test.html

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="utf-8" />
    <title>Mocha Tests</title>
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <link rel="stylesheet" href="./node_modules/mocha/mocha.css" />
    <script src="./dist/index-browser.js"></script>
</head>

<body>
    <div id="mocha"></div>

    <script src="./node_modules/chai/chai.js"></script>
    <script src="./node_modules/mocha/mocha.js"></script>

    <script class="mocha-init">
        mocha.setup('bdd');
        mocha.checkLeaks();
    </script>
    <script src="./dist-test/index.umd.js"></script>
    <script class="mocha-exec">
        mocha.run();
    </script>
</body>

</html>