ioredis-mock

What is ioredis-mock?

ioredis-mock is a mock implementation of the ioredis library, which is used for interacting with Redis databases. This package is particularly useful for testing purposes, as it allows developers to simulate Redis operations without needing a real Redis server.

What are ioredis-mock's main functionalities?

Basic Redis Commands

This feature allows you to perform basic Redis commands such as SET and GET. The code sample demonstrates setting a key-value pair and then retrieving the value.

const Redis = require('ioredis-mock');
const redis = new Redis();

redis.set('key', 'value').then(() => {
  return redis.get('key');
}).then(value => {
  console.log(value); // 'value'
});

Pub/Sub

This feature allows you to use the publish/subscribe pattern. The code sample demonstrates subscribing to a channel and publishing a message to that channel.

const Redis = require('ioredis-mock');
const pub = new Redis();
const sub = new Redis();

sub.subscribe('channel', (err, count) => {
  pub.publish('channel', 'message');
});

sub.on('message', (channel, message) => {
  console.log(channel, message); // 'channel', 'message'
});

Transactions

This feature allows you to perform transactions using the MULTI command. The code sample demonstrates setting a key-value pair and then retrieving the value within a transaction.

const Redis = require('ioredis-mock');
const redis = new Redis();

redis.multi()
  .set('key', 'value')
  .get('key')
  .exec((err, results) => {
    console.log(results); // [[null, 'OK'], [null, 'value']]
  });

Other packages similar to ioredis-mock

redis-mock

redis-mock is another mock implementation of the Redis API. It provides a similar set of functionalities for testing purposes. However, it is generally considered less feature-rich and less actively maintained compared to ioredis-mock.

fakeredis

fakeredis is a pure Python implementation of the Redis API, which can be used for testing purposes. It is similar to ioredis-mock but is intended for use in Python environments rather than Node.js.

README

ioredis-mock ·

This library emulates ioredis by performing all operations in-memory. The best way to do integration testing against redis and ioredis is on a real redis-server instance. However, there are cases where mocking the redis-server is a better option.

Cases like:

• Your workflow already use a local redis-server instance for the dev server.
• You're on a platform without an official redis release, that's even worse than using an emulator.
• You're running tests on a CI, setting it up is complicated. If you combine it with CI that also run selenium acceptance testing it's even more complicated, as two redis-server instances on the same CI build is hard.
• The GitHub repo have bots that run the testing suite and is limited through npm package.json install scripts and can't fire up servers. (Having Renovatebot notifying you when a new release of ioredis is out and wether your code breaks or not is awesome).

Check the compatibility table for supported redis commands.

Usage (try it in your browser with RunKit)

const Redis = require('ioredis-mock')
const redis = new Redis({
  // `options.data` does not exist in `ioredis`, only `ioredis-mock`
  data: {
    user_next: '3',
    emails: {
      '[e-mail]': '1',
      '[e-mail]': '2',
    },
    'user:1': { id: '1', username: 'superman', email: '[e-mail]' },
    'user:2': { id: '2', username: 'batman', email: '[e-mail]' },
  },
})
// Basically use it just like ioredis

Browser usage (Experimental)

There's a browser build available. You can import it directly (import Redis from 'ioredis-mock/browser.js'), or use it on unpkg.com:

import Redis from 'https://unpkg.com/ioredis-mock'

const redis = new Redis()
redis.set('foo', 'bar')
console.log(await redis.get('foo'))

Breaking Changes

from v7 to v8

ioredis@v4 support dropped

ioredis@v5 is the new baseline. Stay on ioredis-mock@v7 until you're ready to upgrade to ioredis@v5.

PromiseContainer has been removed.

Support for third-party Promise libraries is dropped. The native Promise library will always be used.

from v6 to v7

createConnectedClient is removed

Replace it with .duplicate() or use another new Redis instance.

Dropped support for Node v10

It's been EOL since Apr, 2021 and it's recommended to upgrade to v14.x LTS.

ioredis-mock/jest.js is removed

ioredis-mock is no longer doing a import { Command } from 'ioredis' internally, it's now doing a direct import import Command from 'ioredis/built/command' and thus the jest.js workaround is no longer needed:

-jest.mock('ioredis', () => require('ioredis-mock/jest'))
+jest.mock('ioredis', () => require('ioredis-mock'))

from v5 to v6

Before v6, each instance of ioredis-mock lived in isolation:

const Redis = require('ioredis-mock')
const redis1 = new Redis()
const redis2 = new Redis()

await redis1.set('foo', 'bar')
console.log(await redis1.get('foo'), await redis2.get('foo')) // 'bar', null

In v6 the internals were rewritten to behave more like real life redis, if the host and port is the same, the context is now shared:

const Redis = require('ioredis-mock')
const redis1 = new Redis()
const redis2 = new Redis()
const redis3 = new Redis(6380) // 6379 is the default port

await redis1.set('foo', 'bar')
console.log(
  await redis1.get('foo'), // 'bar'
  await redis2.get('foo'), // 'bar'
  await redis3.get('foo') // null
)

And since ioredis-mock now persist data between instances, you'll likely need to run flushall between testing suites:

const Redis = require('ioredis-mock')

afterEach(done => {
  new Redis().flushall().then(() => done())
})

Pub/Sub channels

We also support redis publish/subscribe channels. Like ioredis, you need two clients:

const Redis = require('ioredis-mock')
const redisPub = new Redis()
const redisSub = new Redis()

redisSub.on('message', (channel, message) => {
  console.log(`Received ${message} from ${channel}`)
})
redisSub.subscribe('emails')
redisPub.publish('emails', '[e-mail]')

Lua scripting

You can use the defineCommand to define custom commands using lua or eval to directly execute lua code.

In order to create custom commands, using lua scripting, ioredis exposes the defineCommand method.

You could define a custom command multiply which accepts one key and one argument. A redis key, where you can get the multiplicand, and an argument which will be the multiplicator:

const Redis = require('ioredis-mock')
const redis = new Redis({ data: { k1: 5 } })
const commandDefinition = {
  numberOfKeys: 1,
  lua: 'return redis.call("GET", KEYS[1]) * ARGV[1]',
}
redis.defineCommand('multiply', commandDefinition) // defineCommand(name, definition)
// now we can call our brand new multiply command as an ordinary command
redis.multiply('k1', 10).then(result => {
  expect(result).toBe(5 * 10)
})

You can also achieve the same effect by using the eval command:

const Redis = require('ioredis-mock')
const redis = new Redis({ data: { k1: 5 } })
const result = redis.eval(`return redis.call("GET", "k1") * 10`)
expect(result).toBe(5 * 10)

note we are calling the ordinary redis GET command by using the global redis object's call method.

As a difference from ioredis we currently don't support:

• dynamic key number by passing the number of keys as the first argument of the command.
• automatic definition of the custom command buffer companion (i.e. for the custom command multiply the multiplyBuffer which returns values using Buffer.from(...))
• the evalsha command
• the script command

Cluster(Experimental)

Work on Cluster support has started, the current implementation is minimal and PRs welcome #359

const Redis = require('ioredis-mock')

const cluster = new Redis.Cluster(['redis://localhost:7001'])
const nodes = cluster.nodes()
expect(nodes.length).toEqual(1)

Roadmap

You can check the roadmap project page, and the compat table, to see how close we are to feature parity with ioredis.

I need a feature not listed here

Just create an issue and tell us all about it or submit a PR with it! 😄