fix: suppress "View not found" alert and update pane index on group removal

src/vs/workbench/browser/parts/editor/editor.ts

@@ -223,6 +223,9 @@ export interface IEditorGroupsView {
 
 	readonly onDidVisibilityChange: Event<boolean>;
 
+	readonly onDidAddGroup: Event<IEditorGroupView>;
+	readonly onDidRemoveGroup: Event<IEditorGroupView>;
+
 	getGroup(identifier: GroupIdentifier): IEditorGroupView | undefined;
 	getGroups(order: GroupsOrder): IEditorGroupView[];
 

src/vs/workbench/browser/parts/editor/editorGroupView.ts

@@ -1654,7 +1654,7 @@ export class EditorGroupView extends Themable implements IEditorGroupView {
 			this._onDidActiveEditorChange.fire({ editor: undefined });
 
 			// Remove empty group if we should
-			if (closeEmptyGroup) {
+			if (closeEmptyGroup && this.groupsView.getGroup(this.id)) {
 				this.groupsView.removeGroup(this, preserveFocus);
 			}
 		}

src/vs/workbench/browser/parts/editor/multiEditorTabsControl.ts

@@ -188,6 +188,10 @@ export class MultiEditorTabsControl extends EditorTabsControl {
 		this._register(this.editorService.onDidVisibleEditorsChange(() => {
 			this.editorGroupIndexScheduler.value = scheduleAtNextAnimationFrame(getWindow(this.parent), () => this.updateEditorGroupIndex());
 		}));
+
+		// React to group add/remove to update group index badge (Coderm)
+		this._register(this.groupsView.onDidRemoveGroup(() => this.updateEditorGroupIndex()));
+		this._register(this.groupsView.onDidAddGroup(() => this.updateEditorGroupIndex()));
 	}
 
 	protected override create(parent: HTMLElement): HTMLElement {

src/vs/workbench/test/browser/workbenchTestServices.ts

@@ -1032,6 +1032,8 @@ export class TestEditorGroupAccessor implements IEditorGroupsView {
 
 	onDidChangeEditorPartOptions = Event.None;
 	onDidVisibilityChange = Event.None;
+	onDidAddGroup = Event.None;
+	onDidRemoveGroup = Event.None;
 
 	getGroup(identifier: number): IEditorGroupView | undefined { throw new Error('Method not implemented.'); }
 	getGroups(order: GroupsOrder): IEditorGroupView[] { throw new Error('Method not implemented.'); }
@@ -1797,6 +1799,9 @@ export class TestWorkspacesService implements IWorkspacesService {
 	async getWorkspaceIdentifier(workspacePath: URI): Promise<IWorkspaceIdentifier> { throw new Error('Method not implemented.'); }
 }
 
+/**
+ * No-op {@link ITerminalInstanceService} stub for workbench tests.
+ */
 export class TestTerminalInstanceService implements ITerminalInstanceService {
 	onDidCreateInstance = Event.None;
 	onDidRegisterBackend = Event.None;
@@ -1810,6 +1815,12 @@ export class TestTerminalInstanceService implements ITerminalInstanceService {
 	getRegisteredBackends(): IterableIterator<ITerminalBackend> { throw new Error('Method not implemented.'); }
 }
 
+/**
+ * No-op {@link ITerminalEditorService} stub for workbench tests.
+ * Every method throws `"Method not implemented."` — only the events
+ * are wired to `Event.None` so consumers that subscribe during setup
+ * do not explode.
+ */
 export class TestTerminalEditorService implements ITerminalEditorService {
 	_serviceBrand: undefined;
 	activeInstance: ITerminalInstance | undefined;
@@ -1836,6 +1847,10 @@ export class TestTerminalEditorService implements ITerminalEditorService {
 	findPrevious(): void { throw new Error('Method not implemented.'); }
 }
 
+/**
+ * No-op {@link ITerminalGroupService} stub for workbench tests.
+ * Mirrors the pattern used by other `Test*Service` classes in this file.
+ */
 export class TestTerminalGroupService implements ITerminalGroupService {
 	_serviceBrand: undefined;
 	activeInstance: ITerminalInstance | undefined;
@@ -1883,6 +1898,9 @@ export class TestTerminalGroupService implements ITerminalGroupService {
 	updateVisibility(): void { throw new Error('Method not implemented.'); }
 }
 
+/**
+ * No-op {@link ITerminalProfileService} stub for workbench tests.
+ */
 export class TestTerminalProfileService implements ITerminalProfileService {
 	_serviceBrand: undefined;
 	availableProfiles: ITerminalProfile[] = [];
@@ -1901,6 +1919,10 @@ export class TestTerminalProfileService implements ITerminalProfileService {
 	overrideDefaultProfile(extensionIdentifier: string, id: string): IDisposable { return Disposable.None; }
 }
 
+/**
+ * No-op {@link ITerminalProfileResolverService} stub for workbench tests.
+ * Returns minimal defaults so callers that await profile resolution succeed.
+ */
 export class TestTerminalProfileResolverService implements ITerminalProfileResolverService {
 	_serviceBrand: undefined;
 	defaultProfileName = '';
@@ -1916,6 +1938,10 @@ export class TestTerminalProfileResolverService implements ITerminalProfileResol
 	createProfileFromShellAndShellArgs(shell?: unknown, shellArgs?: unknown): Promise<string | ITerminalProfile> { throw new Error('Method not implemented.'); }
 }
 
+/**
+ * Test-friendly subclass of {@link TerminalConfigurationService} that
+ * exposes the internal font-metrics and config setters for unit tests.
+ */
 export class TestTerminalConfigurationService extends TerminalConfigurationService {
 	get fontMetrics() { return this._fontMetrics; }
 	// eslint-disable-next-line local/code-no-any-casts