Welcome to the Newcomers Guide!

DO NOT WORK ON ANY ISSUE WITHOUT ASSIGNMENT! If you do, someone else might work on it as well and we might have no choice but reject one of your Pull Requests - we hate it if anyone wastes their time. For your own sake, please follow this guide. We put a lot of work into this for you!

To become part of the coala developers team, there’s a few steps you need to complete. The newcomer process is as it follows:

You will start as a newcomer, which is kind of a trial. If you complete the following tasks, you will become a developer at coala:

  • run coala on a project of yours
  • merge a difficulty/newcomer Pull Request
  • review at least a difficulty/newcomer Pull Request
  • merge a difficulty/low Pull Request
  • review at least a difficulty/low or higher Pull Request

When you ran coala on a project, please fill our usability survey. Once you got your first Pull Request merged successfully, fill in our survey form. With that you can help us making your experience better!

Once you have achieved all these, just ask for being promoted on the chat and provide links to your reviews and merged Pull Requests. Then, you will be able to name yourself a coala developer!


Do not only fix a newcomer issue! Supervising newcomers is really a lot of work. We’re all volunteers and we can’t keep this up if you don’t help us in other areas as well!

Of course, the order is not important, although, we recommend you to start with a newcomer issue, end with a low issue, and review other PRs in the meantime!

This is a step-based guide that will help you get your first contribution at coala, making you familiar with the work flow!

For more information about Pull Requests, keep reading!


You do not need to read the coala codebase to get started - this guide is intended to help you do that without reading tons of meaningless code. Nobody is good at that.

Most importantly, this guide is not intended to “check if you are fit” to contribute but rather a crash course to make you fit to contribute. We are a bit picky when it comes to code quality but it’s actually not at all hard to get to this level if you bear with us through this guide.

Step 0. Run coala

As a preparation of joining the community you should find out what this project is about - if you didn’t do this already. We highly recommend you install coala and use it on at least one of your projects. Also, we recommend that you read development setup notes to learn how to set up an environment to work on coala.

Most importantly, keep notes of what could be better to make the usage easier! What documentation was missing? What was hard to understand?


Struggling with this? We have a very verbose guide on this topic in our Google Code In resources which can help you find a suitable repository and run coala on a bigger project.

Once you complete this, please take the time and fill this form so we can improve this!

Step 1. Meet the Community!

To get started, the first step is to meet the community. We use gitter to communicate, and there the helpful community will guide you. Join us at coala gitter. The newcomers should ping us “Hello World” to let us know they are here because we care!

Congratulations! You are now part of our community.

Step 2. Grab an Invitation to the Organization

Let us know on gitter that you are interested in contributing and ask for an invitation to our org. This is your first step towards contributing. A maintainer will command cobot (our gitter bot) to invite you and be part of the Newcomer team. The invitation will be sent by mail and you will have to accept it to join. If you don’t find the invitation, accept it here.

Now that you are part of our organization, you can start working on issues. If you are familiar with git, you can skip the next section and pick an issue.

Optional. Get Help With Git

We use GitHub to manage our repository. If you’re not familiar with git, we strongly recommend following a tutorial, such as this one.

We also have a page dedicated to git commands that will help you learn the basics: here.

If there’s anything unclear, or you are encountering problems, feel free to contact us on gitter, and we will help you!

Step 3. Picking Up an Issue

Now it is time to pick an issue. Here is the link that will lead you to Newcomers issues.


You need to be logged in before you follow the Newcomers issues link.

See also

For more information about what bears are, please check the following link: Writing Native bears

The easy issues that will help you get started are labeled as difficulty/newcomer and are only there to give you a glimpse of how it is to work with us and regarding the workflow.

Now pick an issue which isn’t assigned, and if you want to fix it, then leave a comment that you would like to get assigned. This way we don’t have multiple people working on the same issue at the same time. Now you can start working on it.


As stated before, you should never work on an issue without any assignment. Fortunately, cobot is here to help you! So, if you are interested in picking up an issue just write in the gitter chat the following command:

cobot assign <issue_link>

Take care to write the full link to the issue

Before starting to write your first commit, check out this link: Writing good commits.

Step 4. Creating a Fork and Testing Your Changes

This tutorial implies you working on your fork. To fork the repository, go to the official repository of coala/coala-bears and click on the Fork button from the website interface. To add it locally, simply run:

$ git remote add myfork fork_link

where myfork is the name of your fork, and fork_link is a link to your fork repository.


It is important that you do not make your changes on the master branch. To start working on an issue, you first need to create a new branch where you will work.

$ git checkout -b <branchname>

Now you need to make sure your change is actually working. For this, you will need to test it locally before pushing it to your fork, and checking it with concrete examples. The first time, you will need to install some requirements. This can be done by executing the following command while in the root of the coala project directory.

$ pip3 install -r test-requirements.txt -r requirements.txt

After that, you can run coala by simply typing

$ coala

into your bash. This will analyze your code and help you fix it.

See also

Executing tests

Step 5. Sending Your Changes


Before committing your changes, please check that you are indeed in a development branch created in step 4. To check if you are in a branch, type:

$ git branch

Your current branch will have an asterisk (*) next to it. Ensure that there is no asterisk next to the master branch.

Now that you’ve fixed the issue, you’ve tested it and you think it is ready to be merged, create a commit and push it to your fork, using:

$ git push myfork

where myfork is the name of your fork that you added at the previous step.


You could also add a profile picture on your Github account, so that you can be distinguished out from the crowd!

Step 6. Creating a Pull Request

Now that your commit has been sent to your fork, it is time to do a Pull Request. It can be done by accessing your fork on GitHub and clicking New Pull Request.

Congratulations! You have now created your first Pull Request!


Do not delete your comments on Github because it makes it hard for other developers to follow on that issue. If necessary, edit your comment in case there is a typo or a task list to be updated. If you have to add some new information, make a new comment.

If you know you have more work to do on this Pull Request before it is ready to be accepted, you can optionally indicate this to other developers by starting your Pull Request title with wip (case-insensitive).

Step 7. Waiting for Review

After creating a Pull Request, your PR is open to the review process (to read more about it, have patience and it is explained on the next step), and all you can do is wait. The best thing you can do while at this step is review other people’s PRs. Not only will this help the maintainers with the workload, but this is one of the three core steps towards becoming a full-norm coalaian.

For more information about reviewing code, check out this link.


Reviewing code helps you by watching other people’s mistakes and not making them yourself in the future!

We highly encourage you to do reviews. Don’t be afraid of doing something wrong - there will always be someone looking over it before merging it to master.

Step 8. Review Process

After creating your Pull Request, it is under the review process. This can be deduced from the process/pending review label. Now all you have to do is wait, or let the other developers know on Gitter that you have published your changes.


Do not tag the reviewers every time you push a change. They review PRs consistently whenever they have time!

Now there’s two possibilities:

  • your Pull Request gets accepted, and your commits will get merged into the master branch
  • your Pull Request doesn’t get accepted, and therefore you will need to to modify it as per the review comments


Wait until the reviewer has already reviewed your whole Pull Request and has labeled it process/wip. Else, if you push again and his comments disappear, it can be considered rude.


You might be wondering what those CI things on your Pull Request are. For more detailed info about them, see this page.

It’s highly unlikely that your Pull Request will be accepted on the first attempt - but don’t worry, that’s just how it works. It helps us maintain coala clean and stable.

See also

Review Process.

Now, if you need to modify your code, you can simply edit it again, add it and commit it using

$ git commit -a --amend

This will edit your last commit message. If your commit message was considered fine by our reviewers, you can simply send it again like this. If not, edit it and send it. You have successfully edited your last commit!


Don’t forget! After editing your commit, you will have to push it again. This can be done using:

$ git push --force myfork

The meaning of myfork is explained here. The Pull Request will automatically update with the newest changes.

Congratulations! Your PR just got accepted! You’re awesome. Now you should tell us about your experience and go for a low issue - they are really rewarding!


Do not only fix a newcomer issue! It is highly recommended that you fix one newcomer issue to get familiar with the workflow at coala and then proceed to a difficulty/low issue.

However those who are familiar with opensource can start with difficulty/low issues.

We highly encourage you to start reviewing other’s issues after you complete your newcomer issue, as reviewing helps you to learn more about coala and python.


If you need help picking up an issue, you can always ask us and we’ll help you!

If you ever have problems in finding some links maybe you can find the solution in our useful links section.