Contributing to devtools

The goal of this guide is to help you contribute to devtools as quickly and as easily possible. The guide is divided into two main pieces:

  1. Filing a bug report or feature request in an issue.
  2. Suggesting a change via a pull request.

Issues

Before you file an issue:

  1. Check that you’re using the latest version of devtools. It’s quite possible that the problem you’re experiencing has already been fixed.

  2. Check that the issue belongs in devtools. Much functionality now lives in separate packages. Please read the list below and check if you should be submitting your issue on another repo:

    • Building binary packages or anything related to finding R tools: pkgbuild:

    • Anything related to the operation of load_all(): pkgload.

    • Running R CMD check on one package: rcmdcheck. Running R CMD check on all reverse dependencies: revdepcheck

    • Installing packages: remotes

    • Session info: sessioninfo

    • Any function that starts with use_: usethis

  3. Spend a few minutes looking at the existing issues. It’s possible that your issue has already been filed. But it’s almost always better to open a new issue instead of commenting on an existing issue. The only exception is that you are confident that your issue is identical to an existing problem, and your contribution will help us better understand the general case. It’s generally a bad idea to comment on a closed issue or a commit. Those comments don’t show up in the issue tracker and are easily misplaced.

When filing an issue, the most important thing is to include a minimal reproducible example so that we can quickly verify the problem, and then figure out how to fix it. There are three things you need to include to make your example reproducible: required packages, data, code.

  1. Packages should be loaded at the top of the script, so it’s easy to see which ones the example needs. Unless you’ve been specifically asked for it, please don’t include the output of sessionInfo() or devtools::session_info().

  2. The easiest way to include data is to use dput() to generate the R code to recreate it. For example, to recreate the mtcars dataset in R, I’d perform the following steps:

    1. Run dput(mtcars) in R
    2. Copy the output
    3. In my reproducible script, type mtcars <- then paste.

    But even better is if you can create a data.frame() with just a handful of rows and columns that still illustrates the problem.

  3. Spend a little bit of time ensuring that your code is easy for others to read:

    • make sure you’ve used spaces and your variable names are concise, but informative

    • use comments to indicate where your problem lies

    • do your best to remove everything that is not related to the problem.
      The shorter your code is, the easier it is to understand.

    Learn a little markdown so you can correctly format your issue. The most important thing is to surround your code with ``` R and ``` so it’s syntax highlighted (which makes it easier to read).

  4. Check that you’ve actually made a reproducible example by using the reprex package.

Pull requests

  • Your pull request will be easiest for us to read if you use a common style: http://r-pkgs.had.co.nz/r.html#style. Please pay particular attention to whitespace.

  • You should always add a bullet point to NEWS.md motivating the change. It should look like “This is what changed (@yourusername, #issuenumber)”. Please don’t add headings like “bug fix” or “new features” - these are added during the release process.

  • If you can, also write a test. Testing devtools is particularly difficult because most devtools functions are called for their side-effects, but do the best you can.

  • If you’re adding new parameters or a new function, you’ll also need to document them with roxygen2. Make sure to re-run devtools::document() on the code before submitting.

A pull request is a process, and unless you’re a practiced contributor it’s unlikely that your pull request will be accepted as is. Typically the process looks like this:

  1. You submit the pull request.

  2. We review at a high-level and determine if this is something that we want to include in the package. If not, we’ll close the pull request and suggest an alternative home for your code.

  3. We’ll take a closer look at the code and give you feedback.

  4. You respond to our feedback, update the pull request and add a comment like “PTAL” (please take a look). Adding the comment is important, otherwise we don’t get any notification that your pull request is ready for review.

Don’t worry if your pull request isn’t perfect. It’s a learning process and we’ll be happy to help you out.

It can be frustrating that your PR is ignored for months, and then we request a whole bunch on changes within a short time period. Don’t worry - if your PR doesn’t make it for this release, it will for the next one.