const path = require('path');
var Nightmare = require('nightmare');
var nightmare = Nightmare({
    show: true,
    pollInterval: 50
});

nightmare
    .goto('http://news.163.com/domestic/')
    .inject('js', 'jquery-2.1.1.min.js')
    .wait(function() {
        if (document.querySelector('.post_addmore').style["visibility"] == "visible") {
            document.querySelector('.load_more_btn').click();
            return false;
		}
        if (document.querySelector(".post_adding").style["display"] == "block") return false;
        if (document.querySelector(".load_more_tip").style["display"] == "block") return true;
    })
    .evaluate(function() {
        var newsList = [];
        $('.data_row').each(function() {
            var $me = $(this);
            var title = $me.find('.news_title').find('h3').find('a').text();
            var url = $me.find('.news_title').find('h3').find('a').attr('href');
            var item = {
                title: title,
                url: url
            }
            newsList.push(item);
        })
        return newsList
    })
    .end()
    .then(function(result) {
        console.log(result);
        console.log(result.length);
    }).catch(function(err) {
        console.log(err);
    })

@zhoujinhai

var Nightmare = require('nightmare');
var nightmare = Nightmare({
    show: false,
    pollInterval: 50
});

nightmare
    .goto('https://www.youtube.com/playlist?list=PLHPTxTxtC0iaN9kA37m6MRrxFkgby2CDR')
    //.inject('js', 'jquery-2.1.1.min.js')
    .wait(function() {
        var loadMoreText = document.querySelector('.load-more-text');
        if (loadMoreText == null) return true;
        if (/hid/.test(loadMoreText.classList.value)) return false;
        document.querySelector('.browse-items-load-more-button').click();
        return false;
    })
    .evaluate(function() {
        return Array.from(document.querySelectorAll('.pl-video-title')).map(function(item) {
            return item.childNodes[1].innerText;
        })
    })
    .end()
    .then(function(result) {
        console.log(result);
        console.log(result.length);
    }).catch(function(err) {
        console.log(err);
    })

@zhoujinhai @Jackzhangpan

看官网api

pollInterval (default: 250ms)
How long to wait between checks for the .wait() condition to be successful.

.wait(fn[, arg1, arg2,...])
Wait until the fn evaluated on the page with arg1, arg2,... returns true. All the args are optional. See .evaluate() for usage.

每间隔段时间都会调用wait方法，直到wait返回true,在wait方法里面根据dom检查,一般三个状态，加载中（return false），可以加载更多(click，return false)，加载完毕(return true)

@Jackzhangpan

var Nightmare = require('nightmare');
var nightmare = Nightmare({
    show: true,
    pollInterval: 1000
});


nightmare
    .goto('http://roll.news.qq.com/')
    .wait(function() {
        return document.querySelectorAll("#artContainer li").length>0;
    })
    .wait(function() {

        if (window._$qqNews == undefined) {

            window._$qqNews = {
                total: 0,
                page: 0,
                items: []
            }

            //停止自动刷新
            AutoRefresh();
            _$qqNews.total = qq.$("totalPage").value;

            G.showArtList = function(responseText) {
                try {
                    eval("var json = " + responseText);
                    if (json.response.code == "0") {
                        qq.$("artContainer").innerHTML = json.data.article_info;

                        //
                        var newslist = document.querySelectorAll("#artContainer li a");
                        for (var i = 0; i < newslist.length; i++) {

                            _$qqNews.items.push({
                                title: newslist[i].childNodes[0].data,
                                href: newslist[i].href
                            });
                        }

                        qq.$("totalPage").value = json.data.count;

                        if (_$qqNews.total > 1) {
                            _$qqNews.total -= 1;
                            nextPage();
                        }


                    } else if (json.response.code == "2") {
                        qq.$("totalPage").value = 1;
                        G.gotoPage(1);
                        qq.$("artContainer").innerHTML = '<div class="article-tips">该日期没有文章！</div>';
                    } else {
                        qq.$("totalPage").value = 1;
                        G.gotoPage(1);
                        qq.$("artContainer").innerHTML = '<div class="article-tips">文章加载失败！</div>';
                    }
                } catch (e) {}
            }

            //加载第1页
            Refresh();

            return false;
        }

        if (_$qqNews.total == 1)
            return true;

        return false;

    }).evaluate(function() {

        return _$qqNews.items;
    })
    .end()
    .then(function(result) {
        console.log(result, result.length)
    }).catch(function(error) {
        console.log('错误是：' + error);
    })

@zhoujinhai 模拟点击下一页也是可以的，只是没有上一种方法快,

var Nightmare = require('nightmare');
var nightmare = Nightmare({
    show: true //显示electron窗口
        // waitTimeout : 5000
});
nightmare
    .goto('http://roll.news.qq.com/')
    .wait(function() {
        return !document.querySelector(".loading");
    })
    .wait(function() {
        window._$qqNews = [];
        return true;
    })
    .wait(function() {

        //如果显示正在加载中……
        if (document.querySelector(".loading")) return false;

        var newslist = document.querySelectorAll("#artContainer li a");
        for (var i = 0; i < newslist.length; i++) {
            _$qqNews.push({
                title: newslist[i].childNodes[0].data,
                href: newslist[i].href
            });
        }
		//下一页button
        var next_page_button = document.querySelector("#pageArea .f12:last-child");
        if (next_page_button) {
            next_page_button.click();
            return false;
        }
        return true;

    })
    .evaluate(function() {
        return _$qqNews;
    })
    .end()
    .then(function(res) {
        console.log(res[res.length-1], res.length);
    })
    .catch(function(error) {
        console.error('failed:', error);
    });