wd-runjs

wd-runjs is a tiny command which runs JavaScript code on browsers by piping stdin via Selenium WebDriver.

Prerequisite

wd-runjs uses the WebDriver or the Selenium Server for running JavaScript code on browsers.

If you have already installed Docker onto your local machine, you can use docker-compose for starting a Selenium Grid Hub and Selenium nodes. See masnagam/docker-compose-collection for details.

Usage

  Usage: wd-runjs [options] [URI, path to a navigation script or a window index starting with @ ...]

  Run JavaScript code on browsers by piping stdin via Selenium WebDriver


  Options:

    -V, --version                      output the version number
    -a, --script-args <arg>            Arguments passed to the JavaScript code (default: )
    -b, --browser <chrome or firefox>  Browser where the JavaScript code will be run (default: chrome)
    -l, --logging <logger:level>       Filters for the local logging of selenium-webdriver (default: )
    -o, --browser-options <json>       Browser specific options (default: [object Object])
    -s, --server [uri]                 Use a WebDriver server which is already running (default: false)
    --async                            Run the JavaScript code asynchronously
    --script-timeout <sec>             Asynchronous script execution time limit in seconds (default: 10)
    -h, --help                         output usage information

When it is succeeded to execute the JavaScript code, wd-runjs outputs a JSON array of the following format to stdout.

{
  "uri": "<uri>",
  "browser": "<browser>",
  "title": "<title>",
  "result": <result-json>
}

When it is failed, error is output instead of result.

Examples

Maximum depth of nested elements:

$ cat examples/max-depth.js | wd-runjs https://github.com/
[{"uri":"https://github.com/","browser":"chrome","title":"...","result":12}]

Tag statistics:

$ cat examples/tags.js | wd-runjs https://github.com/
[{"uri":"https://github.com/","browser":"chrome","title":"...","result":{"DD":3,"A":34,...}}]

By using jq, it is possible to process a result JSON as follows:

$ cat examples/tags.js | wd-runjs https://github.com/ | \
    jq '.[] | { uri, browser, countTags: [.result[]] | add }'
{
  "uri": "https://github.com/",
  "browser": "chrome",
  "countTags": 496
}

Use of a URI list:

$ cat uris
http://www.bbc.com/
http://edition.cnn.com/
http://abcnews.go.com/
$ echo "return 'hello';" | wd-runjs $(cat uris)

NOTE: The concurrency option has been removed. Because functions which were used for implementing this feature have been removed from the latest selenium-webdriver package. This feature might be implemented again in future.

Navigation script:

$ cat examples/tags.js | wd-runjs examples/navigation.js

The navigation script has to export navigate() function like below:

module.exports.navigate = (driver) => {
  driver.get('http://www.google.com/ncr');
  ...
};

By using the navigation script, it is possible to run a script on web pages where the user authentication is required.

Run JavaScript code asynchronously:

$ browserify examples/html2canvas.js | \
    wd-runjs --async -a li.vevent https://www.w3.org/
[{"uri":"https://www.w3.org/","browser":"chrome","title":"...","result":["data:image/png;base64,...",...]}]

Before running the above command, it is necessary to install Browserify, jQuery and html2canvas.

Logging

By using the logging option, it is possible to output messages for debugging.

The following loggers are defined in wd-runjs.

• wd-runjs.script-runner
• webdriver.Builder
• webdriver.http
• webdriver.http.Executor

For available levels, see selenium-webdriver's document.

It is possible to specify multiple logging options as follows:

$ wd-runjs -l wd-runjs:DEBUG -l promise:FINER https://github.com/

For outputting all log messages, specify the logging option like below:

$ wd-runjs -l :ALL https://github.com/

At this time, the remote logging is not supported.

Running JavaScript code on an existing browser window

At the moment, this feature works only with the ChromeDriver.

$ cat script.js | wd-runjs -o '{"debuggerAddress": "localhost:9222"}'

The JavaScript code will be executed on the current tab/window of the existing Chrome browser launched with --remote-debugging-port=9222.

License

This software is distributed under the MIT license. See LICENSE file for details.