Add tests for R builds

test/testpkg/R/testpkg.R

@@ -0,0 +1,32 @@
+#' @useDynLib testpkg, .registration = TRUE
+"_PACKAGE"
+
+#' Add it together
+#'
+#' @param a Number
+#' @param b Number
+#' @return Sum of numbers
+#' @export
+add_it <- function(a, b) {
+  .Call("add", a, b)
+}
+
+#' Subtract it
+#'
+#' @param a Number
+#' @param b Number
+#' @return Difference of numbers
+#' @export
+subtract_it <- function(a, b) {
+  .Call("subtract", a, b)
+}
+
+#' Square it up
+#'
+#' @param n Integer
+#' @return Square
+#' @export
+square_it <- function(n) {
+  result <- .Fortran("square", n = as.integer(n), answer = as.integer(1))
+  result$answer
+}