Narcoleptic Pasta Manufacturer


1.3.0 • Public • Published


NPM Version Build Status Coverage Status Dependency Status

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


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: 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


    -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)
    -c, --concurrency <number>         Number of ControlFlows to be run at the same time (default: 1)
    -l, --logging <logger:level>       Filters for the local logging of selenium-webdriver (default: [])
    -o, --browser-options <json>       Browser specific options (default: {})
    -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.


Maximum depth of nested elements:

$ cat examples/max-depth.js | wd-runjs

Tag statistics:

$ cat examples/tags.js | wd-runjs

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

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

Use of a URI list:

$ cat uris
$ echo "return 'hello';" | wd-runjs -c 3 $(cat uris)

It is recommended to specify the concurrency number less than the number of available Chrome instances.

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) => {

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

data:image/png;base64,... is copied to the clipboard.

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


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

The following loggers are defined in wd-runjs.

  • wd-runjs.flow-pool
  • wd-runjs.script-runner
  • webdriver.Builder
  • webdriver.http
  • webdriver.http.Executor
  • promise

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

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

$ wd-runjs -l :ALL

At this time, the remote logging is not supported.

Connecting to an existing browser

Chrome running with --remote-debugging-port=9222:

$ wd-runjs -o '{"debuggerAddress": "localhost:9222"}'

The JavaScript code will be executed on the current tab/window of the existing Chrome browser.

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


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


npm i wd-runjs

Downloadsweekly downloads









last publish


  • avatar
Report a vulnerability