R/list_github_files.R

In curso-r/CursoRopen: Utility functions for Curso-R

#' List files in a GitHub repository
#'
#' @param repo Repository name (excluding owner).
#' @param path Subdirectory inside repo.
#' @param regexp A regular expression passed on to [grep()] to filter paths.
#' @param owner GitHub organization (default is `curso-r`).
#'
#' @return A string vector of paths.
#' @examples list_github_files("main-web-scraping", "slides/", "[0-9]-.*html$")
#'
#' @export
list_github_files <- function(repo, path = NULL, regexp = NULL,
                              owner = "curso-r") {

  # Get default branch
  branch <- get_default_branch(repo, owner)

  # Get file tree
  tree <- get_file_tree(repo, branch, owner)

  # Replace NULLs
  if (is.null(path)) path <- ""
  if (is.null(regexp)) regexp <- ""

  # Filter tree given path and regexp
  tree <- Filter(function(x) substr(x$path, 1, nchar(path)) == path, tree)
  tree <- Filter(function(x) grepl(regexp, x$path), tree)

  # Return paths
  sapply(tree, function(x) x$path)
}

#' Get default branch of a GitHub repository
#'
#' @param repo Repository name (excluding owner).
#' @param owner GitHub organization (default is `curso-r`).
#'
#' @return A string.
#' @examples get_default_branch("main-web-scraping")
#'
#' @export
get_default_branch <- function(repo, owner = "curso-r") {
  gh::gh("/repos/{owner}/{repo}", owner = owner, repo = repo)$default_branch
}

#' Get file tree of a GitHub repository
#'
#' @param repo Repository name (excluding owner).
#' @param branch Branch to retrieve (defaults to `main`).
#' @param owner GitHub organization (default is `curso-r`).
#'
#' @return A list of git files.
#' @noRd
get_file_tree <- function(repo, branch = "main", owner = "curso-r") {
  gh::gh(
    "/repos/{owner}/{repo}/git/trees/{branch}",
    owner = owner, repo = repo, branch = branch,
    recursive = 1
  )$tree
}