checking for detritus in the temp directory ... NOTE

[aitap]

Related to Writing Files and Directories to the Home Filespace.

Problem: your package got a NOTE complaining about the "detritus in the temp directory".

Cause: some of the code that runs as a result of R CMD check creates files in the temporary directory specified by the environment variable TMPDIR and doesn't remove them afterwards. This may include your own tests creating files under tempdir(), child processes, or Python code launched using reticulate.

Solution: if you use tempfile()/tempdir() as the default destination for functions called in your examples or tests, unlink() the resulting files as part of the test. In \examples{}, clean-up actions can be wrapped in \dontshow{} for aesthetic reasons. If you launch a browser, Calibre, or Python code, and it creates temporary files, find out what they are and remove them once the launched code is done with them. For example, R packages that use the tensorflow Python package find and remove temporary files created by its auto-gradient feature.

[hturner]

This one looks fine to me.

Probably worth mentioning withr::local_tempfile()/ withr::local_tempdir() that are "self-cleaning". These particularly make sense for {testthat} tests, as {testthat} imports {withr}, but withr is a low-dependency package that can be used independently. See https://r-pkgs.org/testing-design.html#sec-tests-files-where-write.

[jasdumas]

@aitap Thanks for this recipe! Please go ahead and add this as a PR. Here is the template guide to re-format your contribution: https://github.com/r-devel/cran-cookbook/wiki/Contributors-Guide#recipe-template-

[aitap]

Resolved in #69.