Closes #5145

NEWS.md

@@ -25,6 +25,8 @@
   (@teunbrand based on @clauswilke's suggestion #5051).
 * Fixed a regression in `Coord$train_panel_guides()` where names of guides were 
   dropped (@maxsutton, #5063)
+* `update_geom_defaults()` and `update_stat_defaults()` now return properly 
+  classed objects and have updated docs (@dkahle, #5146)
 
 # ggplot2 3.4.0
 This is a minor release focusing on tightening up the internals and ironing out

R/geom-defaults.r

@@ -7,14 +7,38 @@
 #' @keywords internal
 #' @export
 #' @examples
-#' update_geom_defaults("point", list(colour = "darkblue"))
+#'
+#' # updating a geom's default aesthetic settings
+#' # example: change geom_point()'s default color
+#' GeomPoint$default_aes
+#' update_geom_defaults("point", aes(color = "red"))
+#' GeomPoint$default_aes
 #' ggplot(mtcars, aes(mpg, wt)) + geom_point()
-#' update_geom_defaults("point", list(colour = "black"))
+#'
+#' # reset default
+#' update_geom_defaults("point", aes(color = "black"))
+#'
+#'
+#' # updating a stat's default aesthetic settings
+#' # example: change stat_bin()'s default y-axis to the density scale
+#' StatBin$default_aes
+#' update_stat_defaults("bin", aes(y = after_stat(density)))
+#' StatBin$default_aes
+#' ggplot(data.frame(x = rnorm(1e3)), aes(x)) +
+#'   geom_histogram() +
+#'   geom_function(fun = dnorm, color = "red")
+#'
+#' # reset default
+#' update_stat_defaults("bin", aes(y = after_stat(count)))
+#'
 #' @rdname update_defaults
 update_geom_defaults <- function(geom, new) {
   g <- check_subclass(geom, "Geom", env = parent.frame())
   old <- g$default_aes
-  g$default_aes <- defaults(rename_aes(new), old)
+  new <- rename_aes(new)
+  new_names_order <- unique(c(names(old), names(new)))
+  new <- defaults(new, old)[new_names_order]
+  g$default_aes[names(new)] <- new
   invisible()
 }
 
@@ -23,6 +47,9 @@ update_geom_defaults <- function(geom, new) {
 update_stat_defaults <- function(stat, new) {
   g <- check_subclass(stat, "Stat", env = parent.frame())
   old <- g$default_aes
-  g$default_aes <- defaults(rename_aes(new), old)
+  new <- rename_aes(new)
+  new_names_order <- unique(c(names(old), names(new)))
+  new <- defaults(new, old)[new_names_order]
+  g$default_aes[names(new)] <- new
   invisible()
 }

tests/testthat/test-geom-.R

@@ -5,3 +5,47 @@ test_that("aesthetic checking in geom throws correct errors", {
   aes <- list(a = 1:4, b = letters[1:4], c = TRUE, d = 1:2, e = 1:5)
   expect_snapshot_error(check_aesthetics(aes, 4))
 })
+
+
+
+test_that("updating geom aesthetic defaults preserves class and order", {
+
+  original_defaults <- GeomPoint$default_aes
+
+  update_geom_defaults("point", aes(color = "red"))
+
+  updated_defaults <- GeomPoint$default_aes
+
+  expect_s3_class(updated_defaults, "uneval")
+
+  intended_defaults <- original_defaults
+  intended_defaults[["colour"]] <- "red"
+
+  expect_equal(updated_defaults, intended_defaults)
+
+  update_geom_defaults("point", original_defaults)
+
+})
+
+
+
+
+test_that("updating stat aesthetic defaults preserves class and order", {
+
+  original_defaults <- StatBin$default_aes
+
+  update_stat_defaults("bin", aes(y = after_stat(density)))
+
+  updated_defaults <- StatBin$default_aes
+
+  expect_s3_class(updated_defaults, "uneval")
+
+  intended_defaults <- original_defaults
+  intended_defaults[["y"]] <- expr(after_stat(density))
+  attr(intended_defaults[["y"]], ".Environment") <- attr(updated_defaults[["y"]], ".Environment")
+
+  expect_equal(updated_defaults, intended_defaults)
+
+  update_stat_defaults("bin", original_defaults)
+
+})