How to contribute to JuMP

Welcome! This document explains some of the ways you can contribute to JuMP.

Code of Conduct

This project and everyone participating in it is governed by the JuMP Code of Conduct. By participating, you are expected to uphold this code.

Join the community forum

First up, join the community forum.

The forum is a good place to ask questions about how to use JuMP. You can also use the forum to discuss possible feature requests and bugs before raising a GitHub issue (more on this below).

Aside from asking questions, the easiest way you can contribute to JuMP is to help answer questions on the forum!

Join the developer chatroom

If you're interested in contributing code to JuMP, the next place to join is the developer chatroom. Let us know what you have in mind, and we can point you in the right direction.

Improve the documentation

Chances are, if you asked (or answered) a question on the community forum, then it is a sign that the documentation could be improved. Moreover, since it is your question, you are probably the best-placed person to improve it!

The docs are written in Markdown and are built using Documenter.jl. You can find the source of all the docs here.

If your change is small (like fixing typos, or one or two sentence corrections), the easiest way to do this is via GitHub's online editor. (GitHub has help on how to do this.)

If your change is larger, or touches multiple files, you will need to make the change locally and then use Git to submit a pull request. (See Contribute code to JuMP below for more on this.)

Tip

If you need any help, come join the developer chatroom and we will walk you through the process.

File a bug report

Another way to contribute to JuMP is to file bug reports.

Make sure you read the info in the box where you write the body of the issue before posting. You can also find a copy of that info here.

Tip

If you're unsure whether you have a real bug, post on the community forum first. Someone will either help you fix the problem, or let you know the most appropriate place to open a bug report.

Contribute code to JuMP

Finally, you can also contribute code to JuMP!

Warning

If you do not have experience with Git, GitHub, and Julia development, the first steps can be a little daunting. However, there are lots of tutorials available online, including these for:

If you need any help, come join the developer chatroom and we will walk you through the process.

Once you are familiar with Git and GitHub, the workflow for contributing code to JuMP is along the lines of the following:

Step 1: decide what to work on

The first step is to find an open issue (or open a new one) for the problem you want to solve. Then, before spending too much time on it, discuss what you are planning to do in the issue to see if other contributors are fine with your proposed changes. Getting feedback early can improve code quality, and avoid time spent writing code that does not get merged into JuMP.

Tip

At this point, remember to be patient and polite; you may get a lot of comments on your issue! However, do not be afraid! Comments mean that people are willing to help you improve the code that you are contributing to JuMP.

Step 2: fork JuMP

Go to https://github.com/jump-dev/JuMP.jl and click the "Fork" button in the top-right corner. This will create a copy of JuMP under your GitHub account.

Step 3: install JuMP locally

Open Julia and run:

] dev JuMP

This will download the JuMP Git repository to ~/.julia/dev/JuMP. If you're on Windows, this will be C:\\Users\\<my_name>\\.julia\\dev\\JuMP.

Warning

] command means "first type ] to enter the Julia pkg mode, then type the rest. Don't copy-paste the code directly.

Step 4: checkout a new branch

Note

In the following, replace any instance of GITHUB_ACCOUNT with your GitHub user name.

The next step is to checkout a development branch. In a terminal (or command prompt on Windows), run:

$ cd ~/.julia/dev/JuMP

$ git remote add GITHUB_ACCOUNT https://github.com/GITHUB_ACCOUNT/JuMP.jl.git

$ git checkout master

$ git pull

$ git checkout -b my_new_branch
Tip

Lines starting with $ mean "run these in a terminal (command prompt on Windows)."

Step 5: make changes

Now make any changes to the source code inside the ~/.julia/dev/JuMP directory.

Make sure you:

  • Follow the Style guide
  • Add tests and documentation for any changes or new features
Tip

When you change the source code, you'll need to restart Julia for the changes to take effect. This is a pain, so install Revise.jl.

Step 6a: test your code changes

To test that your changes work, run the JuMP test-suite by opening Julia and running:

cd("~/.julia/dev/JuMP")
] activate .
] test
Warning

Running the tests might take a long time (~10-15 minutes).

Tip

If you're using Revise.jl, you can also run the tests by calling include:

include("test/runtests.jl")

This can be faster if you want to re-run the tests multiple times.

Step 6b: test your documentation changes

Open Julia, then run:

cd("~/.julia/dev/JuMP/docs")
] activate .
include("src/make.jl")
Warning

Building the documentation might take a long time (~10 minutes).

Tip

If there's a problem with the tests that you don't know how to fix, don't worry. Continue on to step 5, and one of the JuMP contributors will comment on your pull request telling you how to fix things.

Step 7: make a pull request

Once you've made changes, you're ready to push the changes to GitHub. Run:

$ cd ~/.julia/dev/JuMP

$ git add .

$ git commit -m "A descriptive message of the changes"

$ git push -u GITHUB_ACCOUNT my_new_branch

Then go to https://github.com/jump-dev/JuMP.jl and follow the instructions that pop up to open a pull request.

Step 8: respond to comments

At this point, remember to be patient and polite; you may get a lot of comments on your pull request! However, do not be afraid! A lot of comments means that people are willing to help you improve the code that you are contributing to JuMP.

To respond to the comments, go back to step 5, make any changes, test the changes in step 6, and then make a new commit in step 7. Your PR will automatically update.

Step 9: cleaning up

Once the PR is merged, clean-up your Git repository ready for the next contribution!

$ cd ~/.julia/dev/JuMP

$ git checkout master

$ git pull
Note

If you have suggestions to improve this guide, please make a pull request! It's particularly helpful if you do this after your first pull request because you'll know all the parts that could be explained better.

Thanks for contributing to JuMP!