Rendering your README with GitHub Actions

There’s one factor that has bugged me for some time about growing R packages. We’ve got all these good, trendy instruments now we have for monitoring our code, producing websites from the roxygen documentation, an so on. But for each code commit I make to the grasp department of a bundle repo, there’s usually two or extra extra steps I have to take to maintain the bundle README.md and pkgdown web site in sync with the code. Don’t get me mistaken; it’s superb that now we have these instruments accessible to assist customers become familiar with our R packages. It’s simply that there’s a number of additional issues to recollect to do to maintain the whole lot updated. The event of free-to-use providers resembling Travis CI or Appveyor have been very helpful as they will automate many of those repetitive duties. A more moderen newcomer to the sector is GitHub Actions. The opposite day I used to be grappling with getting a GitHub Actions workflow to render a README.Rmd file to README.md on GitHub, in order that I didn’t should do it domestically on a regular basis. After a number of trial and error, that is how I bought it working.

The final use case I’m imagining right here is the bundle writer that has a README.Rmd file that comprises R code chunks, which they wish to render to README.md so it is going to get displayed properly on GitHub. You may wish to do that to offer a easy overview of methods to use some key performance of your bundle or exhibit a plot or two that may be generated by the bundle. It’s fairly simple to render this domestically with a Makefile or by merely invoking the right R incantation immediately within the terminal. Nonetheless, wouldn’t or not it’s nice if we may automate this!

Step one in getting this working was to recognise that the R Infrastructure organisation has been working to make R-related GitHub Actions workflows accessible to customers. This effort has been lead by Jim Hester and Jim has very helpfully supplied a workflow instance YAML file displaying how one may go about rendering a README.Rmd file to README.md utilizing the rmarkdown bundle.

Additionally, the usethis bundle has made it extremely simple to get began utilizing GitHub Actions; usethis offers use_github_actions() to set your bundle as much as begin utilizing GitHub Actions to examine your bundle builds with out errors. There’s additionally a use_github-action() operate that may add workflows from the r-lib/actions repo to your bundle.

Should you don’t have usethis put in, set up it (set up.packages(“usethis”)), then you possibly can set your R bundle repo as much as run R CMD examine in your bundle on GitHub’s servers by operating

usethis::use_github_actions()

in an R session within the bundle root folder. Working this may produce one thing like this

> usethis::use_github_actions()
 Setting lively mission to '/residence/gavin/work/git/gratia/gratia'
 Creating '.github/'
 Including '*.html' to '.github/.gitignore'
 Creating '.github/workflows/'
 Writing '.github/workflows/R-CMD-check.yaml'
 Copy and paste the following strains into '/residence/gavin/work/git/gratia/gratia/README.md':  [![R build status](https://github.com/gavinsimpson/gratia/workflows/R-CMD-examine/badge.svg)](https://github.com/gavinsimpson/gratia/actions) 

which outlines the steps usethis has taken in your behalf. The final line prints out some textual content that you could paste into the README.Rmd to indicate a standing badge for the GitHub Motion; on this case it is going to present whether or not or not your bundle handed R CMD examine with out error.

This additionally properly illustrates the way you may set issues up by hand after all, particularly in case you don’t wish to run R CMD examine on every push.

GitHub Actions workflows are configurations that describe the steps within the workflow and are saved in YAML recordsdata. These recordsdata needs to be situated in a .github/workflows folder within the bundle root. If all you wish to do is render a README.Rmd to README.md you might simply as simply create this folder your self. I’m undecided why usethis additionally creates a .gitignore containing ’*.html’ within the .github folder, but when that is wanted for what you’re doing, go forward and create it too.

To get set-up shortly to render README.Rmd to markdown, now you can use use_github_action(“render-readme.yaml”). It will copy the render-readme.yaml file from r-lib/actions/examples to .github/workflows/render-readme.yaml. Alternatively, you possibly can contact .github/workflows/render-readme.yaml and add what you want by hand.

That is what the contents of render-readme.yaml seem like, on the time of writing, in case you used usethis to create it:

on: push: paths: - README.Rmd identify: Render README jobs: render: identify: Render README runs-on: macOS-latest steps: - makes use of: actions/[email protected] - makes use of: r-lib/actions/[email protected] - makes use of: r-lib/actions/[email protected] - identify: Set up rmarkdown run: Rscript -e 'set up.packages("rmarkdown")' - identify: Render README run: Rscript -e 'rmarkdown::render("README.Rmd")' - identify: Commit outcomes run: | git commit README.md -m 'Re-build README.Rmd' || echo "No adjustments to commit" git push origin || echo "No adjustments to commit"

The primary bit below on: controls when the workflow is triggered. The best way the instance workflow is about up means it is going to solely be triggered if a file matching the trail README.Rmd is included within the commit when pushed to the repo. It’s additionally value noting that till the workflow is definitely triggered, it received’t present up within the Actions tab in your repo on GitHub — this brought about me no finish of grief till I figured our this GitHub Actions characteristic. To set off this workflow, you must edit README.Rmd, add and commit these adjustments utilizing git, after which push the adjustments to GitHub.

That didn’t swimsuit my use case nevertheless; what if I alter the bundle code in such a method that any output or plots produced by code within the README.Rmd would additionally change? On this case, I must needlessly tweak one thing in README.Rmd and push that change simply to set off rendering.

There’s in all probability a greater method to do that — resembling setting paths: to a wildcard that might match any .R file within the R folder so the workflow could be triggered on any change to the bundle code — however to only get one thing up and operating I modified the on: half to learn:

on: push: branches: grasp

which signifies that the workflow ought to run for any push to the grasp department of the repo.

The highest-level identify: aspect is how your workflow will probably be listed within the Actions tab in your repo. Set this to one thing quick however descriptive so it’s simple to filter the assorted outputs from workflows which might be run on the GitHub Actions service.

All workflows include a number of jobs, listed below the jobs: aspect. Within the instance YAML file, there’s a single job listed as render:, which has a reputation, Render README.

The runs-on aspect signifies what system the job will probably be run on; right here is is a Mac OS system. I’m undecided why the r-lib/actions instance workflows all run on Mac OS techniques? Anyway, they work, so no want to alter that except you want one thing particular.

The steps: part is the place the phases of the job are outlined.

 steps: - makes use of: actions/[email protected] - makes use of: r-lib/actions/[email protected] - makes use of: r-lib/actions/[email protected]

Every of the makes use of: components pulls in some pre-existing worfklow steps that you could construct to upon to bootstrap the answer you want. For instance, the actions/[email protected] workflow comprises the whole lot you must checkout your repo and make it accessible to the present job. That is fairly basic; except the GitHub Actions service can get on the code in your repo, it received’t be capable of do something helpful in anyway.

The subsequent two makes use of: are workflows present by r-lib/actions that arrange a working R set up (r-lib/actions/[email protected]) and the Pandoc library utilized by rmarkdown (r-lib/actions/[email protected]).

After the makes use of: declarations, the YAML file features a sequence of steps that describe instructions which might be run on the service. That is the place the actual motion takes place.

 - identify: Set up rmarkdown run: Rscript -e 'set up.packages("rmarkdown")' - identify: Render README run: Rscript -e 'rmarkdown::render("README.Rmd")' - identify: Commit outcomes run: | git commit README.md -m 'Re-build README.Rmd' || echo "No adjustments to commit" git push origin || echo "No adjustments to commit"

Right here we see three units of instructions that will probably be run

  1. the primary installs the rmarkdown bundle,
  2. the second runs rmarkdown::render() on README.Rmd to render it, and
  3. the third commits the rendered README.md file and pushes it to your repo, or echos a remark if no adjustments are wanted.

Discover how the run: aspect for the final step has a | after run:. This means that this explicit step entails a number of strains of instructions to be executed one after one other.

Should you’ve not come throughout Rscript earlier than, it’s a method to make use of R like a scripting language, non-interactively. Right here we’re utilizing the -e flag to inform Rscript what R code to run, somewhat than passing it a .R to run.

Out of the field, these steps aren’t going to be very helpful for R bundle maintainers if the README.Rmd makes use of something aside from the bottom R set up and advisable packages. On the very least you will wish to additionally set up the R bundle you might be documenting within the README.Rmd, plus another packages you want for the Rmd that may not be dependencies of the bundle within the repo.

In my case, I simply wanted to put in the gratia bundle alongside rmarkdown, so I modified that run: aspect to be

 - identify: Set up rmarkdown run: Rscript -e 'set up.packages(c("rmarkdown", "gratia"))'

I additionally determined to alter the rmarkdown::render() name; by default this may generate HTML output by rendering the .Rmd first to .md and thence to .html. As we don’t want this latter step, I modified the output_format argument of render() to be “md_document”, in order that aspect now appears like this

 - identify: Render README run: Rscript -e 'rmarkdown::render("README.Rmd", output_format = "md_document")'

Doing this implies I don’t additionally generate a README.html file (which may be why the .gitignore was created by usethis earlier?); preserving the .gitignore can’t damage provided that it solely excludes any .html recordsdata from a commit, so I left it alone.

I additionally modified the commit step too. The default assumes you have already got a README.md within the repo and that that is the one file you wish to add to the commit. Should you render any plots within the .Rmd, then you definately’ll additionally wish to add these to the commit. So, I added an specific git add line previous to the commit, and in addition simplified the latter

 - identify: Commit outcomes run: | git add README.md man/figures/README-* git commit -m 'Re-build README.Rmd' || echo "No adjustments to commit" git push origin || echo "No adjustments to commit"

As you possibly can see, I used a wildcard to catch any figures created by the render. Within the README.Rmd I used a setup chunk to set the fig.path knitr possibility in order that any plots had been generated within the man/figures folder and had the prefix README- prepended to the file identify:

knitr::opts_chunk$set( fig.path = "man/figures/README-"
)

The man/figures folder is a helpful place to retailer figures generated like this as they’ll be carried alongside along with your R bundle and accessible on CRAN, the place the README.md file can also be displayed if current. This folder can also be used in case you generate and embrace figures within the bundle documentation utilizing roxygen, for instance.

I used the prefix README- in order that I may restrict what I used to be including within the git add step of the workflow. I’m all the time a bit nervous when staging recordsdata for a commit and by no means use git commit -a for instance. This fashion I’ve an inexpensive technique of solely including plots that had been created by rendering README.Rmd.

After these adjustments (and some others as I used to be troubleshooting some points) my workflow to render README.Rmd recordsdata appears like this

identify: render readme # Controls when the motion will run
on: push: branches: grasp jobs: render: # The kind of runner that the job will run on runs-on: macOS-latest steps: # Checks-out your repository below $GITHUB_WORKSPACE, so your job can entry it - makes use of: actions/[email protected] - makes use of: r-lib/actions/[email protected] - makes use of: r-lib/actions/[email protected] # set up packages wanted - identify: set up required packages run: Rscript -e 'set up.packages(c("rmarkdown","gratia"))' # Render READEME.md utilizing rmarkdown - identify: render README run: Rscript -e 'rmarkdown::render("README.Rmd", output_format = "md_document")' - identify: commit rendered README run: | git add README.md man/figures/README-* git commit -m "Re-build README.md" || echo "No adjustments to commit" git push origin grasp || echo "No adjustments to commit"

It is a first move at getting one thing working; it’s simply occurred to me that the git add line in all probability must be linked with the git commit line so it solely tries to commit if recordsdata had been staged with git add.

It will even be good to attempt to cache the put in packages so the workflow doesn’t want to put in the whole lot for rmarkdown and gratia each time it’s run. There’s an instance of caching packages within the pkgdown motion r-lib/actions/examples/pkgdown.yaml. Nonetheless, I used to be operating into points associated to the R 4.0.Zero launch and packages within the cache not getting refreshed although they had been outdated. So I eliminated that step from my pkgdown.yaml workflow, and consequently didn’t attempt to implement it for rendering README.Rmd recordsdata. But anyway…

For reference the workflow takes between two and three minutes to run on GitHub, even with out bundle caching, which isn’t too dangerous, however rendering the README.Rmd domestically takes just a few seconds, so there’s tons to be gained right here by determining a dependable caching mechanism.

You probably have applied one thing related for a GitHub Actions workflow, let me know within the feedback under; that is all fairly new to me and I’m occupied with how different individuals might need tackled this. Now that I’ve this working reliably I solely want to recollect to git pull from GitHub extra usually to get the adjustments to README.md. The subsequent challenge I wish to have a look at is getting the appropriate paths: settings so the README.Rmd is rendered solely when related recordsdata are modified within the bundle, not on each push to the repo.

Lastly, a giant thanks to Jim Hester and everybody else who’s contributed to the R-related GitHub Actions workflows. That is an amazingly helpful service for the R Neighborhood, and I for one am extremely grateful that now we have such useful and educated individuals amongst us which might be doing all this nice work to make growing R packages that a lot simpler.



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