yorunor/web_driver_client

WebDriverClient

A low-level WebDriver client for Elixir. This library is still a work in progress.

Overview

WebDriverClient is designed to be a low-level library that allows projects to call WebDriver REST APIs while abstracting away the differences between the JWP and W3C protocols. This library is designed to be the API client for higher-level libraries, like Wallaby or Hound.

{:ok, session} =
  "http://localhost:9515"
  |> WebDriverClient.Config.build(protocol: :w3c)
  |> WebDriverClient.start_session(%{"capabilities" => %{}})


:ok = WebDriverClient.navigate_to(session, "http://dockyard.com")

{:ok, element} = WebDriverClient.find_element(session, :css_selector, ".site-nav__logo__link")

WebDriverClient.fetch_element_text(session, element) # => {:ok, "DockYard Home"}

:ok = WebDriverClient.end_session(session)

Design considerations

• Should be a thin, well-documented API client that calls the WebDriver REST APIs.

• Should provide a main API that abstracts away the differences between the JWP and W3C protocols.

• (Future) Should provide protocol-specific APIs as an escape-hatch to access functionality that is not common to both protocols.

• Sometimes the user will request one protocol and the server returns the other protocol. This happens if the user sends the incorrect payload on session start, or requests an endpoint that is not tied to an individual session (like listing sessions).

  This library should gracefully handle these situations, while still notifying the user that the wrong protocol was returned.

What this library is not

• This is not a high-level library to be used for day to day testing. Features like retries, pipeline commands, etc are outside the scope of this project. These features are better delegated to a high-level library like Wallaby or Hound.

Testing

In order to ensure the reliability of this library, test coverage is very important. This comes through the following types of tests.

Unit test

The unit test suite can be run with the following command.

mix test

Integration tests

Although each webdriver implementation should be the same in theory, it's good to double-check that this library actually works. The following webdriver implementations are supported via the test suite:

• chromedriver
• phantomjs
• selenium_2
• selenium_3

Note: This project does not start any WebDriver program. Those need to be started separately.

ChromeDriver

To install ChromeDriver on OS X:

$ brew cask install chromedriver

Before running test suite, start up chromedriver

$ chromedriver

Then to run the integration tests, run:

$ mix test --only integration_test_driver:chromedriver

PhantomJS

To install PhantomJS on OS X:

$ brew cask install phantomjs

Before running test suite, start up phantomjs

$ phantomjs --wd

Then to run the integration tests, run:

$ mix test --only integration_test_driver:phantomjs

Selenium

To install ChromeDriver on OS x:

$ brew install selenium-server-standalone

You also need to install the webdriver servers

For firefox:

$ brew install geckodriver

For chrome:

$ brew install chromedriver

Before running test suite, start up selenium

$ selenium-server

Then to run the integration tests, run:

$ mix test --only integration_test_driver:selenium_3

If you'd like to run only the selenium tests for chrome, run:

$ mix test --only integration_test_driver_browser:selenium_3-chrome

And to only run selenium tests for firefox, run:

$ mix test --only integration_test_driver_browser:selenium_3-firefox

Selenium 2

If you'd like to run integration tests for selenium_2, just replace selenium_3 with selenium_2.

$ mix test --only integration_test_driver:selenium_2

Running on remote webdriver servers

Sometimes it's nice to be able to run against a remote webdriver server. Here's an example that runs the tests against a docker container.

1. Start the docker container for the webdriver server

   $ docker run -p 4446:4444 --shm-size=2g selenium/standalone-chrome:3
   

2. Run the tests

   $ SELENIUM_3_BASE_URL="http://localhost:4446/wd/hub" TEST_SERVER_HOSTAME="host.docker.internal" mix test --only integration_test_driver_browser:selenium_3-chrome
   

   The environment variables work like this:

   • <DRIVER_NAME>_BASE_URL - The base url for the webdriver server to run against. Can also use WEBDRIVER_BASE_URL to set this across all scenarios.

   • TEST_SERVER_HOSTNAME - The hostname the webdriver server should use to access the machine that's running the test suite.

     The test suite starts up a test HTTP server, but when using a remote webdriver server, the webdriver server needs to where the test pages live. When running in docker for Mac, the hostname of the host computer is host.docker.internal.

Installation

If available in Hex, the package can be installed by adding web_driver_client to your list of dependencies in mix.exs:

def deps do
  [
    {:web_driver_client, "~> 0.2.0"}
  ]
end

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/web_driver_client.

Documentation

Documentation can be built locally with the following command.

$ mix docs

To view documentation for pre-release APIs, docs can be built with:

$ MIX_ENV=docs_prerelease mix docs

It's important to note the pre-release APIs aren't public and may change at any time.