download single files from private or public github repositories

getGithubFile.R

getGithubFile = function(githubPath,branch = 'master', downloadPath = NULL,token = NULL){
    if(is.null(downloadPath)){
        downloadPath = tempfile()
    }
    
    path = strsplit(githubPath,'/')[[1]]
    file = paste(path[3:length(path)], collapse = '/')
    contents = gh::gh('GET /repos/:username/:reponame/contents/:dir?ref=:branch',
                  username = path[1],
                  reponame = path[2],
                  branch = branch,
                  dir = dirname(file),
                  .token = token)
    
    names(contents) = contents %>% purrr::map_chr('name')
    
    fileInfo = contents[contents %>% purrr::map_chr('name') %>% {.%in%basename(file)}][[1]]
    
    blob = gh::gh('GET /repos/:username/:reponame/git/blobs/:sha',
                  username = path[1],
                  reponame = path[2],
                  sha = fileInfo$sha,
                  .token = token)
    
    decodeContent = openssl::base64_decode(blob$content)
    writeBin(decodeContent,downloadPath)
    
    return(invisible(downloadPath))
}