Get the Diff of 2 file solely with R functions

Differ.R

rm(list=ls())
library(git2r)

differ = function(file1, file2){
  path <- tempfile(pattern="git2r-")
  dir.create(path)
  repo <- init(path)

  suppressWarnings({
    f1 = readLines(file1)
    })
  suppressWarnings({
    f2 = readLines(file2)
  })    
  ## Create a file, add, commit
  base = "test.txt"
  tfile = file.path(path, base)
  writeLines(f1, tfile)
  
  add(repo, base)
  commit(repo, "Added First File")
  
  ## Change the file
  writeLines(f2, tfile)
  diff_1 <- diff(repo, as_char = TRUE)
  diff_1 = gsub("a/test.txt", file1, diff_1, fixed = TRUE)
  diff_1 = gsub("b/test.txt", file2, diff_1, fixed = TRUE)
  # summary(diff_1)
  # cat(diff(repo, as_char=TRUE))
  return(diff_1)
}

file1 = "~/Desktop/difftest.txt"
file2 = "~/Desktop/difftest2.txt"

diff_msg = differ(file1, file2)
cat(diff_msg)