Welcome to the Doctrine Project Contributors Guide. This documentation aims to document how contributors and maintainers should work when using git, development workflow, build process, dependency management, etc.


The Doctrine Project is the home of a selected set of PHP libraries primarily focused on providing persistence services and related functionality. Its prize projects are the Object Relational Mapper and the Database Abstraction Layer it is built on top of. You can view a list of all projects on the website.

Contributors vs Maintainers

Before continuing you need to understand the difference between a contributor and a maintainer.

  • Contributor: A contributor is someone from the outside not on the core development team of the project that wants to contribute some changes to a project.
  • Maintainer: A maintainer is someone on the core development team of the project and has commit access to the main repository of the project.

Contributor Workflow

Who is a contributor? A contributor can be anyone! It could be you. Continue reading this section if you wish to get involved and start contributing back to a Doctrine project.

Initial Setup

  • Setup a GitHub account.
  • Fork the repository of the project you want to contribute to. In this example it will be DBAL
  • Clone your fork locally
$ git clone [email protected]:username/dbal.git
  • Enter the dbal directory and add the doctrine remote
$ cd dbal
$ git remote add doctrine git://

Branching from the default branch

New pull requests are created with the repository's default branch as base branch. The default branch is the branch you see when you enter the repository page on GitHub.

The default branch

In this DBAL example, it's the branch with the name 2.11.x. The branch name reflects the current lowest supported version of a repository.

Newly introduced changes to 2.11.x will be up-merged at a later point in time to newer version branches (e.g. 2.12.x, 3.0.x). This way you don't have to re-introduce a new fix or feature of 2.11.x with another pull request to the other version branches.

Keeping the default branch up-to-date!

Once all this is done, you'll be able to keep your local branches up to date with the following command:

$ git fetch doctrine

Branching Model

The following names will be used to differentiate between the different repositories:

  • doctrine - The "official" Doctrine DBAL repository
  • origin - Your fork of the official repository on GitHub
  • local - This will be your local clone of origin

As a contributor you will push your completed local topic branch to origin. As a contributor you will pull updates from doctrine. As a maintainer (write-access) you will merge branches from contributors into doctrine.

Primary Branches

The doctrine repository holds the following primary branches:

  • doctrine/2.11.x Development towards the next release.
  • doctrine/\* Maintenance branches of existing releases.

These branches exist in parallel and are defined as follows:

doctrine/2.11.x is the branch where the source code of HEAD always reflects the latest version. Each released stable version will be a tagged commit in a doctrine/\* branch. Each released unstable version will be a tagged commit in the doctrine/2.11.x branch.

NOTE You should never commit to your forked default branch (origin/2.11.x). Changes to origin/2.11.x will never be merged into doctrine/2.11.x. All work must be done in a topic branch, which are explained below.

Topic Branches

Topic branches are for contributors to develop bug fixes, new features, etc. so that they can be easily merged to 2.11.x. They must follow a few rules as listed below:

  • May branch off from: 2.11.x whenever possible, or a newer version branch otherwise. Keep in mind that your changes will be up-merged to higher version branches by maintainers after the merge if they are applicable.
  • Branch naming convention: anything except master, the default branch name, or version branch names.

Topic branches are used to develop new features and fix reported issues. When starting development of a feature, the target release in which this feature will be incorporated may well be unknown. The essence of a topic branch is that it exists as long as the feature is in development, but will eventually be merged into 2.11.x or a release branch (to add the new feature or bugfix to a next release) or discarded (in case of a disappointing experiment).

Topic branches should exist in your local and origin repositories only, there is no need for them to exist in doctrine.

Creating a topic branch

First create an appropriately named branch. When starting work on a new topic, branch off from doctrine/2.11.x or a doctrine/\* branch:

$ git checkout -b fix-weird-bug doctrine/2.11.x
Switched to a new branch "fix-weird-bug"

Now do some work, make some changes then commit them:

$ git status
$ git add -p
$ git commit -v

Crafting meaningful commit messages

Commit messages should look like emails, meaning they should have a subject, but also a body. The subject should be on the first line, and not exceed 50 chars. It should tell us what you did, and every change in the diff should have to do with that subject. The body should be separated from it by a blank line and should tell us why you did what you did. That is also a good place to tell people about alternate solutions that were considered and the reasons for rejecting them. Links to related issues are more than welcome, but should be summarized so that the pull request can be understood without resorting to them. Ideally, the git history should be understandable without a network connection. Here is an example of a good although fictitious commit message:

Call foo::bar() instead of bar::baz()

This fixes a bug that arises when doing this or that, because baz()
needs a flux capacitor object that might not be defined.
I considered calling foobar(), but decided against because
Fixes #42

Wrap the lines in the commit body at 72 chars to make commits easier to read in different tools.

There are already a few articles (or even single purpose websites) about this in case you want to read more about this:

To squash or not to squash

The best way to avoid having to squash anything in the first place is to amend your last commit if that's indeed where your extra change is meant to go. That being said, sometimes you end up with many commits and it's too late for that. Some other times, code review has already started and it can be better not to touch already reviewed commits. You can signal that they should ultimately be squashed by using git commit --fixup=HEAD, which will also spare you the creation of a commit message since it will reuse the previous one.

Now let's say that code review is finished, or that it hasn't started, and that you want to squash some commits.

If you are in the fairly simple case where you want squash all your commits into one, you can take the following steps described in the manual to achieve that.

If you are in a more complex case where you would very much like to keep your commits separate, there are other solutions. To take a specific example, let us say that you made 3 commits A, B, C, and you have CS issues in A and in C. To make sure that is no longer the case, fixing each of these commits can be done like this: git rebase --exec "vendor/bin/phpcbf && vendor/bin/phpcs" A^ That command will run phpcbf and then phpcs for each of your commits and will halt for A and C, but not for B because in the case of B they would exit with a zero status code. That will let you amend A, after which you can resume the rebase until you do the same for C. Here is how it would look like on A:

$ vendor/bin/phpcs      # check for issues phpcbf could not fix
$ git add -p            # commit whatever issues were fixed
$ git commit --amend    # change A
$ git rebase --continue # resume the rebase

You should be able to apply the example above with any tool we use in our CI pipelines, such as PHPUnit, PHPStan or Psalm.

git rebase --interactive is a really powerful tool and we barely scratched the tip of the iceberg here. If you want to learn more about it, we recommend you watch this talk from Pauline Vos

Of course, if you want to craft good commits with good messages, you will have a hard time if the changeset you are describing does too many things. That might very well happen if you notice small things along the way that are unrelated to your PR, but too small to warrant a separate one. git add --patch or git add -p will be of invaluable help to commit things separately. On the contrary, there are commits that typically do not need to exist, such as commits that fix coding style or address minor review comments. Bear in mind that the git log is not only aimed at reviewers, but also at anyone who wants to understand some change you made. Do not distract them with cs fixes. Instead, try to produce a commit that contains your changes and the necessary fixes to pass coding standard checks. Also, it's best if all of your commits pass the build, because that makes them git bisect friendly, but it also means they are likely to be revertable independently from other commits in your PR. While being revertable is not particularly crucial to us, it can help you decide whether to squash or whether to split. For instance, it would not make sense to revert a commit documenting a feature without also reverting the code for that feature. That means there should be only once commit with both the code and the docs here.

Rebasing on upstream changes

Next, merge or rebase your commit against doctrine/2.11.x. With your work done in a local topic branch, you'll want to assist upstream merge by rebasing your commits. You can either do this manually with fetch then rebase, or use the pull --rebase shortcut. You may encounter merge conflicts, which you should fix and then mark as fixed with add, and then continue rebasing with rebase --continue. At any stage, you can abort the rebase with rebase --abort unlike nasty merges which will leave files strewn everywhere.

$ git fetch doctrine
$ git rebase doctrine/2.11.x fix-weird-bug

Push your branch to origin:

Finished topic branches should be pushed to origin for a maintainer to review and pull into doctrine as appropriate:

$ git push origin fix-weird-bug
To [email protected]:hobodave/dbal.git
    * [new branch]      fix-weird-bug -> fix-weird-bug

Now you are ready to send a pull request from this branch and ask for a review from a maintainer.

Topic Branch Cleanup

Once your work has been merged by the branch maintainer, it will no longer be necessary to keep the local branch or remote branch, so you can remove them!

Sync your local 2.11.x branch:

$ git checkout 2.11.x
$ git pull --rebase

Remove your local topic branch using -d to ensure that it has been merged by upstream. Branch -d will not delete a branch that is not an ancestor of your current head.

From the git-branch man page:

    Delete a branch. The branch must be fully merged in HEAD.
    Delete a branch irrespective of its merged status.

Remove your local topic branch:

$ git branch -d fix-weird-bug

Remove your remote branch at origin:

$ git push origin :fix-weird-bug

Project Dependencies

Project dependencies between Doctrine projects are handled through composer. The code of the particular Doctrine project you have cloned is located under lib/Doctrine. The source code of dependencies to other projects resides under vendor/.

To bump/upgrade a dependency version you just need to update the version constraint in composer.json and run:

$ composer update

Running Tests

You must have installed the library with composer and the dev dependencies (default). To run the tests:

$ ./vendor/bin/phpunit

Security Disclosures

You can read more about how to report security issues in our Security Policy.

Maintainer Workflow

You can learn more about the maintainer workflow here. Continue reading if you are interested in learning more about how to get started with your first contribution.


The website is completely open source! If you want to learn how to contribute to the Doctrine website and documentation you can read more about it here.