Add support for enhancemend string configs for credential properties

src/adapters/z2m.ts

@@ -2,6 +2,7 @@ import mqtt from "mqtt";
 import { Z2MConfig, Thing, Channel, ChannelType, ItemType } from "@types";
 import { snakecase } from "../utils/string";
 import { Adapter } from "./abstract";
+import { enhancedStringConfig } from "../utils/config";
 
 type Device = {
   definition?: Definition;
@@ -140,7 +141,11 @@ export class Z2MAdapter extends Adapter<Z2MConfig> {
     const { brokerURL, username, password, clientId, prefix } = this.config;
 
     return new Promise<Device[]>((resolve, reject) => {    
-      const client = mqtt.connect(brokerURL, { username, password, clientId: clientId || "oh-importer" });
+      const client = mqtt.connect(brokerURL, { 
+        username: enhancedStringConfig(username), 
+        password: enhancedStringConfig(password), 
+        clientId: clientId || "oh-importer" 
+      });
     
       client.on("message", (_, message) => {    
         client.end();    

src/openhab/index.ts

@@ -1,5 +1,6 @@
 import { OpenHABConfig, Thing } from "@types";
 import axios, { AxiosInstance } from "axios";
+import { enhancedStringConfig } from "../utils/config";
 
 export class OpenHAB {
   #api: AxiosInstance;
@@ -12,7 +13,7 @@ export class OpenHAB {
     this.#api = axios.create({
       baseURL: `${baseURL}/rest`,
       headers: {
-        Authorization: `Bearer ${token}`
+        Authorization: `Bearer ${enhancedStringConfig(token)}`
       }
     });
   }

src/utils/config.ts

@@ -0,0 +1,17 @@
+import { readFileSync } from "fs";
+
+const specialOptions: Record<string, (text: string) => string> = {
+  $__file: (arg: string) => readFileSync(arg, 'utf8')
+};
+
+export const enhancedStringConfig = (value: string) => {  
+  const trimmed = value.trim();
+
+  for(const opt of Object.keys(specialOptions)) {
+    if(trimmed.startsWith(`${opt}:`) && opt in specialOptions) {      
+      return specialOptions[opt](trimmed.slice(opt.length + 1));
+    }
+  }
+
+  return trimmed;
+};