[BUG] Code-index status subscription is not refreshed when workspace folders change

[WebMad]

Problem (one or two sentences)

Code-index status updates can stop reaching the UI when a workspace-folder change changes the selected indexing workspace without changing the active editor. Status routing remains subscribed to the previous workspace until an active-editor change triggers a refresh.

Context (who is affected and when)

Users working with multiple workspace folders can encounter stale indexing status after adding or removing a folder while keeping the same editor selected. This affects status delivery; it does not by itself establish that indexing stops.

Reproduction steps

This is a code-verified finding; the following manual scenario has not yet been executed in a real VS Code extension host.

1. Use the source build based on main commit 778ad3e (package version 3.84.0), with code indexing configured and a multi-root workspace.
2. Include a parent folder and a nested folder as separate workspace roots, plus another folder listed first so that removing the nested root does not change the first root.
3. Keep a file from the nested root active, using the default active-editor workspace selection. Initialize indexing status routing for the nested root.
4. Remove the nested root from the workspace while retaining its parent root and leaving the same file/editor active. The selected workspace now resolves to the parent root.
5. Generate indexing progress for the parent root without switching editors. Observe whether its status is delivered to the UI.
6. Switch active editors and compare status delivery after the subscription refresh.

A focused unit regression test should deterministically simulate the selected workspace changing, emit only the workspace-folder change event (no editor-change event), and assert immediate status publication and subscription switching.

Expected result

When a workspace-folder change changes the selected workspace, status routing immediately unsubscribes from the previous manager, subscribes to the newly selected manager, and publishes its current status without requiring an editor change.

Actual result

Initialization subscribes only to active-editor changes. After the selected workspace changes, the old progress callback rejects events because its manager no longer matches the currently resolved manager, while no subscription exists for the new manager. Status delivery remains stale until an editor change refreshes routing.

Variations tried (optional)

Static inspection of main commit 778ad3e and rebased PR #1778 commit 68383e7; no manual cross-platform reproduction performed.

The affected implementation is already in main via #1768 and is no longer part of the remaining diff in #1778. Rebasing #1778 did not fix this finding.

App Version

Source package version 3.84.0, main commit 778ad3e. This identifies the inspected source revision, not a confirmed affected Marketplace release.

API Provider (optional)

Not Applicable / Other

Model Used (optional)

N/A

Zoo Code Task Links (optional)

None.

Relevant logs or errors (optional)

No runtime logs collected. Original review finding: #1778 (comment)

Implementation references:

• Status manager initialization
• Subscription switching and stale-event guard
• Subscription disposal

Planned fix and acceptance criteria:

• Subscribe to workspace-folder changes and refresh status routing when they occur.
• Dispose the new subscription alongside editor and progress subscriptions, preserving idempotent cleanup and error handling.
• Add focused unit coverage for switching managers without an editor change, immediate publication of the new status, rejecting stale events, and disposal of the new subscription.
• Verify that a folder change which leaves the selected manager unchanged does not duplicate progress subscriptions.

Related indexing work: #1594.

[WebMad]

Contributor guide: scope for a good first issue

This is a small, focused status-routing fix. You do not need to understand or refactor the indexing pipeline, configure an embedding provider, or run a vector database to implement and unit-test it.

In scope

Keep the implementation and regression coverage in these two files unless a concrete blocker requires otherwise:

• Status manager
• Existing status-manager tests

1. Subscribe to workspace-folder changes alongside the existing active-editor subscription.
2. Have that event invoke the existing subscription-refresh logic. Do not introduce a second workspace-selection algorithm.
3. Store and release the new subscription using the existing cleanup pattern. Preserve idempotent disposal and error handling.
4. Extend the local VS Code mock and add focused unit tests for the event and cleanup behavior.

Out of scope

• Refactoring the indexing manager, registry, workspace scopes, scan execution, or file watchers.
• Changing how the workspace root is selected or adding settings/configuration-change handling.
• Starting/stopping indexing or creating/discarding workspace managers in response to folder changes beyond existing behavior.
• Changing status payloads, webview rendering, or the UI behavior when no workspace is selected.
• Broad test-helper cleanup, new dependencies, changelog entries, or changesets.
• Building a new end-to-end test harness. The regression can be represented with the existing unit-test setup.

Acceptance criteria

• A test starts with manager A selected, changes workspace-folder resolution so manager B is selected, and emits only the workspace-folder event — no active-editor event.
• That event disposes A's progress subscription, subscribes to B, and immediately publishes B's current status.
• Subsequent B progress updates are published; stale A events are ignored.
• A workspace-folder event that leaves the selected manager unchanged does not create a duplicate progress subscription or redundant initial publication.
• If no workspace remains selected, the previous progress subscription is released and stale events are ignored. No new UI reset behavior is required.
• Disposal releases the workspace-folder listener along with existing listeners. Repeated disposal is safe, and a cleanup exception does not prevent cleanup of the other subscriptions.
• The existing status-manager tests continue to pass, including active-editor switching and publication/error-handling behavior.

Suggested workflow and validation

First add a regression test for a workspace-folder event without an editor event and confirm it fails on the current implementation. Then make the minimal subscription/cleanup change and run the focused suite from the extension package directory (not the repository root).

Use the repository's documented Vitest, ESLint, and type-check procedures. ESLint suppression counts must not increase.

Manual VS Code reproduction is useful supplementary evidence, but is not required to replace the deterministic unit regression test. The manual scenario in the issue has not yet been verified; please distinguish tests you actually ran from scenarios inferred from code.

If the fix appears to require changes outside the two files above, explain the blocker in this issue before expanding the scope.