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/// Pads string on the left side if it's shorter than length. Padding str are truncated if they exceed length.
///
/// # Arguments
///
/// * `s` - The string to pad.
/// * `length` - The padding length.
/// * `pad_with` - The string used as padding.
///
/// # Returns
///
/// Returns the padded string.
///
/// # Examples
///
/// ```
/// use rufl::string;
///
/// let foo = string::pad_start("foobar", 6, "*");
/// assert_eq!("foobar", foo);
///
/// let bar = string::pad_start("foobar", 10, "**");
/// assert_eq!("****foobar", bar);
///
/// ```
pub fn pad_start(s: impl AsRef<str>, length: usize, pad_with: &str) -> String {
if s.as_ref().len() >= length || pad_with.len() == 0 {
return s.as_ref().to_string();
}
let pad_len = length - s.as_ref().len();
let pad_str = &pad_with.repeat(pad_len)[..pad_len];
format!("{:pad_len$}{}", pad_str, s.as_ref().to_string())
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_pad_start() {
assert_eq!("0000foobar", pad_start("foobar", 10, "0"));
assert_eq!(" foobar", pad_start("foobar", 10, " "));
assert_eq!("foobar", pad_start("foobar", 10, ""));
assert_eq!("foobar", pad_start("foobar", 2, "0"));
assert_eq!("1foobar", pad_start("foobar", 7, "12345678"));
assert_eq!("foobar", pad_start("foobar", 1, ""));
assert_eq!("1234foobar", pad_start("foobar", 10, "12345678"));
}
}