ioredis-mock

ioredis-mock supports Redis publish/subscribe channels. Similar to the real ioredis, you typically require two separate client instances: one for publishing and one for subscribing.

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', 'clark@daily.planet')

In versions prior to v6, each ioredis-mock instance lived in isolation. Starting with v6, instances share context if they use the same host and port (defaulting to 6379). This makes the mock behave more like a real Redis server.

Because data persists between instances sharing the same port, you should run flushall between test suites to ensure isolation.

const Redis = require('ioredis-mock')

// Instances sharing default port 6379 share data
const redis1 = new Redis()
const redis2 = new Redis()

// Recommended pattern for test isolation:
afterEach(done => {
  new Redis().flushall().then(() => done())
})

An experimental browser build is available. You can import it directly from the package or via unpkg.com.

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

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

The ioredis-mock/jest.js file has been removed. Because ioredis-mock now performs a direct import of Command from ioredis/built/command, the previous Jest workaround is no longer necessary.

Update your Jest mock:

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

Upgrading to v8 introduces the following breaking changes:

1. ioredis@v4 support dropped: The new baseline is ioredis@v5. If you are still on ioredis@v4, stay on ioredis-mock@v7.
2. PromiseContainer removed: Support for third-party Promise libraries is dropped. The library now uses native Promises exclusively.

Experimental support for Redis Cluster is available via Redis.Cluster.

const Redis = require('ioredis-mock')

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

You can extend the mock client by defining custom commands using Lua scripts via the defineCommand(name, definition) method. This allows you to simulate complex Redis logic in your tests.

Limitations:

• Does not support dynamic key numbers (passing the number of keys as the first argument).
• Does not automatically define the [commandName]Buffer companion (e.g., multiplyBuffer).
• evalsha and script commands are not supported.

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)

// Call the new command like an ordinary command
redis.multiply('k1', 10).then(result => {
  expect(result).toBe(5 * 10)
})

If you do not want to define a permanent custom command, you can execute Lua code directly using the eval command, just like in a real Redis instance.

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)

You can enable keyspace notifications by providing a notifyKeyspaceEvents string in the RedisMock options. This follows the Redis configuration pattern (e.g., 'g' for generic, 'x' for expired, 'k' for keyspace events).

Supported patterns are defined by Redis documentation at https://redis.io/topics/notifications#configuration.

const redis = new RedisMock({
  notifyKeyspaceEvents: 'gxK'
});

If you attempt to call EVALSHA with a SHA1 hash that has not been previously loaded into memory via EVAL, the command will throw an error.

Error String: NOSCRIPT No matching script. Please use EVAL.

The zscoreBuffer command is a variant of zscore that returns the result as a Buffer instead of a string. This is useful for low-level protocol simulations or when the consumer expects binary data.

// Returns the score as a Buffer
const scoreBuffer = zscoreBuffer(key, member);