynchronously
* @param { MockMethodParams }
* @returns { Promise<MockResponse> }
*/
async post({ data }) {
await new Promise(resolve => setTimeout(resolve, 1000))
users.push({
id: users.length,
name: data.name
})
return { status: 201 }
}
}
axios-mock-server will mock up all axios communications by default.
import axios from 'axios'
import mock from './mocks/$mock.js'
mock()
axios.get('https://example.com/api/foo').then(response => {
/* ... */
})
You can also mock up each axios instance.
import axios from 'axios'
import mock from './mocks/$mock.js'
const client = axios.create({ baseURL: 'https://example.com/api' })
mock(client)
client.get('/foo').then(response => {
/* ... */
})
// axios will not be mocked up
axios.get('https://example.com/api/foo').catch(error => {
console.log(error.response.status) // 404
})
axios-mock-server has several built-in functions available.
setDelayTime(millisecond: number): void
Simulate response delay.
import axios from 'axios'
import mock from './mocks/$mock.js'
mock().setDelayTime(500)
console.time()
axios.get('https://example.com/api/foo').then(() => {
console.timeEnd() // default: 506.590ms
})
enableLog(): void
and disableLog(): void
Switch request log output.
import axios from 'axios'
import mock from './mocks/$mock.js'
const mockServer = mock()
;(async () => {
// To enable
mockServer.enableLog()
await axios.get('/foo', { baseURL: 'https://example.com/api', params: { bar: 'baz' } }) // stdout -> [mock] get: /foo?bar=baz => 200
// To disable
mockServer.disableLog()
await axios.get('/foo', { baseURL: 'https://example.com/api', params: { bar: 'baz' } }) // stdout ->
})()
axios-mock-server includes TypeScript definitions.
.gitignore
Exclude $mock.js
or $mock.ts
generated by axios-mock-server in the build from Git monitoring.
$ echo "\$mock.*" >> .gitignore
# If Windows (Command Prompt)
> echo $mock.* >> .gitignore
@ts-ignore
, eslint-disable
For TypeScript projects, add a // @ ts-ignore
comment to the above line that imports$ mock.ts
.
If @typescript-eslint/ban-ts-ignore
rule is enabled in typescript-eslint, please exclude the // @ ts-ignore
comment from ESLint.
// eslint-disable-next-line @typescript-eslint/ban-ts-ignore
// @ts-ignore: Cannot find module
import mock from './mocks/$mock'
The expected type comes from property 'get' which is declared here on type 'MockMethods'
error in TypeScriptWhen returning a response asynchronously with TypeScript, an error occurs because the type does not match if you try to make the response an array.
Assert MockResponse
or return it as an object.
Example of error (Note that the axios-mock-server build will pass!)
import { MockMethods } from 'axios-mock-server'
const methods: MockMethods = {
async get() {
await new Promise(resolve => setTimeout(resolve, 100))
return [200, { foo: 'bar' }] // Error
}
}
export default methods
Resolve by asserting MockResponse
.
import { MockMethods, MockResponse } from 'axios-mock-server'
const methods: MockMethods = {
async get() {
await new Promise(resolve => setTimeout(resolve, 100))
return [200, { foo: 'bar' }] as MockResponse // Type safe
}
}
export default methods
If the response can be an object, no assertion is required.
import { MockMethods } from 'axios-mock-server'
const methods: MockMethods = {
async get() {
await new Promise(resolve => setTimeout(resolve, 100))
return { status: 200, data: { foo: 'bar' } } // Type safe
}
}
export default methods
The following options can be specified in the Command Line Interface.
Settings are written in .mockserverrc
file with JSON syntax.
axios-mock-server is licensed under a MIT License.