library(fs)
library(stringr)
library(dplyr)
library(purrr)

old_full_file_names <- dir_ls(recurse = TRUE, glob = "*.R")
extract_file_names <- function(filenames) {
  filenames %>%
    basename() %>%
    tools::file_path_sans_ext()
}

old_filenames <- extract_file_names(old_full_file_names)
new_filenames <- stringr::str_replace_all(old_filenames, "_", "-")

new_full_file_names <- purrr::pmap_chr(
  list(old_full_file_names, old_filenames, new_filenames),
  stringr::str_replace
) %>%
  unname()

purrr::walk2(
  old_full_file_names,
  new_full_file_names,
  ~ fs::file_move(.x, .y)
)