Bug: where facet variable is character & drop = F

[davidhodge931]

This is pretty minor, as users shouldn't use drop = F if variable is character - but still be nice if it worked anyway, as does scale_*_discrete(..., drop = F) with characters

library(tidyverse)
#> Warning: package 'purrr' was built under R version 4.3.1
#> Warning: package 'dplyr' was built under R version 4.3.1
#> Warning: package 'lubridate' was built under R version 4.3.1
library(palmerpenguins)

#bugs if character & drop = F  
penguins |>
  mutate(sex = as.character(sex)) |>
  ggplot() +
  geom_point(aes(x = body_mass_g, y = flipper_length_mm)) +
  facet_wrap(~sex, drop = F)
#> Error in `scale_apply()`:
#> ! `scale_id` must not contain any "NA"
#> Backtrace:
#>      ▆
#>   1. ├─base::tryCatch(...)
#>   2. │ └─base (local) tryCatchList(expr, classes, parentenv, handlers)
#>   3. │   ├─base (local) tryCatchOne(...)
#>   4. │   │ └─base (local) doTryCatch(return(expr), name, parentenv, handler)
#>   5. │   └─base (local) tryCatchList(expr, names[-nh], parentenv, handlers[-nh])
#>   6. │     └─base (local) tryCatchOne(expr, names, parentenv, handlers[[1L]])
#>   7. │       └─base (local) doTryCatch(return(expr), name, parentenv, handler)
#>   8. ├─base::withCallingHandlers(...)
#>   9. ├─base::saveRDS(...)
#>  10. ├─base::do.call(...)
#>  11. ├─base (local) `<fn>`(...)
#>  12. └─global `<fn>`(input = base::quote("sour-puppy_reprex.R"))
#>  13.   └─rmarkdown::render(input, quiet = TRUE, envir = globalenv(), encoding = "UTF-8")
#>  14.     └─knitr::knit(knit_input, knit_output, envir = envir, quiet = quiet)
#>  15.       └─knitr:::process_file(text, output)
#>  16.         ├─base::withCallingHandlers(...)
#>  17.         ├─base::withCallingHandlers(...)
#>  18.         ├─knitr:::process_group(group)
#>  19.         └─knitr:::process_group.block(group)
#>  20.           └─knitr:::call_block(x)
#>  21.             └─knitr:::block_exec(params)
#>  22.               └─knitr:::eng_r(options)
#>  23.                 ├─knitr:::in_input_dir(...)
#>  24.                 │ └─knitr:::in_dir(input_dir(), expr)
#>  25.                 └─knitr (local) evaluate(...)
#>  26.                   └─evaluate::evaluate(...)
#>  27.                     └─evaluate:::evaluate_call(...)
#>  28.                       ├─evaluate (local) handle(...)
#>  29.                       │ └─base::try(f, silent = TRUE)
#>  30.                       │   └─base::tryCatch(...)
#>  31.                       │     └─base (local) tryCatchList(expr, classes, parentenv, handlers)
#>  32.                       │       └─base (local) tryCatchOne(expr, names, parentenv, handlers[[1L]])
#>  33.                       │         └─base (local) doTryCatch(return(expr), name, parentenv, handler)
#>  34.                       ├─base::withCallingHandlers(...)
#>  35.                       ├─base::withVisible(value_fun(ev$value, ev$visible))
#>  36.                       └─knitr (local) value_fun(ev$value, ev$visible)
#>  37.                         └─knitr (local) fun(x, options = options)
#>  38.                           ├─base::withVisible(knit_print(x, ...))
#>  39.                           ├─knitr::knit_print(x, ...)
#>  40.                           └─knitr:::knit_print.default(x, ...)
#>  41.                             └─evaluate (local) normal_print(x)
#>  42.                               ├─base::print(x)
#>  43.                               └─ggplot2:::print.ggplot(x)
#>  44.                                 ├─ggplot2::ggplot_build(x)
#>  45.                                 └─ggplot2:::ggplot_build.ggplot(x)
#>  46.                                   └─layout$train_position(data, scale_x(), scale_y())
#>  47.                                     └─ggplot2 (local) train_position(..., self = self)
#>  48.                                       └─self$facet$train_scales(...)
#>  49.                                         └─ggplot2 (local) train_scales(...)
#>  50.                                           └─ggplot2:::scale_apply(layer_data, x_vars, "train", SCALE_X, x_scales)
#>  51.                                             └─cli::cli_abort("{.arg scale_id} must not contain any {.val NA}")
#>  52.                                               └─rlang::abort(...)

#works if factor
penguins |>
  ggplot() +
  geom_point(aes(x = body_mass_g, y = flipper_length_mm)) +
  facet_wrap(~sex, drop = F)
#> Warning: Removed 2 rows containing missing values or values outside the scale range
#> (`geom_point()`).

^{Created on 2023-10-16 with reprex v2.0.2}