js-api-examples/index.html

<!doctype html>

<html>

  <head>
    <meta charset="utf-8">
    <title>WASM test</title>
  </head>

  <body>
    <script>
      const importObject = {
        my_namespace: {
          imported_func: arg => {
            console.log(arg);
          }
        }
      };

      fetch("simple.wasm").then(response =>
        response.arrayBuffer()
      ).then(bytes =>
        WebAssembly.instantiate(bytes, importObject)
      ).then(result => {
        result.instance.exports.exported_func();
      });
    </script>
  </body>

</html>