Mark private emitters as readonly

src/vs/base/browser/browser.ts

@@ -15,7 +15,7 @@ class WindowManager {
 	// --- Zoom Level
 	private _zoomLevel: number = 0;
 	private _lastZoomLevelChangeTime: number = 0;
-	private _onDidChangeZoomLevel: Emitter<number> = new Emitter<number>();
+	private readonly _onDidChangeZoomLevel: Emitter<number> = new Emitter<number>();
 
 	public readonly onDidChangeZoomLevel: Event<number> = this._onDidChangeZoomLevel.event;
 	public getZoomLevel(): number {
@@ -61,7 +61,7 @@ class WindowManager {
 
 	// --- Fullscreen
 	private _fullscreen: boolean;
-	private _onDidChangeFullscreen: Emitter<void> = new Emitter<void>();
+	private readonly _onDidChangeFullscreen: Emitter<void> = new Emitter<void>();
 
 	public readonly onDidChangeFullscreen: Event<void> = this._onDidChangeFullscreen.event;
 	public setFullscreen(fullscreen: boolean): void {
@@ -78,7 +78,7 @@ class WindowManager {
 
 	// --- Accessibility
 	private _accessibilitySupport = Platform.AccessibilitySupport.Unknown;
-	private _onDidChangeAccessibilitySupport: Emitter<void> = new Emitter<void>();
+	private readonly _onDidChangeAccessibilitySupport: Emitter<void> = new Emitter<void>();
 
 	public readonly onDidChangeAccessibilitySupport: Event<void> = this._onDidChangeAccessibilitySupport.event;
 	public setAccessibilitySupport(accessibilitySupport: Platform.AccessibilitySupport): void {

src/vs/base/browser/ui/sash/sash.ts

@@ -301,7 +301,7 @@ export class VSash extends Disposable implements IVerticalSashLayoutProvider {
 	private position: number;
 	private dimension: Dimension;
 
-	private _onPositionChange: Emitter<number> = new Emitter<number>();
+	private readonly _onPositionChange: Emitter<number> = new Emitter<number>();
 	public get onPositionChange(): Event<number> { return this._onPositionChange.event; }
 
 	constructor(container: HTMLElement, private minWidth: number) {

src/vs/base/browser/ui/selectBox/selectBoxCustom.ts

@@ -78,7 +78,7 @@ export class SelectBoxList implements ISelectBoxDelegate, IDelegate<ISelectOptio
 	private options: string[];
 	private selected: number;
 	private disabledOptionIndex: number;
-	private _onDidSelect: Emitter<ISelectData>;
+	private readonly _onDidSelect: Emitter<ISelectData>;
 	private toDispose: IDisposable[];
 	private styles: ISelectBoxStyles;
 	private listRenderer: SelectListRenderer;

src/vs/base/browser/ui/selectBox/selectBoxNative.ts

@@ -16,7 +16,7 @@ export class SelectBoxNative implements ISelectBoxDelegate {
 	private selectElement: HTMLSelectElement;
 	private options: string[];
 	private selected: number;
-	private _onDidSelect: Emitter<ISelectData>;
+	private readonly _onDidSelect: Emitter<ISelectData>;
 	private toDispose: IDisposable[];
 	private styles: ISelectBoxStyles;
 

src/vs/base/common/async.ts

@@ -424,7 +424,7 @@ export class Limiter<T> {
 	private runningPromises: number;
 	private maxDegreeOfParalellism: number;
 	private outstandingPromises: ILimitedTaskFactory[];
-	private _onFinished: Emitter<void>;
+	private readonly _onFinished: Emitter<void>;
 
 	constructor(maxDegreeOfParalellism: number) {
 		this.maxDegreeOfParalellism = maxDegreeOfParalellism;

src/vs/base/common/event.ts

@@ -163,7 +163,7 @@ export class Emitter<T> {
 
 export class EventMultiplexer<T> implements IDisposable {
 
-	private emitter: Emitter<T>;
+	private readonly emitter: Emitter<T>;
 	private hasListeners = false;
 	private events: { event: Event<T>; listener: IDisposable; }[] = [];
 

src/vs/base/node/config.ts

@@ -50,7 +50,7 @@ export class ConfigWatcher<T> implements IConfigWatcher<T>, IDisposable {
 	private loaded: boolean;
 	private timeoutHandle: NodeJS.Timer;
 	private disposables: IDisposable[];
-	private _onDidUpdateConfiguration: Emitter<IConfigurationChangeEvent<T>>;
+	private readonly _onDidUpdateConfiguration: Emitter<IConfigurationChangeEvent<T>>;
 	private configName: string;
 
 	constructor(private _path: string, private options: IConfigOptions<T> = { changeBufferDelay: 0, defaultConfig: Object.create(null), onError: error => console.error(error) }) {

src/vs/base/parts/tree/browser/treeView.ts

@@ -440,10 +440,10 @@ export class TreeView extends HeightMap {
 	private highlightedItemWasDraggable: boolean;
 	private onHiddenScrollTop: number;
 
-	private _onDOMFocus: Emitter<void> = new Emitter<void>();
+	private readonly _onDOMFocus: Emitter<void> = new Emitter<void>();
 	get onDOMFocus(): Event<void> { return this._onDOMFocus.event; }
 
-	private _onDOMBlur: Emitter<void> = new Emitter<void>();
+	private readonly _onDOMBlur: Emitter<void> = new Emitter<void>();
 	get onDOMBlur(): Event<void> { return this._onDOMBlur.event; }
 
 	constructor(context: _.ITreeContext, container: HTMLElement) {

src/vs/code/electron-main/keyboard.ts

@@ -20,7 +20,7 @@ export class KeyboardLayoutMonitor {
 
 	public static readonly INSTANCE = new KeyboardLayoutMonitor();
 
-	private _emitter: Emitter<void>;
+	private readonly _emitter: Emitter<void>;
 	private _registered: boolean;
 
 	private constructor() {

src/vs/editor/browser/services/abstractCodeEditorService.ts

@@ -14,12 +14,12 @@ export abstract class AbstractCodeEditorService implements ICodeEditorService {
 
 	_serviceBrand: any;
 
-	private _onCodeEditorAdd: Emitter<ICodeEditor>;
-	private _onCodeEditorRemove: Emitter<ICodeEditor>;
+	private readonly _onCodeEditorAdd: Emitter<ICodeEditor>;
+	private readonly _onCodeEditorRemove: Emitter<ICodeEditor>;
 	private _codeEditors: { [editorId: string]: ICodeEditor; };
 
-	private _onDiffEditorAdd: Emitter<IDiffEditor>;
-	private _onDiffEditorRemove: Emitter<IDiffEditor>;
+	private readonly _onDiffEditorAdd: Emitter<IDiffEditor>;
+	private readonly _onDiffEditorRemove: Emitter<IDiffEditor>;
 	private _diffEditors: { [editorId: string]: IDiffEditor; };
 
 	constructor() {

src/vs/editor/browser/widget/codeEditorWidget.ts

@@ -455,7 +455,7 @@ class CodeEditorWidgetFocusTracker extends Disposable {
 	private _hasFocus: boolean;
 	private _domFocusTracker: dom.IFocusTracker;
 
-	private _onChange: Emitter<void> = this._register(new Emitter<void>());
+	private readonly _onChange: Emitter<void> = this._register(new Emitter<void>());
 	public readonly onChange: Event<void> = this._onChange.event;
 
 	constructor(domElement: HTMLElement) {

src/vs/editor/common/config/commonEditorConfig.ts

@@ -34,7 +34,7 @@ export interface ITabFocus {
 export const TabFocus: ITabFocus = new class implements ITabFocus {
 	private _tabFocus: boolean = false;
 
-	private _onDidChangeTabFocus: Emitter<boolean> = new Emitter<boolean>();
+	private readonly _onDidChangeTabFocus: Emitter<boolean> = new Emitter<boolean>();
 	public readonly onDidChangeTabFocus: Event<boolean> = this._onDidChangeTabFocus.event;
 
 	public getTabFocusMode(): boolean {

src/vs/editor/common/config/editorZoom.ts

@@ -16,7 +16,7 @@ export const EditorZoom: IEditorZoom = new class implements IEditorZoom {
 
 	private _zoomLevel: number = 0;
 
-	private _onDidChangeZoomLevel: Emitter<number> = new Emitter<number>();
+	private readonly _onDidChangeZoomLevel: Emitter<number> = new Emitter<number>();
 	public readonly onDidChangeZoomLevel: Event<number> = this._onDidChangeZoomLevel.event;
 
 	public getZoomLevel(): number {

src/vs/editor/common/modes/languageConfigurationRegistry.ts

@@ -177,7 +177,7 @@ export class LanguageConfigurationRegistryImpl {
 
 	private _entries: RichEditSupport[];
 
-	private _onDidChange: Emitter<LanguageConfigurationChangeEvent> = new Emitter<LanguageConfigurationChangeEvent>();
+	private readonly _onDidChange: Emitter<LanguageConfigurationChangeEvent> = new Emitter<LanguageConfigurationChangeEvent>();
 	public readonly onDidChange: Event<LanguageConfigurationChangeEvent> = this._onDidChange.event;
 
 	constructor() {

src/vs/editor/common/modes/languageFeatureRegistry.ts

@@ -21,7 +21,7 @@ export default class LanguageFeatureRegistry<T> {
 
 	private _clock: number = 0;
 	private _entries: Entry<T>[] = [];
-	private _onDidChange: Emitter<number> = new Emitter<number>();
+	private readonly _onDidChange: Emitter<number> = new Emitter<number>();
 
 	constructor() {
 	}

src/vs/editor/common/modes/modesRegistry.ts

@@ -20,7 +20,7 @@ export class EditorModesRegistry {
 
 	private _languages: ILanguageExtensionPoint[];
 
-	private _onDidAddLanguages: Emitter<ILanguageExtensionPoint[]> = new Emitter<ILanguageExtensionPoint[]>();
+	private readonly _onDidAddLanguages: Emitter<ILanguageExtensionPoint[]> = new Emitter<ILanguageExtensionPoint[]>();
 	public readonly onDidAddLanguages: Event<ILanguageExtensionPoint[]> = this._onDidAddLanguages.event;
 
 	constructor() {

src/vs/editor/common/modes/tokenizationRegistry.ts

@@ -13,7 +13,7 @@ export class TokenizationRegistryImpl implements ITokenizationRegistry {
 
 	private _map: { [language: string]: ITokenizationSupport };
 
-	private _onDidChange: Emitter<ITokenizationSupportChangedEvent> = new Emitter<ITokenizationSupportChangedEvent>();
+	private readonly _onDidChange: Emitter<ITokenizationSupportChangedEvent> = new Emitter<ITokenizationSupportChangedEvent>();
 	public readonly onDidChange: Event<ITokenizationSupportChangedEvent> = this._onDidChange.event;
 
 	private _colorMap: Color[];

src/vs/editor/common/services/modelServiceImpl.ts

@@ -193,9 +193,9 @@ export class ModelServiceImpl implements IModelService {
 	private _configurationService: IConfigurationService;
 	private _configurationServiceSubscription: IDisposable;
 
-	private _onModelAdded: Emitter<ITextModel>;
-	private _onModelRemoved: Emitter<ITextModel>;
-	private _onModelModeChanged: Emitter<{ model: ITextModel; oldModeId: string; }>;
+	private readonly _onModelAdded: Emitter<ITextModel>;
+	private readonly _onModelRemoved: Emitter<ITextModel>;
+	private readonly _onModelModeChanged: Emitter<{ model: ITextModel; oldModeId: string; }>;
 
 	private _modelCreationOptionsByLanguageAndResource: {
 		[languageAndResource: string]: ITextModelCreationOptions;

src/vs/editor/contrib/find/findState.ts

@@ -70,7 +70,7 @@ export class FindReplaceState implements IDisposable {
 	private _matchesPosition: number;
 	private _matchesCount: number;
 	private _currentMatch: Range;
-	private _onFindReplaceStateChange: Emitter<FindReplaceStateChangedEvent>;
+	private readonly _onFindReplaceStateChange: Emitter<FindReplaceStateChangedEvent>;
 
 	public get searchString(): string { return this._searchString; }
 	public get replaceString(): string { return this._replaceString; }

src/vs/editor/contrib/find/test/findController.test.ts

@@ -28,7 +28,7 @@ export class TestFindController extends CommonFindController {
 	public delayUpdateHistory: boolean = false;
 	public delayedUpdateHistoryPromise: TPromise<void>;
 
-	private _delayedUpdateHistoryEvent: Emitter<void> = new Emitter<void>();
+	private readonly _delayedUpdateHistoryEvent: Emitter<void> = new Emitter<void>();
 
 	constructor(
 		editor: ICodeEditor,

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

@@ -34,8 +34,8 @@ class MarkerModel {
 	private _nextIdx: number;
 	private _toUnbind: IDisposable[];
 	private _ignoreSelectionChange: boolean;
-	private _onCurrentMarkerChanged: Emitter<IMarker>;
-	private _onMarkerSetChanged: Emitter<MarkerModel>;
+	private readonly _onCurrentMarkerChanged: Emitter<IMarker>;
+	private readonly _onMarkerSetChanged: Emitter<MarkerModel>;
 
 	constructor(editor: ICodeEditor, markers: IMarker[]) {
 		this._editor = editor;

src/vs/editor/contrib/suggest/suggestModel.ts

@@ -96,9 +96,9 @@ export class SuggestModel implements IDisposable {
 	private _currentSelection: Selection;
 
 	private _completionModel: CompletionModel;
-	private _onDidCancel: Emitter<ICancelEvent> = new Emitter<ICancelEvent>();
-	private _onDidTrigger: Emitter<ITriggerEvent> = new Emitter<ITriggerEvent>();
-	private _onDidSuggest: Emitter<ISuggestEvent> = new Emitter<ISuggestEvent>();
+	private readonly _onDidCancel: Emitter<ICancelEvent> = new Emitter<ICancelEvent>();
+	private readonly _onDidTrigger: Emitter<ITriggerEvent> = new Emitter<ITriggerEvent>();
+	private readonly _onDidSuggest: Emitter<ISuggestEvent> = new Emitter<ISuggestEvent>();
 
 	readonly onDidCancel: Event<ICancelEvent> = this._onDidCancel.event;
 	readonly onDidTrigger: Event<ITriggerEvent> = this._onDidTrigger.event;

src/vs/editor/standalone/browser/simpleServices.ts

@@ -73,7 +73,7 @@ export class SimpleEditor implements IEditor {
 export class SimpleModel implements ITextEditorModel {
 
 	private model: ITextModel;
-	private _onDispose: Emitter<void>;
+	private readonly _onDispose: Emitter<void>;
 
 	constructor(model: ITextModel) {
 		this.model = model;
@@ -308,7 +308,7 @@ export class StandaloneCommandService implements ICommandService {
 	private readonly _instantiationService: IInstantiationService;
 	private _dynamicCommands: { [id: string]: ICommand; };
 
-	private _onWillExecuteCommand: Emitter<ICommandEvent> = new Emitter<ICommandEvent>();
+	private readonly _onWillExecuteCommand: Emitter<ICommandEvent> = new Emitter<ICommandEvent>();
 	public readonly onWillExecuteCommand: Event<ICommandEvent> = this._onWillExecuteCommand.event;
 
 	constructor(instantiationService: IInstantiationService) {

src/vs/editor/standalone/browser/standaloneThemeServiceImpl.ts

@@ -118,7 +118,7 @@ export class StandaloneThemeServiceImpl implements IStandaloneThemeService {
 	private _knownThemes: Map<string, StandaloneTheme>;
 	private _styleElement: HTMLStyleElement;
 	private _theme: IStandaloneTheme;
-	private _onThemeChange: Emitter<IStandaloneTheme>;
+	private readonly _onThemeChange: Emitter<IStandaloneTheme>;
 
 
 	constructor() {

src/vs/platform/broadcast/electron-browser/broadcastService.ts

@@ -29,7 +29,7 @@ export interface IBroadcastService {
 export class BroadcastService implements IBroadcastService {
 	public _serviceBrand: any;
 
-	private _onBroadcast: Emitter<IBroadcast>;
+	private readonly _onBroadcast: Emitter<IBroadcast>;
 
 	constructor(
 		private windowId: number,

src/vs/platform/configuration/common/configurationRegistry.ts

@@ -108,7 +108,7 @@ class ConfigurationRegistry implements IConfigurationRegistry {
 	private overrideIdentifiers: string[] = [];
 	private overridePropertyPattern: string;
 
-	private _onDidRegisterConfiguration: Emitter<string[]> = new Emitter<string[]>();
+	private readonly _onDidRegisterConfiguration: Emitter<string[]> = new Emitter<string[]>();
 	readonly onDidRegisterConfiguration: Event<string[]> = this._onDidRegisterConfiguration.event;
 
 	constructor() {

src/vs/platform/configuration/node/configuration.ts

@@ -14,7 +14,7 @@ export class UserConfiguration extends Disposable {
 
 	private userConfigModelWatcher: ConfigWatcher<ConfigurationModelParser>;
 
-	private _onDidChangeConfiguration: Emitter<ConfigurationModel> = this._register(new Emitter<ConfigurationModel>());
+	private readonly _onDidChangeConfiguration: Emitter<ConfigurationModel> = this._register(new Emitter<ConfigurationModel>());
 	readonly onDidChangeConfiguration: Event<ConfigurationModel> = this._onDidChangeConfiguration.event;
 
 	constructor(settingsPath: string) {

src/vs/platform/configuration/node/configurationService.ts

@@ -23,7 +23,7 @@ export class ConfigurationService extends Disposable implements IConfigurationSe
 	private _configuration: Configuration;
 	private userConfiguration: UserConfiguration;
 
-	private _onDidChangeConfiguration: Emitter<IConfigurationChangeEvent> = this._register(new Emitter<IConfigurationChangeEvent>());
+	private readonly _onDidChangeConfiguration: Emitter<IConfigurationChangeEvent> = this._register(new Emitter<IConfigurationChangeEvent>());
 	readonly onDidChangeConfiguration: Event<IConfigurationChangeEvent> = this._onDidChangeConfiguration.event;
 
 	constructor(

src/vs/platform/jsonschemas/common/jsonContributionRegistry.ts

@@ -55,7 +55,7 @@ class JSONContributionRegistry implements IJSONContributionRegistry {
 
 	private schemasById: { [id: string]: IJSONSchema };
 
-	private _onDidChangeSchema: Emitter<string> = new Emitter<string>();
+	private readonly _onDidChangeSchema: Emitter<string> = new Emitter<string>();
 	readonly onDidChangeSchema: Event<string> = this._onDidChangeSchema.event;
 
 	constructor() {

src/vs/platform/list/browser/listService.ts

@@ -455,7 +455,7 @@ export interface IResourceResultsNavigationOptions {
 
 export class TreeResourceNavigator extends Disposable {
 
-	private _openResource: Emitter<IOpenResourceOptions> = new Emitter<IOpenResourceOptions>();
+	private readonly _openResource: Emitter<IOpenResourceOptions> = new Emitter<IOpenResourceOptions>();
 	readonly openResource: Event<IOpenResourceOptions> = this._openResource.event;
 
 	constructor(private tree: WorkbenchTree, private options?: IResourceResultsNavigationOptions) {

src/vs/platform/notification/common/notification.ts

@@ -194,7 +194,7 @@ export interface INotificationService {
 export class NoOpNotification implements INotificationHandle {
 	readonly progress = new NoOpProgress();
 
-	private _onDidDispose: Emitter<void> = new Emitter();
+	private readonly _onDidDispose: Emitter<void> = new Emitter();
 
 	public get onDidDispose(): Event<void> {
 		return this._onDidDispose.event;

src/vs/platform/theme/common/themeService.ts

@@ -100,7 +100,7 @@ export interface IThemingRegistry {
 
 class ThemingRegistry implements IThemingRegistry {
 	private themingParticipants: IThemingParticipant[] = [];
-	private onThemingParticipantAddedEmitter: Emitter<IThemingParticipant>;
+	private readonly onThemingParticipantAddedEmitter: Emitter<IThemingParticipant>;
 
 	constructor() {
 		this.themingParticipants = [];

src/vs/platform/url/electron-main/urlService.ts

@@ -16,7 +16,7 @@ export class URLService implements IURLService {
 
 	_serviceBrand: any;
 
-	private openUrlEmitter: Emitter<string> = new Emitter<string>();
+	private readonly openUrlEmitter: Emitter<string> = new Emitter<string>();
 	onOpenURL: Event<URI>;
 
 	constructor(

src/vs/platform/workspaces/electron-main/workspacesMainService.ts

@@ -37,8 +37,8 @@ export class WorkspacesMainService implements IWorkspacesMainService {
 
 	protected workspacesHome: string;
 
-	private _onWorkspaceSaved: Emitter<IWorkspaceSavedEvent>;
-	private _onUntitledWorkspaceDeleted: Emitter<IWorkspaceIdentifier>;
+	private readonly _onWorkspaceSaved: Emitter<IWorkspaceSavedEvent>;
+	private readonly _onUntitledWorkspaceDeleted: Emitter<IWorkspaceIdentifier>;
 
 	constructor(
 		@IEnvironmentService private environmentService: IEnvironmentService,

src/vs/workbench/api/electron-browser/mainThreadEditor.ts

@@ -185,7 +185,7 @@ export class MainThreadTextEditor {
 	private _codeEditorListeners: IDisposable[];
 
 	private _properties: MainThreadTextEditorProperties;
-	private _onPropertiesChanged: Emitter<IEditorPropertiesChangeData>;
+	private readonly _onPropertiesChanged: Emitter<IEditorPropertiesChangeData>;
 
 	constructor(
 		id: string,

src/vs/workbench/api/electron-browser/mainThreadHeapService.ts

@@ -32,7 +32,7 @@ export class HeapService implements IHeapService {
 
 	_serviceBrand: any;
 
-	private _onGarbageCollection: Emitter<number[]> = new Emitter<number[]>();
+	private readonly _onGarbageCollection: Emitter<number[]> = new Emitter<number[]>();
 	public readonly onGarbageCollection: Event<number[]> = this._onGarbageCollection.event;
 
 	private _activeSignals = new WeakMap<any, object>();

src/vs/workbench/api/electron-browser/mainThreadTreeViews.ts

@@ -59,10 +59,10 @@ type TreeItemHandle = string;
 
 class TreeViewDataProvider implements ITreeViewDataProvider {
 
-	private _onDidChange: Emitter<ITreeItem[] | undefined | null> = new Emitter<ITreeItem[] | undefined | null>();
+	private readonly _onDidChange: Emitter<ITreeItem[] | undefined | null> = new Emitter<ITreeItem[] | undefined | null>();
 	readonly onDidChange: Event<ITreeItem[] | undefined | null> = this._onDidChange.event;
 
-	private _onDispose: Emitter<void> = new Emitter<void>();
+	private readonly _onDispose: Emitter<void> = new Emitter<void>();
 	readonly onDispose: Event<void> = this._onDispose.event;
 
 	private itemsMap: Map<TreeItemHandle, ITreeItem> = new Map<TreeItemHandle, ITreeItem>();

src/vs/workbench/api/node/extHostDebugService.ts

@@ -29,19 +29,19 @@ export class ExtHostDebugService implements ExtHostDebugServiceShape {
 	private _debugServiceProxy: MainThreadDebugServiceShape;
 	private _debugSessions: Map<DebugSessionUUID, ExtHostDebugSession> = new Map<DebugSessionUUID, ExtHostDebugSession>();
 
-	private _onDidStartDebugSession: Emitter<vscode.DebugSession>;
+	private readonly _onDidStartDebugSession: Emitter<vscode.DebugSession>;
 	get onDidStartDebugSession(): Event<vscode.DebugSession> { return this._onDidStartDebugSession.event; }
 
-	private _onDidTerminateDebugSession: Emitter<vscode.DebugSession>;
+	private readonly _onDidTerminateDebugSession: Emitter<vscode.DebugSession>;
 	get onDidTerminateDebugSession(): Event<vscode.DebugSession> { return this._onDidTerminateDebugSession.event; }
 
-	private _onDidChangeActiveDebugSession: Emitter<vscode.DebugSession | undefined>;
+	private readonly _onDidChangeActiveDebugSession: Emitter<vscode.DebugSession | undefined>;
 	get onDidChangeActiveDebugSession(): Event<vscode.DebugSession | undefined> { return this._onDidChangeActiveDebugSession.event; }
 
 	private _activeDebugSession: ExtHostDebugSession | undefined;
 	get activeDebugSession(): ExtHostDebugSession | undefined { return this._activeDebugSession; }
 
-	private _onDidReceiveDebugSessionCustomEvent: Emitter<vscode.DebugSessionCustomEvent>;
+	private readonly _onDidReceiveDebugSessionCustomEvent: Emitter<vscode.DebugSessionCustomEvent>;
 	get onDidReceiveDebugSessionCustomEvent(): Event<vscode.DebugSessionCustomEvent> { return this._onDidReceiveDebugSessionCustomEvent.event; }
 
 	private _activeDebugConsole: ExtHostDebugConsole;
@@ -50,7 +50,7 @@ export class ExtHostDebugService implements ExtHostDebugServiceShape {
 	private _breakpoints: Map<string, vscode.Breakpoint>;
 	private _breakpointEventsActive: boolean;
 
-	private _onDidChangeBreakpoints: Emitter<vscode.BreakpointsChangeEvent>;
+	private readonly _onDidChangeBreakpoints: Emitter<vscode.BreakpointsChangeEvent>;
 
 
 	constructor(mainContext: IMainContext, workspace: ExtHostWorkspace) {

src/vs/workbench/api/node/extHostTerminalService.ts

@@ -98,7 +98,7 @@ export class ExtHostTerminal implements vscode.Terminal {
 
 export class ExtHostTerminalService implements ExtHostTerminalServiceShape {
 
-	private _onDidCloseTerminal: Emitter<vscode.Terminal>;
+	private readonly _onDidCloseTerminal: Emitter<vscode.Terminal>;
 	private _proxy: MainThreadTerminalServiceShape;
 	private _terminals: ExtHostTerminal[];
 

src/vs/workbench/browser/composite.ts

@@ -28,8 +28,8 @@ import { IDisposable } from 'vs/base/common/lifecycle';
  * layout and focus call, but only one create and dispose call.
  */
 export abstract class Composite extends Component implements IComposite {
-	private _onTitleAreaUpdate: Emitter<void>;
-	private _onDidFocus: Emitter<void>;
+	private readonly _onTitleAreaUpdate: Emitter<void>;
+	private readonly _onDidFocus: Emitter<void>;
 
 	private _focusTracker?: DOM.IFocusTracker;
 	private _focusListenerDisposable?: IDisposable;

src/vs/workbench/browser/parts/compositebar/compositeBar.ts

@@ -37,7 +37,7 @@ export interface ICompositeBarOptions {
 
 export class CompositeBar implements ICompositeBar {
 
-	private _onDidContextMenu: Emitter<MouseEvent>;
+	private readonly _onDidContextMenu: Emitter<MouseEvent>;
 
 	private dimension: Dimension;
 	private toDispose: IDisposable[];

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

@@ -24,7 +24,7 @@ import { ResourceViewerContext, ResourceViewer } from 'vs/workbench/browser/part
  * This class is only intended to be subclassed and not instantiated.
  */
 export abstract class BaseBinaryResourceEditor extends BaseEditor {
-	private _onMetadataChanged: Emitter<void>;
+	private readonly _onMetadataChanged: Emitter<void>;
 	private metadata: string;
 
 	private binaryContainer: Builder;

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

@@ -160,7 +160,7 @@ export class EditorGroupsControl extends Themable implements IEditorGroupsContro
 
 	private visibleEditorFocusTrackerDisposable: IDisposable[];
 
-	private _onGroupFocusChanged: Emitter<void>;
+	private readonly _onGroupFocusChanged: Emitter<void>;
 
 	private onStacksChangeScheduler: RunOnceScheduler;
 	private stacksChangedBuffer: IStacksModelChangeEvent[];

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

@@ -106,11 +106,11 @@ export class EditorPart extends Part implements IEditorPart, IEditorGroupService
 	private revealIfOpen: boolean;
 
 	private _onEditorsChanged: ThrottledEmitter<void>;
-	private _onEditorOpening: Emitter<IEditorOpeningEvent>;
-	private _onEditorGroupMoved: Emitter<void>;
-	private _onEditorOpenFail: Emitter<EditorInput>;
-	private _onGroupOrientationChanged: Emitter<void>;
-	private _onTabOptionsChanged: Emitter<IEditorTabOptions>;
+	private readonly _onEditorOpening: Emitter<IEditorOpeningEvent>;
+	private readonly _onEditorGroupMoved: Emitter<void>;
+	private readonly _onEditorOpenFail: Emitter<EditorInput>;
+	private readonly _onGroupOrientationChanged: Emitter<void>;
+	private readonly _onTabOptionsChanged: Emitter<IEditorTabOptions>;
 
 	private textCompareEditorVisible: IContextKey<boolean>;
 

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

@@ -25,7 +25,7 @@ export class RangeHighlightDecorations implements IDisposable {
 	private editor: ICodeEditor = null;
 	private editorDisposables: IDisposable[] = [];
 
-	private _onHighlightRemoved: Emitter<void> = new Emitter<void>();
+	private readonly _onHighlightRemoved: Emitter<void> = new Emitter<void>();
 	public readonly onHighlghtRemoved: Event<void> = this._onHighlightRemoved.event;
 
 	constructor(@IWorkbenchEditorService private editorService: IWorkbenchEditorService) {

src/vs/workbench/browser/parts/notifications/notificationsCenter.ts

@@ -36,7 +36,7 @@ export class NotificationsCenter extends Themable {
 	private notificationsList: NotificationsList;
 	private _isVisible: boolean;
 	private workbenchDimensions: Dimension;
-	private _onDidChangeVisibility: Emitter<void>;
+	private readonly _onDidChangeVisibility: Emitter<void>;
 	private notificationsCenterVisibleContextKey: IContextKey<boolean>;
 
 	constructor(

src/vs/workbench/browser/parts/quickopen/quickOpenController.ts

@@ -84,8 +84,8 @@ export class QuickOpenController extends Component implements IQuickOpenService
 
 	private static readonly ID = 'workbench.component.quickopen';
 
-	private _onShow: Emitter<void>;
-	private _onHide: Emitter<void>;
+	private readonly _onShow: Emitter<void>;
+	private readonly _onHide: Emitter<void>;
 
 	private quickOpenWidget: QuickOpenWidget;
 	private pickOpenWidget: QuickOpenWidget;

src/vs/workbench/browser/parts/views/viewsViewlet.ts

@@ -194,7 +194,7 @@ export class ViewsViewlet extends PanelViewlet implements IViewsViewlet {
 	protected viewsStates: Map<string, IViewState> = new Map<string, IViewState>();
 	private areExtensionsReady: boolean = false;
 
-	private _onDidChangeViewVisibilityState: Emitter<string> = new Emitter<string>();
+	private readonly _onDidChangeViewVisibilityState: Emitter<string> = new Emitter<string>();
 	readonly onDidChangeViewVisibilityState: Event<string> = this._onDidChangeViewVisibilityState.event;
 
 	constructor(

src/vs/workbench/common/editor.ts

@@ -96,7 +96,7 @@ export interface IEditorInputFactory {
  * Each editor input is mapped to an editor that is capable of opening it through the Platform facade.
  */
 export abstract class EditorInput implements IEditorInput {
-	private _onDispose: Emitter<void>;
+	private readonly _onDispose: Emitter<void>;
 	protected _onDidChangeDirty: Emitter<void>;
 	protected _onDidChangeLabel: Emitter<void>;
 
@@ -475,7 +475,7 @@ export interface ITextEditorModel extends IEditorModel {
  * are typically cached for some while because they are expensive to construct.
  */
 export class EditorModel extends Disposable implements IEditorModel {
-	private _onDispose: Emitter<void>;
+	private readonly _onDispose: Emitter<void>;
 
 	constructor() {
 		super();

src/vs/workbench/common/editor/editorStacksModel.ts

@@ -61,17 +61,17 @@ export class EditorGroup implements IEditorGroup {
 	private toDispose: IDisposable[];
 	private editorOpenPositioning: 'left' | 'right' | 'first' | 'last';
 
-	private _onEditorActivated: Emitter<EditorInput>;
-	private _onEditorOpened: Emitter<EditorInput>;
-	private _onEditorClosed: Emitter<EditorCloseEvent>;
-	private _onEditorDisposed: Emitter<EditorInput>;
-	private _onEditorDirty: Emitter<EditorInput>;
-	private _onEditorLabelChange: Emitter<EditorInput>;
-	private _onEditorMoved: Emitter<EditorInput>;
-	private _onEditorPinned: Emitter<EditorInput>;
-	private _onEditorUnpinned: Emitter<EditorInput>;
-	private _onEditorStateChanged: Emitter<EditorInput>;
-	private _onEditorsStructureChanged: Emitter<EditorInput>;
+	private readonly _onEditorActivated: Emitter<EditorInput>;
+	private readonly _onEditorOpened: Emitter<EditorInput>;
+	private readonly _onEditorClosed: Emitter<EditorCloseEvent>;
+	private readonly _onEditorDisposed: Emitter<EditorInput>;
+	private readonly _onEditorDirty: Emitter<EditorInput>;
+	private readonly _onEditorLabelChange: Emitter<EditorInput>;
+	private readonly _onEditorMoved: Emitter<EditorInput>;
+	private readonly _onEditorPinned: Emitter<EditorInput>;
+	private readonly _onEditorUnpinned: Emitter<EditorInput>;
+	private readonly _onEditorStateChanged: Emitter<EditorInput>;
+	private readonly _onEditorsStructureChanged: Emitter<EditorInput>;
 
 	constructor(
 		arg1: string | ISerializedEditorGroup,
@@ -709,22 +709,22 @@ export class EditorStacksModel implements IEditorStacksModel {
 	private _activeGroup: EditorGroup;
 	private groupToIdentifier: { [id: number]: EditorGroup };
 
-	private _onGroupOpened: Emitter<EditorGroup>;
-	private _onGroupClosed: Emitter<EditorGroup>;
-	private _onGroupMoved: Emitter<EditorGroup>;
-	private _onGroupActivated: Emitter<EditorGroup>;
-	private _onGroupDeactivated: Emitter<EditorGroup>;
-	private _onGroupRenamed: Emitter<EditorGroup>;
+	private readonly _onGroupOpened: Emitter<EditorGroup>;
+	private readonly _onGroupClosed: Emitter<EditorGroup>;
+	private readonly _onGroupMoved: Emitter<EditorGroup>;
+	private readonly _onGroupActivated: Emitter<EditorGroup>;
+	private readonly _onGroupDeactivated: Emitter<EditorGroup>;
+	private readonly _onGroupRenamed: Emitter<EditorGroup>;
 
-	private _onEditorDisposed: Emitter<EditorIdentifier>;
-	private _onEditorDirty: Emitter<EditorIdentifier>;
-	private _onEditorLabelChange: Emitter<EditorIdentifier>;
-	private _onEditorOpened: Emitter<EditorIdentifier>;
+	private readonly _onEditorDisposed: Emitter<EditorIdentifier>;
+	private readonly _onEditorDirty: Emitter<EditorIdentifier>;
+	private readonly _onEditorLabelChange: Emitter<EditorIdentifier>;
+	private readonly _onEditorOpened: Emitter<EditorIdentifier>;
 
-	private _onWillCloseEditor: Emitter<EditorCloseEvent>;
-	private _onEditorClosed: Emitter<EditorCloseEvent>;
+	private readonly _onWillCloseEditor: Emitter<EditorCloseEvent>;
+	private readonly _onEditorClosed: Emitter<EditorCloseEvent>;
 
-	private _onModelChanged: Emitter<IStacksModelChangeEvent>;
+	private readonly _onModelChanged: Emitter<IStacksModelChangeEvent>;
 
 	constructor(
 		private restoreFromStorage: boolean,

src/vs/workbench/common/editor/untitledEditorInput.ts

@@ -35,8 +35,8 @@ export class UntitledEditorInput extends EditorInput implements IEncodingSupport
 	private cachedModel: UntitledEditorModel;
 	private modelResolve: TPromise<UntitledEditorModel>;
 
-	private _onDidModelChangeContent: Emitter<void>;
-	private _onDidModelChangeEncoding: Emitter<void>;
+	private readonly _onDidModelChangeContent: Emitter<void>;
+	private readonly _onDidModelChangeEncoding: Emitter<void>;
 
 	private toUnbind: IDisposable[];
 

src/vs/workbench/common/editor/untitledEditorModel.ts

@@ -28,9 +28,9 @@ export class UntitledEditorModel extends BaseTextEditorModel implements IEncodin
 	private toDispose: IDisposable[];
 
 	private dirty: boolean;
-	private _onDidChangeContent: Emitter<void>;
-	private _onDidChangeDirty: Emitter<void>;
-	private _onDidChangeEncoding: Emitter<void>;
+	private readonly _onDidChangeContent: Emitter<void>;
+	private readonly _onDidChangeDirty: Emitter<void>;
+	private readonly _onDidChangeEncoding: Emitter<void>;
 
 	private versionId: number;
 

src/vs/workbench/common/notifications.ts

@@ -44,7 +44,7 @@ export interface INotificationChangeEvent {
 }
 
 export class NotificationHandle implements INotificationHandle {
-	private _onDidDispose: Emitter<void> = new Emitter();
+	private readonly _onDidDispose: Emitter<void> = new Emitter();
 
 	constructor(private item: INotificationViewItem, private disposeItem: (item: INotificationViewItem) => void) {
 		this.registerListeners();
@@ -89,7 +89,7 @@ export class NotificationsModel implements INotificationsModel {
 
 	private _notifications: INotificationViewItem[];
 
-	private _onDidNotificationChange: Emitter<INotificationChangeEvent>;
+	private readonly _onDidNotificationChange: Emitter<INotificationChangeEvent>;
 	private toDispose: IDisposable[];
 
 	constructor() {
@@ -253,7 +253,7 @@ export interface INotificationViewItemProgress extends INotificationProgress {
 export class NotificationViewItemProgress implements INotificationViewItemProgress {
 	private _state: INotificationViewItemProgressState;
 
-	private _onDidChange: Emitter<void>;
+	private readonly _onDidChange: Emitter<void>;
 	private toDispose: IDisposable[];
 
 	constructor() {
@@ -358,9 +358,9 @@ export class NotificationViewItem implements INotificationViewItem {
 	private _actions: INotificationActions;
 	private _progress: NotificationViewItemProgress;
 
-	private _onDidExpansionChange: Emitter<void>;
-	private _onDidDispose: Emitter<void>;
-	private _onDidLabelChange: Emitter<INotificationViewItemLabelChangeEvent>;
+	private readonly _onDidExpansionChange: Emitter<void>;
+	private readonly _onDidDispose: Emitter<void>;
+	private readonly _onDidLabelChange: Emitter<INotificationViewItemLabelChangeEvent>;
 
 	public static create(notification: INotification): INotificationViewItem {
 		if (!notification || !notification.message || isPromiseCanceledError(notification.message)) {

src/vs/workbench/common/views.ts

@@ -79,10 +79,10 @@ export interface IViewsRegistry {
 
 export const ViewsRegistry: IViewsRegistry = new class implements IViewsRegistry {
 
-	private _onViewsRegistered: Emitter<IViewDescriptor[]> = new Emitter<IViewDescriptor[]>();
+	private readonly _onViewsRegistered: Emitter<IViewDescriptor[]> = new Emitter<IViewDescriptor[]>();
 	readonly onViewsRegistered: Event<IViewDescriptor[]> = this._onViewsRegistered.event;
 
-	private _onViewsDeregistered: Emitter<IViewDescriptor[]> = new Emitter<IViewDescriptor[]>();
+	private readonly _onViewsDeregistered: Emitter<IViewDescriptor[]> = new Emitter<IViewDescriptor[]>();
 	readonly onViewsDeregistered: Event<IViewDescriptor[]> = this._onViewsDeregistered.event;
 
 	private _viewLocations: ViewLocation[] = [];

src/vs/workbench/electron-browser/resources.ts

@@ -19,7 +19,7 @@ export class ResourceGlobMatcher {
 
 	private static readonly NO_ROOT: string = null;
 
-	private _onExpressionChange: Emitter<void>;
+	private readonly _onExpressionChange: Emitter<void>;
 	private toUnbind: IDisposable[];
 	private mapRootToParsedExpression: Map<string, ParsedExpression>;
 	private mapRootToExpressionConfig: Map<string, IExpression>;

src/vs/workbench/electron-browser/workbench.ts

@@ -174,7 +174,7 @@ export class Workbench implements IPartService {
 
 	private static readonly fontAliasingConfigurationKey = 'workbench.fontAliasing';
 
-	private _onTitleBarVisibilityChange: Emitter<void>;
+	private readonly _onTitleBarVisibilityChange: Emitter<void>;
 
 	public _serviceBrand: any;
 

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

@@ -733,10 +733,10 @@ export class Model implements IModel {
 	private toDispose: lifecycle.IDisposable[];
 	private replElements: IReplElement[];
 	private schedulers = new Map<string, RunOnceScheduler>();
-	private _onDidChangeBreakpoints: Emitter<IBreakpointsChangeEvent>;
-	private _onDidChangeCallStack: Emitter<void>;
-	private _onDidChangeWatchExpressions: Emitter<IExpression>;
-	private _onDidChangeREPLElements: Emitter<void>;
+	private readonly _onDidChangeBreakpoints: Emitter<IBreakpointsChangeEvent>;
+	private readonly _onDidChangeCallStack: Emitter<void>;
+	private readonly _onDidChangeWatchExpressions: Emitter<IExpression>;
+	private readonly _onDidChangeREPLElements: Emitter<void>;
 
 	constructor(
 		private breakpoints: Breakpoint[],

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

@@ -14,9 +14,9 @@ export class ViewModel implements IViewModel {
 	private _focusedThread: IThread;
 	private selectedExpression: IExpression;
 	private selectedFunctionBreakpoint: IFunctionBreakpoint;
-	private _onDidFocusProcess: Emitter<IProcess | undefined>;
-	private _onDidFocusStackFrame: Emitter<{ stackFrame: IStackFrame, explicit: boolean }>;
-	private _onDidSelectExpression: Emitter<IExpression>;
+	private readonly _onDidFocusProcess: Emitter<IProcess | undefined>;
+	private readonly _onDidFocusStackFrame: Emitter<{ stackFrame: IStackFrame, explicit: boolean }>;
+	private readonly _onDidSelectExpression: Emitter<IExpression>;
 	private multiProcessView: boolean;
 	private expressionSelectedContextKey: IContextKey<boolean>;
 	private breakpointSelectedContextKey: IContextKey<boolean>;

src/vs/workbench/parts/debug/electron-browser/debugService.ts

@@ -68,10 +68,10 @@ export class DebugService implements debug.IDebugService {
 	public _serviceBrand: any;
 
 	private sessionStates: Map<string, debug.State>;
-	private _onDidChangeState: Emitter<debug.State>;
-	private _onDidNewProcess: Emitter<debug.IProcess>;
-	private _onDidEndProcess: Emitter<debug.IProcess>;
-	private _onDidCustomEvent: Emitter<debug.DebugEvent>;
+	private readonly _onDidChangeState: Emitter<debug.State>;
+	private readonly _onDidNewProcess: Emitter<debug.IProcess>;
+	private readonly _onDidEndProcess: Emitter<debug.IProcess>;
+	private readonly _onDidCustomEvent: Emitter<debug.DebugEvent>;
 	private model: Model;
 	private viewModel: ViewModel;
 	private allProcesses: Map<string, debug.IProcess>;

src/vs/workbench/parts/debug/electron-browser/rawDebugSession.ts

@@ -54,16 +54,16 @@ export class RawDebugSession extends V8Protocol implements debug.ISession {
 	private _capabilities: DebugProtocol.Capabilities;
 	private allThreadsContinued: boolean;
 
-	private _onDidInitialize: Emitter<DebugProtocol.InitializedEvent>;
-	private _onDidStop: Emitter<DebugProtocol.StoppedEvent>;
-	private _onDidContinued: Emitter<DebugProtocol.ContinuedEvent>;
-	private _onDidTerminateDebugee: Emitter<SessionTerminatedEvent>;
-	private _onDidExitAdapter: Emitter<SessionExitedEvent>;
-	private _onDidThread: Emitter<DebugProtocol.ThreadEvent>;
-	private _onDidOutput: Emitter<DebugProtocol.OutputEvent>;
-	private _onDidBreakpoint: Emitter<DebugProtocol.BreakpointEvent>;
-	private _onDidCustomEvent: Emitter<debug.DebugEvent>;
-	private _onDidEvent: Emitter<DebugProtocol.Event>;
+	private readonly _onDidInitialize: Emitter<DebugProtocol.InitializedEvent>;
+	private readonly _onDidStop: Emitter<DebugProtocol.StoppedEvent>;
+	private readonly _onDidContinued: Emitter<DebugProtocol.ContinuedEvent>;
+	private readonly _onDidTerminateDebugee: Emitter<SessionTerminatedEvent>;
+	private readonly _onDidExitAdapter: Emitter<SessionExitedEvent>;
+	private readonly _onDidThread: Emitter<DebugProtocol.ThreadEvent>;
+	private readonly _onDidOutput: Emitter<DebugProtocol.OutputEvent>;
+	private readonly _onDidBreakpoint: Emitter<DebugProtocol.BreakpointEvent>;
+	private readonly _onDidCustomEvent: Emitter<debug.DebugEvent>;
+	private readonly _onDidEvent: Emitter<DebugProtocol.Event>;
 
 	constructor(
 		id: string,

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

@@ -358,7 +358,7 @@ export class ExtensionsWorkbenchService implements IExtensionsWorkbenchService {
 	private autoUpdateDelayer: ThrottledDelayer<void>;
 	private disposables: IDisposable[] = [];
 
-	private _onChange: Emitter<void> = new Emitter<void>();
+	private readonly _onChange: Emitter<void> = new Emitter<void>();
 	get onChange(): Event<void> { return this._onChange.event; }
 
 	private _extensionAllowedBadgeProviders: string[];

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

@@ -165,10 +165,10 @@ export interface IOutputChannelRegistry {
 class OutputChannelRegistry implements IOutputChannelRegistry {
 	private channels = new Map<string, IOutputChannelIdentifier>();
 
-	private _onDidRegisterChannel: Emitter<string> = new Emitter<string>();
+	private readonly _onDidRegisterChannel: Emitter<string> = new Emitter<string>();
 	readonly onDidRegisterChannel: Event<string> = this._onDidRegisterChannel.event;
 
-	private _onDidRemoveChannel: Emitter<string> = new Emitter<string>();
+	private readonly _onDidRemoveChannel: Emitter<string> = new Emitter<string>();
 	readonly onDidRemoveChannel: Event<string> = this._onDidRemoveChannel.event;
 
 	public registerChannel(id: string, label: string, file?: URI): void {

src/vs/workbench/parts/output/electron-browser/outputServices.ts

@@ -315,7 +315,7 @@ class OutputChannelBackedByFile extends AbstractFileOutputChannel implements Out
 
 class OutputFileListener extends Disposable {
 
-	private _onDidChange: Emitter<void> = new Emitter<void>();
+	private readonly _onDidChange: Emitter<void> = new Emitter<void>();
 	readonly onDidContentChange: Event<void> = this._onDidChange.event;
 
 	private watching: boolean = false;
@@ -423,7 +423,7 @@ export class OutputService extends Disposable implements IOutputService, ITextMo
 	private activeChannel: IOutputChannel;
 	private readonly outputDir: string;
 
-	private _onActiveOutputChannel: Emitter<string> = new Emitter<string>();
+	private readonly _onActiveOutputChannel: Emitter<string> = new Emitter<string>();
 	readonly onActiveOutputChannel: Event<string> = this._onActiveOutputChannel.event;
 
 	private _outputPanel: OutputPanel;
@@ -651,7 +651,7 @@ class BufferredOutputChannel extends Disposable implements OutputChannel {
 	protected _onDidAppendedContent: Emitter<void> = new Emitter<void>();
 	readonly onDidAppendedContent: Event<void> = this._onDidAppendedContent.event;
 
-	private _onDispose: Emitter<void> = new Emitter<void>();
+	private readonly _onDispose: Emitter<void> = new Emitter<void>();
 	readonly onDispose: Event<void> = this._onDispose.event;
 
 	private modelUpdater: RunOnceScheduler;

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

@@ -398,7 +398,7 @@ class PreferencesRenderersController extends Disposable {
 	private _lastQuery: string;
 	private _lastFilterResult: IFilterResult;
 
-	private _onDidFilterResultsCountChange: Emitter<IPreferencesCount> = this._register(new Emitter<IPreferencesCount>());
+	private readonly _onDidFilterResultsCountChange: Emitter<IPreferencesCount> = this._register(new Emitter<IPreferencesCount>());
 	public readonly onDidFilterResultsCountChange: Event<IPreferencesCount> = this._onDidFilterResultsCountChange.event;
 
 	constructor(
@@ -782,10 +782,10 @@ class SideBySidePreferencesWidget extends Widget {
 
 	private settingsTargetsWidget: SettingsTargetsWidget;
 
-	private _onFocus: Emitter<void> = new Emitter<void>();
+	private readonly _onFocus: Emitter<void> = new Emitter<void>();
 	readonly onFocus: Event<void> = this._onFocus.event;
 
-	private _onDidSettingsTargetChange: Emitter<SettingsTarget> = new Emitter<SettingsTarget>();
+	private readonly _onDidSettingsTargetChange: Emitter<SettingsTarget> = new Emitter<SettingsTarget>();
 	readonly onDidSettingsTargetChange: Event<SettingsTarget> = this._onDidSettingsTargetChange.event;
 
 	private lastFocusedEditor: BaseEditor;

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

@@ -69,13 +69,13 @@ export class UserSettingsRenderer extends Disposable implements IPreferencesRend
 	private modelChangeDelayer: Delayer<void> = new Delayer<void>(200);
 	private associatedPreferencesModel: IPreferencesEditorModel<ISetting>;
 
-	private _onFocusPreference: Emitter<ISetting> = new Emitter<ISetting>();
+	private readonly _onFocusPreference: Emitter<ISetting> = new Emitter<ISetting>();
 	public readonly onFocusPreference: Event<ISetting> = this._onFocusPreference.event;
 
-	private _onClearFocusPreference: Emitter<ISetting> = new Emitter<ISetting>();
+	private readonly _onClearFocusPreference: Emitter<ISetting> = new Emitter<ISetting>();
 	public readonly onClearFocusPreference: Event<ISetting> = this._onClearFocusPreference.event;
 
-	private _onUpdatePreference: Emitter<{ key: string, value: any, source: IIndexedSetting }> = new Emitter<{ key: string, value: any, source: IIndexedSetting }>();
+	private readonly _onUpdatePreference: Emitter<{ key: string, value: any, source: IIndexedSetting }> = new Emitter<{ key: string, value: any, source: IIndexedSetting }>();
 	public readonly onUpdatePreference: Event<{ key: string, value: any, source: IIndexedSetting }> = this._onUpdatePreference.event;
 
 	private filterResult: IFilterResult;
@@ -257,13 +257,13 @@ export class DefaultSettingsRenderer extends Disposable implements IPreferencesR
 	private extensionCodelensRenderer: ExtensionCodelensRenderer;
 	private filterResult: IFilterResult;
 
-	private _onUpdatePreference: Emitter<{ key: string, value: any, source: IIndexedSetting }> = new Emitter<{ key: string, value: any, source: IIndexedSetting }>();
+	private readonly _onUpdatePreference: Emitter<{ key: string, value: any, source: IIndexedSetting }> = new Emitter<{ key: string, value: any, source: IIndexedSetting }>();
 	public readonly onUpdatePreference: Event<{ key: string, value: any, source: IIndexedSetting }> = this._onUpdatePreference.event;
 
-	private _onFocusPreference: Emitter<ISetting> = new Emitter<ISetting>();
+	private readonly _onFocusPreference: Emitter<ISetting> = new Emitter<ISetting>();
 	public readonly onFocusPreference: Event<ISetting> = this._onFocusPreference.event;
 
-	private _onClearFocusPreference: Emitter<ISetting> = new Emitter<ISetting>();
+	private readonly _onClearFocusPreference: Emitter<ISetting> = new Emitter<ISetting>();
 	public readonly onClearFocusPreference: Event<ISetting> = this._onClearFocusPreference.event;
 
 	constructor(protected editor: ICodeEditor, public readonly preferencesModel: DefaultSettingsEditorModel,
@@ -481,7 +481,7 @@ class DefaultSettingsHeaderRenderer extends Disposable {
 
 export class SettingsGroupTitleRenderer extends Disposable implements HiddenAreasProvider {
 
-	private _onHiddenAreasChanged: Emitter<void> = new Emitter<void>();
+	private readonly _onHiddenAreasChanged: Emitter<void> = new Emitter<void>();
 	get onHiddenAreasChanged(): Event<void> { return this._onHiddenAreasChanged.event; }
 
 	private settingsGroups: ISettingsGroup[];
@@ -1031,7 +1031,7 @@ class EditSettingRenderer extends Disposable {
 	public associatedPreferencesModel: IPreferencesEditorModel<ISetting>;
 	private toggleEditPreferencesForMouseMoveDelayer: Delayer<void>;
 
-	private _onUpdateSetting: Emitter<{ key: string, value: any, source: IIndexedSetting }> = new Emitter<{ key: string, value: any, source: IIndexedSetting }>();
+	private readonly _onUpdateSetting: Emitter<{ key: string, value: any, source: IIndexedSetting }> = new Emitter<{ key: string, value: any, source: IIndexedSetting }>();
 	public readonly onUpdateSetting: Event<{ key: string, value: any, source: IIndexedSetting }> = this._onUpdateSetting.event;
 
 	constructor(private editor: ICodeEditor, private masterSettingsModel: ISettingsEditorModel,
@@ -1295,7 +1295,7 @@ class SettingHighlighter extends Disposable {
 	private volatileHighlighter: RangeHighlightDecorations;
 	private highlightedSetting: ISetting;
 
-	constructor(private editor: ICodeEditor, private focusEventEmitter: Emitter<ISetting>, private clearFocusEventEmitter: Emitter<ISetting>,
+	constructor(private editor: ICodeEditor, private readonly focusEventEmitter: Emitter<ISetting>, private readonly clearFocusEventEmitter: Emitter<ISetting>,
 		@IInstantiationService instantiationService: IInstantiationService
 	) {
 		super();

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

@@ -49,7 +49,7 @@ export class PreferencesService extends Disposable implements IPreferencesServic
 
 	private lastOpenedSettingsInput: PreferencesEditorInput = null;
 
-	private _onDispose: Emitter<void> = new Emitter<void>();
+	private readonly _onDispose: Emitter<void> = new Emitter<void>();
 
 	private _defaultSettingsUriCounter = 0;
 	private _defaultSettingsContentModel: DefaultSettings;

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

@@ -461,7 +461,7 @@ export class SettingsTargetsWidget extends Widget {
 
 	private _settingsTarget: SettingsTarget;
 
-	private _onDidTargetChange: Emitter<SettingsTarget> = new Emitter<SettingsTarget>();
+	private readonly _onDidTargetChange: Emitter<SettingsTarget> = new Emitter<SettingsTarget>();
 	public readonly onDidTargetChange: Event<SettingsTarget> = this._onDidTargetChange.event;
 
 	constructor(
@@ -573,10 +573,10 @@ export class SearchWidget extends Widget {
 	private inputBox: InputBox;
 	private controlsDiv: HTMLElement;
 
-	private _onDidChange: Emitter<string> = this._register(new Emitter<string>());
+	private readonly _onDidChange: Emitter<string> = this._register(new Emitter<string>());
 	public readonly onDidChange: Event<string> = this._onDidChange.event;
 
-	private _onFocus: Emitter<void> = this._register(new Emitter<void>());
+	private readonly _onFocus: Emitter<void> = this._register(new Emitter<void>());
 	public readonly onFocus: Event<void> = this._onFocus.event;
 
 	constructor(parent: HTMLElement, protected options: SearchOptions,
@@ -705,7 +705,7 @@ export class FloatingClickWidget extends Widget implements IOverlayWidget {
 
 	private _domNode: HTMLElement;
 
-	private _onClick: Emitter<void> = this._register(new Emitter<void>());
+	private readonly _onClick: Emitter<void> = this._register(new Emitter<void>());
 	public readonly onClick: Event<void> = this._onClick.event;
 
 	constructor(
@@ -766,7 +766,7 @@ export class EditPreferenceWidget<T> extends Disposable {
 
 	private _editPreferenceDecoration: string[];
 
-	private _onClick: Emitter<IEditorMouseEvent> = new Emitter<IEditorMouseEvent>();
+	private readonly _onClick: Emitter<IEditorMouseEvent> = new Emitter<IEditorMouseEvent>();
 	public get onClick(): Event<IEditorMouseEvent> { return this._onClick.event; }
 
 	constructor(private editor: ICodeEditor

src/vs/workbench/parts/preferences/common/preferencesModels.ts

@@ -119,7 +119,7 @@ export class SettingsEditorModel extends AbstractSettingsModel implements ISetti
 	private _settingsGroups: ISettingsGroup[];
 	protected settingsModel: ITextModel;
 
-	private _onDidChangeGroups: Emitter<void> = this._register(new Emitter<void>());
+	private readonly _onDidChangeGroups: Emitter<void> = this._register(new Emitter<void>());
 	readonly onDidChangeGroups: Event<void> = this._onDidChangeGroups.event;
 
 	constructor(reference: IReference<ITextEditorModel>, private _configurationTarget: ConfigurationTarget) {
@@ -597,7 +597,7 @@ export class DefaultSettingsEditorModel extends AbstractSettingsModel implements
 
 	private _model: ITextModel;
 
-	private _onDidChangeGroups: Emitter<void> = this._register(new Emitter<void>());
+	private readonly _onDidChangeGroups: Emitter<void> = this._register(new Emitter<void>());
 	readonly onDidChangeGroups: Event<void> = this._onDidChangeGroups.event;
 
 	constructor(

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

@@ -98,7 +98,7 @@ export class SearchView extends Viewlet implements IViewlet, IPanel {
 
 	private currentSelectedFileMatch: FileMatch;
 
-	private selectCurrentMatchEmitter: Emitter<string>;
+	private readonly selectCurrentMatchEmitter: Emitter<string>;
 	private delayedRefresh: Delayer<void>;
 	private changedWhileHidden: boolean;
 

src/vs/workbench/parts/search/common/searchModel.ts

@@ -682,7 +682,7 @@ export class SearchModel extends Disposable {
 	private _replaceString: string = null;
 	private _replacePattern: ReplacePattern = null;
 
-	private _onReplaceTermChanged: Emitter<void> = this._register(new Emitter<void>());
+	private readonly _onReplaceTermChanged: Emitter<void> = this._register(new Emitter<void>());
 	public readonly onReplaceTermChanged: Event<void> = this._onReplaceTermChanged.event;
 
 	private currentRequest: PPromise<ISearchComplete, ISearchProgressItem>;

src/vs/workbench/parts/tasks/electron-browser/task.contribution.ts

@@ -453,7 +453,7 @@ class TaskService implements ITaskService {
 	private _recentlyUsedTasks: LinkedMap<string, string>;
 
 	private _outputChannel: IOutputChannel;
-	private _onDidStateChange: Emitter<TaskEvent>;
+	private readonly _onDidStateChange: Emitter<TaskEvent>;
 
 	constructor(
 		@IConfigurationService private configurationService: IConfigurationService,

src/vs/workbench/parts/tasks/electron-browser/terminalTaskSystem.ts

@@ -91,7 +91,7 @@ export class TerminalTaskSystem implements ITaskSystem {
 	private idleTaskTerminals: LinkedMap<string, string>;
 	private sameTaskTerminals: IStringDictionary<string>;
 
-	private _onDidStateChange: Emitter<TaskEvent>;
+	private readonly _onDidStateChange: Emitter<TaskEvent>;
 
 	constructor(private terminalService: ITerminalService, private outputService: IOutputService,
 		private markerService: IMarkerService, private modelService: IModelService,

src/vs/workbench/parts/tasks/node/processTaskSystem.ts

@@ -54,7 +54,7 @@ export class ProcessTaskSystem implements ITaskSystem {
 	private activeTask: CustomTask;
 	private activeTaskPromise: TPromise<ITaskSummary>;
 
-	private _onDidStateChange: Emitter<TaskEvent>;
+	private readonly _onDidStateChange: Emitter<TaskEvent>;
 
 	constructor(markerService: IMarkerService, modelService: IModelService, telemetryService: ITelemetryService,
 		outputService: IOutputService, configurationResolverService: IConfigurationResolverService, outputChannelId: string) {

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

@@ -31,7 +31,7 @@ export abstract class TerminalService implements ITerminalService {
 	protected abstract _terminalInstances: ITerminalInstance[];
 
 	private _activeTabIndex: number;
-	private _onActiveTabChanged: Emitter<void>;
+	private readonly _onActiveTabChanged: Emitter<void>;
 
 	public get activeTabIndex(): number { return this._activeTabIndex; }
 	public get onActiveTabChanged(): Event<void> { return this._onActiveTabChanged.event; }

src/vs/workbench/parts/terminal/electron-browser/terminalInstance.ts

@@ -78,10 +78,10 @@ export class TerminalInstance implements ITerminalInstance {
 	private _processState: ProcessState;
 	private _processReady: TPromise<void>;
 	private _isDisposed: boolean;
-	private _onDisposed: Emitter<ITerminalInstance>;
-	private _onFocused: Emitter<ITerminalInstance>;
-	private _onProcessIdReady: Emitter<ITerminalInstance>;
-	private _onTitleChanged: Emitter<string>;
+	private readonly _onDisposed: Emitter<ITerminalInstance>;
+	private readonly _onFocused: Emitter<ITerminalInstance>;
+	private readonly _onProcessIdReady: Emitter<ITerminalInstance>;
+	private readonly _onTitleChanged: Emitter<string>;
 	private _process: cp.ChildProcess;
 	private _processId: number;
 	private _skipTerminalCommands: string[];

src/vs/workbench/parts/terminal/electron-browser/terminalTab.ts

@@ -248,9 +248,9 @@ export class TerminalTab extends Disposable implements ITerminalTab {
 
 	public get terminalInstances(): ITerminalInstance[] { return this._terminalInstances; }
 
-	private _onDisposed: Emitter<ITerminalTab>;
+	private readonly _onDisposed: Emitter<ITerminalTab>;
 	public get onDisposed(): Event<ITerminalTab> { return this._onDisposed.event; }
-	private _onInstancesChanged: Emitter<void>;
+	private readonly _onInstancesChanged: Emitter<void>;
 	public get onInstancesChanged(): Event<void> { return this._onInstancesChanged.event; }
 
 	constructor(

src/vs/workbench/parts/webview/electron-browser/webviewEditor.ts

@@ -31,7 +31,7 @@ export class WebviewEditor extends BaseWebviewEditor {
 	private editorFrame: HTMLElement;
 	private content: HTMLElement;
 	private webviewContent: HTMLElement | undefined;
-	private _onDidFocusWebview: Emitter<void>;
+	private readonly _onDidFocusWebview: Emitter<void>;
 	private _webviewFocusTracker?: DOM.IFocusTracker;
 	private _webviewFocusListenerDisposable?: IDisposable;
 

src/vs/workbench/services/commands/common/commandService.ts

@@ -18,7 +18,7 @@ export class CommandService extends Disposable implements ICommandService {
 
 	private _extensionHostIsReady: boolean = false;
 
-	private _onWillExecuteCommand: Emitter<ICommandEvent> = this._register(new Emitter<ICommandEvent>());
+	private readonly _onWillExecuteCommand: Emitter<ICommandEvent> = this._register(new Emitter<ICommandEvent>());
 	public readonly onWillExecuteCommand: Event<ICommandEvent> = this._onWillExecuteCommand.event;
 
 	constructor(

src/vs/workbench/services/configuration/node/configuration.ts

@@ -79,7 +79,7 @@ export class WorkspaceConfiguration extends Disposable {
 	private _workspaceConfigurationWatcher: ConfigWatcher<WorkspaceConfigurationModelParser>;
 	private _workspaceConfigurationWatcherDisposables: IDisposable[] = [];
 
-	private _onDidUpdateConfiguration: Emitter<void> = this._register(new Emitter<void>());
+	private readonly _onDidUpdateConfiguration: Emitter<void> = this._register(new Emitter<void>());
 	public readonly onDidUpdateConfiguration: Event<void> = this._onDidUpdateConfiguration.event;
 
 	private _workspaceConfigurationModelParser: WorkspaceConfigurationModelParser = new WorkspaceConfigurationModelParser(this._workspaceConfigPath ? this._workspaceConfigPath.fsPath : '');
@@ -182,7 +182,7 @@ export class FolderConfiguration extends Disposable {
 	private _cache: ConfigurationModel = new ConfigurationModel();
 
 	private reloadConfigurationScheduler: RunOnceScheduler;
-	private reloadConfigurationEventEmitter: Emitter<ConfigurationModel> = new Emitter<ConfigurationModel>();
+	private readonly reloadConfigurationEventEmitter: Emitter<ConfigurationModel> = new Emitter<ConfigurationModel>();
 
 	constructor(private folder: URI, private configFolderRelativePath: string, workbenchState: WorkbenchState) {
 		super();

src/vs/workbench/services/extensions/electron-browser/extensionHost.ts

@@ -39,7 +39,7 @@ import { INotificationService, Severity } from 'vs/platform/notification/common/
 
 export class ExtensionHostProcessWorker {
 
-	private _onCrashed: Emitter<[number, string]> = new Emitter<[number, string]>();
+	private readonly _onCrashed: Emitter<[number, string]> = new Emitter<[number, string]>();
 	public readonly onCrashed: Event<[number, string]> = this._onCrashed.event;
 
 	private readonly _toDispose: IDisposable[];

src/vs/workbench/services/extensions/electron-browser/extensionService.ts

@@ -113,7 +113,7 @@ const NO_OP_VOID_PROMISE = TPromise.wrap<void>(void 0);
 export class ExtensionService extends Disposable implements IExtensionService {
 	public _serviceBrand: any;
 
-	private _onDidRegisterExtensions: Emitter<void>;
+	private readonly _onDidRegisterExtensions: Emitter<void>;
 
 	private _registry: ExtensionDescriptionRegistry;
 	private readonly _installedExtensionsReady: Barrier;

src/vs/workbench/services/files/node/fileService.ts

@@ -119,8 +119,8 @@ export class FileService implements IFileService {
 	private tmpPath: string;
 	private options: IFileServiceOptions;
 
-	private _onFileChanges: Emitter<FileChangesEvent>;
-	private _onAfterOperation: Emitter<FileOperationEvent>;
+	private readonly _onFileChanges: Emitter<FileChangesEvent>;
+	private readonly _onAfterOperation: Emitter<FileOperationEvent>;
 
 	private toDispose: IDisposable[];
 

src/vs/workbench/services/files/test/node/watcher.test.ts

@@ -14,7 +14,7 @@ import { IRawFileChange, toFileChangesEvent, normalize } from 'vs/workbench/serv
 import Event, { Emitter } from 'vs/base/common/event';
 
 class TestFileWatcher {
-	private _onFileChanges: Emitter<FileChangesEvent>;
+	private readonly _onFileChanges: Emitter<FileChangesEvent>;
 
 	constructor() {
 		this._onFileChanges = new Emitter<FileChangesEvent>();

src/vs/workbench/services/keybinding/electron-browser/keybindingService.ts

@@ -46,7 +46,7 @@ export class KeyboardMapperFactory {
 	private _keyboardMapper: IKeyboardMapper;
 	private _initialized: boolean;
 
-	private _onDidChangeKeyboardMapper: Emitter<void> = new Emitter<void>();
+	private readonly _onDidChangeKeyboardMapper: Emitter<void> = new Emitter<void>();
 	public readonly onDidChangeKeyboardMapper: Event<void> = this._onDidChangeKeyboardMapper.event;
 
 	private constructor() {

src/vs/workbench/services/textMate/electron-browser/TMSyntax.ts

@@ -28,7 +28,7 @@ export class TMScopeRegistry {
 	private _scopeNameToLanguageRegistration: { [scopeName: string]: TMLanguageRegistration; };
 	private _encounteredLanguages: boolean[];
 
-	private _onDidEncounterLanguage: Emitter<LanguageId> = new Emitter<LanguageId>();
+	private readonly _onDidEncounterLanguage: Emitter<LanguageId> = new Emitter<LanguageId>();
 	public readonly onDidEncounterLanguage: Event<LanguageId> = this._onDidEncounterLanguage.event;
 
 	constructor() {

src/vs/workbench/services/textfile/common/textFileEditorModel.ts

@@ -63,8 +63,8 @@ export class TextFileEditorModel extends BaseTextEditorModel implements ITextFil
 	private disposed: boolean;
 	private lastSaveAttemptTime: number;
 	private createTextEditorModelPromise: TPromise<TextFileEditorModel>;
-	private _onDidContentChange: Emitter<StateChange>;
-	private _onDidStateChange: Emitter<StateChange>;
+	private readonly _onDidContentChange: Emitter<StateChange>;
+	private readonly _onDidStateChange: Emitter<StateChange>;
 
 	private inConflictMode: boolean;
 	private inOrphanMode: boolean;

src/vs/workbench/services/textfile/common/textFileEditorModelManager.ts

@@ -17,14 +17,14 @@ import { ResourceMap } from 'vs/base/common/map';
 export class TextFileEditorModelManager implements ITextFileEditorModelManager {
 	private toUnbind: IDisposable[];
 
-	private _onModelDisposed: Emitter<URI>;
-	private _onModelContentChanged: Emitter<TextFileModelChangeEvent>;
-	private _onModelDirty: Emitter<TextFileModelChangeEvent>;
-	private _onModelSaveError: Emitter<TextFileModelChangeEvent>;
-	private _onModelSaved: Emitter<TextFileModelChangeEvent>;
-	private _onModelReverted: Emitter<TextFileModelChangeEvent>;
-	private _onModelEncodingChanged: Emitter<TextFileModelChangeEvent>;
-	private _onModelOrphanedChanged: Emitter<TextFileModelChangeEvent>;
+	private readonly _onModelDisposed: Emitter<URI>;
+	private readonly _onModelContentChanged: Emitter<TextFileModelChangeEvent>;
+	private readonly _onModelDirty: Emitter<TextFileModelChangeEvent>;
+	private readonly _onModelSaveError: Emitter<TextFileModelChangeEvent>;
+	private readonly _onModelSaved: Emitter<TextFileModelChangeEvent>;
+	private readonly _onModelReverted: Emitter<TextFileModelChangeEvent>;
+	private readonly _onModelEncodingChanged: Emitter<TextFileModelChangeEvent>;
+	private readonly _onModelOrphanedChanged: Emitter<TextFileModelChangeEvent>;
 
 	private _onModelsDirtyEvent: Event<TextFileModelChangeEvent[]>;
 	private _onModelsSaveError: Event<TextFileModelChangeEvent[]>;

src/vs/workbench/services/textfile/common/textFileService.ts

@@ -51,10 +51,10 @@ export abstract class TextFileService implements ITextFileService {
 	private toUnbind: IDisposable[];
 	private _models: TextFileEditorModelManager;
 
-	private _onFilesAssociationChange: Emitter<void>;
+	private readonly _onFilesAssociationChange: Emitter<void>;
 	private currentFilesAssociationConfig: { [key: string]: string; };
 
-	private _onAutoSaveConfigurationChange: Emitter<IAutoSaveConfiguration>;
+	private readonly _onAutoSaveConfigurationChange: Emitter<IAutoSaveConfiguration>;
 	private configuredAutoSaveDelay: number;
 	private configuredAutoSaveOnFocusChange: boolean;
 	private configuredAutoSaveOnWindowChange: boolean;

src/vs/workbench/services/themes/electron-browser/colorThemeStore.ts

@@ -47,7 +47,7 @@ let themesExtPoint = ExtensionsRegistry.registerExtensionPoint<IThemeExtensionPo
 export class ColorThemeStore {
 
 	private extensionsColorThemes: ColorThemeData[];
-	private onDidChangeEmitter: Emitter<ColorThemeData[]>;
+	private readonly onDidChangeEmitter: Emitter<ColorThemeData[]>;
 
 	public get onDidChange(): Event<ColorThemeData[]> { return this.onDidChangeEmitter.event; }
 

src/vs/workbench/services/themes/electron-browser/fileIconThemeStore.ts

@@ -41,7 +41,7 @@ let iconThemeExtPoint = ExtensionsRegistry.registerExtensionPoint<IThemeExtensio
 export class FileIconThemeStore {
 
 	private knownIconThemes: FileIconThemeData[];
-	private onDidChangeEmitter: Emitter<FileIconThemeData[]>;
+	private readonly onDidChangeEmitter: Emitter<FileIconThemeData[]>;
 
 	public get onDidChange(): Event<FileIconThemeData[]> { return this.onDidChangeEmitter.event; }
 

src/vs/workbench/services/themes/electron-browser/workbenchThemeService.ts

@@ -74,11 +74,11 @@ export class WorkbenchThemeService implements IWorkbenchThemeService {
 	private colorThemeStore: ColorThemeStore;
 	private currentColorTheme: ColorThemeData;
 	private container: HTMLElement;
-	private onColorThemeChange: Emitter<IColorTheme>;
+	private readonly onColorThemeChange: Emitter<IColorTheme>;
 
 	private iconThemeStore: FileIconThemeStore;
 	private currentIconTheme: IFileIconTheme;
-	private onFileIconThemeChange: Emitter<IFileIconTheme>;
+	private readonly onFileIconThemeChange: Emitter<IFileIconTheme>;
 
 	private themingParticipantChangeListener: IDisposable;
 	private _configurationWriter: ConfigurationWriter;

src/vs/workbench/services/untitled/common/untitledEditorService.ts

@@ -110,10 +110,10 @@ export class UntitledEditorService implements IUntitledEditorService {
 	private mapResourceToInput = new ResourceMap<UntitledEditorInput>();
 	private mapResourceToAssociatedFilePath = new ResourceMap<boolean>();
 
-	private _onDidChangeContent: Emitter<URI>;
-	private _onDidChangeDirty: Emitter<URI>;
-	private _onDidChangeEncoding: Emitter<URI>;
-	private _onDidDisposeModel: Emitter<URI>;
+	private readonly _onDidChangeContent: Emitter<URI>;
+	private readonly _onDidChangeDirty: Emitter<URI>;
+	private readonly _onDidChangeEncoding: Emitter<URI>;
+	private readonly _onDidDisposeModel: Emitter<URI>;
 
 	constructor(
 		@IInstantiationService private instantiationService: IInstantiationService,

src/vs/workbench/test/workbenchTestServices.ts

@@ -77,9 +77,9 @@ export class TestContextService implements IWorkspaceContextService {
 	private workspace: IWorkbenchWorkspace;
 	private options: any;
 
-	private _onDidChangeWorkspaceName: Emitter<void>;
-	private _onDidChangeWorkspaceFolders: Emitter<IWorkspaceFoldersChangeEvent>;
-	private _onDidChangeWorkbenchState: Emitter<WorkbenchState>;
+	private readonly _onDidChangeWorkspaceName: Emitter<void>;
+	private readonly _onDidChangeWorkspaceFolders: Emitter<IWorkspaceFoldersChangeEvent>;
+	private readonly _onDidChangeWorkbenchState: Emitter<WorkbenchState>;
 
 	constructor(workspace: any = TestWorkspace, options: any = null) {
 		this.workspace = workspace;
@@ -475,12 +475,12 @@ export class TestEditorGroupService implements IEditorGroupService {
 
 	private stacksModel: EditorStacksModel;
 
-	private _onEditorsChanged: Emitter<void>;
-	private _onEditorOpening: Emitter<IEditorOpeningEvent>;
-	private _onEditorOpenFail: Emitter<IEditorInput>;
-	private _onEditorsMoved: Emitter<void>;
-	private _onGroupOrientationChanged: Emitter<void>;
-	private _onTabOptionsChanged: Emitter<IEditorTabOptions>;
+	private readonly _onEditorsChanged: Emitter<void>;
+	private readonly _onEditorOpening: Emitter<IEditorOpeningEvent>;
+	private readonly _onEditorOpenFail: Emitter<IEditorInput>;
+	private readonly _onEditorsMoved: Emitter<void>;
+	private readonly _onGroupOrientationChanged: Emitter<void>;
+	private readonly _onTabOptionsChanged: Emitter<IEditorTabOptions>;
 
 	constructor(callback?: (method: string) => void) {
 		this._onEditorsMoved = new Emitter<void>();
@@ -679,8 +679,8 @@ export class TestFileService implements IFileService {
 
 	public _serviceBrand: any;
 
-	private _onFileChanges: Emitter<FileChangesEvent>;
-	private _onAfterOperation: Emitter<FileOperationEvent>;
+	private readonly _onFileChanges: Emitter<FileChangesEvent>;
+	private readonly _onAfterOperation: Emitter<FileOperationEvent>;
 
 	private content = 'Hello Html';