Fix and improve MQTT broker URL validation

README was actually wrong, and we should allow mqtts:// too

README.md

@@ -100,7 +100,7 @@ Options:
                                                        [boolean] [default: true]
   -a, --httpListenAddress    The address to listen (HTTP)   [default: "0.0.0.0"]
   -p, --httpPort             The port to listen on (HTTP)        [default: 8080]
-  -m, --mqttBrokerUrl        The URL to the MQTT broker, e.g. tcp://localhost:18
+  -m, --mqttBrokerUrl        The URL to the MQTT broker, e.g. mqtt://localhost:18
                              83. Omit to disable MQTT support.
       --mqttUsername         The username to use when connecting to the MQTT bro
                              ker. Omit to disable authentication.

app/mqtt.mjs

@@ -150,7 +150,7 @@ export const handleMessage = async (modbusClient, mqttClient, topicName, payload
 }
 
 export const validateBrokerUrl = (brokerUrl) => {
-    return brokerUrl.startsWith('tcp://')
+    return brokerUrl.startsWith('mqtt://') || brokerUrl.startsWith('mqtts://')
 }
 
 const createBinaryValue = (value) => {

tests/mqtt.test.mjs

@@ -1,8 +1,9 @@
 import { validateBrokerUrl } from '../app/mqtt.mjs'
 
 test('validateMqttUrl', () => {
-    expect(validateBrokerUrl('tcp://localhost:1883')).toEqual(true)
-    expect(validateBrokerUrl('tcp://localhost')).toEqual(true)
+    expect(validateBrokerUrl('mqtt://localhost:1883')).toEqual(true)
+    expect(validateBrokerUrl('mqtts://localhost:1883')).toEqual(true)
+    expect(validateBrokerUrl('mqtt://localhost')).toEqual(true)
     expect(validateBrokerUrl('localhost:1883')).toEqual(false)
     expect(validateBrokerUrl('localhost')).toEqual(false)
 })