Issue when specifying both the size and color mapping in a scatter plots

Hi,

I can not manage to specify both the size and the color mapping with completely satisfactory results.

If I specify the size mapping globally:

library(plotly)
df <- data.frame(x = 1:12, y = 1:12, s = 1:12, g = rep(c("A", "B", "C"), 4))

plot_ly(data = df, x = ~x, y = ~y, size = ~s, color= ~g)%>% 
  add_markers()

I have a perfect plot but I suffer from the spurious line.width warning already mentioned in https://github.com/ropensci/plotly/issues/1367

If I specify the size mapping in the marker itself:

plot_ly(data = df, x = ~x, y = ~y, color= ~g)%>% 
  add_markers(marker = list(size = ~s))

The sizes are wrong: it seems there is an ordering by group within plotly which is not used in the markers.

Indeed, sorting the data.frame according to the colors fixes the issue:

df_sorted = df[order(df[['g']]), ]
plot_ly(data = df_sorted, x = ~x, y = ~y, color= ~g)%>% 
  add_markers(marker = list(size = ~s))

Let me know how I can help!

Start with the two unsorted examples using plot_ly() and add_markers(), then compare their marker-size behavior with the sorted data.frame example. Trace how color grouping and marker size mappings are aligned, and verify that unsorted data preserves the intended sizes without the reported line.width warning.