Always require an explicit argument for Emitter.fire

Calling `fire` with zero arguments results in the emitter firing with `undefined`. This is often not expected or desired. It should be explicit that the emitter is fired with undefined

src/vs/base/browser/ui/grid/gridview.ts

@@ -21,7 +21,7 @@ export interface IView {
 	readonly maximumWidth: number;
 	readonly minimumHeight: number;
 	readonly maximumHeight: number;
-	readonly onDidChange: Event<{ width: number; height: number; }>;
+	readonly onDidChange: Event<{ width: number; height: number; } | undefined>;
 	readonly priority?: LayoutPriority;
 	readonly snapSize?: number;
 	layout(width: number, height: number): void;
@@ -308,7 +308,7 @@ class BranchNode implements ISplitView, IDisposable {
 		this.childrenSashResetDisposable.dispose();
 		this.childrenSashResetDisposable = onDidChildrenSashReset(this._onDidSashReset.fire, this._onDidSashReset);
 
-		this._onDidChange.fire();
+		this._onDidChange.fire(undefined);
 	}
 
 	trySet2x2(other: BranchNode): IDisposable {
@@ -348,8 +348,8 @@ class BranchNode implements ISplitView, IDisposable {
 		mySash.linkedSash = otherSash;
 		otherSash.linkedSash = mySash;
 
-		this._onDidChange.fire();
-		other._onDidChange.fire();
+		this._onDidChange.fire(undefined);
+		other._onDidChange.fire(undefined);
 
 		return toDisposable(() => {
 			mySash.linkedSash = otherSash.linkedSash = undefined;
@@ -391,7 +391,7 @@ class LeafNode implements ISplitView, IDisposable {
 	set linkedWidthNode(node: LeafNode | undefined) {
 		this._onDidLinkedWidthNodeChange.input = node ? node._onDidViewChange : Event.None;
 		this._linkedWidthNode = node;
-		this._onDidSetLinkedNode.fire();
+		this._onDidSetLinkedNode.fire(undefined);
 	}
 
 	private _onDidLinkedHeightNodeChange = new Relay<number | undefined>();
@@ -400,7 +400,7 @@ class LeafNode implements ISplitView, IDisposable {
 	set linkedHeightNode(node: LeafNode | undefined) {
 		this._onDidLinkedHeightNodeChange.input = node ? node._onDidViewChange : Event.None;
 		this._linkedHeightNode = node;
-		this._onDidSetLinkedNode.fire();
+		this._onDidSetLinkedNode.fire(undefined);
 	}
 
 	private _onDidSetLinkedNode = new Emitter<number | undefined>();

src/vs/base/browser/ui/splitview/panelview.ts

@@ -77,7 +77,7 @@ export abstract class Panel implements IView {
 
 	set minimumBodySize(size: number) {
 		this._minimumBodySize = size;
-		this._onDidChange.fire();
+		this._onDidChange.fire(undefined);
 	}
 
 	get maximumBodySize(): number {
@@ -86,7 +86,7 @@ export abstract class Panel implements IView {
 
 	set maximumBodySize(size: number) {
 		this._maximumBodySize = size;
-		this._onDidChange.fire();
+		this._onDidChange.fire(undefined);
 	}
 
 	private get headerSize(): number {
@@ -145,7 +145,7 @@ export abstract class Panel implements IView {
 
 		this._headerVisible = !!visible;
 		this.updateHeader();
-		this._onDidChange.fire();
+		this._onDidChange.fire(undefined);
 	}
 
 	render(): void {

src/vs/base/common/event.ts

@@ -137,7 +137,7 @@ export namespace Event {
 						output = undefined;
 						handle = undefined;
 						if (!leading || numDebouncedCalls > 1) {
-							emitter.fire(_output);
+							emitter.fire(_output!);
 						}
 
 						numDebouncedCalls = 0;
@@ -332,17 +332,17 @@ export namespace Event {
 		return result.event;
 	}
 
-	export function fromPromise<T =any>(promise: Promise<T>): Event<T> {
-		const emitter = new Emitter<T>();
+	export function fromPromise<T = any>(promise: Promise<T>): Event<undefined> {
+		const emitter = new Emitter<undefined>();
 		let shouldEmit = false;
 
 		promise
 			.then(undefined, () => null)
 			.then(() => {
 				if (!shouldEmit) {
-					setTimeout(() => emitter.fire(), 0);
+					setTimeout(() => emitter.fire(undefined), 0);
 				} else {
-					emitter.fire();
+					emitter.fire(undefined);
 				}
 			});
 
@@ -466,7 +466,7 @@ export class Emitter<T> {
 	private readonly _leakageMon: LeakageMonitor | undefined;
 	private _disposed: boolean = false;
 	private _event: Event<T> | undefined;
-	private _deliveryQueue: [Listener, (T | undefined)][] | undefined;
+	private _deliveryQueue: [Listener, T][] | undefined;
 	protected _listeners: LinkedList<Listener> | undefined;
 
 	constructor(options?: EmitterOptions) {
@@ -541,7 +541,7 @@ export class Emitter<T> {
 	 * To be kept private to fire an event to
 	 * subscribers
 	 */
-	fire(event?: T): any {
+	fire(event: T): any {
 		if (this._listeners) {
 			// put all [listener,event]-pairs into delivery queue
 			// then emit all event. an inner/nested event might be

src/vs/base/parts/ipc/node/ipc.net.ts

@@ -292,7 +292,7 @@ function createBufferedEvent<T>(source: Event<T>): Event<T> {
 		}
 		isDeliveringMessages = true;
 		while (hasListeners && bufferedMessages.length > 0) {
-			emitter.fire(bufferedMessages.shift());
+			emitter.fire(bufferedMessages.shift()!);
 		}
 		isDeliveringMessages = false;
 	};

src/vs/base/test/browser/ui/grid/util.ts

@@ -9,20 +9,20 @@ import { IView, GridNode, isGridBranchNode, } from 'vs/base/browser/ui/grid/grid
 
 export class TestView implements IView {
 
-	private _onDidChange = new Emitter<{ width: number; height: number; }>();
+	private _onDidChange = new Emitter<{ width: number; height: number; } | undefined>();
 	readonly onDidChange = this._onDidChange.event;
 
 	get minimumWidth(): number { return this._minimumWidth; }
-	set minimumWidth(size: number) { this._minimumWidth = size; this._onDidChange.fire(); }
+	set minimumWidth(size: number) { this._minimumWidth = size; this._onDidChange.fire(undefined); }
 
 	get maximumWidth(): number { return this._maximumWidth; }
-	set maximumWidth(size: number) { this._maximumWidth = size; this._onDidChange.fire(); }
+	set maximumWidth(size: number) { this._maximumWidth = size; this._onDidChange.fire(undefined); }
 
 	get minimumHeight(): number { return this._minimumHeight; }
-	set minimumHeight(size: number) { this._minimumHeight = size; this._onDidChange.fire(); }
+	set minimumHeight(size: number) { this._minimumHeight = size; this._onDidChange.fire(undefined); }
 
 	get maximumHeight(): number { return this._maximumHeight; }
-	set maximumHeight(size: number) { this._maximumHeight = size; this._onDidChange.fire(); }
+	set maximumHeight(size: number) { this._maximumHeight = size; this._onDidChange.fire(undefined); }
 
 	private _element: HTMLElement = document.createElement('div');
 	get element(): HTMLElement { this._onDidGetElement.fire(); return this._element; }

src/vs/base/test/browser/ui/splitview/splitview.test.ts

@@ -14,10 +14,10 @@ class TestView implements IView {
 	readonly onDidChange = this._onDidChange.event;
 
 	get minimumSize(): number { return this._minimumSize; }
-	set minimumSize(size: number) { this._minimumSize = size; this._onDidChange.fire(); }
+	set minimumSize(size: number) { this._minimumSize = size; this._onDidChange.fire(undefined); }
 
 	get maximumSize(): number { return this._maximumSize; }
-	set maximumSize(size: number) { this._maximumSize = size; this._onDidChange.fire(); }
+	set maximumSize(size: number) { this._maximumSize = size; this._onDidChange.fire(undefined); }
 
 	private _element: HTMLElement = document.createElement('div');
 	get element(): HTMLElement { this._onDidGetElement.fire(); return this._element; }

src/vs/base/test/common/event.test.ts

@@ -111,7 +111,7 @@ suite('Event', function () {
 		Errors.setUnexpectedErrorHandler(() => null);
 
 		try {
-			let a = new Emitter();
+			let a = new Emitter<undefined>();
 			let hit = false;
 			a.event(function () {
 				throw 9;
@@ -134,19 +134,19 @@ suite('Event', function () {
 		}
 		const context = {};
 
-		let emitter = new Emitter();
+		let emitter = new Emitter<undefined>();
 		let reg1 = emitter.event(listener, context);
 		let reg2 = emitter.event(listener, context);
 
-		emitter.fire();
+		emitter.fire(undefined);
 		assert.equal(counter, 2);
 
 		reg1.dispose();
-		emitter.fire();
+		emitter.fire(undefined);
 		assert.equal(counter, 3);
 
 		reg2.dispose();
-		emitter.fire();
+		emitter.fire(undefined);
 		assert.equal(counter, 3);
 	});
 

src/vs/editor/contrib/gotoError/gotoError.ts

@@ -31,7 +31,7 @@ class MarkerModel {
 	private _nextIdx: number;
 	private _toUnbind: IDisposable[];
 	private _ignoreSelectionChange: boolean;
-	private readonly _onCurrentMarkerChanged: Emitter<IMarker>;
+	private readonly _onCurrentMarkerChanged: Emitter<IMarker | undefined>;
 	private readonly _onMarkerSetChanged: Emitter<MarkerModel>;
 
 	constructor(editor: ICodeEditor, markers: IMarker[]) {

src/vs/monaco.d.ts

@@ -21,7 +21,7 @@ declare namespace monaco {
 	export class Emitter<T> {
 		constructor();
 		readonly event: IEvent<T>;
-		fire(event?: T): void;
+		fire(event: T): void;
 		dispose(): void;
 	}
 

src/vs/platform/actions/common/actions.ts

@@ -104,7 +104,7 @@ export interface IMenuActionOptions {
 }
 
 export interface IMenu extends IDisposable {
-	onDidChange: Event<IMenu>;
+	readonly onDidChange: Event<IMenu | undefined>;
 	getActions(options?: IMenuActionOptions): [string, Array<MenuItemAction | SubmenuItemAction>][];
 }
 
@@ -123,7 +123,7 @@ export interface IMenuRegistry {
 	getCommands(): ICommandsMap;
 	appendMenuItem(menu: MenuId, item: IMenuItem | ISubmenuItem): IDisposable;
 	getMenuItems(loc: MenuId): Array<IMenuItem | ISubmenuItem>;
-	onDidChangeMenu: Event<MenuId>;
+	readonly onDidChangeMenu: Event<MenuId>;
 }
 
 export interface ICommandsMap {

src/vs/platform/actions/common/menuService.ts

@@ -29,7 +29,7 @@ type MenuItemGroup = [string, Array<IMenuItem | ISubmenuItem>];
 
 class Menu implements IMenu {
 
-	private readonly _onDidChange = new Emitter<IMenu>();
+	private readonly _onDidChange = new Emitter<IMenu | undefined>();
 	private readonly _disposables: IDisposable[] = [];
 
 	private _menuGroups: MenuItemGroup[];
@@ -56,7 +56,7 @@ class Menu implements IMenu {
 			this._contextKeyService.onDidChangeContext,
 			(last, event) => last || event.affectsSome(this._contextKeys),
 			50
-		)(e => e && this._onDidChange.fire(), this, this._disposables);
+		)(e => e && this._onDidChange.fire(undefined), this, this._disposables);
 	}
 
 	private _build(): void {
@@ -100,7 +100,7 @@ class Menu implements IMenu {
 		this._onDidChange.dispose();
 	}
 
-	get onDidChange(): Event<IMenu> {
+	get onDidChange(): Event<IMenu | undefined> {
 		return this._onDidChange.event;
 	}
 

src/vs/platform/download/node/downloadIpc.ts

@@ -19,7 +19,7 @@ export function upload(uri: URI): Event<UploadResponse> {
 	const readstream = fs.createReadStream(uri.fsPath);
 	readstream.on('data', data => stream.fire(data));
 	readstream.on('error', error => stream.fire(error.toString()));
-	readstream.on('close', () => stream.fire());
+	readstream.on('close', () => stream.fire(undefined));
 	return stream.event;
 }
 

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

@@ -142,7 +142,7 @@ export class EditorControl extends Disposable {
 		}
 
 		// Indicate that size constraints could have changed due to new editor
-		this._onDidSizeConstraintsChange.fire();
+		this._onDidSizeConstraintsChange.fire(undefined);
 	}
 
 	private doSetInput(control: BaseEditor, editor: EditorInput, options: EditorOptions): Promise<boolean> {

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

@@ -920,7 +920,7 @@ export class EditorPart extends Part implements EditorGroupsServiceImpl, IEditor
 			this._onDidSizeConstraintsChange.input = gridWidget.onDidChange;
 		}
 
-		this.onDidSetGridWidget.fire();
+		this.onDidSetGridWidget.fire(undefined);
 	}
 
 	private updateContainer(): void {

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

@@ -198,7 +198,7 @@ export class SideBySideEditor extends BaseEditor {
 			Event.map(master.onDidSizeConstraintsChange, () => undefined)
 		);
 
-		this.onDidCreateEditors.fire();
+		this.onDidCreateEditors.fire(undefined);
 
 		return Promise.all([this.detailsEditor.setInput(detailsInput, null, token), this.masterEditor.setInput(masterInput, options, token)]).then(() => this.focus());
 	}

src/vs/workbench/browser/parts/quickinput/quickInput.ts

@@ -482,7 +482,7 @@ class QuickPick<T extends IQuickPickItem> extends QuickInput implements IQuickPi
 						this._selectedItems = [this.activeItems[0]];
 						this.onDidChangeSelectionEmitter.fire(this.selectedItems);
 					}
-					this.onDidAcceptEmitter.fire();
+					this.onDidAcceptEmitter.fire(undefined);
 				}),
 				this.ui.list.onDidChangeFocus(focusedItems => {
 					if (this.activeItemsUpdated) {
@@ -507,7 +507,7 @@ class QuickPick<T extends IQuickPickItem> extends QuickInput implements IQuickPi
 					this._selectedItems = selectedItems as T[];
 					this.onDidChangeSelectionEmitter.fire(selectedItems as T[]);
 					if (selectedItems.length) {
-						this.onDidAcceptEmitter.fire();
+						this.onDidAcceptEmitter.fire(undefined);
 					}
 				}),
 				this.ui.list.onChangedCheckedElements(checkedItems => {
@@ -570,7 +570,7 @@ class QuickPick<T extends IQuickPickItem> extends QuickInput implements IQuickPi
 			if (wasTriggerKeyPressed && this.activeItems[0]) {
 				this._selectedItems = [this.activeItems[0]];
 				this.onDidChangeSelectionEmitter.fire(this.selectedItems);
-				this.onDidAcceptEmitter.fire();
+				this.onDidAcceptEmitter.fire(undefined);
 			}
 		});
 	}
@@ -723,7 +723,7 @@ class InputBox extends QuickInput implements IInputBox {
 					this._value = value;
 					this.onDidValueChangeEmitter.fire(value);
 				}),
-				this.ui.onDidAccept(() => this.onDidAcceptEmitter.fire()),
+				this.ui.onDidAccept(() => this.onDidAcceptEmitter.fire(undefined)),
 			);
 			this.valueSelectionUpdated = true;
 		}

src/vs/workbench/parts/codeEditor/electron-browser/suggestEnabledInput.ts

@@ -156,7 +156,7 @@ export class SuggestEnabledInput extends Widget implements IThemable {
 			let content = this.getValue();
 			this.placeholderText.style.visibility = content ? 'hidden' : 'visible';
 			if (preexistingContent.trim() === content.trim()) { return; }
-			this._onInputDidChange.fire();
+			this._onInputDidChange.fire(undefined);
 			preexistingContent = content;
 		}));
 

src/vs/workbench/parts/comments/electron-browser/commentThreadWidget.ts

@@ -798,6 +798,6 @@ export class ReviewZoneWidget extends ZoneWidget {
 
 		this._globalToDispose.forEach(global => global.dispose());
 		this._localToDispose.forEach(local => local.dispose());
-		this._onDidClose.fire();
+		this._onDidClose.fire(undefined);
 	}
 }
\ No newline at end of file

src/vs/workbench/parts/debug/common/debugModel.ts

@@ -786,7 +786,7 @@ export class DebugModel implements IDebugModel {
 			return true;
 		});
 		this.sessions.push(session);
-		this._onDidChangeCallStack.fire();
+		this._onDidChangeCallStack.fire(undefined);
 	}
 
 	get onDidChangeBreakpoints(): Event<IBreakpointsChangeEvent> {
@@ -805,7 +805,7 @@ export class DebugModel implements IDebugModel {
 		let session = this.sessions.filter(p => p.getId() === data.sessionId).pop();
 		if (session) {
 			session.rawUpdate(data);
-			this._onDidChangeCallStack.fire();
+			this._onDidChangeCallStack.fire(undefined);
 		}
 	}
 
@@ -816,7 +816,7 @@ export class DebugModel implements IDebugModel {
 
 		if (session) {
 			session.clearThreads(removeThreads, reference);
-			this._onDidChangeCallStack.fire();
+			this._onDidChangeCallStack.fire(undefined);
 		}
 	}
 
@@ -881,7 +881,7 @@ export class DebugModel implements IDebugModel {
 				const ebp = this.exceptionBreakpoints.filter(ebp => ebp.filter === d.filter).pop();
 				return new ExceptionBreakpoint(d.filter, d.label, ebp ? ebp.enabled : d.default);
 			});
-			this._onDidChangeBreakpoints.fire();
+			this._onDidChangeBreakpoints.fire(undefined);
 		}
 	}
 
@@ -891,7 +891,7 @@ export class DebugModel implements IDebugModel {
 
 	setBreakpointsActivated(activated: boolean): void {
 		this.breakpointsActivated = activated;
-		this._onDidChangeBreakpoints.fire();
+		this._onDidChangeBreakpoints.fire(undefined);
 	}
 
 	addBreakpoints(uri: uri, rawData: IBreakpointData[], fireEvent = true): IBreakpoint[] {
@@ -1052,7 +1052,7 @@ export class DebugModel implements IDebugModel {
 
 	removeWatchExpressions(id: string | null = null): void {
 		this.watchExpressions = id ? this.watchExpressions.filter(we => we.getId() !== id) : [];
-		this._onDidChangeWatchExpressions.fire();
+		this._onDidChangeWatchExpressions.fire(undefined);
 	}
 
 	moveWatchExpression(id: string, position: number): void {
@@ -1060,7 +1060,7 @@ export class DebugModel implements IDebugModel {
 		this.watchExpressions = this.watchExpressions.filter(we => we.getId() !== id);
 		this.watchExpressions = this.watchExpressions.slice(0, position).concat(we, this.watchExpressions.slice(position));
 
-		this._onDidChangeWatchExpressions.fire();
+		this._onDidChangeWatchExpressions.fire(undefined);
 	}
 
 	sourceIsNotAvailable(uri: uri): void {
@@ -1070,7 +1070,7 @@ export class DebugModel implements IDebugModel {
 				source.available = false;
 			}
 		});
-		this._onDidChangeCallStack.fire();
+		this._onDidChangeCallStack.fire(undefined);
 	}
 
 	dispose(): void {

src/vs/workbench/parts/extensions/node/extensionsWorkbenchService.ts

@@ -449,7 +449,7 @@ export class ExtensionsWorkbenchService implements IExtensionsWorkbenchService,
 						return extension;
 					});
 
-					this._onChange.fire();
+					this._onChange.fire(undefined);
 					return this.local;
 				}));
 	}
@@ -971,7 +971,7 @@ export class ExtensionsWorkbenchService implements IExtensionsWorkbenchService,
 		const uninstalling = this.uninstalling.filter(e => e.local.identifier.id === id)[0] || extension;
 		this.uninstalling = [uninstalling, ...this.uninstalling.filter(e => e.local.identifier.id !== id)];
 
-		this._onChange.fire();
+		this._onChange.fire(undefined);
 	}
 
 	private onDidUninstallExtension({ identifier, error }: DidUninstallExtensionEvent): void {
@@ -986,7 +986,7 @@ export class ExtensionsWorkbenchService implements IExtensionsWorkbenchService,
 			return;
 		}
 
-		this._onChange.fire();
+		this._onChange.fire(undefined);
 	}
 
 	private onEnablementChanged(identifier: IExtensionIdentifier) {

src/vs/workbench/parts/markers/electron-browser/markersTreeViewer.ts

@@ -549,7 +549,7 @@ export class MarkersViewState extends Disposable {
 		});
 		this.bulkUpdate = false;
 		if (changed) {
-			this._onDidChangeViewState.fire();
+			this._onDidChangeViewState.fire(undefined);
 		}
 	}
 

src/vs/workbench/parts/preferences/browser/preferencesEditor.ts

@@ -123,7 +123,7 @@ export class PreferencesEditor extends BaseEditor {
 
 		const editorsContainer = DOM.append(parent, DOM.$('.preferences-editors-container'));
 		this.sideBySidePreferencesWidget = this._register(this.instantiationService.createInstance(SideBySidePreferencesWidget, editorsContainer));
-		this._onDidCreateWidget.fire();
+		this._onDidCreateWidget.fire(undefined);
 		this._register(this.sideBySidePreferencesWidget.onFocus(() => this.lastFocusedWidget = this.sideBySidePreferencesWidget));
 		this._register(this.sideBySidePreferencesWidget.onDidSettingsTargetChange(target => this.switchSettings(target)));
 

src/vs/workbench/parts/search/browser/patternInputWidget.ts

@@ -154,10 +154,10 @@ export class PatternInputWidget extends Widget {
 	private onInputKeyUp(keyboardEvent: IKeyboardEvent) {
 		switch (keyboardEvent.keyCode) {
 			case KeyCode.Enter:
-				this._onSubmit.fire();
+				this._onSubmit.fire(false);
 				return;
 			case KeyCode.Escape:
-				this._onCancel.fire();
+				this._onCancel.fire(false);
 				return;
 			default:
 				return;

src/vs/workbench/parts/search/browser/searchView.ts

@@ -733,7 +733,7 @@ export class SearchView extends Viewlet implements IViewlet, IPanel {
 			this.tree.setFocus([next]);
 			this.tree.setSelection([next]);
 			this.tree.reveal(next);
-			this.selectCurrentMatchEmitter.fire();
+			this.selectCurrentMatchEmitter.fire(undefined);
 		}
 	}
 
@@ -774,7 +774,7 @@ export class SearchView extends Viewlet implements IViewlet, IPanel {
 			this.tree.setFocus([prev]);
 			this.tree.setSelection([prev]);
 			this.tree.reveal(prev);
-			this.selectCurrentMatchEmitter.fire();
+			this.selectCurrentMatchEmitter.fire(undefined);
 		}
 	}
 

src/vs/workbench/parts/search/browser/searchWidget.ts

@@ -114,7 +114,7 @@ export class SearchWidget extends Widget {
 	private _onReplaceStateChange = this._register(new Emitter<boolean>());
 	readonly onReplaceStateChange: Event<boolean> = this._onReplaceStateChange.event;
 
-	private _onReplaceValueChanged = this._register(new Emitter<string>());
+	private _onReplaceValueChanged = this._register(new Emitter<string | undefined>());
 	readonly onReplaceValueChanged: Event<string> = this._onReplaceValueChanged.event;
 
 	private _onReplaceAll = this._register(new Emitter<void>());
@@ -343,7 +343,7 @@ export class SearchWidget extends Widget {
 		this._register(attachInputBoxStyler(this.replaceInput, this.themeService));
 		this.onkeydown(this.replaceInput.inputElement, (keyboardEvent) => this.onReplaceInputKeyDown(keyboardEvent));
 		this.replaceInput.value = options.replaceValue || '';
-		this._register(this.replaceInput.onDidChange(() => this._onReplaceValueChanged.fire()));
+		this._register(this.replaceInput.onDidChange(() => this._onReplaceValueChanged.fire(undefined)));
 		this._register(this.replaceInput.onDidHeightChange(() => this._onDidHeightChange.fire()));
 
 		this.replaceAllAction = ReplaceAllAction.INSTANCE;

src/vs/workbench/parts/terminal/common/terminal.ts

@@ -197,7 +197,7 @@ export interface ITerminalService {
 	onInstanceRequestExtHostProcess: Event<ITerminalProcessExtHostRequest>;
 	onInstancesChanged: Event<void>;
 	onInstanceTitleChanged: Event<ITerminalInstance>;
-	onActiveInstanceChanged: Event<ITerminalInstance>;
+	onActiveInstanceChanged: Event<ITerminalInstance | undefined>;
 	terminalInstances: ITerminalInstance[];
 	terminalTabs: ITerminalTab[];
 

src/vs/workbench/parts/terminal/common/terminalService.ts

@@ -46,8 +46,8 @@ export abstract class TerminalService implements ITerminalService {
 	public get onInstancesChanged(): Event<void> { return this._onInstancesChanged.event; }
 	protected readonly _onInstanceTitleChanged = new Emitter<ITerminalInstance>();
 	public get onInstanceTitleChanged(): Event<ITerminalInstance> { return this._onInstanceTitleChanged.event; }
-	protected readonly _onActiveInstanceChanged = new Emitter<ITerminalInstance>();
-	public get onActiveInstanceChanged(): Event<ITerminalInstance> { return this._onActiveInstanceChanged.event; }
+	protected readonly _onActiveInstanceChanged = new Emitter<ITerminalInstance | undefined>();
+	public get onActiveInstanceChanged(): Event<ITerminalInstance | undefined> { return this._onActiveInstanceChanged.event; }
 	protected readonly _onTabDisposed = new Emitter<ITerminalTab>();
 	public get onTabDisposed(): Event<ITerminalTab> { return this._onTabDisposed.event; }
 

src/vs/workbench/parts/terminal/node/windowsShellHelper.ts

@@ -25,7 +25,7 @@ const SHELL_EXECUTABLES = [
 let windowsProcessTree: typeof WindowsProcessTreeType;
 
 export class WindowsShellHelper {
-	private _onCheckShell: Emitter<Promise<string>>;
+	private _onCheckShell: Emitter<Promise<string> | undefined>;
 	private _isDisposed: boolean;
 	private _currentRequest: Promise<string> | null;
 	private _newLineFeed: boolean;
@@ -64,12 +64,12 @@ export class WindowsShellHelper {
 			this._xterm.on('linefeed', () => this._newLineFeed = true);
 			this._xterm.on('cursormove', () => {
 				if (this._newLineFeed) {
-					this._onCheckShell.fire();
+					this._onCheckShell.fire(undefined);
 				}
 			});
 
 			// Fire a new check for the shell when any key is pressed.
-			this._xterm.on('keypress', () => this._onCheckShell.fire());
+			this._xterm.on('keypress', () => this._onCheckShell.fire(undefined));
 		});
 	}
 

src/vs/workbench/test/electron-browser/api/extHostTreeViews.test.ts

@@ -41,7 +41,7 @@ suite('ExtHostTreeView', function () {
 
 	let testObject: ExtHostTreeViews;
 	let target: RecordingShape;
-	let onDidChangeTreeNode: Emitter<{ key: string }>;
+	let onDidChangeTreeNode: Emitter<{ key: string } | undefined>;
 	let onDidChangeTreeNodeWithId: Emitter<{ key: string }>;
 	let tree, labels, nodes;
 
@@ -199,7 +199,7 @@ suite('ExtHostTreeView', function () {
 						.then(() => { assert.fail('Should fail with duplicate id'); done(); }, () => done());
 				});
 		});
-		onDidChangeTreeNode.fire();
+		onDidChangeTreeNode.fire(undefined);
 	});
 
 	test('refresh root', function (done) {
@@ -207,7 +207,7 @@ suite('ExtHostTreeView', function () {
 			assert.equal(undefined, actuals);
 			done();
 		});
-		onDidChangeTreeNode.fire();
+		onDidChangeTreeNode.fire(undefined);
 	});
 
 	test('refresh a parent node', () => {
@@ -300,10 +300,10 @@ suite('ExtHostTreeView', function () {
 			assert.equal(undefined, actuals);
 			done();
 		});
-		onDidChangeTreeNode.fire();
-		onDidChangeTreeNode.fire();
-		onDidChangeTreeNode.fire();
-		onDidChangeTreeNode.fire();
+		onDidChangeTreeNode.fire(undefined);
+		onDidChangeTreeNode.fire(undefined);
+		onDidChangeTreeNode.fire(undefined);
+		onDidChangeTreeNode.fire(undefined);
 	});
 
 	test('refresh calls are throttled on elements', function (done) {
@@ -339,7 +339,7 @@ suite('ExtHostTreeView', function () {
 		onDidChangeTreeNode.fire(getNode('a'));
 		onDidChangeTreeNode.fire(getNode('b'));
 		onDidChangeTreeNode.fire(getNode('g'));
-		onDidChangeTreeNode.fire();
+		onDidChangeTreeNode.fire(undefined);
 	});
 
 	test('refresh calls are throttled on elements and root', function (done) {
@@ -350,7 +350,7 @@ suite('ExtHostTreeView', function () {
 
 		onDidChangeTreeNode.fire(getNode('a'));
 		onDidChangeTreeNode.fire(getNode('b'));
-		onDidChangeTreeNode.fire();
+		onDidChangeTreeNode.fire(undefined);
 		onDidChangeTreeNode.fire(getNode('a'));
 	});
 
@@ -366,7 +366,7 @@ suite('ExtHostTreeView', function () {
 					done();
 				});
 		});
-		onDidChangeTreeNode.fire();
+		onDidChangeTreeNode.fire(undefined);
 	});
 
 	test('tree with duplicate labels', (done) => {
@@ -415,7 +415,7 @@ suite('ExtHostTreeView', function () {
 				});
 		});
 
-		onDidChangeTreeNode.fire();
+		onDidChangeTreeNode.fire(undefined);
 	});
 
 	test('getChildren is not returned from cache if refreshed', (done) => {
@@ -431,7 +431,7 @@ suite('ExtHostTreeView', function () {
 				});
 		});
 
-		onDidChangeTreeNode.fire();
+		onDidChangeTreeNode.fire(undefined);
 	});
 
 	test('getChildren is returned from cache if not refreshed', () => {