Run R code with different versions of package dependencies, this will work in the same session as long as you don't run into issues unloading the namespaces

0.9.3.png

2.2.0.png

with_pkg_version.R

with_pkg_version <- function(pkg, version, code, ...) {
  if (isNamespaceLoaded(pkg)) {
    unloadNamespace(pkg)
  }
  dir <- tempfile()
  dir.create(dir)
  on.exit(unlink(dir))
  withr::with_libpaths(dir, action = "prefix", {
    on.exit(unloadNamespace(pkg))
    devtools::install_version(pkg, version, ...)
    force(code)
  })
}

with_pkg_version("ggplot2", "0.9.3", {
  library(ggplot2)

  ggsave("0.9.3.png",
    ggplot(mpg, aes(displ, hwy, colour = class)) +
    geom_point())
})

with_pkg_version("ggplot2", "2.2.0", {
  library(ggplot2)

  ggsave("2.2.0.png",
    ggplot(mpg, aes(displ, hwy, colour = class)) +
    geom_point())
})