docs: Define type_sum.accel() only in help page to avoid silent err…

…ors when loading (#721)

R/type.R

@@ -76,14 +76,18 @@ format_full_pillar_type <- function(x) {
 #' @export
 #' @examples
 #' # Default method: show the type with angle brackets
-#' format_type_sum(1, NULL)
+#' writeLines(format_type_sum("dbl", width = NULL))
 #' pillar(1)
 #'
 #' # AsIs method: show the type without angle brackets
 #' type_sum.accel <- function(x) {
 #'   I("kg m/s^2")
 #' }
 #'
+#' # Typically done through NAMESPACE
+#' # (perhaps with an @export directive in roxygen2)
+#' registerS3method("type_sum", "accel", type_sum.accel)
+#'
 #' accel <- structure(9.81, class = "accel")
 #' pillar(accel)
 format_type_sum <- function(x, width, ...) {

R/zzz.R

@@ -36,13 +36,6 @@
 #' @importFrom cli symbol ansi_strwrap
 NULL
 
-# https://github.com/r-lib/pkgdown/issues/1540
-if (Sys.getenv("IN_PKGDOWN") != "") {
-  type_sum.accel <- function(x) {
-    I("kg m/s^2")
-  }
-}
-
 # nolint start
 .onLoad <- function(libname, pkgname) {
   # nolint end
@@ -67,11 +60,6 @@ if (Sys.getenv("IN_PKGDOWN") != "") {
     debug_info()
   }
 
-  # https://github.com/r-lib/pkgdown/issues/1540
-  if (Sys.getenv("IN_PKGDOWN") != "") {
-    s3_register("pillar::type_sum", "accel")
-  }
-
   invisible()
 }