Bump default serialization version in use_data() to 3 (#2044)

* Fixes #1966 - bumped default serialization version in use_data() to 3

* addition of bullet in NEWS.md to alert for update to use_data() version bump

* update param in use_data & related test for default version 3

NEWS.md

@@ -1,5 +1,6 @@
 # usethis (development version)
 
+* `use_data()` now uses serialization version 3 by default. (@laurabrianna, #2044)
 * Reverse dependency checks are only suggested if they exist 
   (#1817, @seankross).
 

R/data.R

@@ -18,9 +18,9 @@
 #'   files. If you really want to do so, set this to `TRUE`.
 #' @param compress Choose the type of compression used by [save()].
 #'   Should be one of "gzip", "bzip2", or "xz".
-#' @param version The serialization format version to use. The default, 2, was
-#'   the default format from R 1.4.0 to 3.5.3. Version 3 became the default from
-#'   R 3.6.0 and can only be read by R versions 3.5.0 and higher.
+#' @param version The serialization format version to use. The default, 3, can
+#'   only be read by R versions 3.5.0 and higher. For R 1.4.0 to 3.5.3, use
+#'   version 2.
 #' @inheritParams base::save
 #'
 #' @seealso The [data chapter](https://r-pkgs.org/data.html) of [R
@@ -38,7 +38,7 @@ use_data <- function(...,
                      internal = FALSE,
                      overwrite = FALSE,
                      compress = "bzip2",
-                     version = 2,
+                     version = 3,
                      ascii = FALSE) {
   check_is_package("use_data()")
 

tests/testthat/test-data.R

@@ -62,14 +62,14 @@ test_that("use_data() honors `overwrite` for internal data", {
   expect_identical(letters2, rev(letters))
 })
 
-test_that("use_data() writes version 2 by default", {
+test_that("use_data() writes version 3 by default", {
   create_local_package()
 
   x <- letters
-  use_data(x, internal = TRUE, version = 2, compress = FALSE)
+  use_data(x, internal = TRUE,  compress = FALSE)
   expect_identical(
     rawToChar(readBin(proj_path("R", "sysdata.rda"), n = 4, what = "raw")),
-    "RDX2"
+    "RDX3"
   )
 })