Validate user provided viewletId

src/vs/workbench/parts/explorers/browser/treeExplorerViewlet.contribution.ts

@@ -16,11 +16,14 @@ import { ITreeExplorerViewletService, TreeExplorerViewletService } from 'vs/work
 import { registerSingleton } from 'vs/platform/instantiation/common/extensions';
 import { ViewletRegistry, Extensions as ViewletExtensions, ViewletDescriptor } from 'vs/workbench/browser/viewlet';
 import { ITreeExplorer } from 'vs/platform/extensionManagement/common/extensionManagement';
-import { toCustomViewletId, toCustomViewletCSSClass } from 'vs/workbench/parts/explorers/common/treeExplorer';
+import { toCustomViewletId, toCustomViewletCSSClass, isValidViewletId } from 'vs/workbench/parts/explorers/common/treeExplorer';
+import { IWorkbenchContribution } from 'vs/workbench/common/contributions';
+import { IWorkbenchContributionsRegistry, Extensions as WorkbenchExtensions } from 'vs/workbench/common/contributions';
+import { IMessageService, Severity } from 'vs/platform/message/common/message';
 
 registerSingleton(ITreeExplorerViewletService, TreeExplorerViewletService);
 
-const explorerContribtion: IJSONSchema = {
+const explorerSchema: IJSONSchema = {
 	description: localize('vscode.extension.contributes.explorer', "Contributes custom tree explorer viewlet to the sidebar"),
 	type: 'object',
 	properties: {
@@ -29,7 +32,7 @@ const explorerContribtion: IJSONSchema = {
 			type: 'string'
 		},
 		treeLabel: {
-			description: localize('vscode.extension.contributes.explorer.treeLabel', 'Human readable string used to render the custom tree viewlet'),
+			description: localize('vscode.extension.contributes.explorer.treeLabel', 'Human readable string used to render the custom tree explorer'),
 			type: 'string'
 		},
 		icon: {
@@ -39,10 +42,27 @@ const explorerContribtion: IJSONSchema = {
 	}
 };
 
-ExtensionsRegistry.registerExtensionPoint<ITreeExplorer>('explorer', [], explorerContribtion).setHandler(extensions => {
+export class ExplorerContribtion implements IWorkbenchContribution {
+
+	constructor(
+		@IMessageService private messageService: IMessageService
+	) {
+		this.init();
+	}
+
+	public getId(): string {
+		return 'vs.explorer';
+	}
+
+	private init() {
+		ExtensionsRegistry.registerExtensionPoint<ITreeExplorer>('explorer', [], explorerSchema).setHandler(extensions => {
 			for (let extension of extensions) {
 				const { treeExplorerNodeProviderId, treeLabel, icon } = extension.value;
 
+				if (!isValidViewletId(treeExplorerNodeProviderId)) {
+					return this.messageService.show(Severity.Error, localize('customExplorer.invalidId', 'Tree Explorer extension {0} has invalid id and failed to activate.', treeLabel));
+				}
+
 				const getIconRule = (iconPath) => { return `background-image: url('${iconPath}')`; };
 				if (icon) {
 					const iconClass = `.monaco-workbench > .activitybar .monaco-action-bar .action-label.${toCustomViewletCSSClass(treeExplorerNodeProviderId)}`;
@@ -60,4 +80,8 @@ ExtensionsRegistry.registerExtensionPoint<ITreeExplorer>('explorer', [], explore
 					true
 				));
 			}
-});
\ No newline at end of file
+		});
+	}
+}
+
+(<IWorkbenchContributionsRegistry>Registry.as(WorkbenchExtensions.Workbench)).registerWorkbenchContribution(ExplorerContribtion);
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src/vs/workbench/parts/explorers/common/treeExplorer.ts

@@ -15,3 +15,8 @@ export function toCustomViewletActionId(viewletId: string): string {
 export function toCustomViewletCSSClass(viewletId: string): string {
 	return 'customExplorer-' + viewletId;
 }
+
+export function isValidViewletId(viewletId: string): boolean {
+	// Only allow alphanumeric letters, `_` and `-`.
+	return /^[a-z0-9_-]+$/i.test(viewletId);
+}
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