Walk an R source file and run each command in RStudio automatically on a delay

walk_source.R

walk_source <- function(
  file = NULL, 
  delay = 1.5, 
  clear_each_cmd = TRUE,
  style = styler::tidyverse_style
) {
  options("walk_source_cancel" = FALSE)
  if (is.null(file)) {
    txt <- rstudioapi::getSourceEditorContext()$contents
  } else {
    txt <- readLines(file, warn = FALSE)
  }
  calls <- rlang::parse_exprs(paste(txt, collapse = "\n"))
  i <- 0
  next_call <- function() {
    i <<- i + 1
    if (clear_each_cmd) cat("\f")
    text <- rlang::expr_text(calls[[i]])
    if (!is.null(style)) {
      text <- styler::style_text(text, style = style)
    }
    text <- paste(text, collapse = "\n")
    for (j in seq_len(nchar(text))) {
      if (isTRUE(getOption("walk_source_cancel", FALSE))) {
        stop("canceled")
      }
      if (substring(text, j, j) == " ") {
        Sys.sleep(runif(1, 0.1, 0.333))
      } else {
        Sys.sleep(runif(1, 0.01, 0.25))
      }
      rstudioapi::sendToConsole("", FALSE, focus = FALSE)
      rstudioapi::sendToConsole(
        code = substring(text, 1, j),
        execute = j == nchar(text)
      )
    }
    if (i < length(calls)) later::later(next_call, delay)
  }
  readline("Press enter when ready!")
  cat("\f")
  later::later(next_call, delay)
}

walk_cancel <- function() {
  options("walk_source_cancel" = TRUE)
}

walk_cancel()