selenium
Selenium
Selenium is an umbrella project encapsulating a variety of tools and libraries enabling web browser automation. Selenium specifically provides an 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.
This README is for developers interested in contributing to the project. For people looking to get started using Selenium, please check out our User Manual for detailed examples and descriptions, and if you get stuck, there are several ways to Get Help.
Please read CONTRIBUTING.md before submitting your pull requests.
These are the requirements to create your own local dev environment to contribute to Selenium.
Bazelisk, a Bazel wrapper that automatically downloads
the version of Bazel specified in .bazelversion file and transparently passes through all
command-line arguments to the real Bazel binary.
Java JDK version 17 or greater (e.g., Java 17 Temurin)
Set JAVA_HOME environment variable to location of Java executable (the JDK not the 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.
Xcode including the command-line tools. Install the latest version using: xcode-select --install
Rosetta for Apple Silicon Macs. Add build --host_platform=//:rosetta to the .bazelrc.local file. We are working
to make sure this isn't required in the long run.
Several years ago Jim Evans published a great article on Setting Up a Windows Development Environment for the Selenium .NET Language Bindings; This article is out of date, but it includes more detailed descriptions and screenshots that some people might find useful.
This script will ensure a complete ready to execute developer environment. (nothing is installed or set that is already present unless otherwise prompted)
Open Powershell as an Administrator
Execute: Set-ExecutionPolicy Bypass -Scope Process -Force to allow running the script in the process
Navigate to the directory you want to clone Selenium in, or the parent directory of an already cloned Selenium repo
Download and execute this script in the powershell terminal: [scripts/dev-environment-setup.ps1]`
Allow running scripts in Selenium in general:
Set-ExecutionPolicy -ExecutionPolicy RemoteSigned
Enable Developer Mode:
reg add "HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionAppModelUnlock" /t REG_DWORD /f /v "AllowDevelopmentWithoutDevLicense" /d "1"
Install MSYS2, which is an alternative shell environment that provides Unix-like commands
Add bin directory to PATH environment variable (e.g., "C:toolsmsys64usrbin")
Add bash.exe location as the BAZEL_SH environment variable (e.g., "C:toolsmsys64usrbinbash.exe")
Install the latest version of Visual Studio Community
Use the visual studio installer to modify and add the "Desktop development with C++" Workload
Add Visual C++ build tools installation directory location to BAZEL_VC environment variable (e.g. "C:Program FilesMicrosoft Visual Studio2022CommunityVC")
Add Visual C++ Build tools version to BAZEL_VC_FULL_VERSION environment variable (this can be discovered from the directory name in "$BAZEL_VCToolsMSVC)
Add support for long file names (bazel has a lot of nested directories that can exceed default limits in Windows)
reg add "HKEY_LOCAL_MACHINESOFTWAREMicrosoftCommand Processor" /t REG_DWORD /f /v "DisableUNCCheck" /d "1"reg add "HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlFileSystem" /t REG_DWORD /f /v "LongPathsEnabled" /d "1"
Create a file selenium/.bazelrc.windows.local
Add "startup --output_user_root=C:/tmp" to the file
Allow Bazel to create short name versions of long file paths: fsutil 8dot3name set 0
Set bazel output to C:/tmp instead of nested inside project directory:
Enable Long Paths support with these 2 registry commands:
If you want to contribute to the project, but do not want to set up your own local dev environment, there are two alternatives available.
Rather than creating your own local dev environment, GitPod provides a ready to use environment for you.
As an alternative you can build a Dev Container - basically a docker container - suitable for building and testing Selenium using the devcontainer.json in the .devcontainer directory. Supporting IDEs like VS Code or IntelliJ IDEA should point you to how such a container can be created.
You can also build a Docker image suitable for building and testing Selenium using the Dockerfile in the dev image directory.
Selenium is built using a common build tool called Bazel, to allow us to easily manage dependency downloads, generate required binaries, build and release packages, and execute tests; all in a fast, efficient manner. For a more detailed discussion, read Simon Stewart's article on Building Selenium
Often we wrap Bazel commands with our custom Rake wrapper. These are run with the ./go command.
The common Bazel commands are:
bazel build — evaluates dependencies, compiles source files and generates output files for the specified target.
It's used to create executable binaries, libraries, or other artifacts.
bazel run — builds the target and then executes it.
It's typically used for targets that produce executable binaries.
bazel test — builds and runs the target in a context with additional testing functionality
bazel query — identifies available targets for the provided path.
Each module that can be built is defined in a BUILD.bazel file. To execute the module you refer to it starting with a//, then include the relative path to the file that defines it, then :, then the name of the target.
For example, the target to build the Grid is named executable-grid and it is
defined in the 'selenium/java/src/org/openqa/selenium/grid/BAZEL.build' file.
So to build the grid you would run: bazel build //java/src/org/openqa/selenium/grid:executable-grid.
The Bazel documentation has a handy guide for various shortcuts and all the ways to build multiple targets, which Selenium makes frequent use of.
To build everything for a given language:
bazel build ///...
To build just the grid there is an alias name to use (the log will show where the output jar is located):
bazel build grid
To make things more simple, building each of the bindings is available with this ./go command
./go:build
Most of the team uses Intellij for their day-to-day editing. If you're working in IntelliJ, then we highly recommend installing the Bazel IJ plugin which is documented on its own site.
To use Selenium with the IntelliJ Bazel plugin, import the repository as a Bazel project, and select the project
view file from the scripts directory. ij.bazelproject for Mac/Linux and ij-win.bazelproject for Windows.
We also use Google Java Format for linting, so using the Google Java Formatter Plugin is useful;
there are a few steps to get it working, so read their configuration documentation.
There is also an auto-formatting script that can be run: ./scripts/format.sh
While Selenium is not built with Maven, you can build and install the Selenium pieces
for Maven to use locally by deploying to your local maven repository (~/.m2/repository), using:
./go java:install
Dependencies are defined in the file maven_deps.bzl. To automatically update and pin new dependencies, run:
./go java:update
You can run Python code locally by updating generated files in the python directory using:
./go py:update
To install Selenium locally based on a specific commit, you can use:
./go py:install
Instead of using irb, you can create an interactive REPL with all gems loaded using: bazel run //rb:console
If you want to debug code, you can do it via debug gem:
Add binding.break to the code where you want the debugger to start.
Run tests with ruby_debug configuration: bazel test --config ruby_debug .
When debugger starts, run the following in a separate terminal to connect to debugger:
bazel-selenium/external/bundle/bin/rdbg -A
If you want to use RubyMine for development, you can configure it use Bazel artifacts:
Open rb/ as a main project directory.
Run bundle exec rake update as necessary to create up-to-date artifacts. If this does not work, run ./go rb:update from the selenium (parent) directory.
InSettings / Languages & Frameworks / Ruby SDK and Gemsadd newInterpreterpointing to ../bazel-selenium/external/rules_ruby_dist/dist/bin/ruby.
You should now be able to run and debug any spec. It uses Chrome by default, but you can alter it using environment variables secified in Ruby Testing section below.
To keep Carbo.Bazel.lock synchronized with Cargo.lock, run:
CARGO_BAZEL_REPIN=true bazel sync --only=crates
There are a number of bazel configurations specific for testing.
Here are examples of arguments we make use of in testing the Selenium code:
--pin_browsers - run specific browser versions defined in the build (versions are updated regularly)
--headless - run browsers in headless mode (supported be Chrome, Edge and Firefox)
--flaky_test_attempts 3 - re-run failed tests up to 3 times
--local_test_jobs 1 - control parallelism of tests
--cache_test_results=no, -t- - disable caching of test results and re-runs all of them
--test_output all - print all output from the tests, not just errors
--test_output streamed - run all tests one by one and print its output immediately
--test_env FOO=bar - pass extra environment variable to test process
--run_under="xvfb-run -a" - prefix to insert before the execution
Selenium tests can be filtered by size:
small — typically unit tests where no browser is opened
large — typically tests that actually drive a browser
medium — tests that are more involved than simple unit tests, but not fully driving a browser
These can be filtered using the test_size_filters argument like this:
bazel test ///... --test_size_filters=small
Tests can also be filtered by tag like:
bazel test ///... --test_tag_filters=this,-not-this
To run unit tests:
bazel test //java/... --test_size_filters=small
To run integration tests:
bazel test //java/... --test_size_filters=medium
To run browser tests:
bazel test //java/... --test_size_filters=large --test_tag_filters=
To run a specific test:
bazel test //java/test/org/openqa/selenium/chrome:ChromeDriverFunctionalTest
To run the tests run:
bazel test //javascript/node/selenium-webdriver:tests
You can use --test_env to pass in the browser name as SELENIUM_BROWSER.
bazel test //javascript/node/selenium-webdriver:tests --test_env=SELENIUM_BROWSER=firefox
Run unit tests with:
bazel test //py:unit
To run tests with a specific browser:
bazel test //py:test-
To run all Python tests:
bazel test //py:all
Test targets:
| Command | Description |
|---|---|
bazel test //rb/... | Run unit, all integration tests and lint |
bazel test //rb:lint | Run RuboCop linter |
bazel test //rb/spec/... | Run unit and integration tests for all browsers |
bazel test //rb/spec/... --test_size_filters small | Run unit tests |
bazel test //rb/spec/unit/... | Run unit tests |
bazel test //rb/spec/... --test_size_filters large | Run integration tests for all browsers |
bazel test //rb/spec/integration/... | Run integration tests for all browsers |
bazel test //rb/spec/integration/... --test_tag_filters firefox | Run integration tests for local Firefox only |
bazel test //rb/spec/integration/... --test_tag_filters firefox-remote | Run integration tests for remote Firefox only |
bazel test //rb/spec/integration/... --test_tag_filters firefox,firefox-remote | Run integration tests for local and remote Firefox |
Ruby test targets have the same name as the spec file with _spec.rb removed, so you can run them individually.
Integration tests targets also have a browser and remote suffix to control which browser to pick and whether to use Grid.
| Test file | Test target |
|---|---|
rb/spec/unit/selenium/webdriver/proxy_spec.rb | //rb/spec/unit/selenium/webdriver:proxy |
rb/spec/integration/selenium/webdriver/driver_spec.rb | //rb/spec/integration/selenium/webdriver:driver-chrome |
rb/spec/integration/selenium/webdriver/driver_spec.rb | //rb/spec/integration/selenium/webdriver:driver-chrome-remote |
rb/spec/integration/selenium/webdriver/driver_spec.rb | //rb/spec/integration/selenium/webdriver:driver-firefox |
rb/spec/integration/selenium/webdriver/driver_spec.rb | //rb/spec/integration/selenium/webdriver:driver-firefox-remote |
Supported browsers:
chrome
edge
firefox
firefox-beta
ie
safari
safari-preview
In addition to the Common Options Examples, here are some additional Ruby specific ones:
--test_arg "-eTimeouts" - test only specs which name include "Timeouts"
--test_arg " - pass any extra RSpec arguments (see bazel run @bundle//bin:rspec -- --help)
Supported environment variables for use with --test_env:
WD_SPEC_DRIVER - the driver to test; either the browser name or 'remote' (gets set by Bazel)
WD_REMOTE_BROWSER - when WD_SPEC_DRIVER is remote; the name of the browser to test (gets set by Bazel)
WD_REMOTE_URL - URL of an already running server to use for remote tests
DOWNLOAD_SERVER - when WD_REMOTE_URL not set; whether to download and use most recently released server version for remote tests
DEBUG - turns on verbose debugging
HEADLESS - for chrome, edge and firefox; runs tests in headless mode
DISABLE_BUILD_CHECK - for chrome and edge; whether to ignore driver and browser version mismatches (allows testing Canary builds)
CHROME_BINARY - path to test specific Chrome browser
CHROMEDRIVER_BINARY - path to test specific ChromeDriver
EDGE_BINARY - path to test specific Edge browser
MSEDGEDRIVER_BINARY - path to test specific msedgedriver
FIREFOX_BINARY - path to test specific Firefox browser
GECKODRIVER_BINARY - path to test specific GeckoDriver
To run with a specific version of Ruby you can change the version in rb/.ruby-version or from command line:
echo '' > rb/.ruby-version
.NET tests currently only work with pinned browsers, so make sure to include that.
Run all tests with:
bazel test //dotnet/test/common:AllTests --pin_browsers=true
You can run specific tests by specifying the class name:
bazel test //dotnet/test/common:ElementFindingTest --pin_browsers=true
If the module supports multiple browsers:
bazel test //dotnet/test/common:ElementFindingTest-edge --pin_browsers=true
Rust tests are run with:
bazel test //rust/...
By default, Bazel runs these tests in your current X-server UI. If you prefer, you can alternatively run them in a virtual or nested X-server.
Run the X server Xvfb :99 or Xnest :99
Run a window manager, for example, DISPLAY=:99 jwm
Run the tests you are interested in:
bazel test --test_env=DISPLAY=:99 //java/... --test_tag_filters=chrome
An easy way to run tests in a virtual X-server is to use Bazel's --run_underfunctionality:
bazel test --run_under="xvfb-run -a" //java/...
API documentation can be found here:
C#
JavaScript
Java
Python
Ruby
To update API documentation for a specific language: ./go
To update all documentation: ./go all:docs
Note that JavaScript generation is currently broken.
The full process for doing a release can be found in the wiki
Releasing is a combination of building and publishing, which often requires coordination of multiple executions
and additional processing.
As discussed in the Building section, we use Rake tasks with the ./go command for these things.
These ./go commands include the --stamp argument to provide necessary information about the constructed asset.
You can build and release everything with:
./go all:release
To build and release a specific language:
./go:release
If you have access to the Selenium EngFlow repository, you can have the assets built remotely and downloaded locally using:
./go all:release['--config', 'release']
