R/mitm.R

In ropenscilabs/middlechild: Tools to Intercept, Validate and Consume Web/Network Traffic

#' R CMD check a package (source tree), capturing network calls.
#'
#' @param package_path  Path to a local copy of a R package
#' @param timeout Wait time after launching MITM server to run R code
#' @param quiet passed on to [devtools::check()]; Default `FALSE`.
#' @param mitm_host,mitm_port IP address of the system `mitmproxy` tools will be 
#'        running on and the port. Defaults to `127.0.0.1` and `8080` respectively. 
#' @param extra_args command-line arguments passed on to `mitmdump`.  
#' @return data frame (tibble) of safety check results or `NULL` if package check errors
#' @export
#' @examples
#' \dontrun{
#' mitm_check(package_path = "/local/path")
#' }
mitm_check <- function(package_path, timeout = 3, quiet = FALSE,
                       mitm_host = "127.0.0.1", mitm_port = "8080",
                       extra_args = NULL) {
  
  if (is.null(package_path)) {
    stop("Need a local path to a package to run checks", call. = FALSE)
  }
  
  har_script <-
    system.file("mitm", "har_dump.py", package = "middlechild")
  
  dump_file <- tempfile(fileext = ".har")
  
  on.exit(unlink(dump_file), add = TRUE) # remove tmp file when done w/f()
  
  args <- c("-s", har_script, "--set", sprintf("hardump=%s", dump_file))
  args <- c(args, "--listen-host", mitm_host)
  args <- c(args, "--listen-port", mitm_port)
  args <- c(args, extra_args)
  
  pid <- call_mitm(args = args) # mitmdump -s ./har_dump.py --set hardump=./dump.har
  
  on.exit(tools::pskill(pid), add = TRUE) # kill mitmproxy when done w/f() if errors
  
  Sys.sleep(timeout) # give mitm a chance to run
  
  devtools::check( # do the thing
    pkg = package_path,
    quiet = quiet,
    env_vars = c(http_proxy = sprintf("http://%s:%s", mitm_host, mitm_port),
                 https_proxy = sprintf("http://%s:%s", mitm_host, mitm_port))
  ) -> res
  
  if (length(res$errors) > 0) {
    warning(
      "Package check failed with errors. Please run manually and fix errors before running mitm_check()."
    )
    return(NULL)
  }
  
  tools::pskill(pid) # kill mitmproxy so we can get the HAR file
  
  Sys.sleep(timeout) # give mitm a chance to quit
  
  out <- HARtools::readHAR(dump_file)
  
  check_check(out)

}