diff --git a/src/vs/workbench/api/electron-browser/mainThreadDocumentsAndEditors.ts b/src/vs/workbench/api/electron-browser/mainThreadDocumentsAndEditors.ts
index 974d8a45c70..a6be9198dd5 100644
--- a/src/vs/workbench/api/electron-browser/mainThreadDocumentsAndEditors.ts
+++ b/src/vs/workbench/api/electron-browser/mainThreadDocumentsAndEditors.ts
@@ -10,7 +10,7 @@ import { compare } from 'vs/base/common/strings';
 import { delta } from 'vs/base/common/arrays';
 import { IDisposable, dispose } from 'vs/base/common/lifecycle';
 import { ICodeEditorService } from 'vs/editor/common/services/codeEditorService';
-import Event, { Emitter, any } from 'vs/base/common/event';
+import Event, { Emitter } from 'vs/base/common/event';
 import { ExtHostContext, ExtHostDocumentsAndEditorsShape, IModelAddedData, ITextEditorAddData, IDocumentsAndEditorsDelta } from '../node/extHost.protocol';
 import { MainThreadTextEditor } from './mainThreadEditor';
 import { IThreadService } from 'vs/workbench/services/thread/common/threadService';
@@ -127,12 +127,9 @@ class MainThreadDocumentAndEditorStateComputer {
 	}
 
 	private _onDidAddEditor(e: ICommonCodeEditor): void {
-		const listener = any<any>(
-			e.onDidChangeModel,
-			e.onDidFocusEditor,
-			e.onDidBlurEditor
-		)(this._updateState, this);
-		this._toDisposeOnEditorRemove.set(e.getId(), listener);
+		this._toDisposeOnEditorRemove.set(e.getId(), e.onDidChangeModel(() => this._updateState()));
+		this._toDisposeOnEditorRemove.set(e.getId(), e.onDidFocusEditor(() => this._updateState()));
+		this._toDisposeOnEditorRemove.set(e.getId(), e.onDidBlurEditor(() => this._updateState()));
 		this._updateState();
 	}
 
diff --git a/src/vs/workbench/api/node/extHost.api.impl.ts b/src/vs/workbench/api/node/extHost.api.impl.ts
index 7808ff172bb..92943aa1520 100644
--- a/src/vs/workbench/api/node/extHost.api.impl.ts
+++ b/src/vs/workbench/api/node/extHost.api.impl.ts
@@ -129,7 +129,7 @@ export function createApiFactory(
 				return extHostCommands.registerCommand(id, command, thisArgs);
 			},
 			registerTextEditorCommand(id: string, callback: (textEditor: vscode.TextEditor, edit: vscode.TextEditorEdit, ...args: any[]) => void, thisArg?: any): vscode.Disposable {
-				return extHostCommands.registerCommand(id, (...args: any[]) => {
+				return extHostCommands.registerCommand(id, (...args: any[]): any => {
 					let activeTextEditor = extHostEditors.getActiveTextEditor();
 					if (!activeTextEditor) {
 						console.warn('Cannot execute ' + id + ' because there is no active text editor.');
@@ -313,7 +313,7 @@ export function createApiFactory(
 			},
 			withScmProgress<R>(task: (progress: vscode.Progress<number>) => Thenable<R>) {
 				console.warn(`[Deprecation Warning] function 'withScmProgress' is deprecated and should no longer be used. Use 'withProgress' instead.`);
-				return extHostProgress.withProgress(extension, { location: extHostTypes.ProgressLocation.SourceControl }, task);
+				return extHostProgress.withProgress(extension, { location: extHostTypes.ProgressLocation.SourceControl }, (progress, token) => task({ report(n: number) { /*noop*/ } }));
 			},
 			withProgress<R>(options: vscode.ProgressOptions, task: (progress: vscode.Progress<{ message?: string; percentage?: number }>) => Thenable<R>) {
 				return extHostProgress.withProgress(extension, options, task);
diff --git a/src/vs/workbench/api/node/extHost.protocol.ts b/src/vs/workbench/api/node/extHost.protocol.ts
index c7f432d81bb..20cf8960029 100644
--- a/src/vs/workbench/api/node/extHost.protocol.ts
+++ b/src/vs/workbench/api/node/extHost.protocol.ts
@@ -84,9 +84,9 @@ export class InstanceCollection {
 	public define<T>(id: ProxyIdentifier<T>): InstanceSetter<T> {
 		let that = this;
 		return new class {
-			set(value: T) {
+			set<R extends T>(value: T): R {
 				that._set(id, value);
-				return value;
+				return <R>value;
 			}
 		};
 	}
diff --git a/src/vs/workbench/api/node/extHostCommands.ts b/src/vs/workbench/api/node/extHostCommands.ts
index 2095dac3b4a..e9c3afe662b 100644
--- a/src/vs/workbench/api/node/extHostCommands.ts
+++ b/src/vs/workbench/api/node/extHostCommands.ts
@@ -218,7 +218,7 @@ export class CommandsConverter {
 		}
 	}
 
-	private _executeConvertedCommand(...args: any[]) {
+	private _executeConvertedCommand<R>(...args: any[]): Thenable<R> {
 		const actualCmd = this._heap.get<vscode.Command>(args[0]);
 		return this._commands.executeCommand(actualCmd.command, ...actualCmd.arguments);
 	}
diff --git a/src/vs/workbench/api/node/extHostMessageService.ts b/src/vs/workbench/api/node/extHostMessageService.ts
index 32572895213..31d5cbdcd22 100644
--- a/src/vs/workbench/api/node/extHostMessageService.ts
+++ b/src/vs/workbench/api/node/extHostMessageService.ts
@@ -31,7 +31,9 @@ export class ExtHostMessageService {
 		this._proxy = threadService.get(MainContext.MainThreadMessageService);
 	}
 
-	showMessage(severity: Severity, message: string, optionsOrFirstItem: vscode.MessageOptions | string | vscode.MessageItem, rest: (string | vscode.MessageItem)[]): Thenable<string | vscode.MessageItem> {
+	showMessage(severity: Severity, message: string, optionsOrFirstItem: vscode.MessageOptions | string, rest: string[]): Thenable<string | undefined>;
+	showMessage(severity: Severity, message: string, optionsOrFirstItem: vscode.MessageOptions | vscode.MessageItem, rest: vscode.MessageItem[]): Thenable<vscode.MessageItem | undefined>;
+	showMessage(severity: Severity, message: string, optionsOrFirstItem: vscode.MessageOptions | string | vscode.MessageItem, rest: (string | vscode.MessageItem)[]): Thenable<string | vscode.MessageItem | undefined> {
 		const { options, items } = parseMessageArguments(optionsOrFirstItem, rest);
 		const commands: { title: string; isCloseAffordance: boolean; handle: number; }[] = [];
 
diff --git a/src/vs/workbench/api/node/extHostQuickOpen.ts b/src/vs/workbench/api/node/extHostQuickOpen.ts
index 05cab704c0f..183dcd1d7bc 100644
--- a/src/vs/workbench/api/node/extHostQuickOpen.ts
+++ b/src/vs/workbench/api/node/extHostQuickOpen.ts
@@ -24,7 +24,9 @@ export class ExtHostQuickOpen extends ExtHostQuickOpenShape {
 		this._proxy = threadService.get(MainContext.MainThreadQuickOpen);
 	}
 
-	showQuickPick(itemsOrItemsPromise: Item[] | Thenable<Item[]>, options?: QuickPickOptions, token: CancellationToken = CancellationToken.None): Thenable<Item> {
+	showQuickPick(itemsOrItemsPromise: string[] | Thenable<string[]>, options?: QuickPickOptions, token?: CancellationToken): Thenable<string | undefined>;
+	showQuickPick(itemsOrItemsPromise: QuickPickItem[] | Thenable<QuickPickItem[]>, options?: QuickPickOptions, token?: CancellationToken): Thenable<QuickPickItem | undefined>;
+	showQuickPick(itemsOrItemsPromise: Item[] | Thenable<Item[]>, options?: QuickPickOptions, token: CancellationToken = CancellationToken.None): Thenable<Item | undefined> {
 
 		// clear state from last invocation
 		this._onDidSelectItem = undefined;