Adding fixing save chat session overwriting

[arafatkatze]

Linear Issue

Problem

Previously, whenever a user deleted a chat, disposeChat would call clearAndRestartSession(), which in turn triggered saveSession(). This saved the just-deleted chat back into local storage, negating the deletion.

Solution

Introduce a skipSave boolean to conditionally skip the clearAndRestartSession() flow during deletion. If skipSave is true (e.g., for a deletion), clearAndRestartSession() is not called. This prevents the race condition of re-saving an already-deleted chat.

Why It Works

1.	Avoid Conflicts – If the user explicitly wants to remove a chat, we no longer re-create or re-save the session.
2.	Maintain Clean State – Normal operations (skipSave = false) still clear and restart sessions. Deletions (skipSave = true) skip that path to maintain data consistency.
3.	Prevent Race Conditions – The skip logic ensures no stale data overwrites the freshly updated local storage.

Using the skipSave flag to conditionally skip clearAndRestartSession() is safe because:

1. During normal operations (when skipSave is false), you want to clear and restart the session to maintain a clean state

2. During deletion (when skipSave is true), you want to skip this step because:
   The chat is being deleted anyway
   clearAndRestartSession() includes a saveSession() call which could race with the deletion

3. There's no need to create a new session when we're removing the chat
   The condition helps prevent potential issues where:

• The deletion operation is trying to remove chat history
• While simultaneously, clearAndRestartSession() might try to save the session
• Which could lead to inconsistent state or race conditions

So yes, using the skipSave flag to conditionally skip clearAndRestartSession() during deletion is a good practice for maintaining data consistency.

Test plan

Run this code in Vscode/Jetbrains debugger and delete a chat from history

Changelog

[abeatrix]

Thanks for catching this! Left a comment in line, will do a proper review once I'm back on my computer later.

Would be great if we can have a test covering this behavior!

[abeatrix]

Haven't looked into the code yet but wonder if it would work if we dispose the chat before we deleting the chat?

[arafatkatze]

Would be great if we can have a test covering this behavior!

So I could possibly write some kind of "number of times called" kind of test on chatcontroller but I would ideally love to have webview based UI test(see slack)

[arafatkatze]

wonder if it would work if we dispose the chat before we deleting the chat?

While disposing before deleting seems like a good approach to prevent race conditions, it doesn't fully solve the problem. Here's why:

private async clearHistory(chatID?: string): Promise<void> {
    // ... other code ...

    // Even if we do this:
    this.disposeChat(chatID, true)  // Step 1: Dispose first
    await chatHistory.deleteChat(authStatus, chatID)  // Step 2: Then delete

    // The issue is that disposeChat() itself triggers a save operation:
    // 1. When disposing the chat controller
    // 2. When clearing/restarting the session

The race condition still exists because:
disposeChat() triggers a save operation as part of its cleanup
Then we immediately try to delete the chat history
These operations can overlap since saves are asynchronous
That's why the current solution uses a skipSave flag:

this.disposeChat(chatID, true, { skipSave: true }) // Prevents the save during disposal
await chatHistory.deleteChat(authStatus, chatID)

This ensures we're not trying to save and delete the same chat data simultaneously. Simply changing the order of operations (dispose then delete) isn't enough to prevent the race condition.

[abeatrix]

thanks!

[abeatrix]

nice!