in helpers/mdbook-exercise-linker/src/lib.rs [19:37]
fn run(&self, ctx: &PreprocessorContext, mut book: Book) -> Result<Book, Error> {
let config = ctx
.config
.get_preprocessor(self.name())
.context("Failed to get preprocessor configuration")?;
let key = String::from("exercise_root_url");
let root_url = config
.get(&key)
.context("Failed to get `exercise_root_url`")?;
let root_url = root_url
.as_str()
.context("`exercise_root_url` is not a string")?
.to_owned();
book.sections
.iter_mut()
.for_each(|i| process_book_item(i, &ctx.renderer, &root_url));
Ok(book)
}