Node.js Readable Stream error Event

The ‘error’ event in Readable stream can be emitted at any time. It takes place when the hidden stream is not able to generate data due to some hidden internal failure or when the implementation of stream pushes a chunk of data which is not valid. Moreover, a single Error object is passed as an argument to the listener callback.

Syntax:

Event: 'error'

Below examples illustrate the use of error event in Node.js:
Example 1:

javascript

// Node.js program to demonstrate the
// readable error event

// Including fs module
const fs = require('fs');

// Constructing readable stream
const readable = fs.createReadStream("input.txt");

// Handling error event
readable.on("error", err => {
    console.log(err);
});

console.log("Done...");

Output:

Done...
{ [Error: ENOENT: no such file or directory, open 'input.txt'] errno: -2,
 code: 'ENOENT', syscall: 'open', path: 'input.text' }

Example 2:

javascript

// Node.js program to demonstrate the
// readable error event

// Including fs module
const fs = require('fs');

// Constructing readable stream
const readable = fs.createReadStream("input.txt");

// Handling error event
readable.on("error", err => {
    console.log(err);
});

console.log("Done...");

Output:

Done...

Here, no error occurs so error event is not emitted.
Reference: https://nodejs.org/api/stream.html#stream_event_error_1