Error: Cannot find module 'escpos-usb'

[slexsys]

HI. I run code in documentation and get exception. Could You help me, please?

(node:20296) [DEP0005] DeprecationWarning: Buffer() is deprecated due to security and usability issues. Please use the Buffer.alloc(), Buffer.allocUnsafe(), or Buffer.from() methods instead. (node:20296) UnhandledPromiseRejectionWarning: Error: Cannot find module 'escpos-usb' Require stack:

• /home/slexsys/projects/esc_pos_ang/electron-quick-start/main.js
• /home/slexsys/projects/esc_pos_ang/electron-quick-start/node_modules/electron/dist/resources/default_app.asar/main.js
• at Module._resolveFilename (internal/modules/cjs/loader.js:961:15) at Function.o._resolveFilename (electron/js2c/browser_init.js:257:921) at Module._load (internal/modules/cjs/loader.js:844:27) at Function.Module._load (electron/js2c/asar.js:769:28) at Module.require (internal/modules/cjs/loader.js:1023:19) at require (internal/modules/cjs/helpers.js:77:18) at escPos (/home/slexsys/projects/esc_pos_ang/electron-quick-start/main.js:24:18) at createWindow (/home/slexsys/projects/esc_pos_ang/electron-quick-start/main.js:17:3) at /home/slexsys/projects/esc_pos_ang/electron-quick-start/main.js:65:3 (node:20296) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag --unhandled-rejections=strict (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1) (node:20296) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

[oliverdotbecker]

run: npm i escpos-usb Then try again. Also make sure you have read the USB readme: https://github.com/song940/node-escpos/blob/v3/packages/usb/README.md

[slexsys]

I use electron project. git clone https://github.com/electron/electron-quick-start cd electron-quick-start npm install npm i escpos-usb sudo apt-get install build-essential libudev-dev (for Ubuntu 18.04)

Then add code from documentation (https://github.com/song940/node-escpos) const escpos = require('escpos'); escpos.USB = require('escpos-usb'); const device = new escpos.USB(); Then npm start And get exception

(node:10171) [DEP0005] DeprecationWarning: Buffer() is deprecated due to security and usability issues. Please use the Buffer.alloc(), Buffer.allocUnsafe(), or Buffer.from() methods instead. (node:10171) UnhandledPromiseRejectionWarning: Error: Cannot find module 'escpos-usb' Require stack:

• /home/slexsys/projects/electron-quick-start/main.js
• /home/slexsys/projects/electron-quick-start/node_modules/electron/dist/resources/default_app.asar/main.js
• at Module._resolveFilename (internal/modules/cjs/loader.js:961:15) at Function.o._resolveFilename (electron/js2c/browser_init.js:257:921) at Module._load (internal/modules/cjs/loader.js:844:27) at Function.Module._load (electron/js2c/asar.js:769:28) at Module.require (internal/modules/cjs/loader.js:1023:19) at require (internal/modules/cjs/helpers.js:77:18) at createWindow (/home/slexsys/projects/electron-quick-start/main.js:23:14) at /home/slexsys/projects/electron-quick-start/main.js:33:3 (node:10171) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag --unhandled-rejections=strict (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1) (node:10171) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

[oliverdotbecker]

Did you try to leave the line escpos.USB = require('escpos-usb'); out?

Worked for me as the escpos defines escpos.USB inside the package already and is containing the referring sources. At least in version 2.4.4, which I'm using.

[slexsys]

When leave the line escpos.USB = require('escpos-usb'); out get exception.

(node:6665) [DEP0005] DeprecationWarning: Buffer() is deprecated due to security and usability issues. Please use the Buffer.alloc(), Buffer.allocUnsafe(), or Buffer.from() methods instead. (node:6665) UnhandledPromiseRejectionWarning: TypeError: escpos.USB is not a constructor at createWindow (/home/slexsys/projects/test/electron-quick-start/main.js:22:18) at /home/slexsys/projects/test/electron-quick-start/main.js:29:3 (node:6665) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag --unhandled-rejections=strict (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1) (node:6665) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.