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Contributions to manystates, whether in the form of issue identification, bug fixes, new code or documentation are encouraged and welcome:

Please note that the manystates project is released with a Contributor Code of Conduct. By contributing to this project, you agree to abide by its terms.


Please use the issue tracker on GitHub to identify problems or suggest new functionality, before submitting changes to the code. We use issues to identify bugs and tasks, discuss feature requests, and to track implementation of changes.

When submitting an issue, please provide at least a ‘Type’ label that best describes what the issue is about. The most useful issues are ones that precisely identify a bug, or propose a test that should pass but instead fails.


Another way of contributing to the package is in developing the vignettes/articles that illustrate the value added in the package. Please contact us directly with proposals for updating the documentation, or submit an issue if existing documentation is unclear.

Adding new code

Independent or assigned code contributions are most welcome. When writing new code, please follow tidyverse style guide which is based on standard R guidelines. It can help to use packages such as lintr and goodpractice to ensure these are followed. The styler package fixes in a non-invasive way the code to adhere to the tidyverse formatting rules, and it also provides an RStudio Addins to help with this task. To run the lintr and goodpractice checks or use styler in a file run:

# basic lintr checking
lintr::lint_package(path = "manystates/")

# goodpractices checks. Exclude length 80
goodpractice::gp(path = "globalgov/manystates/",
   checks = all_checks()[-c(8)])

# styler fix some of the styling issues

If you develop new code in C++, please follow the Google C++ Style Guide.


We use two main branches in this project:

  1. The origin/master branch is reserved for fully functional releases of the model. When the develop branch reaches a stable point, a code maintainer merges it back into to the master branch, and tags it with a release number there.

  2. The origin/develop branch reflects the latest model development stage. Contributers are encouraged to submit minor changes to this branch that enhance existing functionality. New features that may break existing functionality should be committed to supporting branches.

We use two types of supporting branches:

  1. Feature branches are used to develop new functionality. They exist as long as the feature is developed, and are then either merged into the develop branch for incorporation in a release, or deleted if the feature is abandoned. Feature branches should branch off from origin/develop.

  2. Hotfix branches are used to provide fixes to severe bugs in the master branch. That way, the code maintainer does not have to incorporate (potentially unstable) changes from the develop branch to fix an issue. Branch names should be prefixed with hotfix-.

This branching model is based on:

Master Branch (code maintainer only)

To create a release version of the code:

  1. Ensure that the repository is up-to-date: git pull.
  2. Switch to the master branch: git checkout master.
  3. Merge changes to the develop branch: git merge --no-ff develop.
  4. Tag release version: git tag -a VX.Y.Z -m "VERSION-NAME".
  5. Push changes to this repository git push origin master --tags.

Develop Branch (minor changes to existing functionality)

To make minor changes directly to the develop branch, follow standard git procedures:

  1. Make sure you switched to the develop branch of the project: git checkout -b develop.
  2. Make sure your local version of the code is up-to-date: git pull origin develop.
  3. Make your changes
  4. Stage your changes for a commit: git add PATH-TO-CHANGED-FILE.
  5. Commit your changes using an appropriate message: git commit -m "DESCRIPTION".
  6. Push your commit: git push origin develop.

Feature Branches (new functionality)

To create a new feature branch: git checkout -b myfeature develop.

To merge a feature branch back into develop:

git checkout develop
git merge --no-ff myfeature
git branch -d myfeature
git push origin develop

Hotfix Branches (to fix critical bugs in release versions)

To create a new hotfix branch: git checkout -b hotfix-VERSION master.

To merge a hotfix back into master (code maintainer only):

git checkout master
git merge --no-ff hotfix-VERSION 
git tag -a VERSION
git push origin develop

And into develop:

git checkout develop
git merge --no-ff hotfix-VERSION

Every hotfix should increment the PATCH digit of the version number: a hotfix branch for V1.3.0 is named hotfix-V1.3.1, and the new release is tagged as V1.3.1.

Once merged into master and develop, the hotfix branch can be deleted: git branch -d hotfix-VERSION.

Commit messages

Commits that relate to existing issues should reference the updated status of those issues, and mention the issue number (preceded by a hash symbol: #) in the commit description:

Resolved #31 by adding a new function that does things, also updated documentation

Where the issue hash (i.e. #31) is preceded by resolve, resolves, resolved, close, closes, closed, fix, fixes, or fixed (capitalised or not), the status of the issue(s) mentioned is updated automatically. Our current syntactical standard is to mention the issue first and then provide a short description of what the committed changes do in relation to that issue. Any ancillary changes can be mentioned after a comma.

It should all be written in a single line, like so: #{verb} {issue} {describe main action/changes}, {additional actions/changes}.


We use the testthat package to write unit tests. By convention, tests are located in testthat/tests/.

You should verify that all tests pass before issuing a commit to existing code. To run all tests for the latest version manually:

git pull

When writing a new function, consider writing a unit test for that function. We follow several conventions for writing tests:

  • A unit test file should test one or more aspects of a single function. This makes it easier to identify the source of bugs, and prevents lower-level tests from failing when higher-level functions change.

  • The naming convention for test files is: test-FILENAME_IN_R_DIRECTORY-FUNCTION_NAME.R, i.e. test files are named after the file containing the original function in the R directory, pre-fixed with “test”, and optionally post-fixed with the name of the function that is being tested.

  • If a test requires auxiliary functions from the package, e.g. to initialize a network with sample data, these belong in a helper file. There should be only one helper file for each R file, named helper-FILENAME_IN_R_DIRECTORY-FUNCTION_NAME.R. Re-using existing test data is preferable to creating new data for every test.


Note that the manystates package is version according to semantic versioning. This means that versions follow the Major.Minor.Patch semantic format.