Add device error handling (#10)

Add device error handling

Author: codetheweb

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "@tuyapi/driver",
-  "version": "0.0.4",
+  "version": "0.0.5",
   "description": "⚡️ next-gen driver for Tuya devices",
   "keywords": [
     "🚗",

package.json

@@ -4,6 +4,7 @@ import debug from 'debug';
 import Messenger from './lib/messenger';
 import Frame from './lib/frame';
 import {COMMANDS, SUPPORTED_PROTOCOLS} from './lib/constants';
+import {DeviceError} from './lib/helpers';
 
 interface Device {
   readonly ip: string;
@@ -162,6 +163,12 @@ class Device extends EventEmitter implements Device {
       // Emit Frame as data event
       this.emit('data', frame);
 
+      // Check return code
+      if (frame.returnCode !== 0) {
+        // As a non-zero return code should not occur during normal operation, we throw here instead of emitting an error
+        throw new DeviceError(frame.payload.toString('ascii'));
+      }
+
       // Check if it's a heartbeat packet
       if (frame.command === COMMANDS.HEART_BEAT) {
         this._lastHeartbeat = new Date();

src/device.ts

@@ -7,6 +7,7 @@ interface FrameInterface {
   payload: Buffer;
   packet: Buffer;
   encrypted: boolean;
+  returnCode: number;
 }
 
 class Frame implements FrameInterface {
@@ -20,12 +21,15 @@ class Frame implements FrameInterface {
 
   encrypted: boolean;
 
+  returnCode: number;
+
   constructor() {
     this.version = 3.1;
     this.command = COMMANDS.UDP;
     this.payload = Buffer.from('');
     this.packet = Buffer.from('');
     this.encrypted = false;
+    this.returnCode = 0;
   }
 
   setPayload(data: Buffer | object): Frame {

src/lib/frame.ts

@@ -0,0 +1,8 @@
+class DeviceError extends Error {
+  constructor(m: string) {
+    super(`Error from device: ${m}`);
+    Error.captureStackTrace(this, DeviceError);
+  }
+}
+
+export {DeviceError};

src/lib/helpers.ts

@@ -57,17 +57,10 @@ class Messenger extends EventEmitter {
     // Get the return code, 0 = success
     // This field is only present in messages from the devices
     // Absent in messages sent to device
-    // Should we throw here or attach the return code to the Frame and bubble up?
-    const returnCode = packet.readUInt32BE(16) & 0xFFFFFF00;
+    const returnCode = packet.readUInt32BE(16);
 
     // Get the payload
-    // Adjust for messages lacking a return code
-    let payload;
-    if (returnCode === 0) {
-      payload = packet.slice(HEADER_SIZE + 4, HEADER_SIZE + payloadSize - 8);
-    } else {
-      payload = packet.slice(HEADER_SIZE, HEADER_SIZE + payloadSize - 8);
-    }
+    let payload = packet.slice(HEADER_SIZE + 4, HEADER_SIZE + payloadSize - 8);
 
     // Check CRC
     const expectedCrc = packet.readInt32BE(HEADER_SIZE + payloadSize - 8);
@@ -82,6 +75,7 @@ class Messenger extends EventEmitter {
     frame.version = this._version;
     frame.packet = packet;
     frame.command = command;
+    frame.returnCode = returnCode;
 
     // Check if packet is encrypted
     if (payload.indexOf(this._version.toString()) === 0) {