How to detect if an element is accompanied by some text with jQuery?

There are several conditions that need to be checked. The way I think it's the right one is to go through all childNodes and check how many there are that are not empty. At the same time check if at least one of them has the desired element / class:

function temSoClasse(elInicial, seletor) {
    return = $(elInicial).filter(function () {
        var hasLink = false;
        var nodes = $(this.childNodes).filter(function (i, el) {
            if (el.nodeType == 1) {
                if ($(el).parent().find(seletor).length) hasLink = true;
                return true;
            }
            return el.textContent.trim().length;
        });
        return nodes.length == 1 && hasLink;
    });
}

And then you can use it like this:

var els = temSoClasse('.box', 'a.link');
els.css('color', 'blue'); // vai mudar a côr do elemento que se procura

jsFiddle: link

A more compressed version might look like this:

function temSoClasse(elInicial, seletor) {
    return $(elInicial).filter(function () {
        return this.querySelector(seletor) && $(this.childNodes).filter(function (i, el) {
            return el.textContent.trim().length;
        }).length == 1;
    });
}

jsFiddle: link

As @DontVoteMeDown said, "... this is a good exercise."

$(".box").filter(function(i) 
{
    var $that =  $(this);

    var node = $that.contents().get(0);

     if ($that.contents().length == 1 && $(node).is('a')) {
        return true;
     }

     return false;

});

When we use the $.contents function, jQuery returns the nodes present within that element.

So, I check if there is only one node with $(this).contents().length == 1 .

I then check if the node is an element whose tag is a , via $(node).is('a') .

Using the $.is function, we check if the element is a link. Since node is not a jQuery selector, you need to use it with jQuery through $(...) .

The $(this).contents().get(0) is in charge of getting the first element.

So we have the check that div.box has a node, and if that node is a link.

Update : Following the example of the @DontVoteMeDown response, we could also, instead of using $(node).is('a') , do as follows:

 if ($that.contents().length == 1 && node.nodeType == 3) {
     return true;
 }

I think I found a way:

var list = $(".box").filter(function(i, el) 
{
    return Array.from(el.childNodes).filter(function(cn) 
    {
        return  cn.textContent.trim() != "" && 
                cn.nodeType == 3;
    }).length == 0;
});

Fiddle

Explanation:

UPDATE

$.fn.checarElemento = function(checarFilhos)
{
    return $(this).filter(function(i, el) 
    {
        return $(el).find(checarFilhos).length > 0 && Array.from(el.childNodes).filter(function(cn) 
        {
            return  cn.textContent.trim() != "" && 
                    cn.nodeType == 3;
        }).length == 0;
    });
};

And to ensure that there is the selector you want within the element in question, I have added the simple condition $(el).find(checarFilhos).length > 0 , which if not satisfied, nor does it spin filter() on childNodes . Micro optimization maybe? Usage:

$(".box").checarElemento("a.link");

Fiddle