usb.on is not a function

[JuanDa237]

Node v18.15.0

"dependencies": {
"escpos": "^3.0.0-alpha.6",
"escpos-usb": "^3.0.0-alpha.4"
}

Code:

const escpos = require('escpos');
escpos.USB = require('escpos-usb');

const device = new escpos.USB(0x2BDF, 0x0280);
const printer = new escpos.Printer(device);

device.open(function (error) {
if (error) {
console.error('Error opening USB device:', error);
return;
}

printer
    .font('a')
    .align('ct')
    .style('bu')
    .size(1, 1)
    .text('Your Store Name')
    .text('----------------')
    .align('lt')
    .text('Item 1       $10.00')
    .text('Item 2        $7.50')
    .text('----------------')
    .align('rt')
    .text('Total:      $17.50')
    .cut()
    .close();

});

Error:
C:\Users\juan\Desktop\test-printer\node_modules\escpos-usb\index.js:52
usb.on('detach', function(device){
^

TypeError: usb.on is not a function
at new USB (C:\Users\x\Desktop\test-printer\node_modules\escpos-usb\index.js:52:7)
at Object. (C:\Users\x\Desktop\test-printer\index.js:5:16)
at Module._compile (node:internal/modules/cjs/loader:1254:14)
at Module._extensions..js (node:internal/modules/cjs/loader:1308:10)
at Module.load (node:internal/modules/cjs/loader:1117:32)
at Module._load (node:internal/modules/cjs/loader:958:12)
at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12)
at node:internal/main/run_main_module:23:47

[SZZH]

maybe you can try, usb module version to 1

[SZZH]

maybe you can try, usb module version to 1

pnpm i [email protected]

[giegiey]

npm install -S [email protected]

[joshuayoes]

You can also run apply this patch-package patch

Add this to patch/escpos-usb+3.0.0-alpha.4.patch

diff --git a/node_modules/escpos-usb/index.js b/node_modules/escpos-usb/index.js
index 8c21546..7b3aa42 100644
--- a/node_modules/escpos-usb/index.js
+++ b/node_modules/escpos-usb/index.js
@@ -25,7 +25,7 @@ const IFACE_CLASS = {
 function USB(vid, pid){
 
   if (!usb) {
-    usb = require('usb');
+    usb = require('usb').usb;
   }
 
   EventEmitter.call(this);
@@ -67,7 +67,7 @@ function USB(vid, pid){
  */
 USB.findPrinter = function(){
   if (!usb) {
-    usb = require('usb');
+    usb = require('usb').usb
   }
   return usb.getDeviceList().filter(function(device){
     try{

Then run npx patch-package in your project.

[codewithshinde]

This worked for me !!

• go to node_modules/escpos-usb/index.js
• comment down the following lines

  // usb.on('detach', function(device){
  //   if(device == self.device) {
  //     self.emit('detach'    , device);
  //     self.emit('disconnect', device);
  //     self.device = null;
  //   }
  // });