fix missing global TextEncoder when requiring jsdom

Author: lobsterkatie

packages/browser/test/package/npm-build.js

@@ -1,10 +1,14 @@
 /* eslint-disable no-console */
 const fs = require('fs');
 const path = require('path');
+const { TextEncoder } = require('util');
 
 const webpack = require('webpack');
 const { JSDOM } = require('jsdom');
 
+// This is a workaround for https://github.com/jsdom/jsdom/issues/2524
+global.TextEncoder = TextEncoder;
+
 webpack(
   {
     entry: path.join(__dirname, 'test-code.js'),