Import and type windows-process-tree

Fixes #43287

src/typings/windows-process-tree.d.ts

@@ -9,6 +9,8 @@ declare module 'windows-process-tree' {
 		name: string,
 		children: ProcessTreeNode[]
 	}
+
 	function get(rootPid: number, callback: (tree: ProcessTreeNode) => void): void;
+
 	export = get;
 }

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

@@ -8,10 +8,11 @@ import { TPromise } from 'vs/base/common/winjs.base';
 import { Emitter, debounceEvent } from 'vs/base/common/event';
 import { ITerminalInstance } from 'vs/workbench/parts/terminal/common/terminal';
 import { Terminal as XTermTerminal } from 'vscode-xterm';
+import WindowsProcessTreeType = require('windows-process-tree');
 
 const SHELL_EXECUTABLES = ['cmd.exe', 'powershell.exe', 'bash.exe'];
 
-let windowsProcessTree;
+let windowsProcessTree: typeof WindowsProcessTreeType;
 
 export class WindowsShellHelper {
 	private _onCheckShell: Emitter<TPromise<string>>;
@@ -28,11 +29,14 @@ export class WindowsShellHelper {
 			throw new Error(`WindowsShellHelper cannot be instantiated on ${platform.platform}`);
 		}
 
-		if (!windowsProcessTree) {
-			windowsProcessTree = require.__$__nodeRequire('windows-process-tree');
+		this._isDisposed = false;
+
+		(import('windows-process-tree')).then(mod => {
+			if (this._isDisposed) {
+				return;
 			}
 
-		this._isDisposed = false;
+			windowsProcessTree = mod;
 			this._onCheckShell = new Emitter<TPromise<string>>();
 			// The debounce is necessary to prevent multiple processes from spawning when
 			// the enter key or output is spammed
@@ -56,6 +60,7 @@ export class WindowsShellHelper {
 
 			// Fire a new check for the shell when any key is pressed.
 			this._xterm.on('keypress', () => this._onCheckShell.fire());
+		});
 	}
 
 	private checkShell(): void {