Clone, fetch, and checkout from GitHub.com repositories

In reproducible research, not only do packages and R version have to be consistent, but also specific versions of version controlled scripts. This function allows a simple way to create an exactly copy locally of a git repository. It can use ssh keys (including GitHub deploy keys) or GitHub Personal Access Tokens.

checkoutVersion(repo, localRepoPath = ".", cred = "", ...)

Arguments

repo	Repository address in the format username/repo[/subdir][@ref|#pull]. Alternatively, you can specify subdir and/or ref using the respective parameters (see below); if both are specified, the values in repo take precedence.
localRepoPath	Character string. The path into which the git repo should be cloned, fetched, and checked out from.
cred	Character string. Either the name of the environment variable that contains the GitHub PAT or filename of the GitHub private key file.
...	Additional arguments passed to git2r functions.

Value

Invisibly returns a git_repository class object, defined in git2r.

Examples

# NOT RUN {
  tmpDir <- tempfile("")
  dir.create(tmpDir)
  repo <- "PredictiveEcology/reproducible"

  ## get latest from master branch
  localRepo <- checkoutVersion("PredictiveEcology/reproducible",
                               localRepoPath = tmpDir)
  git2r::summary(localRepo)
  unlink(tmpDir, recursive = TRUE)

  ## get latest from development branch
  localRepo <- checkoutVersion(paste0(repo, "@", "development"), localRepoPath = tmpDir)
  git2r::summary(localRepo)
  unlink(tmpDir, recursive = TRUE)

  ## get a particular commit by sha
  sha <- "8179e1910e7c617fdeacad0f9d81323e6aad57c3"
  localRepo <- checkoutVersion(paste0(repo, "@", sha), localRepoPath = tmpDir)
  git2r::summary(localRepo)
  unlink(tmpDir, recursive = TRUE)

  rm(localRepo, repo)
# }