fix: read/parse buffers as hex strings (#797)

lib/ZwaveClient.js

@@ -1092,15 +1092,27 @@ function updateValue (zwaveNode, args) {
     const valueId = node.values[getValueID(args)]
 
     if (valueId) {
-      valueId.value = args.newValue
+      let newValue = args.newValue
+      if (Buffer.isBuffer(newValue)) {
+        // encode Buffers as HEX strings
+        newValue = utils.buffer2hex(newValue)
+      }
+
+      let prevValue = args.prevValue
+      if (Buffer.isBuffer(prevValue)) {
+        // encode Buffers as HEX strings
+        prevValue = utils.buffer2hex(prevValue)
+      }
+
+      valueId.value = newValue
       valueId.stateless = !!args.stateless
 
       // ensure duration is never undefined
       if (valueId.type === 'duration' && valueId.value === undefined) {
         valueId.value = new Duration(undefined, 'seconds')
       }
 
-      this.emit('valueChanged', valueId, node, args.prevValue !== args.newValue)
+      this.emit('valueChanged', valueId, node, prevValue !== newValue)
 
       const self = this
 
@@ -2508,6 +2520,10 @@ ZwaveClient.prototype.writeValue = async function (valueId, value) {
       value = value.substr(1)
     }
 
+    if (typeof value === 'string' && utils.isBufferAsHex(value)) {
+      value = utils.bufferFromHex(value)
+    }
+
     try {
       const zwaveNode = await this.getNode(valueId.nodeId)
 

lib/utils.js

@@ -197,6 +197,37 @@ async function verifyPsw (password, hash) {
   })
 }
 
+/**
+ * Checks if a string is a hex buffer
+ *
+ * @param {string} str
+ * @returns {boolean}
+ */
+function isBufferAsHex (str) {
+  return /^0x([a-fA-F0-9]{2})+$/.test(str)
+}
+
+/**
+ * Parses a buffer from a string has the form 0x[a-f0-9]+
+ *
+ * @param {string} hex
+ * @returns {Buffer} the parsed Buffer
+ */
+function bufferFromHex (hex) {
+  return Buffer.from(hex.substr(2), 'hex')
+}
+
+/**
+ * Converts a buffer to an hex string
+ *
+ * @param {Buffer} buffer
+ * @returns {string}
+ */
+function buffer2hex (buffer) {
+  if (buffer.length === 0) return ''
+  return `0x${buffer.toString('hex')}`
+}
+
 module.exports = {
   getPath,
   joinPath,
@@ -209,5 +240,8 @@ module.exports = {
   hasProperty,
   humanSize,
   hashPsw,
-  verifyPsw
+  verifyPsw,
+  isBufferAsHex,
+  bufferFromHex,
+  buffer2hex
 }

src/components/ValueId.vue

@@ -38,7 +38,7 @@
       ></v-text-field>
 
       <v-text-field
-        v-if="!value.list && (value.type === 'any' || value.type === 'buffer')"
+        v-if="!value.list && value.type === 'any'"
         :append-outer-icon="!disable_send ? 'send' : null"
         :suffix="value.unit"
         persistent-hint
@@ -264,17 +264,13 @@ export default {
       get: function () {
         if (this.value.type === 'any') {
           return JSON.stringify(this.value.newValue)
-        } else if (this.value.type === 'buffer') {
-          return this.value.newValue && this.value.newValue.toString('hex')
         }
         return this.value.newValue
       },
       set: function (v) {
         try {
           if (this.value.type === 'any') {
             this.value.newValue = JSON.parse(v)
-          } else if (this.value.type === 'buffer') {
-            this.value.newValue = Buffer.from(v, 'hex')
           } else {
             this.value.newValue = v
           }