Pass a function to nighmarejs evaluate()

Question

I'm trying to pass a function to be called inside the nightmarejs evaluate statement and return a value. Something like this:

var thisfunction = function() {
    var tags = [];
    var list = document.querySelector('#selectSomething');
    list.forEach(function(item) {
        tags.push({
            name: item.attributes[1].value,
            id: item.attributes[2].value
        })
    });
    return tags;
};

return nightmare
    .goto('url')
    .wait('#something')
    .evaluate(function(getValues) {
        getValues();
    }, thisfunction)
    .then(function(list) {
        console.log(list);
    })

I'm getting ReferenceError: getValues is not defined. Tried different approaches with return statements in various place, but no luck.

How can this be done?

Thanks!

score 2 · Accepted Answer · answered Jun 21 '17 at 10:38

I suppose that you can simply write the following code:

var thisfunction = function() {
    var tags = [];
    var list = document.querySelector('#selectSomething');
    list.forEach(function(item) {
        tags.push({
            name: item.attributes[1].value,
            id: item.attributes[2].value
        })
    });
    return tags;
};

return nightmare
    .goto('url')
    .wait('#something')
    .evaluate(thisfunction)
    .then(function(list) {
        console.log(list);
    })

score 2 · Answer 2 · answered Jun 21 '17 at 11:19

Reason Behind the Behaviour

You can pass strings/numbers as parameters but not functions/object as they serialised before passing to the evaluate method.

You can checkout the explaination here

Also there is ticket on Github of users with similar experiences.

Pass a function to nighmarejs evaluate()

2 Answers2

Reason Behind the Behaviour