Fix #4008 allow NULL to be passed through new_mapped_discrete() (#4009)

thomasp85 · web-flow · commit f802c5e7ec71 · 2020-05-19T08:36:43.000+02:00
diff --git a/R/scale-discrete-.r b/R/scale-discrete-.r
@@ -131,6 +131,9 @@ ScaleDiscretePosition <- ggproto("ScaleDiscretePosition", ScaleDiscrete,
 
 # TODO: This is a clear candidate for vctrs once we adopt it
 new_mapped_discrete <- function(x) {
+  if (is.null(x)) {
+    return(x)
+  }
   if (!is.numeric(x)) {
     abort("`mapped_discrete` objects can only be created from numeric vectors")
   }

Original file line number	Diff line number	Diff line change
`@@ -131,6 +131,9 @@ ScaleDiscretePosition <- ggproto("ScaleDiscretePosition", ScaleDiscrete,`
`131`	`131`
`132`	`132`	`# TODO: This is a clear candidate for vctrs once we adopt it`
`133`	`133`	`new_mapped_discrete <- function(x) {`
	`134`	`+ if (is.null(x)) {`
	`135`	`+ return(x)`
	`136`	`+ }`
`134`	`137`	`if (!is.numeric(x)) {`
`135`	`138`	abort("`mapped_discrete` objects can only be created from numeric vectors")
`136`	`139`	`}`