title: VSCode extension test runner for jest
body: <p>When using the <a href="https://code.visualstudio.com/docs/extensions/yocode" rel="nofollow noreferrer">official generator</a> to start a VSCode extension, it automatically generates the <code>extension.test.ts</code> and <code>index.ts</code> files. <a href="https://github.com/Microsoft/vscode-generator-code/blob/master/generators/app/templates/ext-command-ts/src/test/index.ts" rel="nofollow noreferrer"><code>index.ts</code></a> just contains the setup for the test runner to use for extension tests, and it is Mocha based. The Mocha test runner itself can be seen here: <a href="https://github.com/Microsoft/vscode-extension-vscode/blob/master/lib/testrunner.js" rel="nofollow noreferrer">https://github.com/Microsoft/vscode-extension-vscode/blob/master/lib/testrunner.js</a>.</p>
  
  <p>I've been scouring around trying to find any official Jest based one. Does anyone know of one?</p>