Selenium is an umbrella project encapsulating a variety of tools and libraries enabling web browser automation. Selenium specifically provides infrastructure for the W3C WebDriver specification — a platform and language-neutral coding interface compatible with all major web browsers.
The project is made possible by volunteer contributors who've generously donated thousands of hours in code development and upkeep.
Selenium's source code is made available under the Apache 2.0 license.
Narrative documentation:
- User Manual
- New Handbook (work in progress)
API documentation:
Please read CONTRIBUTING.md before submitting your pull requests.
In order to build Selenium, you'll generally use the ./go command. ./go is a Rake script,
which wraps the main build too, bazel.
Bazel was built by the fine folks at Google. Bazel manages dependency downloads, generates the Selenium binaries, executes tests and does it all rather quickly.
More detailed instructions for getting Bazel running are below, but if you can successfully get the java and javascript folders to build without errors, you should be confident that you have the correct binaries on your system.
Ensure that you have Chrome installed and the
chromedriver that matches
your Chrome version available on your $PATH. You may have to update this from time to time.
To build the most commonly-used modules of Selenium from source, execute this command from the root project folder:
bazel build java/...If you have some extra time on your hands, you can run this command to get extra confidence that your build is successful. This will do a lot more work to build all the javascript artifacts:
bazel build java/... javascript/...If you're making changes to the java/ or javascript/ folders in this project, and this command executes without errors, you should be able to create a PR of your changes. (See also CONTRIBUTING.md)
- Bazel files are called BUILD.bazel
- crazyfun build files are called build.desc. This is an older build system, still in use in the project
- There is also a main Rakefile
The order the modules are built is determined by the build system. If you want to build an individual module (assuming all dependent modules have previously been built), try the following:
./go javascript/atoms:test:runIn this case, javascript/atoms is the module directory,
test is a target in that directory's build.desc file,
and run is the action to run on that target.
As you see build targets scroll past in the log,
you may want to run them individually. crazyfun can run them individually,
by target name, as long as :run is appended (see above).
To list all available targets, you can append the -T flag:
./go -T- The latest version of the Java 11 OpenJDK
javaandjaron the PATH (make sure you usejavaexecutable from JDK but not JRE).- To test this, try running the command
javac. This command won't exist if you only have the JRE installed. If you're met with a list of command-line options, you're referencing the JDK properly.
- To test this, try running the command
- Python
pythonon the PATH- The Requests Library for Python:
pip install requests - MacOS users should have the latest version of XCode installed, including the command-line tools. The following command should work:
xcode-select --installAlthough the build system is based on rake, it's strongly advised
to rely on the version of JRuby in third_party/ that is invoked by
go. The only developer type who would want to deviate from this is
the “build maintainer” who's experimenting with a JRuby upgrade.
- Python 3.4+ (if you want to run Python tests for this version)
- Ruby 2.0
If you plan to compile the IE driver, you also need:
- Visual Studio 2008
- 32 and 64 bit cross compilers
The build will work on any platform, but the tests for IE will be skipped silently if you are not building on Windows.
To build the bulk of the Selenium binaries from source, run the following command from the root folder:
bazel build java/... javascript/...To build the grid deployment jar, run this command:
bazel build gridTo run tests within a particular area of the project, use the "test" command, followed
by the folder or target. Tests are tagged with "small", "medium", or "large", and can be filtered
with the --test_size_filters option:
bazel test --test_size_filters=small,medium java/...Bazel's "test" command will run all tests in the package, including integration tests. Expect
the test java/... to launch browsers and consume a considerable amount of time and resources.
The code base is generally segmented around the languages used to write the component. Selenium makes extensive use of JavaScript, so let's start there. Working on the JavaScript is easy. First of all, start the development server:
./go debug-serverNow, navigate to
http://localhost:2310/javascript.
You'll find the contents of the javascript/ directory being shown.
We use the Closure
Library for
developing much of the JavaScript, so now navigate to
http://localhost:2310/javascript/atoms/test.
The tests in this directory are normal HTML files with names ending
with _test.html. Click on one to load the page and run the test. You
can run all the JavaScript tests using:
./go test_javascriptHere is the public Selenium Maven repository.
./go only makes a top-level build directory. Outputs are placed
under that relative to the target name. Which is probably best
described with an example. For the target:
./go //java/client/src/org/openqa/selenium:selenium-apiThe output is found under:
build/java/client/src/org/openqa/selenium/selenium-api.jarIf you watch the build, each step should print where its output is
going. Java test outputs appear in one of two places: either under
build/test_logs for JUnit or in
build/build_log.xml for TestNG
tests. If you'd like the build to be chattier, just append log=true
to the build command line.
More general, but basic, help for go…
./go --helpgo is just a wrapper around
Rake, so you can use the standard
commands such as rake -T to get more information about available
targets.
If it is not clear already, Selenium is not built with Maven. It is
built with bazel, though that is invoked with go as outlined above,
so you do not really have to learn too much about that.
That said, it is possible to relatively quickly build Selenium pieces
for Maven to use. You are only really going to want to do this when
you are testing the cutting-edge of Selenium development (which we
welcome) against your application. Here is the quickest way to build
and deploy into your local maven repository (~/.m2/repository), while
skipping Selenium's own tests.
./go maven-installThe maven jars should now be in your local ~/.m2/repository.
Refer to the Building Web Driver wiki page for the last word on building the bits and pieces of Selenium.
Bazelisk is a Mac-friendly launcher for Bazel. To install, follow these steps:
brew tap bazelbuild/tap && \
brew uninstall bazel; \
brew install bazelbuild/tap/bazeliskIf you're getting errors that mention XCode, you'll need to install the command-line tools.
Bazel for Mac requires some additional steps to configure properly. First things first: use the Bazelisk project (courtesy of philwo), a pure golang implementation of Bazel. In order to install Bazelisk, first verify that your XCode will cooperate: execute the following command:
xcode-select -p
If the value is /Applications/Xcode.app/Contents/Developer/, you can proceed with bazelisk
installation. If, however, the return value is /Library/Developer/CommandLineTools/, you'll
need to redirect the XCode system to the correct value.
sudo xcode-select -s /Applications/Xcode.app/Contents/Developer/
sudo xcodebuild -license
The first command will prompt you for a password. The second step requires you to read a new XCode license, and then accept it by typing "agree".
(Thanks to this thread for these steps)