Added test case

Author: BeppoBrem

Diff for: R/plotly_build.R

@@ -890,7 +890,9 @@ map_color <- function(traces, stroke = FALSE, title = "", colorway, na.color = "
     # 3D needs a z property
     if ("scatter3d" %in% types) {
       colorBarTrace$type <- "scatter3d"
-      colorBarTrace$z <- range(unlist(lapply(traces, "[[", "z")), na.rm = TRUE)
+      zValues <- unlist(lapply(traces, "[[", "x"))
+      zValues <- if (is.numeric(zValues)) range(zValues, na.rm = TRUE) else zValues
+      colorBarTrace$z <- zValues
     }
     if (length(type <- intersect(c("scattergeo", "scattermapbox"), types))) {
       colorBarTrace$type <- type

Diff for: tests/testthat/test-plotly-color.R

@@ -20,6 +20,13 @@ test_that("Mapping a factor variable to color works", {
   expect_equivalent(length(cols), 3)
 })
 
+test_that("A scatterplot with a factor variable and discrete color works", {
+  d <- palmerpenguins::penguins 
+  p <- plot_ly(d, x = ~bill_length_mm, y = ~sex, color = ~bill_depth_mm, 
+               type = 'scatter', mode = 'markers')
+  l <- expect_traces(p, 2, "scatterplot-factor-continous-color")
+})
+
 test_that("Custom RColorBrewer pallette works for factor variable", {
   d <- palmerpenguins::penguins %>% 
     filter(!is.na(bill_length_mm))