Merge pull request plotly#2042 from moutikabdessabour/implement_geomFunction

Closes plotly#1872. Implemented to_basic for `geom_function`

Author: moutikabdessabour

R/layers2traces.R

@@ -173,6 +173,12 @@ to_basic <- function(data, prestats_data, layout, params, p, ...) {
   UseMethod("to_basic")
 }
 
+#' @export 
+to_basic.GeomFunction <- function (data, prestats_data, layout, params, p, ...) {
+   data$y <- params$fun(data$x)
+   prefix_class(data, "GeomPath")
+}
+
 #' @export
 to_basic.GeomCol <- function(data, prestats_data, layout, params, p, ...) {
   prefix_class(data, "GeomBar")

tests/testthat/_snaps/ggplot-function/geomfunction.svg

@@ -0,0 +1,18 @@
+p <- ggplot(data = data.frame(x = 0), mapping = aes(x = x)) 
+
+test_that("ggplotly correctly handles stat_function", {
+  pl <- p + 
+    stat_function(fun = function(x) x^2+3) + 
+    xlim(1, 5)
+
+    expect_doppelganger(ggplotly(pl), "stat-function")
+})
+
+test_that("ggplotly correctly handles stat_function", {
+  pl <- p + 
+    geom_function(fun = function(x) x^2+3) + 
+    stat_function(fun = function(x) 5) + 
+    xlim(1, 5)
+
+    expect_doppelganger(ggplotly(pl), "geomfunction")
+})