Close #2220: provide a default if the fatten param is missing in to_basic.GeomCrossbar

Author: cpsievert

R/layers2traces.R

@@ -562,7 +562,7 @@ to_basic.GeomCrossbar <- function(data, prestats_data, layout, params, p, ...) {
   # from GeomCrossbar$draw_panel()
   middle <- base::transform(data, x = xmin, xend = xmax, yend = y, alpha = NA)
   nm <- linewidth_or_size(GeomCrossbar)
-  data[[nm]] <- data[[nm]] * params$fatten
+  data[[nm]] <- data[[nm]] * (params$fatten %||% formals(geom_crossbar)$fatten)
   list(
     prefix_class(to_basic.GeomRect(data), "GeomCrossbar"),
     prefix_class(to_basic.GeomSegment(middle), "GeomCrossbar")

tests/testthat/test-ggplot-summary.R

@@ -0,0 +1,7 @@
+test_that("stat_summary works", {
+  p <- ggplot(iris, aes(x = Species, y = Sepal.Length)) +
+    stat_summary(fun = mean, fun.max = max, fun.min = min) +
+    stat_summary(fun = median, geom = "crossbar", linetype = "dashed")
+
+  expect_doppelganger_built(p, "stat-summary") 
+})