r-development

R Package Development

Use this skill when working with R packages to ensure proper development workflows, testing patterns, and documentation standards.

Development Workflow

R Environment

• Use radian with R as an alias so call R scripts using Rscript
• Do not run devtools::test with grep; read the whole output

Package Building and Management

# Load package for interactive development
devtools::load_all()

# Update documentation (REQUIRED before committing R changes)
devtools::document()

# Run all tests
devtools::test()

# Run specific test file
testthat::test_file("tests/testthat/test-filename.R")

# Run tests matching a pattern
devtools::test(filter = "pattern")
testthat::test_local(filter = "pattern")

# Check package (R CMD check)
devtools::check()

# Build package
devtools::build()

# Install package locally
devtools::install()

# Check with vignettes built
devtools::check(build_args = c("--compact-vignettes=both"))

Code Quality and Style

# Lint package (configuration in .lintr)
lintr::lint_package()

# Lint specific file
lintr::lint("R/filename.R")

# Style code (pre-commit hook typically uses tidyverse style)
styler::style_pkg()

# Check test coverage
covr::package_coverage()

Documentation Building

# Build vignettes
devtools::build_vignettes()

# Build specific vignette
rmarkdown::render("vignettes/name.Rmd")

# Build pkgdown site locally
pkgdown::build_site()

Testing Best Practices

testthat Patterns

Preferred expectations:

• expect_identical() > expect_equal() (when exact match expected)
• Multiple expect_true() calls > stacking conditions with &&
• expect_s3_class() > expect_true(inherits(...))
• Use specific expect_* functions:
  • expect_lt(), expect_gt(), expect_lte(), expect_gte()
  • expect_length()
  • expect_named()
  • expect_type()

Examples:

# Good
expect_identical(result, expected)
expect_s3_class(obj, "data.frame")
expect_lt(value, 10)
expect_true(condition1)
expect_true(condition2)

# Avoid
expect_equal(result, expected)  # when identical match is needed
expect_true(inherits(obj, "data.frame"))
expect_true(value < 10)
expect_true(condition1 && condition2)