gecko-dev/testing/geckodriver/README.md

geckodriver
===========

Proxy for using W3C WebDriver-compatible clients to interact with
Gecko-based browsers.

This program provides the HTTP API described by the [WebDriver protocol]
to communicate with Gecko browsers, such as Firefox.  It translates calls
into the [Firefox remote protocol] by acting as a proxy between the local-
and remote ends.

You can consult the [change log] for a record of all notable changes
to the program.  [Releases] are made available on GitHub on [supported
platforms].

The canonical source code repository for geckodriver now lives in
[mozilla-central] under [testing/geckodriver].  You can read more about
[working with Mozilla source code] on MDN.  This means we do no longer
accept pull requests on GitHub.  Patches should be uploaded to a bug in
the [Testing :: GeckoDriver] component.

[WebDriver protocol]: http://w3c.github.io/webdriver/webdriver-spec.html#protocol
[Firefox remote protocol]: https://developer.mozilla.org/en-US/docs/Mozilla/QA/Marionette
[change log]: https://searchfox.org/mozilla-central/source/testing/geckodriver/CHANGES.md
[Releases]: https://github.com/mozilla/geckodriver/releases
[supported platforms]: #supported-firefoxen
[mozilla-central]: https://hg.mozilla.org/mozilla-central/
[testing/geckodriver]: https://hg.mozilla.org/mozilla-central/file/tip/testing/geckodriver
[working with Mozilla source code]: https://developer.mozilla.org/en-US/docs/Mozilla/Developer_guide/Source_Code
[Testing :: geckodriver]: https://bugzilla.mozilla.org/buglist.cgi?product=Testing&component=geckodriver&resolution=---&list_id=13613952


Supported clients
=================

[Selenium] users must update to [version 3.5] or later to
use geckodriver.  Other clients that follow the [W3C WebDriver
specification] are also supported.

[version 3.5]: https://github.com/SeleniumHQ/selenium/releases/tag/selenium-3.5.0
[W3C WebDriver specification]: https://w3c.github.io/webdriver/webdriver-spec.html


Supported Firefoxen
===================

geckodriver is not yet feature complete.  This means that it does not
yet offer full conformance with the [WebDriver] standard or complete
compatibility with [Selenium].  You can track the [implementation
status] of the latest [Firefox Nightly](http://whattrainisitnow.com/)
on [MDN].  We also keep track of known [Selenium], [remote protocol],
and [specification] problems in our [issue tracker].

Support is best in Firefox 55 and greater, although generally the more
recent the Firefox version, the better the experience as they have more
bug fixes and features.  Some features will only be available in the
most recent Firefox versions, and we strongly advise using the latest
[Firefox Nightly] with geckodriver.  Since Windows XP support in Firefox
was dropped with Firefox 53, we do not support this platform.

[implementation status]: https://developer.mozilla.org/en-US/docs/Mozilla/QA/Marionette/WebDriver/status
[MDN]: https://developer.mozilla.org/
[selenium]: https://github.com/mozilla/geckodriver/issues?q=is%3Aissue+is%3Aopen+label%3Aselenium
[remote protocol]: https://github.com/mozilla/geckodriver/issues?q=is%3Aissue+is%3Aopen+label%3Amarionette
[specification]: https://github.com/mozilla/geckodriver/issues?q=is%3Aissue+is%3Aopen+label%3Aspec
[issue tracker]: https://github.com/mozilla/geckodriver/issues
[Firefox Nightly]: https://nightly.mozilla.org/


WebDriver capabilities
======================

geckodriver supports a number of [capabilities]:

[capabilities]: https://w3c.github.io/webdriver/webdriver-spec.html#capabilities

<table>
 <thead>
  <tr>
   <th>Name
   <th>Type
   <th>Default
   <th>Description
  </tr>
 </thead>

 <tr>
  <td><code>acceptInsecureCerts</code>
  <td>boolean
  <td>Boolean initially set to false,
   indicating the session will not implicitly trust untrusted
   or self-signed TLS certificates on navigation.
  <td>
 </tr>

 <tr>
  <td><code>pageLoadStrategy</code>
  <td>string
  <td>Defines the page load strategy
   to use for the duration of the session.
   Setting a page load strategy will cause navigation
   to be "<code>eager</code>",
   waiting for the <code>interactive</code> document ready state;
   "<code>normal</code>" (the default),
   waiting for the <code>complete</code> ready state;
   or "<code>none</code>",
   which will return immediately after starting navigation.
  <td>
 </tr>

 <tr>
  <td><code>proxy</code>
  <td><a href=#proxy-object><code>proxy</code></a>&nbsp;object
  <td>
  <td>Sets browser proxy settings.
 </tr>
</table>


`proxy` object
--------------

<table>
 <thead>
  <tr>
   <th>Name
   <th>Type
   <th>Description
  </tr>
 </thead>

 <tr>
  <td><code>proxyType</code>
  <td>string
  <td>Indicates the type of proxy configuration.
   This value must be one of
   <code>pac</code>,
   <code>direct</code>,
   <code>autodetect</code>,
   <code>system</code>,
   or <code>manual</code>.
 </tr>

 <tr>
  <td><code>proxyAutoconfigUrl</code>
  <td>string
  <td>Defines the URL for a proxy auto-config file.
   This property should only be set
   when <code>proxyType</code> is <code>pac</code>.
 </tr>

 <tr>
  <td><code>ftpProxy</code>
  <td>string
  <td>Defines the proxy hostname with an optional port for FTP traffic.
   This property should only be set when <code>proxyType</code>
   is set to <code>manual</code>.
 </tr>

 <tr>
  <td><code>httpProxy</code>
  <td>string
  <td>Defines the proxy hostname with an optional port for HTTP traffic.
   This property should only be set when <code>proxyType</code>
   is set to <code>manual</code>.
 </tr>

 <tr>
  <td><code>noProxy</code>
  <td>list
  <td>Lists the addresses for which the proxy should be bypassed.
   This property should only be set when <code>proxyType</code>
   is set to <code>manual</code>.
 </tr>

 <tr>
  <td><code>sslProxy</code>
  <td>string
  <td>Defines the proxy hostname with an optional port for encrypted TLS traffic.
   This property should only be set when <code>proxyType</code>
   is set to <code>manual</code>.
 </tr>

 <tr>
  <td><code>socksProxy</code>
  <td>string
  <td>Defines the hostname with on optional port for a SOCKS proxy.
   This property should only be set when <code>proxyType</code>
   is set to <code>manual</code>.
 </tr>

 <tr>
  <td><code>socksVersion</code>
  <td>number
  <td>Defines the SOCKS proxy version. This property has only to be set
   when <code>proxyType</code> is set to <code>manual</code>.
 </tr>
</table>


Firefox capabilities
====================

geckodriver has a few capabilities that are specific to Firefox.

moz:firefoxOptions
------------------

A dictionary used to define options which control how Firefox gets started
and run. It may contain any of the following fields:

<table>
 <thead>
  <tr>
   <th>Name
   <th>Type
   <th>Description
  </tr>
 </thead>

 <tr id=capability-binary>
  <td><code>binary</code>
  <td>string
  <td>Absolute path of the Firefox binary,
   e.g. <code>/usr/bin/firefox</code>
   or <code>/Applications/Firefox.app/Contents/MacOS/firefox</code>,
   to select which custom browser binary to use.
   If left undefined geckodriver will attempt
   to deduce the default location of Firefox
   on the current system.
 </tr>

 <tr id=capability-args>
  <td><code>args</code>
  <td>array&nbsp;of&nbsp;strings
  <td><p>Command line arguments to pass to the Firefox binary.
   These must include the leading dash (<code>-</code>) where required,
   e.g. <code>["-devtools"]</code>.

   <p>To have geckodriver pick up an existing profile on the filesystem,
    you may pass <code>["-profile", "/path/to/profile"]</code>.
 </tr>

 <tr id=capability-profile>
  <td><code>profile</code>
  <td>string
  <td><p>Base64-encoded ZIP of a profile directory to use for the Firefox instance.
   This may be used to e.g. install extensions or custom certificates,
   but for setting custom preferences
   we recommend using the <a href=#capability-prefs><code>prefs</code></a> entry
   instead of passing a profile.

   <p>Profiles are created in the system’s temporary folder.
    This is also where the encoded profile is extracted
    when <code>profile</code> is provided.
    By default, geckodriver will create a new profile in this location.

   <p>The effective profile in use by the WebDriver session
    is returned to the user in the <code>moz:profile</code> capability
    in the new session response.

   <p>To have geckodriver pick up an <em>existing profile</em> on the filesystem,
    please set the <a href=#capability-args><code>args</code></a> field
    to <code>{"args": ["-profile", "/path/to/your/profile"]}</code>.
 </tr>

 <tr id=capability-log>
  <td><code>log</code>
  <td><a href=#log-object><code>log</code></a>&nbsp;object
  <td>To increase the logging verbosity of geckodriver and Firefox,
   you may pass a <a href=#log-object><code>log</code> object</a>
   that may look like <code>{"log": {"level": "trace"}}</code>
   to include all trace-level logs and above.
 </tr>

 <tr id=capability-prefs>
  <td><code>prefs</code>
  <td><a href=#prefs-object><code>prefs</code></a>&nbsp;object
  <td>Map of preference name to preference value, which can be a
   string, a boolean or an integer.
 </tr>
</table>

moz:useNonSpecCompliantPointerOrigin
------------------------------------

A boolean value to indicate how the pointer origin for an action command
will be calculated.

With Firefox 59 the calculation will be based on the requirements by the
[WebDriver] specification. This means that the pointer origin is no longer
computed based on the top and left position of the referenced element, but
on the in-view center point.

To temporarily disable the WebDriver conformant behavior use `false` as value
for this capability.

Please note that this capability exists only temporarily, and that it will be
removed once all Selenium bindings can handle the new behavior.

moz:webdriverClick
------------------

A boolean value to indicate which kind of interactability checks to run
when performing a click or sending keys to an elements. For Firefoxen prior to
version 58.0 some legacy code as imported from an older version of
[FirefoxDriver] was in use.

With Firefox 58 the interactability checks as required by the [WebDriver]
specification are enabled by default. This means geckodriver will additionally
check if an element is obscured by another when clicking, and if an element is
focusable for sending keys.

Because of this change in behaviour, we are aware that some extra errors could
be returned. In most cases the test in question might have to be updated
so it's conform with the new checks. But if the problem is located in
geckodriver, then please raise an issue in the [issue tracker].

To temporarily disable the WebDriver conformant checks use `false` as value
for this capability.

Please note that this capability exists only temporarily, and that it will be
removed once the interactability checks have been stabilized.

`log` object
------------

<table>
 <thead>
  <tr>
   <th>Name
   <th>Type
   <th>Description
  </tr>
 </thead>

 <tr>
  <td><code>level</code>
  <td>string
  <td>Set the level of verbosity of geckodriver and Firefox.
   Available levels are <code>trace</code>,
   <code>debug</code>, <code>config</code>,
   <code>info</code>, <code>warn</code>,
   <code>error</code>, and <code>fatal</code>.
   If left undefined the default is <code>info</code>.
 </tr>
</table>


`prefs` object
--------------

<table>
 <thead>
  <tr>
   <th>Name
   <th>Type
   <th>Description
  </tr>
 </thead>

 <tr>
  <td><var>preference name</var>
  <td>string, number, boolean
  <td>One entry per preference to override.
 </tr>
</table>


Capabilities example
====================

The following example selects a specific Firefox binary to run with
a prepared profile from the filesystem in headless mode (available on
certain systems and recent Firefoxen).  It also increases the number of
IPC processes through a preference and enables more verbose logging.

	{
		"capabilities": {
			"alwaysMatch": {
				"moz:firefoxOptions": {
					"binary": "/usr/local/firefox/bin/firefox",
					"args": ["-headless", "-profile", "/path/to/my/profile"],
					"prefs": {
						"dom.ipc.processCount": 8
					},
					"log": {
						"level": "trace"
					}
				}
			}
		}
	}


Usage
=====

Usage steps are [documented on
MDN](https://developer.mozilla.org/en-US/docs/Mozilla/QA/Marionette/WebDriver),
but how you invoke geckodriver largely depends on your use case.


Selenium
--------

If you are using geckodriver through [Selenium], you must ensure that
you have version 3.5 and greater.  Because geckodriver implements the
[W3C WebDriver standard][WebDriver] and not the same Selenium wire
protocol older drivers are using, you may experience incompatibilities
and migration problems when making the switch from FirefoxDriver to
geckodriver.

Generally speaking, Selenium 3 enabled geckodriver as the default
WebDriver implementation for Firefox.  With the release of Firefox 47,
FirefoxDriver had to be discontinued for its lack of support for the
[new multi-processing architecture in Gecko][e10s].

Selenium client bindings will pick up the _geckodriver_ binary executable
from your [system’s `PATH` environmental variable][PATH] unless you
override it by setting the `webdriver.gecko.driver` [Java VM system
property]:

	System.setProperty("webdriver.gecko.driver", "/home/user/bin");

Or by passing it as a flag to the [java(1)] launcher:

	% java -Dwebdriver.gecko.driver=/home/user/bin YourApplication

Your milage with this approach may vary based on which programming
language bindings you are using.  It is in any case generally the case
that geckodriver will be picked up if it is available on the system path.
In a bash compatible shell, you can make other programs aware of its
location by exporting or setting the `PATH` variable:

	% export PATH=$PATH:/home/user/bin
	% whereis geckodriver
	geckodriver: /home/user/bin/geckodriver

On Window systems you can change the system path by right-clicking **My
Computer** and choosing **Properties**.  In the dialogue that appears,
navigate **Advanced** → **Environmental Variables** → **Path**.

Or in the Windows console window:

	$ set PATH=%PATH%;C:\bin\geckodriver


Standalone
----------

Since geckodriver is a separate HTTP server that is a complete remote end
implementation of [WebDriver], it is possible to avoid using the Selenium
remote server if you have no requirements to distribute processes across
a matrix of systems.

Given a W3C WebDriver conforming client library (or _local end_) you
may interact with the geckodriver HTTP server as if you were speaking
to any Selenium server.

Using [curl(1)]:

	% geckodriver &
	[1] 16010
	% 1491834109194   geckodriver     INFO    Listening on 127.0.0.1:4444
	% curl -d '{"capabilities": {"alwaysMatch": {"acceptInsecureCerts": true}}}' http://localhost:4444/session
	{"sessionId":"d4605710-5a4e-4d64-a52a-778bb0c31e00","value":{"XULappId":"{ec8030f7-c20a-464f-9b0e-13a3a9e97384}","acceptSslCerts":false,"appBuildId":"20160913030425","browserName":"firefox","browserVersion":"51.0a1","command_id":1,"platform":"LINUX","platformName":"linux","platformVersion":"4.9.0-1-amd64","processId":17474,"proxy":{},"raisesAccessibilityExceptions":false,"rotatable":false,"specificationLevel":0,"takesElementScreenshot":true,"takesScreenshot":true,"version":"51.0a1"}}
	% curl -d '{"url": "https://mozilla.org"}' http://localhost:4444/session/d4605710-5a4e-4d64-a52a-778bb0c31e00/url
	{}
	% curl http://localhost:4444/session/d4605710-5a4e-4d64-a52a-778bb0c31e00/url
	{"value":"https://www.mozilla.org/en-US/"
	% curl -X DELETE http://localhost:4444/session/d4605710-5a4e-4d64-a52a-778bb0c31e00
	{}
	% fg
	geckodriver
	^C
	%

Using the Python [wdclient] library:

	import webdriver

	with webdriver.Session("127.0.0.1", 4444) as session:
	    session.url = "https://mozilla.org"
	    print "The current URL is %s" % session.url

And to run:

	% geckodriver &
	[1] 16054
	% python example.py
	1491835308354   geckodriver     INFO    Listening on 127.0.0.1:4444
	The current URL is https://www.mozilla.org/en-US/
	% fg
	geckodriver
	^C
	%

[Selenium]: http://seleniumhq.org/
[e10s]: https://developer.mozilla.org/en-US/Firefox/Multiprocess_Firefox
[PATH]: https://en.wikipedia.org/wiki/PATH_(variable)
[Java VM system property]: http://docs.oracle.com/javase/tutorial/essential/environment/sysprop.html
[java(1)]: http://www.manpagez.com/man/1/java/
[WebDriver]: https://w3c.github.io/webdriver/webdriver-spec.html
[curl(1)]: http://www.manpagez.com/man/1/curl/
[wdclient]: https://github.com/w3c/wpt-tools/tree/master/webdriver


Flags
=====

#### <code>-b <var>BINARY</var></code>/<code>--binary <var>BINARY</var></code>

Path to the Firefox binary to use.  By default geckodriver tries to find
and use the system installation of Firefox, but that behaviour can be
changed by using this option.  Note that the `binary` capability of the
`moz:firefoxOptions` object that is passed when [creating a new session]
will override this option.

On Linux systems it will use the first _firefox_ binary found by searching
the `PATH` environmental variable, which is roughly equivalent to calling
[whereis(1)] and extracting the second column:

	% whereis firefox
	firefox: /usr/bin/firefox /usr/local/firefox

On macOS, the binary is found by looking for the first _firefox-bin_
binary in the same fashion as on Linux systems.  This means it is
possible to also use `PATH` to control where geckodriver should find
Firefox on macOS.  It will then look for _/Applications/Firefox.app_.

On Windows systems, geckodriver looks for the system Firefox by scanning
the Windows registry.

[creating a new session]: https://w3c.github.io/webdriver/webdriver-spec.html#new-session
[whereis(1)]: http://www.manpagez.com/man/1/whereis/


#### `--connect-existing`

Connecting to an existing Firefox instance.  The instance must have
Marionette enabled.

To enable the Marionette remote protocol you can pass the `--marionette`
flag to Firefox.


#### <code>--host <var>HOST</var></code>

Host to use for the WebDriver server.  Defaults to 127.0.0.1.


#### <code>--log <var>LEVEL</var></code>

Set the Gecko and geckodriver log level.  Possible values are `fatal`,
`error`, `warn`, `info`, `config`, `debug`, and `trace`.


#### <code>--marionette-port <var>PORT</var></code>

Selects the port for geckodriver’s connection to the [Marionette]
remote protocol.

In the default mode where geckodriver starts and manages the Firefox
process, it will pick a free port assigned by the system and set the
`marionette.port` preference in the profile.

When [`--connect-existing`] is used and the Firefox process is not
under geckodriver’s control, it will simply connect to <var>PORT</var>.

[`--connect-existing`]: #connect-existing


#### <code>-p <var>PORT</var></code>/<code>--port <var>PORT</var></code>

Port to use for the WebDriver server.  Defaults to 4444.

A helpful trick is that it is possible to bind to 0 to get the
system to atomically assign a free port.


#### <code>--jsdebugger</code>

Attach [browser toolbox] debugger when Firefox starts.  This is
useful for debugging [Marionette] internals.

[browser toolbox]: https://developer.mozilla.org/en-US/docs/Tools/Browser_Toolbox


#### <code>-v<var>[v]</var></code>

Increases the logging verbosity by to debug level when passing
a single `-v`, or to trace level if `-vv` is passed.  This is
analogous to passing `--log debug` and `--log trace`, respectively.


Building
========

geckodriver is written in [Rust], a systems programming language from
[Mozilla].  Crucially, it relies on the [webdriver crate] to provide
the HTTPD and do most of the heavy lifting of marshalling the WebDriver
protocol.  geckodriver translates WebDriver [commands], [responses],
and [errors] to the [Marionette protocol], and acts as a proxy between
[WebDriver] and [Marionette].

geckodriver is built in the [Firefox CI] by default but _not_ if you
build Firefox locally.  To enable building of geckodriver locally,
ensure you put this in your [mozconfig]:

	ac_add_options --enable-geckodriver

You build geckodriver with the `./mach build testing/geckodriver`
command, run tests with `./mach test testing/geckodriver`, and run
the built executable with `./mach geckodriver -- --other --flags`.

[Rust]: https://www.rust-lang.org/
[Mozilla]: https://www.mozilla.org/en-US/
[webdriver crate]: https://crates.io/crates/webdriver
[commands]: https://docs.rs/webdriver/newest/webdriver/command/index.html
[responses]: https://docs.rs/webdriver/newest/webdriver/response/index.html
[errors]: https://docs.rs/webdriver/newest/webdriver/error/enum.ErrorStatus.html
[Marionette protocol]: https://firefox-source-docs.mozilla.org/testing/marionette/marionette/Protocol.html
[WebDriver]: https://w3c.github.io/webdriver/webdriver-spec.html
[FirefoxDriver]: https://github.com/SeleniumHQ/selenium/wiki/FirefoxDriver
[Marionette]: https://firefox-source-docs.mozilla.org/testing/marionette/marionette/
[Firefox CI]: https://treeherder.mozilla.org/
[mozconfig]: https://developer.mozilla.org/en-US/docs/Mozilla/Developer_guide/Build_Instructions/Configuring_Build_Options


Contact
=======

The mailing list for geckodriver discussion is
tools-marionette@lists.mozilla.org ([subscribe], [archive]).

There is also an IRC channel to talk about using and developing
geckodriver in #ateam on irc.mozilla.org.

[subscribe]: https://lists.mozilla.org/listinfo/tools-marionette
[archive]: https://groups.google.com/group/mozilla.tools.marionette