JQuery验证“扩展”规则不起作用

我使用JQuery来验证HTML表单,但是“扩展”规则不起作用(尽管我已经包含了 additional-methods.js 文件。我已经测试了我的其他“规则”(也来自那个js文件),这些规则似乎工作得很好,所以我不确定为什么扩展名一不工作。

以下是html/JS代码:

<script src="http://ajax.aspnetcdn.com/ajax/jquery.validate/1.11.1/additional-methods.js"></script>


<form method="POST" id="regForm" action="{{ url_for('pipeline') }}">
  <div class="tab">
    <h3>User Assets:</h3>
    <br>
    <label>Interval BED File</label>
    {{ form.target(placeholder="(e.g. Exome-NGv3.bed)...", oninput="this.className = ''") }}
    <div class="form-group required">
        <label>Sentieon Package Name</label>
        {{ form.sentieon_package_name(placeholder="(e.g. sentieon-genomics-201711.01.tar.gz)...", oninput="this.className = ''") }}
    </div>
    <div class="form-group required">
        <label>Sentieon License Name</label>
        {{ form.sentieon_license_name(placeholder="(e.g mylicense.lic)...", oninput="this.className = ''") }}
    </div>
  </div>
</form>

<script>

$(document).ready(function () {

    $('#regForm').validate({ // initialize the plugin
        rules: {
            sentieon_package_name: {
                required: true,
                extension: "tar|tar.gz"
            },
            sentieon_license_name: {
                required: true,
                extension: "lic"
            },
        submitHandler: function (form) { // for demo
            alert('valid form submitted'); // for demo
            return false; // for demo
        }
    });

});

</script>