TypeError: client.evalsha is not a function

[epubreader]

did not support node-redis,
const redis = require("redis");

TypeError: client.evalsha is not a function
at Redlock._attemptOperationOnClient (/home/mason/project/epubpub/epub-search/node_modules/redlock/dist/cjs/index.js:362:49)
at process.processTicksAndRejections (node:internal/process/task_queues:95:5)

const redisClient = require("./redisClient");
const { default: Redlock, ResourceLockedError } = require("redlock");

const redLock = new Redlock([redisClient], {
// the expected clock drift; for more details
// see http://redis.io/topics/distlock
driftFactor: 0.01, // time in ms

// the max number of times Redlock will attempt
// to lock a resource before erroring
retryCount: 4,

// the time in ms between attempts
retryDelay: 50, // time in ms

// the max time in ms randomly added to retries
// to improve performance under high contention
// see https://www.awsarchitectureblog.com/2015/03/backoff.html
retryJitter: 25, // time in ms
});

redLock.on("error", (error) => {
// Ignore cases where a resource is explicitly marked as locked on a client.
if (error instanceof ResourceLockedError) {
return;
}

// Log all other errors.
console.error(error);
});

module.exports = redLock;

const config = require("../config");

const redis = require("redis");
const redisPort = config.redis.port;
const redisHost = config.redis.host;
const redisPass = config.redis.password;

let redisConfig = {
socket: {
host: redisHost,
port: redisPort,
},
password: redisPass,
};

const redisClient = redis.createClient(redisConfig);

redisClient.on("error", (err) => {
console.error("Error: %o ", err);
});

redisClient.on("connect", () => {
console.log("Connected to Redis");
});

redisClient.on("close", () => {
console.log("Connection to redis has closed");
});

redisClient.connect();

module.exports = redisClient;

[priyadarshy]

I was expecting that using node-redis would work but I fixed this by swapping to the ioredis package.

[jopealgorta]

Hi, the problem is that older versions of redis supported all-lower-cased methods, but newer versions switched to camel casing. You should patch your redis client. Something like:

client = createClient({ url: `redis://${REDIS_HOST}:${REDIS_PORT}` });
if (!(client as any).evalsha) {
  (client as any).evalsha = client.evalSha.bind(client);
}

credits: @gfzabarino

[junereycasuga]

Hi, the problem is that older versions of redis supported all-lower-cased methods, but newer versions switched to camel casing. You should patch your redis client. Something like:

client = createClient({ url: `redis://${REDIS_HOST}:${REDIS_PORT}` });
if (!(client as any).evalsha) {
  (client as any).evalsha = client.evalSha.bind(client);
}

credits: @gfzabarino

this didn't work for us. we got a different error after doing this.

/projects/distlock/node_modules/@redis/client/dist/lib/commands/generic-transformers.js:248
        args.push(options.keys.length.toString(), ...options.keys);

redis: 4.6.14
redlock: 4.2.0