Merge from vscode 8e0f348413f4f616c23a88ae30030efa85811973 (#6381)

* Merge from vscode 8e0f348413f4f616c23a88ae30030efa85811973

* disable strict null check

src/vs/workbench/api/browser/mainThreadCommands.ts

@@ -12,7 +12,7 @@ import { revive } from 'vs/base/common/marshalling';
 @extHostNamedCustomer(MainContext.MainThreadCommands)
 export class MainThreadCommands implements MainThreadCommandsShape {
 
-	private readonly _disposables = new Map<string, IDisposable>();
+	private readonly _commandRegistrations = new Map<string, IDisposable>();
 	private readonly _generateCommandsDocumentationRegistration: IDisposable;
 	private readonly _proxy: ExtHostCommandsShape;
 
@@ -26,8 +26,8 @@ export class MainThreadCommands implements MainThreadCommandsShape {
 	}
 
 	dispose() {
-		this._disposables.forEach(value => value.dispose());
-		this._disposables.clear();
+		this._commandRegistrations.forEach(value => value.dispose());
+		this._commandRegistrations.clear();
 
 		this._generateCommandsDocumentationRegistration.dispose();
 	}
@@ -36,10 +36,9 @@ export class MainThreadCommands implements MainThreadCommandsShape {
 		return this._proxy.$getContributedCommandHandlerDescriptions().then(result => {
 			// add local commands
 			const commands = CommandsRegistry.getCommands();
-			for (let id in commands) {
-				let { description } = commands[id];
-				if (description) {
-					result[id] = description;
+			for (const [id, command] of commands) {
+				if (command.description) {
+					result[id] = command.description;
 				}
 			}
 
@@ -53,7 +52,7 @@ export class MainThreadCommands implements MainThreadCommandsShape {
 	}
 
 	$registerCommand(id: string): void {
-		this._disposables.set(
+		this._commandRegistrations.set(
 			id,
 			CommandsRegistry.registerCommand(id, (accessor, ...args) => {
 				return this._proxy.$executeContributedCommand(id, ...args).then(result => {
@@ -64,10 +63,10 @@ export class MainThreadCommands implements MainThreadCommandsShape {
 	}
 
 	$unregisterCommand(id: string): void {
-		const command = this._disposables.get(id);
+		const command = this._commandRegistrations.get(id);
 		if (command) {
 			command.dispose();
-			this._disposables.delete(id);
+			this._commandRegistrations.delete(id);
 		}
 	}
 
@@ -79,7 +78,7 @@ export class MainThreadCommands implements MainThreadCommandsShape {
 	}
 
 	$getCommands(): Promise<string[]> {
-		return Promise.resolve(Object.keys(CommandsRegistry.getCommands()));
+		return Promise.resolve([...CommandsRegistry.getCommands().keys()]);
 	}
 }