Add telemetry for tree view concurrent refresh

[alexr00]

No description provided.

[Copilot]

Pull request overview

Adds telemetry and retry handling around tree view node resolution when concurrent refreshes invalidate child fetches.

Changes:

• Add bounded retry logic to ExtHostTreeView._resolveTreeNode when getChildren() returns undefined due to concurrent refresh invalidation, and emit retry telemetry via the main thread.
• Extend the ext host ↔ main thread protocol with $logResolveTreeNodeRetry and implement telemetry emission in MainThreadTreeViews.
• Update the MainThreadTreeViews browser test to pass a telemetry service.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
src/vs/workbench/api/test/browser/mainThreadTreeViews.test.ts	Passes NullTelemetryService to MainThreadTreeViews in the test setup.
src/vs/workbench/api/common/extHostTreeViews.ts	Implements retry-on-invalidated-children logic and calls into the main thread to log retry telemetry.
src/vs/workbench/api/common/extHost.protocol.ts	Adds $logResolveTreeNodeRetry to the MainThreadTreeViewsShape RPC surface.
src/vs/workbench/api/browser/mainThreadTreeViews.ts	Injects ITelemetryService and logs the new treeView.resolveRetry telemetry event.

Comments suppressed due to low confidence (2)

src/vs/workbench/api/common/extHostTreeViews.ts:714

• The retry limit 3 is hard-coded in multiple places (condition, log message, telemetry semantics). To avoid accidental divergence if this value changes, consider introducing a single const MAX_RESOLVE_RETRIES = 3 (or similar) and reusing it for the comparison and for the attempt x/y message.

		if (children === undefined && retryCount < 3) {
			const newRetryCount = retryCount + 1;
			this._logService.warn(`[${this._viewId}] Retrying _resolveTreeNode due to concurrent refresh (attempt ${newRetryCount}/3) for element ${handle} from extension ${this._extension.identifier.value}`);

src/vs/workbench/api/common/extHostTreeViews.ts:720

• The new retry/telemetry behavior in _resolveTreeNode isn’t covered by tests. Since this code path is race-sensitive (concurrent refresh invalidating _fetchChildrenNodes leading to getChildren() returning undefined), it would be good to add a focused unit test (e.g. in src/vs/workbench/api/test/browser/extHostTreeViews.test.ts) that simulates token invalidation and asserts: (1) _resolveTreeNode retries up to the limit and (2) $logResolveTreeNodeRetry is called with the expected parameters.

	private async _resolveTreeNode(element: T, parent?: TreeNode, retryCount = 0): Promise<TreeNode> {
		const node = this._nodes.get(element);
		if (node) {
			return node;
		}
		const extTreeItem = await asPromise(() => this._dataProvider.getTreeItem(element));
		const handle = this._createHandle(element, extTreeItem, parent, true);
		const children = await this.getChildren(parent ? parent.item.handle : undefined);
		// If getChildren returned undefined, it means a concurrent refresh invalidated
		// the fetch. Retry a limited number of times to handle transient refresh races.
		if (children === undefined && retryCount < 3) {
			const newRetryCount = retryCount + 1;
			this._logService.warn(`[${this._viewId}] Retrying _resolveTreeNode due to concurrent refresh (attempt ${newRetryCount}/3) for element ${handle} from extension ${this._extension.identifier.value}`);
			if (newRetryCount === 1) {
				// Log telemetry on first retry
				this._proxy.$logResolveTreeNodeRetry(this._viewId, this._extension.identifier.value, newRetryCount, false);
			}
			return this._resolveTreeNode(element, parent, newRetryCount);
		}

[Copilot]

treeViewId is passed over RPC but intentionally unused here. If it’s not meant to be collected, consider removing it from the protocol/method signature to avoid confusion and unnecessary payload; if it is useful, consider including a sanitized/appropriate representation in the telemetry event so the parameter has a purpose.