为什么Selenium WebDriver解决了页面未加载时get（）的承诺

Question

我在版本3.4.0中使用了selenium-webdriver。即使Chrome无法加载页面，下面的代码也会打印成功，因为在端口3333上侦听的服务器尚未启动。

const selenium = require('selenium-webdriver'); 
const webdriver = new selenium.Builder().forBrowser('chrome').build(); 
webdriver.get('http://localhost:3333').then(() => console.log('success')); 

Answer 1

从文档（http://www.seleniumhq.org/docs/03_webdriver.jsp#selenium-webdriver-api-commands-and-operations）：

Dependent on several factors, including the OS/Browser combination, 
WebDriver may or may not wait for the page to load. In some 
circumstances, WebDriver may return control before the page has 
finished, or even started, loading. To ensure robustness, you need to wait 
for the element(s) to exist in the page using Explicit and Implicit Waits. 

所以，你想要么直接调用等待回调或创建一个承诺这样做：

webdriver.wait(function() { 
    webdriver.get('http://localhost:3333').then(() => console.log('success')); 
}, timeout); 

我离开用一个承诺来做这个练习来实现。

Answer 2

设置等待时间为5秒来加载页面或启动服务器。

webdriver.implicitly_wait(5);