usethis (version 2.1.6)

use_r: Create or edit R or test files


This pair of functions makes it easy to create paired R and test files, using the convention that the tests for R/foofy.R should live in tests/testthat/test-foofy.R. You can use them to create new files from scratch by supplying name, or if you use RStudio, you can call to create (or navigate to) the paired file based on the currently open script.


use_r(name = NULL, open = rlang::is_interactive())

use_test(name = NULL, open = rlang::is_interactive())



Either a name without extension, or NULL to create the paired file based on currently open file in the script editor. If the R/ file is open, use_test() will create/open the corresponding test file; if the test file is open, use_r() will create/open the corresponding R/ file.


Whether to open the file for interactive editing.

Renaming files in an existing package

Here are some tips on aligning file names across R/ and tests/testthat/ in an existing package that did not necessarily follow this convention before.

This script generates a data frame of R/ and test files that can help you identify missed opportunities for pairing:


bind_rows( tibble( type = "R", path = dir_ls("R/", regexp = "\\.[Rr]$"), name = as.character(path_ext_remove(path_file(path))), ), tibble( type = "test", path = dir_ls("tests/testthat/", regexp = "/test[^/]+\\.[Rr]$"), name = as.character(path_ext_remove(str_remove(path_file(path), "^test[-_]"))), ) ) %>% pivot_wider(names_from = type, values_from = path) %>% print(n = Inf)

The rename_files() function can also be helpful.

See Also

The testing and R code chapters of R Packages.