PackageDevelopment.md

name	PackageDevelopment
topic	Package Development and Maintenance
maintainer	Lluís Revilla, Heather Turner
email	lluis.revilla@gmail.com
version	2026-10-08
source	https://github.com/cran-task-views/PackageDevelopment/

The maintainers gratefully acknowledge the initial work on this task view by Roger Bivand.

Introduction

Packages extend R by providing additional code and/or data. Package development is typically an iterative process, and maintenance involves responding to changes in R and package dependencies.

The essential tools for building and installing packages are provided as R CMD command line tools. Base R provides many relevant functions in utils alongside the tools package, which is dedicated to package development and maintenance. Contributed packages provide alternative or supplementary helper functions.

The definitive reference for R package development is the Writing R Extensions (WRE) manual. The CRAN Repository Policy sets standards on top of this - see the related links below for policies of other repositories.

Contributed packages designed to facilitate package development are not guaranteed to be consistent with WRE or repository policies. Particular caution should be taken when a helper package must be added as a forward dependency: convenience during development can make maintenance harder, both for package authors and for authors of any reverse dependencies.

To assist package developers, this task view collates contributed packages with reference to relevant sections of WRE, highlighting relevant functionality from base/recommended packages before alternative/supplementary tools.

First steps

Checking the package landscape

Before starting a new package, it's worth searching for already available packages, both from a developer's standpoint ("do not reinvent the wheel") and from a user's one (many packages implementing the same/similar procedures can be confusing). If a package addressing the same functionality already exists, you may consider contributing to it instead of starting a new one.

If you are looking for opportunities to contribute, you may find that an existing package needs a new maintainer or there is an open wish for a package that does not yet exist.

The CRAN Team occasionally use the R-package-devel mailing list to ask for maintainers to take on orphaned packages.

The CRAN Search page links to R-focused search tools, facilitating search of package sources, books, task views, support lists, blogs and the internet at large.

utils::RSiteSearch() facilitates search for keywords/phrases in help pages (all the CRAN packages except those for Windows only and some from Bioconductor), package metadata, vignettes or task views, using the search engine at http://search.r-project.org/.

• rOpenSci maintain a Help Wanted page that can be used to search for rOpenSci packages looking for (co-)maintainers. The Wishlist channel of the rOpenSci forum is used to discuss ideas for new packages/features.
• Bioconductor Code Search is an official tool to search the source files of Bioconductor packages.
• cran GitHub mirror, an unofficial read-only mirror of all CRAN packages (including archived packages), enables search across the full package source files using GitHub Code Search syntax.

Initializing a package

utils::package.skeleton() automates some of the set-up for a new source package. It creates directories, saves functions, data, and R code files provided to appropriate places, and creates skeleton help files and a Read-and-delete-me file describing further steps in packaging.

When initializing a package, it is worth considering how it should be licensed. The CRAN Repository Policy links to a database of licenses acceptable for CRAN.

WRE reference: Package Structure.

• r pkg("available") checks whether a package name is valid and available, i.e., not already in use on CRAN, Bioconductor or GitHub. Also checks for unintended meanings of the name. r pkg("collidr") checks for collisions between a package or function name and existing names of packages and/or functions on CRAN.
• r pkg("usethis", priority = "core") provides create_package() to set up a minimal package structure, along with many utilities to add components, including the use_*_license() functions, where * is replaced by the license name.
• r pkg("pkgKitten") provides an almost empty package skeleton and some utilities to create help pages.
• Rcpp.package.skeleton() from r pkg("Rcpp") extends package.skeleton() to add the components required to use r pkg("Rcpp") for interfacing C or C++ code in R packages. r pkg("usethis") provide similar functionality with the use_c() and use_rcpp() functions.
• r bioc("biocthis") automates setup for Bioconductor packages.
• r github("insightsengineering/r.pkg.template") initializes a GitHub repository for an R package, with the standard files and directories, along with CI/CD configurations and pre-commit git hooks to identify and resolve common issues.
• r pkg("fusen") and r github("jacobbien/litr-project") create a package from a R markdown file. r pkg("noweb") creates a package via literate programming with noweb syntax (as used by Sweave).
• r pkg("DataPackageR") creates a package from a dataset. r pkg("rcompendium") creates the structure for a Research Compendium: an R package structure to support reproducible research including raw data, analysis scripts, outputs and a make script.
• r pkg("leprechaun") adds templating code to a package skeleton for creating a Shiny app as a package, without adding to the dependencies. r pkg("golem") creates a package template for developing and deploying a Shiny app using the r pkg("golem") framework.
• r pkg("pkgverse") creates a meta package that bundles several related packages that can be installed and loaded together.

Package development

Development workflow

Some contributed packages are analogous to tools in that they provide tools that cut across package development tasks.

Writing R Extensions (WRE) describes the fundamental tasks of package development.

See the "Related Links" section for other guides, including those from Bioconductor and rOpenSci.

• r pkg("devtools", priority = "core") facilitates interactive development of R and compiled code via the load_all() function to simulate installing and reloading the package. Additional functions support generating documentation, testing, checking a package and submitting to CRAN.
• r pkg("usethis", priority = "core") provides helpers such as use_r(), use_data(), use_vignette(), or use_news_md() to add new components, along with functions to support specific packages or workflows, such as use_testthat() or use_git().
• r pkg("packager") performs package development tasks (document, build, check, etc) with r pkg("fakemake") or GNU make, so that make targets are only regenerated when files in the make chain have been updated. Provides a create() function to initialize a package with the required structure and an infect() function to work with a package initialized another way. The r codeberg("lgatto/maker") repository provides an external Makefile to perform development tasks.
• r github("rdatsci/rtcl") provides command line utilities for development tasks, which are also provided as regular R functions.
• r github("unDocUMeantIt/roxyPackage") provides the roxy.package() function to generate help files, vignettes and package-level documentation (e.g., NEWS and README) in both PDF and HTML; check and build packages, and manage a local package repository. Tasks can be performed individually or in combination.
• r github("JamesHWade/gpttools") facilitates using large language models (from an AI service provider or a local model) for package development, e.g. converting code to a function; adding documentation or tests, or identifying improvements.

Package documentation

Help pages must be written for exported R objects, and a help page may also be written for the package as a whole. Packages may also include vignettes to give an overview of package functionality or discuss more complex uses. Some contributed packages provide tools to create other types of documentation such as package websites or tutorials.

Help pages

Source files for help pages use the "R documentation" (Rd) format. utils::prompt() and utils::promptData() may be used to create an Rd template for a function or data set, respectively. tools::checkRd() may be used to validate Rd files, e.g., detecting syntax errors.

WRE reference: Writing R documentation files

• r pkg("roxygen2", priority = "core") provides the roxygenise() function to generate Rd files from comments with specific markup in R source files. When used with Markdown, r pkg("roxygen2") can greatly reduce the markup required in the documentation source. Several development workflow packages support creating documentation with r pkg("roxygen2").
• r pkg("sinew") generates roxygen skeletons and updates the NAMESPACE and DESCRIPTION file as required; can be used to update as well as create roxygen documentation.
• r pkg("Rd2roxygen") provides functions to convert Rd files to r pkg("roxygen2") comments.
• r pkg("roxygen2md") replaces Rd syntax in r pkg("roxygen2") comments with the Markdown equivalent.
• r pkg("roclang") facilitates extracting components of documentation from an Rd file (in the same or another package) for reuse, by insertion in a roxygen comment.
• r pkg("pasteAsComment") provides an RStudio addin to paste clipboard content as a roxygen block - useful for inserting examples; r github("csgillespie/roxygen2Comment") provides an RStudio addin to convert regular code to roxygen commented code and vice versa.
• r pkg("roxyglobals") adds additional roxygen tags to generate R code defining global variables with utils::globalVariables(). This can be used to avoid false positives in the package check when functions in the package call functions that use non-standard evaluation.
• r github("moodymudskipper/devtag") provides the @dev tag for creating developer documentation for unexported functions; r github("ropensci-review-tools/srr") adds tags to document adherence to rOpenSci's standards for software review.
• r pkg("Rdpack") provides functions and Rd macros for developing documentation, e.g. adding template documentation for new arguments; importing references from BibTeX files, and evaluating R code then inserting the resulting output or graphic.
• r pkg("Rd2md") converts Rd files to Markdown and creates a combined Markdown reference manual; r github("Genentech/rd2markdown") generates Markdown from a source Rd file or the help page of an installed package.
• r github("coolbutuseless/rd2list") converts Rd files to an R list.

Vignettes

The default format for vignettes is Sweave format with special metadata described in WRE. R CMD build will use utils::Sweave() as the default vignette engine to build a vignette. Alternative vignette engines can be specified in the metadata in the form <package>::<engine>.

WRE reference: Writing package vignettes, especially Non-Sweave vignettes

• r pkg("knitr", priority = "core") provides vignette engines to compile HTML and PDF vignettes. The knitr::rmarkdown engine can be used with the rmarkdown::html_vignette() format, which is a lightweight alternative to knitr::html_document(). For mathematics to render offline, the math_method argument of rmarkdown::html_vignette() should be set to "katex" or "r-katex".
• r pkg("litedown", priority = "core") provides a vignette engine that can be used with its own output formats for HTML and PDF. It is designed to have minimal dependencies and produce lightweight HTML files. It has sufficient features for most vignettes (e.g., table of contents, cross-references, citations) and is recommended unless richer features are required.
• r pkg("quarto") provides a vignette engine that fixes configurations of the HTML format to produce a lightweight file. This may be preferred for richer features (equivalent to Sweave) or re-using material already using Quarto. Since r pkg("quarto") depends on r pkg("rmarkdown"), and adds Quarto as a system dependency, this option is dependency-heavy.
• r pkg("prettydoc") provides html_pretty() as an alternative to rmarkdown::html_vignette() that produces lightweight files with fancier themes.
• r pkg("R.rsp") provides facilities to include static PDF or HTML vignettes; compile vignettes from plain LaTeX files, and render PDF or HTML vignettes with the R.rsp::rsp engine to use RSP pre-processing directives (e.g., include an external file or use document metadata) and code expressions that allow looping over text with code snippets.

Other forms of documentation

• r pkg("pkgdown", priority = "core") generates a package website based on standard documentation files with the option to complement this with additional content, such as externally hosted r pkg("learnr") tutorials. There are helpers for deploying the site on GitHub Pages.
• r pkg("altdoc") is designed as a lightweight alternative to r pkg("pkgdown") with support for many documentation generators, including Quarto, Docute, Docsify, and MkDocs.
• r github("ropenscilabs/r2readthedocs") converts package documentation to a Read the Docs website.
• r pkg("rdoxygen") creates Doxygen documentation for C++ code in packages, optionally made available as a vignette.

Package metadata and information files

tools::CRAN_package_db() returns a data frame with character columns containing most DESCRIPTION metadata for the current packages in the CRAN package repository.

utils::news(package = "pkg") can be used to extract the NEWS for a package and display it in a browser.

• r pkg("desc") provides tools to read, write, create, and manipulate DESCRIPTION files.
• r pkg("semver") provides tools for operating on semantic version strings.
• r pkg("newsmd") provides functions to create or update a NEWS.md file. r pkg("fledge") and r pkg("autonewsmd") generate NEWS.md from git commit messages following conventions specific to each package.
• r pkg("codemetar") and the leaner r pkg("codemeta") convert metadata from packages sources, such as DESCRIPTION and CITATION, to the CodeMeta JSON-LD format. This is a cross-language metadata standard used by search engines, software repositories etc.
• r pkg("cffr") and r pkg("citation") generate a CITATION.cff file from package metadata and provide utilities to work with such files, e.g. converting to/from "bibentry" objects (see utils::bibentry()). r pkg("cffr") provides helpers for maintenance via git. CITATION.cff is a cross-language citation file format recognized by software repositories and citation managers.
• r pkg("badger") generates URLs for customized badges from providers such as shields.io, commonly added to README files and package websites to display metadata such as current CRAN version.
• r pkg("allcontributors") facilitates acknowledging all contributors to code and repository issues in the README.

Package logos

To help promote packages, it has become popular to create hexagon-shaped logos that may be used in package documentation or information files and may be used to create promotional material such as stickers.

• r pkg("hexSticker") creates hex sticker designs based on R plots or image files.
• r pkg("affiner") provides grid.isocube() to create hex logos in the form of a 3D isometric cube, to look like a box or physical package.
• r github("mitchelloharawild/hexwall") generates an image of tessellated hex sticker designs.

Packages tests

Unit tests or regression tests can be added in a tests directory. Tests can be written in R scripts without depending on additional packages, using base::stopifnot() or similar to throw errors when expectations fail. Test scripts are run by R CMD check, with output saved to a corresponding .Rout file. If a corresponding .Rout.save exists in the tests directory, the two output files are compared, with differences being reported but not causing an error.

WRE reference: Package subdirectories

These packages provide some automation and helpers to test code:

• r pkg("tinytest", priority = "core") allows to add tests to a package with no further dependencies and includes the tests in the installed package, making them available to users.
• r pkg("testthat", priority = "core") provides helpers for tests including snapshot tests. r pkg("patrick") allows to parameterize testing with testthat. r pkg("hySpc.testthat") attaches the tests to functions.
• r pkg("RUnit") and r pkg("svUnit") provide alternative unit testing frameworks, similar to r pkg("testthat")
• r pkg("testit") provides two convenience functions assert() and test_pkg() for a simple unit testing interface with minimal dependencies.
• r pkg("roxytest") and r pkg("roxut") provide r pkg("roxygen2") roclets for testing with r pkg("testthat") and r pkg("tinytest").
• r pkg("exampletestr") and r pkg("doctest") convert examples into tests to be run by testthat. r pkg("testex") converts documentation by roxygen2 into tests to be run by testthat.
• r pkg("realtest") testing with distinct behaviours: expected, acceptable, current, fallback, ideal, or regressive.
• r pkg("unitizer") provides a testing framework for interactive regression testing, making it simpler to review and debug tests.
• r pkg("unittest") testing using the Test Anything Protocol, producing test output in a standard text format.
• r pkg("cucumber") integrates with testthat to run tests specified using the 'Gherkin' language to describe high level scenarios, e.g. when <I do this>, then <this should happen>.
• r pkg("xpectr") provides tools for generating expectations for testthat tests in a systematic way.
• r pkg("quickcheck") and r github("ropensci-review-tools/autotest") check against randomly generated inputs and are compatible with testthat.
• r pkg("muttest") and r pkg("mutator") perform mutation testing to assess the effectiveness of a package's test suite.
• r pkg("CBTF") fuzz tests functions in a package's public interface.

Testing internet requests can be difficult to do reliably. One can use this book "HTTP testing in R" to take inspiration.

• r pkg("vcr") records HTTP requests and replays them during future runs.
• r pkg("webmockr") stubbing (generating dummy results) and setting expectations on 'HTTP' requests.
• r pkg("httptest2") works for recording and saving requests made by the httr2 package without requiring access to the remote service.
• r pkg("webfakes") allows to create and launch fake apps in test files, for testing complex behaviour.

Other packages focused on specific areas:

• r pkg("gdiff") and r pkg("vdiffr") provide helpers for visual tests on graphical output. vdiffr integrates with testthat and provides a Shiny app to manage test cases.
• r pkg("tinysnapshot") provides snapshot tests for the tinytest framework, supporting tests for base R and ggplot2 plots as well as print() output.
• r pkg("shinytest2") provides a testing framework for Shiny applications.
• r pkg("checkmate") and r pkg("testdat") package which extend testthat for data structures unit testing.

Code coverage

• r pkg("covr", priority = "core") tracks and reports code coverage of package tests and optionally uploads the results to a service like Codecov or Coveralls.
• r pkg("covtracer") links tested code to documentation, to evaluate coverage of documented behaviours.

Package-specific options

A simple way to implement package-specific options is to set global options with a package-specific prefix, but there are several packages that provide more refined and robust management of options.

• r pkg("options") provides helpers to define and document package-specific options, managed via base::options(), with corresponding environment variables. The options can be set globally or locally (e.g., within a function).
• r pkg("GlobalOptions") provides similar functionality to r pkg("options"), with extra features such as option validation, setting options as functions of other options, and secret or read-only options.
• r pkg("potions") provides the brew() and pour() functions, that can be used to store and retrieve package-specific global options, without over-writing any global options of the same name.
• r pkg("settings") allows to set up a package-specific options manager, for setting global or local options, with optional validation rules.
• r pkg("futile.options") allows to set up a package-specific options manager for global options.
• r pkg("pkgconfig") allows packages to set package-specific values of global options, that can be queried by other packages.
• r pkg("withr") provides the local_options() function to temporarily change global options within the scope of a function.

Creating user interfaces

For simple interactive interfaces, base::readline() can be used to create a basic prompt, while utils::askYesNo() prompts for a set response, by default "Yes" or "No". utils::menu() and utils::select.list() can provide graphical and console-based selection of items from a list, respectively. utils::txtProgressBar() provides a text progress bar.

tcltk is a base package (not loaded by default) that provides a large set of tools for creating graphical interfaces using Tcl/Tk. Most functions are thin wrappers around the corresponding Tcl and Tk functions.

• r pkg("tcltk2") provides additional Tcl commands and Tk widgets to supplement tcltk.
• r pkg("fgui") facilitates rapid generation of a Tcl/Tk interface to one or multiple functions.
• r pkg("getPass") provides interfaces for securely requesting a passphrase, masking the characters typed in by the user. A GUI is used where possible, with fallback to a terminal interface.
• r pkg("progress") provides configurable text progress bars, for R and C++.
• r pkg("shiny") provides a framework to create browser-based interfaces, from function dialogues to more complex interactive web applications, that can be run locally with runApp() or deployed as static web or dynamic websites. See the Web Technologies and Services task view for other frameworks for building R-based web applications.

Localization

Packages might be addressed to people using a different language and locale. Localization in R uses GNU gettext as described in the notes on Translating R Messages which uses translations stored in PO files.

tools::update_pkg_po() creates or updates the PO template (.pot) files for a package, and updates corresponding PO (.po) files as required. tools::checkPoFile() can be used to check translation files for inconsistently formatted strings.

WRE reference: Internationalization

• r pkg("potools", priority = "core") provides helpers to create/update .pot and .po files, compile the .po files for distribution in a package, and run diagnostics to detect issues, e.g., untranslated messages due to inappropriate R/C code.
• r pkg("stranslate") provides an alternative mechanism for localization of R messages using plain text.
• r github("eliocamp/rhelpi18n") provides experimental support for localization of help pages, based on YAML files provided by companion packages.

Building and installing a source package

The standard tools to build and install a package are R CMD build and R CMD INSTALL.

• r pkg("pkgbuild") provides the build() function to build R packages and has several utilities to facilitate building packages with compiled code.
• r pkg("pkgload") simulates the process of installing a package and then attaching it, enabling rapid iterative development.
• There are many packages to facilitate installing packages from remote source code repositories, including those hosted on platforms like GitHub or GitLab. r pkg("remotes") has no dependencies and will install packages from any git or subversion repository accessible from an URL, with helpers for specific cases. In particular, remotes::install_bioc() can be used to install the development version of a Bioconductor package. r pkg("ipkg") depends on remotes and facilitates installing GitHub packages using a proxy website, if you don't have access to GitHub.

Checking a package

Standard check

The standard package check is implemented in R CMD check, which should be run on a package built with R CMD build. The check runs examples and tests in the package and the contents of the package are tested in various ways for consistency and portability.

WRE reference: Checking and building packages. Listings of environment variables used in R CMD check may be found the the Tools chapter of the R Internals manual. In the Suggested packages section WRE recommends to run R CMD check both with _R_CHECK_DEPENDS_ONLY_=true and _R_CHECK_SUGGESTS_ONLY_=true, as well as with both of these set to false.

CRAN provide the Winbuilder and macOS builder services for checking on Windows and M1 macOS machines, respectively.

• r pkg("rhub", priority = "core") (R-hub v2) enables you to run R CMD check on multiple platforms, including Linux, macOS and Windows, via GitHub Actions. The rhub package helps you set up the GitHub Actions on your own GitHub repository, or if you don’t have a GitHub account, you can submit your package to the r-hub2 GitHub organization to use their shared pool of runners.
• r pkg("rcmdcheck") runs R CMD check from R, returning an "rcmdcheck" object, which you can query and manipulate. The package also provides functions to parse check results from a file or from an URL, including official CRAN check results.
• r bioc("BiocCheck") guides maintainers through Bioconductor best practices.

See the CI/CD section for information on running package checks automatically.

Package authors may supplement the standard package check with additional checks of code or text quality, using tools in the following sub-sections.

Code quality checks

• The recommended package r pkg("codetools", priority = "core") provides checkUsagePackage() to check all R code in a package for possible problems, e.g., calls not consistent with visible function definitions. r pkg("checkglobals") provides a lightweight alternative to codetools::findGlobals() to check for missing function imports and/or variable definitions without the need for package installation or code execution.
• r pkg("lintr", priority = "core") checks code for adherence to a given style, syntax errors and violations of best practices. lintr::lint_package() can be used to lint R code in a package, including in supplementary files such as tests and vignettes. lintr is combined with linters for other languages by tools including MegaLinter, super-linter and CodeFactor. r pkg("adaptalint") infers the coding style from a package, for linting the same package or a different one. r pkg("styler") automatically reformats code to adhere to a given style guide, eliminating some of the problems r pkg("lintr") can detect.
• r pkg("goodpractice") checks a package for good practices, incorporating checks from R CMD check and lintr, as well as further checks such a using r pkg("cyclocomp") to check code complexity. Checks can be run individually, e.g., goodpractice::gp(pkg_path, checks = "rcmdcheck_portable_file_names").
• r github("ropensci-review-tools/pkgcheck") extends r pkg("goodpractice") with additional checks for rOpenSci packages, including static code analysis and checks of package and function name availability on CRAN.

Compiled code checks

WRE reference: Checking memory access documents how memory violations and other issues in compiled code such as undefined behaviour can be detected with tools including Valgrind, Address Sanitizer (ASAN) and Undefined Behaviour Sanitizer (UBSAN). These tools required appropriately configured builds of R.

• rchk is a tool for finding memory protection errors in code that uses R's C API and it is run by CRAN as an additional check on R packages using C. The rchk repository provides the tool in a pre-built Docker container.
• R-hub v2 enables you to run R CMD check with R-devel built with Valgrind, sanitizers, or rchk, along with many other specific configurations of R.
• r pkg("cppcheckR") allows to run Cppcheck on C and C++ files to detect errors and recommend good practices.

Text quality checks

utils provides multiple functions for spell-checking portions of packages, including .Rd files ( utils::aspell_package_Rd_files) and vignettes (utils::aspell_package_vignettes) via the general purpose aspell function, which requires a system spell checking library, such as aspell, hunspell, or ispell.

tools provides check_package_urls() and check_package_dois() for checking URLs and DOIs in package metadata and information files.

• r pkg("spelling") spell checks documents in common formats, including LaTeX and Markdown, as well as R documentation and DESCRIPTION files. Packages may define a wordlist to allow custom terminology.

Debugging issues found in package checks

Using a check service such as Winbuilder or R-hub may reveal a bug in your package that is specific to the computational environment, e.g., the version of R, or the compiler used. The following tools support debugging in such cases.

• The Rocker project provides several Dockers containers with R installed. The versioned stack can be used to work with a specific version of R, while the base stack provides R-devel installed alongside R-release, optionally configured with ASAN and USAN sanitizers.
• The Docker containers used by R-hub are documented on the R-hub containers site, with instructions for how to use them for local debugging. Available containers include builds of R-release, R-patched and R-devel, with the latter available in multiple configurations, including several configured for debugging memory issues.
• r-debug provides a single Docker image containing various builds of R for debugging memory problems. These include images with the debugging tools Valgrind or gdb, as well as images with R compiled for use with ASAN, UBSAN or gctorture.

The CRAN Cookbook is a guide written in collaboration with the CRAN Team that provides "recipes" for solving common issues in package code or documentation found during CRAN (re)-submission checks.

Maintenance

Most packages are developed with long-term use in mind. This requires package developers to keep pace with changes in R, other packages, system tools and environments (e.g. compilers, operating systems) that affect the behaviour of their package. Repositories like CRAN or Bioconductor require packages to meet their latest policies to avoid being archived/deprecated. Issues are typically picked up by a package failing the regular checks run by the repository maintainers, and package authors will be contacted when action is required. It is best if package authors take a proactive approach to maintenance to ensure their package remains useful and available.

Continuous Integration/Continuous Delivery (CI/CD) {#ci-cd}

Continuous Integration (CI) is the practice of automatically running tests as updates are made to the source code in a code repository. It may be paired with Continuous Delivery/deployment (CD) automating release or deployment of software/software products. Some code hosting platforms have their own CI/CD system, e.g. GitHub Actions or GitLab Pipelines; there are also standalone tools such as CircleCI and Woodpecker.

CI/CD workflows are usually triggered by committing to the main branch of a repository, though other events such as a pull request comment can be used as a trigger. CI/CD pipelines can also be scheduled, which is useful for running R CMD check regularly, to check for issues when a package is not under active development.

• The r-lib/actions GitHub repository provides various GitHub Actions for R, including check-r-package to run R CMD check. The example workflow check-standard.yaml uses this action to run R CMD check with R-release on Linux, Mac, and Windows, as well as R-devel and R-oldrel on Linux. Other example workflows compute test coverage with r pkg ("covr"); build and publish a r pkg("pkgdown") site; create documentation with r pkg("roxygen2"), lint R code with r pkg("lintr"), and enforce style conventions with r pkg("styler").
• r pkg("usethis") provides use_github_action() to facilitate using the example workflows from r-lib/actions on the GitHub repository for a package.
• r bioc("biocthis") provides use_bioc_github_action() to set up Bioconductor-friendly GitHub actions. The default workflow is equivalent to check-standard.yaml from r-lib/actions, and this can be extended with optional steps such as running tests and building a r pkg("pkgdown") site.
• r github("ropensci-review-tools/pkgcheck") provides use_github_action_pkgcheck() to set up the ropensci-review-tools/pkgcheck-action which will run pkgcheck::pkgcheck() on a package.
• r pkg("rworkflows") provides use_workflow() to set up GitHub Actions for an R package; each step in the workflow can be enabled/disabled as required. Steps include checking a package with Bioc::BiocCheck(), updating badges on the repository README and pushing a Docker container that has RStudio and the package installed to a container registry such as DockerHub.
• r pkg("gitlabr") provides use_gitlab_ci() to set up GitLab CI/CD pipelines. There is a template that runs R CMD check, computes test coverage with r pkg("covr") and then deploys the r pkg("pkgdown") site for a package.
• r github("ropensci/tic") steps through setting up CI workflows on different systems, with GitHub Actions and CircleCI currently supported. For R packages, the workflow will run R CMD check, and optionally compute test coverage and build a pkgdown site. r github("ropensci/tic") builds on r pkg("circle"), which provides low-level access to the Circle CI API, e.g. to restart builds.
• r-ci provides a shell script for portable CI that can be used with GitHub actions, CircleCI, Docker, etc.
• Codeberg CI/examples includes an example workflow for running R CMD check on an R package with Woodpecker CI.

Dependency management

Most packages have forward dependencies that are declared in the Imports or Suggests fields of the package DESCRIPTION. Packages also typically depend on a minimum version of R, due to explicit or implicit use of base R functions (e.g. for compressing data objects).

In time, a package may in turn be imported or suggested by another package, creating a reverse dependency. For CRAN packages, reverse dependencies are listed on the landing pages (of the form https://CRAN.R-project.org/package={PACKAGE}). Package authors should be aware of these packages that may be impacted as their package evolves. Note that CRAN permits dependencies on Bioconductor packages, as well as other repositories specified in the Additional_repositories field of the DESCRIPTION file.

Forward or reverse dependencies may be identified with tools::package_dependencies(), based on a package database like that returned by utils::available.packages(). Dependencies from either CRAN or Bioconductor can be found by setting the repos argument of utils::available.packages() to BiocManager::repositories().

utils::update.packages() is useful for updating dependencies when trying out changes to a package.

tools::check_packages_in_dir() can be used to check the reverse dependencies of a package (or set of packages).

WRE reference: Package Dependencies.

• r pkg("attachment") provides helpers to update forward dependencies in your DESCRIPTION as required by changes to .R or .Rmd files, and to quickly install missing packages declared in a DESCRIPTION file.
• r pkg("rcheology") provides a dataset of functions in all base and recommended packages of R from version 0.50. This, or its companion rcheology Shiny app can help to determine the minimum version of R on which a package depends.
• r pkg("backports") provides reimplementations of functions introduced or changed since R v3.0.0. This enables package developers to maintain compatibility with older versions of R when using newer functionality.
• r pkg("pacs") and r pkg("pkgndep") provide tools to assess "dependency heaviness", i.e., the number of forward dependencies added by depending on a new package. r pkg("pkgndep") provides suggestions for optimizing package dependencies.
• r pkg("pkgdepends") can be used to identify, visualize and install package dependencies, including those specified via Remotes in the DESCRIPTION, for packages on CRAN, Bioconductor, and git repositories.
• r pkg("pkggraph"), r pkg("pkgnet"), r pkg("deepdep"), r pkg("crandep") and r pkg("cranly") provide functionality to visualise package dependencies.
• r pkg("pkgdepR") can be used to create interactive visualisations of dependencies between functions across packages.
• r pkg("checked") and r pkg("prrd") are designed to run reverse dependency checks in parallel. r github("r-lib/revdepcheck") is an alternative on GitHub with the same aim; usethis::use_revdep() sets up a package to work with r github("r-lib/revdepcheck").
• r-devel/recheck provides a GitHub Action to run reverse dependency checks.

Managing changes

Package authors should communicate changes in their package for the benefit of users and maintainers of reverse dependencies. They should also be vigilant to changes in the functionality, behaviour, or API of any forward dependencies.

utils::sessionInfo is helpful for tracking changes caused by upstream updates; it records the order in which packages are attached or loaded, which can aid debugging when there are namespace conflicts.

• r pkg("lifecycle") helps to communicate changes in the lifecycle of functions, e.g., experimental to stable, or stable to deprecated.
• r pkg("newsmd"), r pkg("autonewsmd") and r pkg("fledge") are designed to streamline the process of updating NEWS. r pkg("fledge") additionally supports versioning R packages developed in git repositories.
• r github("jumpingrivers/diffify") facilitates comparison between different versions of CRAN packages, reporting changes in the NEWS, dependencies, namespace or functions.
• r pkg("remotes") provides install_version() to install a particular version of a package, while r pkg("dateback") can be used to install packages based on a date or date range.
• r pkg("pacs") provides various utilities for managing packages, including pac_timemachine() to get the package version at a certain date and functions to compare the DESCRIPTION or NAMESPACE across versions.
• r pkg("sessioninfo") provides session_info() as an alternative to utils::sessionInfo(). Rather than returning an object with full information on loaded or attached packages, session_info() aims to highlight the key details for these packages, including where packages were installed from. However, the order of loading is lost as the packages are recorded alphabetically.

Tracking usage

• r pkg("cranlogs") and r pkg("dlstats") provide functions to query download statistics from the RStudio CRAN mirror. r pkg("dlstats") also supports querying Bioconductor download statistics.
• r pkg("packageRank") and r pkg("Visualize.CRAN.Downloads") provide functions to visualise CRAN download statistics, to explore trends and compare different packages.

Keeping up to date

WRE is versioned, addressing R-release, R-patched, and R-devel. Changes do occur as R develops and as the software components on which R is built evolve.

The R Blog and the R-devel mailing list can help keep track of developments in R that may affect your package.

The R-announce mailing list announces planned R releases, indicating when it is a good time to test release candidates on critical workflows.

tools::testInstalledPackage can be used to check if an installed package still passes check, while tools::summarize_CRAN_check_status will summarize the CRAN check status for one or more packages.

The R-package-devel mailing list provides help on package development and can help keep up-to-date with best practices.

• The r-mailing-list-archive GitHub repository can be used to search past discussions on the R-devel and R-package-devel mailing lists.
• Changes in the CRAN Repository Policy are tracked in the crp GitHub repository.
• r pkg("badger") provides badge_cran_checks() for adding a badge to your package README.md that either shows a summary or the worst results from the latest CRAN checks.
• r pkg("foghorn") provides functions to query the CRAN checks based on maintainer email or package name, as well as checking where a package is in the CRAN incoming or Winbuilder queues.
• cransays and cransubs provide dashboards of CRAN submissions, helping to track progress of your own packages or its dependencies.
• cranhaven provides dashboards of CRAN packages at risk of being archived or recently archived, helping to track issues with forward dependencies.
• usethis::browse_package() lets you select from URLs in the package DESCRIPTION, which can be a convenient way to find source code repositories of crucial forward dependencies, to track their development.
• r pkg("updateme") modifies library() to tell you if installed packages are up-to-date when you load them, helping to keep up with changes in forward dependencies.

Links

• R-universe Documentation - R-universe is useful for sharing development versions of CRAN packages and as a CI/CD platform.
• Bioconductor Packages: Development, Maintenance, and Peer Review
• rOpenSci Packages: Development, Maintenance, and Peer Review