R .gitignore template

.RData is the saved workspace: every object in memory when the session ended, serialised to disk. Committing it is a common accident with real consequences, because a workspace saved during analysis contains whatever data was loaded, which may be the confidential dataset the repository was carefully written to keep out. It is also the reason results become irreproducible, since a stale workspace silently supplies objects the script no longer creates.

.Rhistory and .Rapp.history are the command histories from the console and the macOS application. .Ruserdata holds per user session state. All three record what one person typed, which is neither shared knowledge nor reproducible input. A history file is also a good record of the paths and connection strings someone worked with, so it leaks a little about the machine it came from as well as adding noise.

.httr-oauth is the one to take seriously. It caches OAuth tokens obtained during an interactive authentication, so it contains live credentials for whatever service you connected to. A committed copy hands anyone with repository access the same API access you have, and unlike a password it is easy to miss in review because the filename looks like configuration.

The package check rules cover /*.Rcheck and /*.tar.gz, both anchored to the root, which is where the check tooling writes its output and the source tarball it builds. *-Ex.R is the extracted example script from the same process. .Rproj.user is the editor's per project working directory.

The rendering rules cover vignettes/*.html and vignettes/*.pdf, plus *.utf8.md and *.knit.md, which are the intermediate markdown files produced while knitting a document. The cache rules /*_cache and /cache cover chunk caches, which are keyed to the exact code that produced them and become misleading the moment the code changes.