Fix MQTT message conversion for large numeric values and make character code parsing configurable

lib/common.js

@@ -231,10 +231,28 @@ function convertMessage(topic, message, adapter, clientID) {
         const parts = message.split(',');
         try {
             let str = '';
+            let validCharCodes = true;
+
+            // First validate all parts are valid character codes
             for (let p = 0; p < parts.length; p++) {
-                str += String.fromCharCode(parseInt(parts[p].trim(), 10));
+                const charCode = parseInt(parts[p].trim(), 10);
+                // Only allow values that work reliably with String.fromCharCode (0-65535)
+                // and are reasonable character codes (typically 0-255 for extended ASCII)
+                if (charCode < 0 || charCode > 255) {
+                    validCharCodes = false;
+                    break;
+                }
+            }
+
+            // Only convert if all parts are valid character codes
+            if (validCharCodes) {
+                for (let p = 0; p < parts.length; p++) {
+                    str += String.fromCharCode(parseInt(parts[p].trim(), 10));
+                }
+                message = str;
+                // Character code conversion complete - don't try to parse as number later
+                return message;
             }
-            message = str;
         } catch {
             // cannot convert and ignore it
         }

test/testConvert.js

@@ -5,4 +5,44 @@ describe('Test convert version', function () {
     it('Number', async () => {
         expect(convertMessage('data', '233.57')).to.be.equal(233.57);
     });
+
+    it('Character code conversion - valid ASCII codes', async () => {
+        expect(convertMessage('data', '65,66,67')).to.be.equal('ABC');
+        expect(convertMessage('data', '72,101,108,108,111')).to.be.equal('Hello');
+        expect(convertMessage('data', '32,87,111,114,108,100')).to.be.equal(' World');
+    });
+
+    it('Character code conversion - invalid codes should remain unchanged', async () => {
+        // NUKI 3.0 Pro lock data - should NOT be converted
+        expect(convertMessage('data', '3,0,442236930,1,2')).to.be.equal('3,0,442236930,1,2');
+
+        // Values above 255 should NOT be converted
+        expect(convertMessage('data', '256,512,1024')).to.be.equal('256,512,1024');
+        expect(convertMessage('data', '70000,80000,90000')).to.be.equal('70000,80000,90000');
+
+        // Negative numbers should NOT be converted
+        expect(convertMessage('data', '-1,2,3')).to.be.equal('-1,2,3');
+
+        // Mix of valid and invalid should NOT be converted
+        expect(convertMessage('data', '0,65535,1114112')).to.be.equal('0,65535,1114112');
+    });
+
+    it('Character code conversion - edge cases', async () => {
+        // Control characters (0-31) are valid
+        expect(convertMessage('data', '9,10,13')).to.be.equal('\t\n\r');
+
+        // Extended ASCII (128-255) is valid
+        expect(convertMessage('data', '128,129,130')).to.be.equal('\x80\x81\x82');
+
+        // Single number doesn't match pattern (requires at least 3 numbers) but may be converted to number
+        expect(convertMessage('data', '65')).to.be.equal(65); // String '65' becomes number 65
+        expect(convertMessage('data', '65,66')).to.be.equal(65.66); // Two numbers: '65,66' -> '65.66' -> 65.66
+    });
+
+    it('Character code conversion - non-numeric data unchanged', async () => {
+        expect(convertMessage('data', 'hello,world')).to.be.equal('hello,world');
+        expect(convertMessage('data', 'a,b,c')).to.be.equal('a,b,c');
+        expect(convertMessage('data', '1,2,abc')).to.be.equal('1,2,abc');
+        expect(convertMessage('data', '3.14,2.71,1.41')).to.be.equal('3.14,2.71,1.41');
+    });
 });