Compare output of plotly::gg2list() in two different versions of plotly

json_diff.R

json_diff <- function(x, old_ref = "master", new_ref) {
  if (!nchar(Sys.which("json-diff"))) 
    stop("The npm module json-diff is required to see json diffs")
  devtools::install_github("ropensci/plotly", ref = old_ref)
  old_json <- paste0(old_ref, ".json")
  cat_json(x, old_json)
  if (missing(new_ref)) {
    if (basename(getwd()) != "plotly") 
      stop("Either set working directory to plotly's R package source or give a GitHub reference to install")
    devtools::load_all()
    new_ref <- "local"
  } else {
    devtools::install_github("ropensci/plotly", ref = new_ref)
  }
  new_json <- paste0(new_ref, ".json")
  cat_json(x, new_json)
  system(paste("json-diff", old_json, new_json))
}
cat_json <- function(y, nm) {
  json <- RJSONIO::toJSON(plotly::gg2list(y), pretty = TRUE)
  cat(json, file = nm)
}

library("plotly")
no_panels <- ggplot(mtcars, aes(mpg, wt)) + geom_point()
free_both <- no_panels + facet_wrap(~am+vs, scales = "free")
# compare master branch on GitHub to local source
json_diff(free_both)
# compare master branch on GitHub to 'carson-scales-free' branch
# json_diff(free_both, new_ref = "carson-scales-free")