pub fn truncate(text: &str, len: usize) -> String {
if text.len() <= len {
return text.to_string();
}
format!(
"{}…",
text[..len]
.rsplitn(2, " ")
.collect::<Vec<&str>>()
.last()
.copied()
.expect("This can never happen >inb4 it happens")
)
}
#[cfg(test)]
mod tests {
use super::truncate;
#[test]
fn test_truncate_with_input_of_lesser_length_than_limit() {
let input = "short text";
let result = truncate(input, input.len() + 1);
assert_eq!(input, result)
}
#[test]
fn test_truncate_with_input_of_equal_length_as_limit() {
let input = "short text";
let result = truncate(input, input.len());
assert_eq!(input, result)
}
#[test]
fn test_truncate_with_input_of_greater_length_than_limit() {
let input = "some longer text";
let result = truncate(input, input.len() - 1);
assert_eq!("some longer…", result)
}
#[test]
fn test_truncate_with_input_of_greater_length_than_limit_oneword() {
let input = "somelongertext";
let result = truncate(input, input.len() - 1);
assert_eq!("somelongertex…", result)
}
}