Contributing to Selenium

The Selenium project welcomes contributions from everyone. There are a number of ways you can help:

Bug Reports

When opening new issues or commenting on existing issues please make sure discussions are related to concrete technical issues with the Selenium software.

It's imperative that issue reports outline the steps to reproduce the defect. If the issue can't be reproduced it will be closed. Please provide concise reproducible test cases and describe what results you are seeing and what results you expect.

Issues shouldn't be used for support. Please address questions to the selenium-users@ mailing list. Discussion of high level project ideas or non-technical topics should move to the selenium-developers@ mailing list instead.

We also need help with triaging issues that needs investigation. This means asking the right questions, procuring the right information to properly debug and verify the issue, and bisecting a commit range if the issue is a regression.

Feature Requests

If you find that Selenium is missing something, feel free to open an issue with details describing what feature(s) you'd like added or changed.

If you'd like a hand at trying to implement the feature yourself, please refer to the Code Contributions section of the document.

Documentation

Selenium is a big software project and documentation is key to understanding how things work and learning effective ways to exploit its potential.

The seleniumhq.github.io repository contains both Selenium’s site and documentation. This is an ongoing effort (not targeted at any specific release) to provide updated information on how to use Selenium effectively, how to get involved and how to contribute to Selenium.

The official documentation of Selenium is at https://selenium.dev/documentation/. More details on how to get involved and contribute, please check the site's and documentation contributing guidelines.

Code Contributions

The Selenium project welcomes new contributors. Individuals making significant and valuable contributions over time are made Committers and given commit-access to the project.

If you're looking for easy bugs, have a look at issues labelled E-easy on Github.

This document will guide you through the contribution process.

Step 1: Fork & Clone

Fork the project on Github and clone the repository locally. Use --depth 1 for a quick clone. The repository is over 2GB and cloning the whole history takes a while.

% git clone git@github.com:username/selenium.git --depth 1
% cd selenium
% git remote add upstream git://github.com/seleniumhq/selenium.git

Dependencies

We bundle dependencies in the third-party/ directory that are not part of the proper project. Any changes to files in this directory or its subdirectories should be sent upstream to the respective projects. Please don't send your patch to us as we cannot accept it.

We do accept help in upgrading our existing dependencies or removing superfluous dependencies. If you need to add a new dependency it's often a good idea to reach out to the committers on the IRC channel or the mailing list to check that your approach aligns with the project's ideas. Nothing is more frustrating than seeing your hard work go to waste because your vision doesn't align with the project's.

Dependencies Managed by Bazel

Java

Edit MODULE.bazel, and either update or add the dependency you want using the regular maven coordinates to the maven.install with the name maven. Once done, run REPIN=1 bazel run @maven//:pin to update the lock file, create a PR and check the change in.

JS

We use pnpm for JS development in the project, and we also use pnpm workspaces. Take a look at the top-level pnpm-workspace.yaml file to find them all, but the main thing to know is that each of the workspaces has its own package.json. You can add dependencies to specific workspaces either by using pnpm installed on your local machine, or by executing:

# Example of adding a dep to the JS webdriver bindings 
cd javascript/selenium-webdriver
bazel run javascript:pnpm -- install my-amazing-dep --dir $PWD

This will install the dependency using the same version of pnpm we build the project with for a single JS project.

To update all dependencies in the tree to the latest version:

bazel run javascript:pnpm -- -r up --dir $PWD

This will also update the lock file, so once a change is made, create a PR and commit all the changed files.

License Headers

Every file in the Selenium project must carry the following license header boilerplate:

Licensed to the Software Freedom Conservancy (SFC) under one
or more contributor license agreements.  See the NOTICE file
distributed with this work for additional information
regarding copyright ownership.  The SFC licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License.  You may obtain a copy of the License at

  http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied.  See the License for the
specific language governing permissions and limitations
under the License.

There's no need to include a copyright statement in the file's header. The copyright attributions can be reviewed in the NOTICE file found in the top-level directory.

Step 2: Branch

Create a feature branch and start hacking:

% git checkout -b my-feature-branch

We practice HEAD-based development, which means all changes are applied directly on top of trunk.

Step 3: Commit

First make sure git knows your name and email address:

% git config --global user.name 'Santa Claus'
% git config --global user.email '[email protected]'

Writing good commit messages is important. A commit message should describe what changed, why, and reference issues fixed (if any). Follow these guidelines when writing one:

1. The first line should be around 50 characters or less and contain a short description of the change.

2. Keep the second line blank.

3. Wrap all other lines at 72 columns.

4. Include Fixes #N, where N is the issue number the commit fixes, if any.

A good commit message can look like this:

explain commit normatively in one line

Body of commit message is a few lines of text, explaining things
in more detail, possibly giving some background about the issue
being fixed, etc.

The body of the commit message can be several paragraphs, and
please do proper word-wrap and keep columns shorter than about
72 characters or so. That way `git log` will show things
nicely even when it is indented.

Fixes #141

The first line must be meaningful as it's what people see when they run git shortlog or git log --oneline.

Step 4: Rebase

Use git rebase (not git merge) to sync your work from time to time.

% git fetch upstream
% git rebase upstream/trunk

Step 5: Test

Bug fixes and features should have tests. Look at other tests to see how they should be structured. Verify that new and existing tests are passing locally before pushing code.

Running tests locally

Build your code for the latest changes and run tests locally.

Python

% bazel test //py:unit

% bazel test --jobs 1 //py:test-remote

% bazel test //py:test-<browsername> #eg test-chrome, test-firefox

Javascript

% bazel test //javascript/selenium-webdriver:all

% bazel test --test_tag_filters=firefox //javascript/atoms/... //javascript/webdriver/...

% cd javascript/grid-ui && npm install && npm test

Java

% bazel test --cache_test_results=no --test_size_filters=small grid java/test/...

% bazel test --cache_test_results=no java/test/org/openqa/selenium/grid/router:large-tests

bazel test --test_size_filters=small,medium --cache_test_results=no --test_tag_filters=-browser-test //java/...

Ruby

Please see https://github.com/SeleniumHQ/selenium#ruby for details about running tests.

Step 6: Push

% git push origin my-feature-branch

Go to https://github.com/yourusername/selenium.git and press the Pull Request and fill out the form.

Pull requests are usually reviewed within a few days. If there are comments to address, apply your changes in new commits (preferably fixups) and push to the same branch.

Step 7: Integration

When code review is complete, a committer will take your PR and integrate it on Selenium's trunk branch. Because we like to keep a linear history on the trunk branch, we will normally squash and rebase your branch history.

Stages of an Issue or PR

From your create your issue or pull request, through code review and towards integration, it will be assigned different Github labels. The labels serve for the committers to more easily keep track of work that's pending or awaiting action.

Component labels are yellow and carry the C prefix. They highlight the subsystem or component your PR makes changes in.

The driver labels (D) indicate if the changes are related to a WebDriver implementation or the Selenium atoms.

The review labels (R) are:

• awaiting answer: awaits an answer from you

• awaiting merge: waits for a committer to integrate the PR

• awaiting reviewer: pending code review

• blocked on external: a change in an upstream repo is required

• needs code changes: waiting for you to fix a review issue

• needs rebase: the branch isn't in sync with trunk and needs to be rebased

Issues are labelled to make them easier to categorise and find by:

• which component they relate to (java, cpp, dotnet, py, rb, nodejs)

• which driver is affected

• their presumed difficulty (easy, less easy, hard)

• what type of issue they are (defect, race condition, cleanup)

Communication

Selenium contributors frequent the #selenium channel on libera.chat. You can also join the selenium-developers@ mailing list. Check https://selenium.dev/support/ for a complete list of options to communicate.

Using the EngFlow RBE

To access the EngFlow RBE, a developer needs to be granted access to our project container repository. Once that has been done, then any bazel command can be run remotely by using --config=rbe. For example: bazel build --config=rbe grid or bazel test --config=rbe java/test/...

When you run a remote build, one of the first lines of output from Bazel will include a link to the EngFlow UI so you can track the progress of the build and gather information about the efficiency of the build.