How can i fix this call back error in Node.js? - node.js

Question

At first, I installed this library,
> npm install rocketchat-api
and then I've ran this code to use rocket.chat REST API
// Node.js code
const RocketChatApi = require('rocketchat-api');
const result='https://rocket.chat/docs/developer-guides/rest-api/users/setavatar';
const userId='A user id';
const avatarUrl='http://www.coca.ir/wp-content/uploads/2017/05/flowers-love-profile-pictures-1.jpg'
const rocketChatClient = new RocketChatApi(
'https',
'rocket.chat',
443,
'username',
'password',
(err, result)=>{
console.info('RC connected', result)
});
rocketChatClient.users.setAvatar(userId, avatarUrl, (err, body)=>{
});
After run this in Node.js, I got following error, anyone can help me?
\node_modules\rocketchat-api\lib\net.js:144
return callback ? callback(error, null) : reject(error);
^
TypeError: callback is not a function
at Request.clientRequest [as _callback] (D:\node js projects\rocketTest\node_modules\rocketchat-api\lib\net.js:144:39)
at self.callback (D:\node js projects\rocketTest\node_modules\request\request.js:185:22)
at Request.emit (events.js:198:13)
at ClientRequest.<anonymous> (D:\node js projects\rocketTest\node_modules\request\request.js:819:16)
at Object.onceWrapper (events.js:286:20)
at ClientRequest.emit (events.js:198:13)
at TLSSocket.emitRequestTimeout (_http_client.js:662:40)
at Object.onceWrapper (events.js:286:20)
at TLSSocket.emit (events.js:198:13)
at TLSSocket.Socket._onTimeout (net.js:442:8)
at ontimeout (timers.js:436:11)
at tryOnTimeout (timers.js:300:5)
at listOnTimeout (timers.js:263:5)
at Timer.processTimers (timers.js:223:10)

Answer 1

That's because setAvatar() only accepts 2 parameters: avatarUrl and callback. If you pass 3 parameters, it would take the second one as callback, and throw TypeError if it is not a function (In your example, the 2nd parameter avatarUrl is a string).
Please refer to the source code of lib/api/users.js in rocketchat-api source code:
setAvatar (avatarUrl, callback) {
return this.client.request("POST", "users.setAvatar", {
avatarUrl
}, callback);
}
Unfortunately, the rocketchat-api module's document is incorrect, which leads the problem.