ai_chain/
utils.rs

1/// Truncate a string to a maximum number of characters, adding "..." if truncated.
2/// Handles Unicode correctly by counting characters, not bytes.
3pub fn truncate(s: &str, max_chars: usize) -> String {
4    let char_count = s.chars().count();
5    if char_count <= max_chars {
6        s.to_string()
7    } else {
8        let truncated: String = s.chars().take(max_chars.saturating_sub(3)).collect();
9        format!("{}...", truncated)
10    }
11}
12
13#[cfg(test)]
14mod tests {
15    use super::*;
16
17    #[test]
18    fn test_truncate_short_string() {
19        assert_eq!(truncate("hello", 10), "hello");
20    }
21
22    #[test]
23    fn test_truncate_exact_length() {
24        assert_eq!(truncate("hello", 5), "hello");
25    }
26
27    #[test]
28    fn test_truncate_long_string() {
29        assert_eq!(truncate("hello world", 8), "hello...");
30    }
31
32    #[test]
33    fn test_truncate_unicode() {
34        assert_eq!(truncate("héllo wörld", 8), "héllo...");
35    }
36
37    #[test]
38    fn test_truncate_emoji() {
39        assert_eq!(truncate("👋🌍🎉🚀🎯", 4), "👋...");
40    }
41
42    #[test]
43    fn test_truncate_empty() {
44        assert_eq!(truncate("", 10), "");
45    }
46
47    #[test]
48    fn test_truncate_zero_max() {
49        assert_eq!(truncate("hello", 0), "...");
50    }
51}
ai_chain/utils.rs

ai_chain/
utils.rs
