Why does R conditional compilation fail using ggplot?

Question

Edit: This question has been flagged as a duplicate of another question related to Rstudio. I would like to clarify that I am running this file with the command R -f figures.R and have never used Rstudio before. While some answers such as https://stackoverflow.com/a/27201707/118153 appear to be relevant, it does not answer why the code operates fine without the if. Answers to the linked question would appear to imply it should not work at all, while it does work without the if.

I would like to selectively build figures for my paper, regenerating only those which I have deleted. However, the following code produces a .tex file with only two comment lines; when run without the if around it, it correctly produces the whole file. I am an R novice - this core code itself comes from a statistical consultant.

Why does the following code not produce the figure when inside an if, but it produces the figure when not inside an if?

figure <- '../paper/figures/recall_by_choices.tex'
if (!file.exists(figure)) {
    tikz(file=figure,width=3.5, height=2)
    mem1percent <- mem |>
        group_by(choices, success1) |>
        summarize(count=n()) |>
        mutate(Percent = count/sum(count) * 100)
    mem1percent |>
        ggplot(aes(x=factor(choices), y=Percent, fill=success1)) +
        geom_bar(stat='identity', position=position_dodge(), color='black') +
        labs(x="Choices", fill="7-day Recall") +
        scale_fill_manual(values=c('black','grey'))
    dev.off()
}

A similar example appears to run fine within an if, not using ggplot:

figure <- '../paper/figures/hmn_density.tex'
if (!file.exists(figure)) {
    tikz(file=figure,width=7, height=4)
    hmn <- table(ifelse(surveys$how_many == 'own' | surveys$how_many == 'n/a' | surveys$how_many == 'lots' | surveys$how_many == '', NA, ifelse(surveys$how_many == 'inf' | nchar(surveys$how_many) > 5, 100000, as.numeric(surveys$how_many))))
    plot(density(hmn), main='', xlab='Number of Choices')
    dev.off()
}

Perhaps ggplot is causing the problem? Both give output with warnings when the if condition is true:

`summarise()` has grouped output by 'choices'. You can override using the `.groups` argument.
null device 
          1 

null device 
          1 
Warning message:
In ifelse(surveys$how_many == "inf" | nchar(surveys$how_many) >  :
  NAs introduced by coercion