make event optional, event naming, relax badge length a little, https://github.com/microsoft/vscode/issues/54938

extensions/git/src/decorationProvider.ts

@@ -15,12 +15,12 @@ class GitIgnoreDecorationProvider implements FileDecorationProvider {
 
 	private static Decoration: FileDecoration = { color: new ThemeColor('gitDecoration.ignoredResourceForeground') };
 
-	readonly onDidChange: Event<Uri[]>;
+	readonly onDidChangeFileDecorations: Event<Uri[]>;
 	private queue = new Map<string, { repository: Repository; queue: Map<string, PromiseSource<FileDecoration | undefined>>; }>();
 	private disposables: Disposable[] = [];
 
 	constructor(private model: Model) {
-		this.onDidChange = fireEvent(anyEvent<any>(
+		this.onDidChangeFileDecorations = fireEvent(anyEvent<any>(
 			filterEvent(workspace.onDidSaveTextDocument, e => /\.gitignore$|\.git\/info\/exclude$/.test(e.uri.path)),
 			model.onDidOpenRepository,
 			model.onDidCloseRepository
@@ -93,7 +93,7 @@ class GitDecorationProvider implements FileDecorationProvider {
 	};
 
 	private readonly _onDidChangeDecorations = new EventEmitter<Uri[]>();
-	readonly onDidChange: Event<Uri[]> = this._onDidChangeDecorations.event;
+	readonly onDidChangeFileDecorations: Event<Uri[]> = this._onDidChangeDecorations.event;
 
 	private disposables: Disposable[] = [];
 	private decorations = new Map<string, FileDecoration>();

src/vs/vscode.proposed.d.ts

@@ -786,9 +786,9 @@ declare module 'vscode' {
 		/**
 		 * An event to signal decorations for one or many files have changed.
 		 *
-		 * @see [EventEmitter](#EventEmitter
+		 * @see [EventEmitter](#EventEmitter)
 		 */
-		onDidChange: Event<undefined | Uri | Uri[]>;
+		onDidChangeFileDecorations?: Event<undefined | Uri | Uri[]>;
 
 		/**
 		 * Provide decorations for a given uri.

src/vs/workbench/api/common/extHostDecorations.ts

@@ -42,7 +42,7 @@ export class ExtHostDecorations implements ExtHostDecorationsShape {
 		this._provider.set(handle, { provider, extensionId });
 		this._proxy.$registerDecorationProvider(handle, extensionId.value);
 
-		const listener = provider.onDidChange(e => {
+		const listener = provider.onDidChangeFileDecorations && provider.onDidChangeFileDecorations(e => {
 			if (!e) {
 				this._proxy.$onDidChange(handle, null);
 				return;
@@ -75,7 +75,7 @@ export class ExtHostDecorations implements ExtHostDecorationsShape {
 		});
 
 		return new Disposable(() => {
-			listener.dispose();
+			listener?.dispose();
 			this._proxy.$unregisterDecorationProvider(handle);
 			this._provider.delete(handle);
 		});

src/vs/workbench/api/common/extHostTypes.ts

@@ -2720,8 +2720,8 @@ export enum ExtensionKind {
 export class FileDecoration {
 
 	static validate(d: FileDecoration): void {
-		if (d.badge && d.badge.length !== 1) {
-			throw new Error(`The 'badge'-property must be undefined or a single character`);
+		if (d.badge && (d.badge.length === 1 || d.badge.length === 2)) {
+			throw new Error(`The 'badge'-property must be undefined or a short character`);
 		}
 		if (!d.color && !d.badge && !d.tooltip) {
 			throw new Error(`The decoration is empty`);