Problem

@ashokkrish, according to the license of GADM data, we aren't allowed to redistribute the shape files (*sp_1.rda) without receiving prior permission to do so. I imagine this is frequently violated by users of GADM because they haven't read the license terms for the data. Have you received prior permission to do so, or should I modify spatialEpisim to download the data on demand on the user's machine, rather than these files being redistributed with spatialEpisim and increasing its download requirements (currently downloading spatialEpisim will require you to download the shapefiles for all countries, even if you're only interested in one).

Quoted from a License file included in a ZIP of a shapefile downloaded from https://www/gadm.org/

These data were extracted from the GADM database (www.gadm.org), version 3.4, April 2018. They can be used for non-commercial purposes only. It is not allowed to redistribute these data, or use them for commercial purposes, without prior consent. See the website (www.gadm.org) for more information.

See https://www.gadm.org/license.html for the license that applies to all formats, which imposes the same restrictions.

Alternative solutions to the problem

One

Either you've already contacted the GADM copyright holders and received prior permission to redistribute the files to suit our purposes, or you should do so that we may continue to redistribute them without continuing to violate their license.

Two

library(geodata)

##' Returns a SpatVector for the requested country on demand, either retrieving
##' the data from disk if it has been downloaded before, or downloading it for
##' the first time.
##'
##' The level one boundaries are the least granular administrative boundaries
##' that countries create to subdivide themselves.
##' @title Retrieve a SpatRaster of level 1 boundaries from local or remote disk
##' @param countryISO3C The uppercase ISO three character code a recognized
##'   country.
##' @return SpatVector
##' @author Bryce
lvl1AdminBorders <- function(ISO3C) {
  geodata::gadm(country = ISO3C,
                level = 1,
                path = here("gadm",
                            sprintf("gadm36_%s_1_sp.rds", tolower(ISO3C))),
                version = "3.6",
                resolution = 1)
}