NightWatchJS

关于Nightwatch?

Nightwatch.js是一个测试web app和web 站点的自动化测试框架， 使用Node.js编写， 基于Selenium WebDriver API.

它是一个完整的浏览器端真实用户场景测试解决方案， 致力于简化继续集成和编写自动化测试。

Nightwatch got its name from the famous painting The Night Watch by Dutch painter Rembrandt van Rijn. The masterpiece is prominently displayed in the Rijksmuseum, in Amsterdam - The Netherlands.

Overview of Selenium

Selenium 是一个直接运行在浏览器中的非常流行的综合测试工具集， 最初为java 语言编写， 现在已经支持许多语言。

Selenium的主要项目:
* Selenium IDE
* Selenium Remote Control
* Selenium WebDriver
* Selenium Grid

Nightwatch uses the Selenium WebDriver, specifically the WebDriver Wire Protocol to perform the browser automation related tasks.

Nightwatch 使用Selenium WebDriver， 特别是WebDriver Wire Protocol 来执行浏览器自动化测试相关任务。

Theory of Operation

Nightwatch works by sending HTTP requests to the Selenium server with the right parameters and interpreting the response. The restful API protocol is defined by the Selenium JsonWireProtocol. See below for an example workflow for browser initialization.
Nightwatch 发送通过 HTTP 请求发送响应的参数到 Selenium 服务器，并解析服务器响应。restful API 文档见Selenium JsonWireProtocol 。浏览器初始化流程见下图。

大部分情况下， Nightwatch 执行一条命令或断言，至少要发送2个请求到 Selenium 服务器。 第一个用来定位元素，可以用 CSS 选择器或者Xpath 表达式。 第二个用来在选中的元素上执行命令或断言操作。

Installation

安装Node.js

From nodejs.org:

“Node.js is a platform built on Chrome’s JavaScript runtime for easily building fast, scalable network applications. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.”

主流操作系统的安装包都可以在nodejs.org上找到。

Install Nightwatch

使用 npm 安装最新的 Nightwatch， 在命令行运行:

npm install -g nightwatch

运行 Selenium 服务器

Selenium WebDriver server 是一个简单的 Java servlet 程序，分别运行在本地机器上和你要进行测试的浏览器上。(todo 真的是浏览器上？)

Download Selenium
Download the latest version of the selenium-server-standalone-{VERSION}.jar file from the Selenium downloads page and place it on the computer with the browser you want to test. In most cases this will be on your local machine and typically inside your project’s source folder.
到Selenium downloads page下载最新版的selenium-server-standalone-{VERSION}.jar 包， (todo)具体放在哪里， 等我试一试再说。

A good practice is to create a separate subfolder (e.g. bin) and place it there as you might have to download other driver binaries if you want to test multiple browsers.

Running Selenium Automatically
如果服务器和Nightwatch 运行在同一台机器上， Nightwatch Test Runner可以启动和停止Selenium 服务器。

Running Selenium Manually
To run the selenium server manually, from the directory with the jar run the following:
要手动启动 server 服务器， 在 jar 包所在目录执行:

java -jar selenium-server-standalone-{VERSION}.jar

更多关于运行 Selenium 服务器的信息参考:
http://code.google.com/p/selenium/wiki/RemoteWebDriverServer

要获取帮助信息, 执行:

java -jar selenium-server-standalone-{VERSION}.jar -help

Configuration

测试需要一个配置文件， 默认会使用当前目录下的 nightwatch.json 文件。nightwatch.json 详细配置如下：

{
  "src_folders" : ["tests"],
  "output_folder" : "reports",
  "custom_commands_path" : "",
  "custom_assertions_path" : "",
  "page_objects_path" : "",
  "globals_path" : "",

  "selenium" : {
    "start_process" : false,
    "server_path" : "",
    "log_path" : "",
    "host" : "127.0.0.1",
    "port" : 4444,
    "cli_args" : {
      "webdriver.chrome.driver" : "",
      "webdriver.ie.driver" : ""
    }
  },

  "test_settings" : {
    "default" : {
      "launch_url" : "http://localhost",
      "selenium_port"  : 4444,
      "selenium_host"  : "localhost",
      "silent": true,
      "screenshots" : {
        "enabled" : false,
        "path" : ""
      },
      "desiredCapabilities": {
        "browserName": "firefox",
        "javascriptEnabled": true,
        "acceptSslCerts": true
      }
    },

    "chrome" : {
      "desiredCapabilities": {
        "browserName": "chrome",
        "javascriptEnabled": true,
        "acceptSslCerts": true
      }
    }
  }
}

Basic settings