如何将使用Javascript的数组检查注入到Nightwatch测试脚本中？

Question

我正在使用守夜人来测试div，并在html上使用'data'属性的正确值来检查div，以检查单击后每个div是否转到正确的url。但是我找不到一个正确的解决方案来一起编写div的脚本。有人可以帮我吗？

module.exports = {
         'test case': function(client) {
           client
              .url()
              .waitForElementVisible('body',1000)

         *** go to a page and then execute this: ***

         .execute (function (){ 
         var list = document.getElementsByClassName('promo');
         for (var i = 0; i < list.length; i++) {
         var num = list[i].getAttribute('data');
       //only data value equals to 4 numbers, click on that element
        if(/^d{4}$/.test(num)) {
            var a = i,
            selector =  "#container > div > div:nth-child("+a+") > div"
       //code doesn't work! No div is clicked!
            return client.click(selector);
        } 
      //after redirecting to the new page, find element there.
     client.waitForElementPresent('#form > button')
           .expect.element('#form > button')
           .text.to.contain("some word");  
    }