Close #2208: make ribbon_dat() a no-op if there is no data

Author: cpsievert

R/layers2traces.R

@@ -1061,6 +1061,7 @@ make_error <- function(data, params, xy = "x") {
 # (note this function is also used for geom_smooth)
 ribbon_dat <- function(dat) {
   n <- nrow(dat)
+  if (n == 0) return(dat)
   o <- order(dat[["x"]])
   o2 <- order(dat[["x"]], decreasing = TRUE)
   used <- c("x", "ymin", "ymax", "y")

tests/testthat/test-ggplot-area.R

@@ -68,3 +68,18 @@ test_that("traces are ordered correctly in geom_area", {
   }
 })
 
+
+test_that("Can handle an 'empty' geom_area()", {
+  p <- ggplot(data.frame(x = 1, y = 1), aes(x, y)) +
+    geom_area() +
+    geom_point()
+  
+  l <- ggplotly(p)$x
+  
+  expect_length(l$data, 2)
+  
+  expect_false(l$data[[1]]$visible)
+  expect_true(l$data[[2]]$x == 1)
+  expect_true(l$data[[2]]$y == 1)
+  expect_true(l$data[[2]]$mode == "markers")
+})