Merge pull request #49 from dschweinbenz/feature/usb-printer

feat: Added getDeviceBySerial function and outsourced isPrinter function

Author: dohooo

.changeset/tricky-maps-listen.md

@@ -0,0 +1,5 @@
+---
+"@node-escpos/usb-adapter": minor
+---
+
+Added getDeviceBySerial and outsourced isPrinter function for reusability

packages/usb-adapter/src/index.ts

@@ -2,6 +2,7 @@ import os from "os";
 
 import { Adapter } from "@node-escpos/adapter";
 import type { Interface, InEndpoint, OutEndpoint, LibUSBException } from "usb";
+import { findBySerialNumber } from "usb";
 import { usb, getDeviceList, findByIds } from "usb";
 
 /**
@@ -57,26 +58,42 @@ export default class USBAdapter extends Adapter<[]> {
     }
   }
 
+  static isPrinter(device: usb.Device): boolean {
+    try {
+      const length = device.configDescriptor?.interfaces.filter((iface) => {
+        return iface.filter((conf) => {
+          return conf.bInterfaceClass === IFACE_CLASS.PRINTER;
+        }).length;
+      }).length;
+      return (length !== undefined && length > 0);
+    }
+    catch (e) {
+      // console.warn(e)
+      return false;
+    }
+  }
+
   static findPrinter() {
-    return getDeviceList().filter((device) => {
+    return getDeviceList().filter((device) => USBAdapter.isPrinter(device));
+  }
+
+  static getDevice(vid: number, pid: number) {
+    return new Promise((resolve, reject) => {
       try {
-        return device.configDescriptor?.interfaces.filter((iface) => {
-          return iface.filter((conf) => {
-            return conf.bInterfaceClass === IFACE_CLASS.PRINTER;
-          }).length;
-        }).length;
+        const device = findByIds(vid, pid);
+        device?.open();
+        resolve(device);
       }
-      catch (e) {
-        // console.warn(e)
-        return false;
+      catch (err) {
+        reject(err);
       }
     });
   }
 
-  static getDevice(vid: number, pid: number) {
-    return new Promise((resolve, reject) => {
+  static getDeviceBySerial(serialNumber: string) {
+    return new Promise(async (resolve, reject) => {
       try {
-        const device = findByIds(vid, pid);
+        const device = await findBySerialNumber(serialNumber);
         device?.open();
         resolve(device);
       }