Fix duplicate missing packages badge

src/vs/workbench/contrib/positronMissingPackages/browser/positronMissingPackages.contribution.ts

@@ -52,15 +52,18 @@ workbenchRegistry.registerWorkbenchContribution(MissingPackagesPrecomputeContrib
 workbenchRegistry.registerWorkbenchContribution(MissingPackagesContextKeyContribution, LifecyclePhase.Restored);
 
 // Editor action bar badge (scenario 2) for scripts whose language has a session
-// that supports missing packages, and Quarto documents. The editor action bar
-// is disabled for notebooks, so notebooks get a separate mount below. Quarto
-// documents are multi-language; the service splits them into per-language code
-// chunks and routes each to its session.
+// that supports missing packages, and Quarto documents. The Positron notebook
+// toolbar also renders this menu, so notebooks are excluded here and get their
+// own mount below. Quarto documents are multi-language; the service splits them
+// into per-language code chunks and routes each to its session.
 PositronActionBarWidgetRegistry.registerWidget({
 	id: 'positronMissingPackages.editorBadge',
 	menuId: MenuId.EditorActionsRight,
 	order: 95,
-	when: MISSING_PACKAGES_SUPPORTED_KEY,
+	when: ContextKeyExpr.and(
+		MISSING_PACKAGES_SUPPORTED_KEY,
+		ContextKeyExpr.notEquals('activeEditor', POSITRON_NOTEBOOK_EDITOR_ID),
+	),
 	selfContained: true,
 	componentFactory: (accessor) => () => React.createElement(MissingPackagesBadgeMount, { accessor }),
 });

src/vs/workbench/contrib/positronMissingPackages/test/browser/missingPackagesBadgeRegistration.vitest.ts

@@ -0,0 +1,38 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (C) 2026 Posit Software, PBC. All rights reserved.
+ *  Licensed under the Elastic License 2.0. See LICENSE.txt for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+/// <reference types="vitest/globals" />
+
+import { MenuId } from '../../../../../platform/actions/common/actions.js';
+import { IContextKeyService } from '../../../../../platform/contextkey/common/contextkey.js';
+import { PositronActionBarWidgetRegistry } from '../../../../../platform/positronActionBar/browser/positronActionBarWidgetRegistry.js';
+import { stubInterface } from '../../../../../test/vitest/stubInterface.js';
+import { POSITRON_NOTEBOOK_EDITOR_ID } from '../../../positronNotebook/common/positronNotebookCommon.js';
+import { MISSING_PACKAGES_SUPPORTED_KEY } from '../../browser/missingPackagesContextKey.js';
+// Registers the badge widgets as a side effect.
+import '../../browser/positronMissingPackages.contribution.js';
+
+function badgesFor(activeEditor: string): string[] {
+	const values: Record<string, unknown> = {
+		activeEditor,
+		[MISSING_PACKAGES_SUPPORTED_KEY.key]: true,
+	};
+	const contextKeyService = stubInterface<IContextKeyService>({
+		contextMatchesRules: rules => !rules || rules.evaluate({ getValue: <T>(key: string) => values[key] as T }),
+	});
+	return PositronActionBarWidgetRegistry.getWidgets(MenuId.EditorActionsRight, contextKeyService)
+		.map(w => w.id)
+		.filter(id => id.startsWith('positronMissingPackages.'));
+}
+
+describe('missing packages badge registration', () => {
+	it('shows only the notebook badge in a Positron notebook', () => {
+		expect(badgesFor(POSITRON_NOTEBOOK_EDITOR_ID)).toEqual(['positronMissingPackages.notebookBadge']);
+	});
+
+	it('shows only the editor badge in a text editor', () => {
+		expect(badgesFor('workbench.editors.files.textFileEditor')).toEqual(['positronMissingPackages.editorBadge']);
+	});
+});