Can't use vscode import within test files

[david-pa]

Normally, I run my tests via vscode-test, but I am now trying to use vscode-extension-tester in my project and have been attempting to add the UI testing features to some existing tests. However, it seems like I'm not able to import the vscode module when I'm using vscode-extension-tester to run my test files. In order to verify this wasn't tied to my own project, I tried to use the module in the activityBar.test.ts file in the sample project:

import { expect } from 'chai';
import { ActivityBar } from 'vscode-extension-tester';
import * as vscode from 'vscode';

// sample tests using the Activity Bar (the left toolbar)
describe('Activity Bar Example Tests', () => {
	let activityBar: ActivityBar;

	before(async () => {
		// init the activity bar page object
		activityBar = new ActivityBar();
	});

	// Test what view controls are available
	it('Shows explorer view control (container)', async () => {
		const commands = vscode.commands.getCommands();
		// get all the view controls
		const controls = await activityBar.getViewControls();
		...

I got back the following error:

Error: Cannot find module 'vscode'

This is exactly what I'm seeing in my own project. I was trying to figure out if the error was caused by my project setup, but it seems like it's more to do with using vscode-extension-tester. Is this a known issue? Is there something I would need to change about my project's configuration to allow for this kind of import to work?

EDIT:
Within my project, it also seems to have problems finding the vscode module outside of the test files, as well:

Error: Cannot find module 'vscode'
Require stack:
- /.../out/explorers/treeUtils.js
- /.../out/test/tree.test.js