From 3fec7684882fc7894a34966f4927eee5f3285f11 Mon Sep 17 00:00:00 2001
From: Andrew Beal <andrew.business@tuta.com>
Date: Mon, 25 May 2026 18:22:07 +0100
Subject: [PATCH] refactor: improve subscription cleanup with token-based
 pattern

Replace object-based subscription tracking with token-based system to prevent memory leaks. Add dispose() method to BaseAIClass and ensure all components properly unsubscribe in onDestroy. Update SettingsService.subscribeToSettingsChanged to return subscription token instead of requiring subscriber object parameter.
---
 AIClasses/BaseAIClass.ts           | 10 ++++++++--
 Components/ChatInput.svelte        |  7 +++----
 Components/ChatModeSelector.svelte | 10 +++++-----
 Components/UserInstruction.svelte  |  5 +++--
 Services/DependencyService.ts      |  8 +++++++-
 Services/SettingsService.ts        |  8 +++++---
 6 files changed, 31 insertions(+), 17 deletions(-)

diff --git a/AIClasses/BaseAIClass.ts b/AIClasses/BaseAIClass.ts
index 9b8fb65..934c5da 100644
--- a/AIClasses/BaseAIClass.ts
+++ b/AIClasses/BaseAIClass.ts
@@ -20,13 +20,15 @@ import { AIToolUsageMode } from "Enums/AIToolUsageMode";
 export abstract class BaseAIClass implements IAIClass {
 
     protected apiKey: string;
-    
+
     protected readonly provider: AIProvider;
     protected readonly abortService: AbortService;
     protected readonly aiFileService: IAIFileService;
     protected readonly settingsService: SettingsService;
     protected readonly streamingService: StreamingService;
 
+    private readonly settingsSubscription: object;
+
     private _systemPrompt: string = "";
     private _userInstruction: string = "";
     private _agentType: AgentType = AgentType.Main;
@@ -40,12 +42,16 @@ export abstract class BaseAIClass implements IAIClass {
         this.settingsService = Resolve<SettingsService>(Services.SettingsService);
         this.streamingService = Resolve<StreamingService>(Services.StreamingService);
 
-        this.settingsService.subscribeToSettingsChanged(this, () => {
+        this.settingsSubscription = this.settingsService.subscribeToSettingsChanged(() => {
             this.apiKey = this.settingsService.getApiKeyForProvider(provider);
         });
         this.apiKey = this.settingsService.getApiKeyForProvider(provider);
     }
 
+    public dispose(): void {
+        this.settingsService.unsubscribe(this.settingsSubscription);
+    }
+
     public get currentProvider(): AIProvider {
         return this.provider;
     }
diff --git a/Components/ChatInput.svelte b/Components/ChatInput.svelte
index f0dd40e..4f22a67 100644
--- a/Components/ChatInput.svelte
+++ b/Components/ChatInput.svelte
@@ -33,8 +33,6 @@
   export let onSubmit: (userRequest: string, formattedRequest: string) => void;
   export let onStop: () => void;
 
-  const componentToken = {};
-
   const inputService: InputService = Resolve<InputService>(Services.InputService);
   const settingsService: SettingsService = Resolve<SettingsService>(Services.SettingsService);
   const userInputService: UserInputService = Resolve<UserInputService>(Services.UserInputService);
@@ -75,14 +73,14 @@
   const diffClosedRef: EventRef = eventService.on(Event.DiffClosed, () => { inputMode = InputMode.Normal; focusInput(); });
   const rateLimitCountdownRef: EventRef = eventService.on(Event.RateLimitCountdown, (delayMs: number) => { startCountdown(delayMs); });
 
-  settingsService.subscribeToSettingsChanged(componentToken, () => {
+  const settingsSubscription: object = settingsService.subscribeToSettingsChanged(() => {
     chatMode = settingsService.settings.chatMode;
     editsAllowed = chatModeAllowsEdits(chatMode);
     if (chatModeButton){
       setIcon(chatModeButton, iconForChatMode(chatMode));
     }
   });
-  
+
   onMount(async () => {
     userInstructionActive = (await aiPrompt.userInstruction()).trim() !== "";
     inputInitialHeight = textareaElement.innerHeight;
@@ -92,6 +90,7 @@
     eventService.offref(diffOpenedRef);
     eventService.offref(diffClosedRef);
     eventService.offref(rateLimitCountdownRef);
+    settingsService.unsubscribe(settingsSubscription);
     stopCountdown();
   });
 
diff --git a/Components/ChatModeSelector.svelte b/Components/ChatModeSelector.svelte
index 51e4264..d6df2b7 100644
--- a/Components/ChatModeSelector.svelte
+++ b/Components/ChatModeSelector.svelte
@@ -1,7 +1,7 @@
 <script lang="ts">
 	import { ChatMode, iconForChatMode } from "Enums/ChatMode";
 	import { Copy } from "Enums/Copy";
-	import { tick } from "svelte";
+	import { onDestroy, tick } from "svelte";
 	import { setIcon } from "obsidian";
 	import type { SettingsService } from "Services/SettingsService";
 	import { Resolve } from "Services/DependencyService";
@@ -10,11 +10,11 @@
     export let focusInput: () => void;
     export let chatModeSelectionAreaActive: boolean;
 
-    const componentToken = {};
-
     const settingsService: SettingsService = Resolve<SettingsService>(Services.SettingsService);
-    
-    settingsService.subscribeToSettingsChanged(componentToken, () => currentChatMode = settingsService.settings.chatMode);
+
+    const settingsSubscription: object = settingsService.subscribeToSettingsChanged(() => currentChatMode = settingsService.settings.chatMode);
+
+    onDestroy(() => settingsService.unsubscribe(settingsSubscription));
 
     let height = 0;
 
diff --git a/Components/UserInstruction.svelte b/Components/UserInstruction.svelte
index f122a4f..4923894 100644
--- a/Components/UserInstruction.svelte
+++ b/Components/UserInstruction.svelte
@@ -80,8 +80,9 @@
 
     function handleInstructionSelect(e?: MouseEvent) {
         if (selectedInstruction < userInstructions.length) {
-            settingsService.settings.userInstruction = userInstructions[selectedInstruction];
-            settingsService.saveSettings();
+            settingsService.updateSettings(settings => {
+                settings.userInstruction = userInstructions[selectedInstruction];
+            });
         }
         userInstructionAreaActive = false;
 
diff --git a/Services/DependencyService.ts b/Services/DependencyService.ts
index 62a68bc..a9bdff7 100644
--- a/Services/DependencyService.ts
+++ b/Services/DependencyService.ts
@@ -35,7 +35,13 @@ export function TryResolve<T>(type: symbol): T | undefined {
 
 export function DeregisterAllServices() {
     services.forEach((service) => {
-        if (service && typeof service === "object" && "unload" in service) {
+        if (!service || typeof service !== "object") {
+            return;
+        }
+        if ("dispose" in service && typeof service.dispose === "function") {
+            (service as { dispose: () => void }).dispose();
+        }
+        if ("unload" in service) {
             (service as Component).unload();
         }
     });
diff --git a/Services/SettingsService.ts b/Services/SettingsService.ts
index a2f9229..65593e8 100644
--- a/Services/SettingsService.ts
+++ b/Services/SettingsService.ts
@@ -98,9 +98,11 @@ export class SettingsService {
         this.ensureValidModels();
     }
 
-    public subscribeToSettingsChanged(subscriber: object, callback: (() => void) | (() => Promise<void>)): void {
-        this.subscribers.set(subscriber, callback);
-        this.subscriberRefs.add(new WeakRef(subscriber));
+    public subscribeToSettingsChanged(callback: (() => void) | (() => Promise<void>)): object {
+        const token = {};
+        this.subscribers.set(token, callback);
+        this.subscriberRefs.add(new WeakRef(token));
+        return token;
     }
 
     public unsubscribe(subscriber: object): void {