Overview

Introduction

This section of the website is dedicated to materials you may need when you want to make a contribution to The Carpentries Workbench. It will detail the minimum developer environment required to contribute to the components of this project.

This section is still under construction!

We are still assembling the documentation for this part of the site. If you would like to contribute, please feel free to open an issue.

The core of The Carpentries Workbench consists of three packages:

{sandpaper}: user interface and workflow engine
{pegboard}: parsing and validation engine
{varnish}: HTML templates, CSS, and JS elements

These packages are all available and released to the Carpentries R-Universe, which checks for updates to the source packages hourly.

Local Workflow

In a broad sense, this is what happens when you run sandpaper::serve() or sandpaper::build_lesson(). The interaction between the three Workbench packages, the lesson content, and the author can be summarised like this where the author makes an edit:

Summary Content

This content is a general picture of what happens between the packages. For a more in-depth discussion and more detailed diagrams, please visit the Flow Diagrams page.

sequenceDiagram
    autonumber
    actor Author
    participant Lesson 
    box rgb(255, 214, 216) The Workbench
    participant {sandpaper}
    participant {pegboard}
    participant {varnish}
    end

    Author ->> {sandpaper}: sandpaper::serve()
    activate Author
    {sandpaper} --) Author: website preview
    note left of {sandpaper}: monitor for changes
    Author ->> Lesson: make an edit
    deactivate Author
    Lesson -->> {sandpaper}: READ changed file(s)
    {sandpaper} -->> {pegboard}: validate Lesson
    activate {pegboard}
    note left of {sandpaper}: provision global menu elements
    {pegboard} --) Author: report accessibility 
    deactivate {pegboard}
    activate {sandpaper}
    note left of {sandpaper}: WRITE markdown
    {varnish} -->> {sandpaper}: load and apply website template
    note left of {sandpaper}: WRITE website
    {sandpaper} --) Author: website preview
    deactivate {sandpaper}

In terms of folder structure, the workflow looks like this:

flowchart TB
    classDef default color:#383838,fill:#FFF7F1,stroke-width:1px
    classDef external color:#383838,fill:#E6EEF8,stroke-width:1px
    classDef normal color:#081457,fill:#E3E6FC,stroke-width:1px
    classDef local fill:#FFC700,stroke:#333,stroke-width:1px
    classDef remote fill:#D2BDF2, color:#201434,stroke-width:1px

    subgraph "local repository"
    BUILT["site/built"]:::local
    SITE["site/docs"]:::local
    SERVE("serve()"):::normal
    BLESS("build_lesson()"):::normal
    BUILDMD(["build_markdown()"]):::normal
    BUILDSITE(["build_site()"]):::normal
    end

    BUILT ~~~ SITE

    SERVE --> BLESS
    BLESS --> BUILDMD
    BLESS --> BUILDSITE
    BUILDMD --> BUILT
    BUILDSITE --> SITE

Resource folder names

Please note, the names of these internal folders may change, so please do not rely on these values being static.

The site/docs folder contains the full website that can be safely used offline. This is the core of the workflow and is used both locally and in a remote setting. The only difference with the remote setting is that we use a few Git tricks to provision the markdown cache without needing to store it in the default branch.

Remote Workflow

In the remote workflow, we still use the same workflow as above, except now we use ci_deploy() to link the branches and folders using worktrees, which you can think of as Git branches assigned to separate folders.

flowchart TB
    classDef default color:#383838,fill:#FFF7F1,stroke-width:1px
    classDef external color:#383838,fill:#E6EEF8,stroke-width:1px
    classDef normal color:#081457,fill:#E3E6FC,stroke-width:1px
    classDef local fill:#FFC700,stroke:#333,stroke-width:1px
    classDef remote fill:#D2BDF2, color:#201434,stroke-width:1px

    subgraph GitHub Actions Runner
    REPO["[repo]"]:::local
    BUILT["[repo]/site/built"]:::local
    SITE["[repo]/site/docs"]:::local
    BUILDMD(["build_markdown()"]):::normal
    BUILDSITE(["build_site()"]):::normal
    end

    subgraph GitHub
    GH[("@main")]:::remote
    MDOUT[("@md-outputs")]:::remote
    PAGES[("@gh-pages")]:::remote
    DEPLOY(["ci_deploy()"]):::external
    CIBUILDMD(["ci_build_markdown()"]):::external
    CIBUILDSITE(["ci_build_site()"]):::external
    end

    GH ---> REPO
    GH ~~~ DEPLOY
    REPO ~~~ BUILDMD
    BUILT ~~~ BUILDSITE

    BUILDMD --> BUILT
    BUILDSITE --> SITE

    DEPLOY -.-> CIBUILDMD
    DEPLOY -.-> CIBUILDSITE
    BUILT -.->  MDOUT
    SITE -.->  PAGES
    CIBUILDMD -.-> BUILDMD
    CIBUILDSITE -.-> BUILDSITE

Development

Development of the Workbench is overseen by Zhian N. Kamvar. New features are added incrementally as pull requests. Pushes to the main branch are rare and discouraged. New features must have tests associated (with the exception of {varnish}).

If you are interested, we have documentation for the release process available.

Software Tools

Development of Workbench components requires the same toolchain for working on lessons:

R
pandoc
Git

It is recommended to have the latest versions of R and pandoc available. You need at least git 2.28 for security purposes.

R version
---

R version 4.5.2 (2025-10-31) -- "[Not] Part in a Rumble"
Copyright (C) 2025 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under the terms of the
GNU General Public License versions 2 or 3.
For more information about these matters see
https://www.gnu.org/licenses/.


pandoc version
---

pandoc 3.1.11
Features: +server +lua
Scripting engine: Lua 5.4
User data directory: /home/runner/.local/share/pandoc
Copyright (C) 2006-2023 John MacFarlane. Web: https://pandoc.org
This is free software; see the source for copying conditions. There is no
warranty, not even for merchantability or fitness for a particular purpose.


git version
---

git version 2.51.2

Once you have these installed, make sure to install ALL of the dependencies for the Workbench:

install.packages(c("sandpaper", "pegboard", "varnish", "tinkr"),
  dependencies = TRUE,
  repos = c(getOption("repos"), "https://carpentries.r-universe.dev"))

In addition, you will need the {devtools} for development.

install.packages("devtools")

Documentation

Reference documentation for individual functions for each package is written alongside the function using {roxygen2}.

This documentation is generated by devtools::document()

Testing

Tests for each package live in tests/testthat/ and follow a test-[file-name].R naming convention. These are controlled by the {testthat} package and run by devtools::test().

You can find more information about testing the core packages in Testing The Workbench

Continous Integration

The continous integration for each package tests on Ubuntu, MacOS, and Windows systems with the last five versions of R (same as the RStudio convention).

More information about the Continous Integration can be found in the Continuous Integration section of the testing section.

Coming up:

Testing Pull Requests (Locally and on your fork)
Resources for R package development
Adding functionality to {sandpaper}
Adding functionality to {pegboard}
Adding styling elements to {varnish}
Adding functionality to carpentries/actions