geom_violinhalf cannnot work when combined with facet_grid()

[PaulineBodson]

Hi,

I wanted to use your function geom_violinhalf that looks really nice with the facet_grid() from ggplot2 but it seems that the two functions are incompatible.
When I was looking for an option online, I found that geom_violin had the same problem: tidyverse/ggplot2#1388
However, the author of the function was able to modify his code to make it work: tidyverse/ggplot2@f7d5e68

I don't know if that is a feature you would like to enable for your geom_violinhalf function and if the link I am providing could help you out in anyway, but I think that could be a good enhancement if you have time to look into it.

Best,
Pauline