Device: Change cleanup approach

Disconnect cannot be used for cleanup as it actually has the property of
disconnecting already connected devices.

This commit removes listener removal from disconnect and places it in its own
function that should be called on a Device object after instantiating it
and before discarding it.

src/Adapter.js

@@ -109,6 +109,8 @@ class Adapter {
 
   /**
    * Init a device instance and returns it.
+   * Caller is responsible of calling cleanup() on the
+   * returned Device before discarding it to free resources.
    * @param {string} uuid - Device Name.
    * @async
    * @returns {Device}

src/Device.js

@@ -119,7 +119,7 @@ class Device extends EventEmitter {
    */
   async disconnect () {
     await this.helper.callMethod('Disconnect')
-    this.helper.removeListeners()
+    await this.cleanup()
   }
 
   /**
@@ -142,6 +142,13 @@ class Device extends EventEmitter {
 
     return `${name} [${address}]`
   }
+
+  /**
+   * Cleanup when discarding device object
+   */
+  async cleanup () {
+    this.helper.removeListeners()
+  }
 }
 
 /**

src/index.d.ts

@@ -45,6 +45,7 @@ declare namespace NodeBle {
         disconnect(): Promise<void>;
         gatt(): Promise<GattServer>;
         toString(): Promise<string>;
+        cleanup(): Promise<void>;
 
         on(event: 'connect', listener: (state: ConnectionState) => void): this;
         on(event: 'disconnect', listener: (state: ConnectionState) => void): this;