pub fn compress(output: &str) -> Option<String> {
let lines: Vec<&str> = output.lines().collect();
if lines.len() < 5 {
return None;
}
let is_long = lines.iter().any(|l| {
l.starts_with('-') || l.starts_with('d') || l.starts_with('l') || l.starts_with("total ")
});
if is_long {
compress_long(output)
} else {
compress_short(output)
}
}
fn compress_long(output: &str) -> Option<String> {
let mut dirs = Vec::new();
let mut files = Vec::new();
for line in output.lines() {
if line.starts_with("total ") || line.trim().is_empty() {
continue;
}
let parts: Vec<&str> = line.split_whitespace().collect();
if parts.len() < 9 {
continue;
}
let name = parts[8..].join(" ");
if name == "." || name == ".." {
continue;
}
if line.starts_with('d') {
dirs.push(format!("{name}/"));
} else {
let size = format_size(parts[4]);
files.push(format!("{name} {size}"));
}
}
if dirs.is_empty() && files.is_empty() {
return None;
}
let mut result = String::new();
for d in &dirs {
result.push_str(d);
result.push('\n');
}
for f in &files {
result.push_str(f);
result.push('\n');
}
result.push_str(&format!("\n{} files, {} dirs", files.len(), dirs.len()));
Some(result)
}
fn compress_short(output: &str) -> Option<String> {
let items: Vec<&str> = output
.split_whitespace()
.filter(|s| !s.is_empty())
.collect();
if items.len() < 10 {
return None;
}
let mut dirs = Vec::new();
let mut files = Vec::new();
for item in &items {
if item.ends_with('/') {
dirs.push(*item);
} else {
files.push(*item);
}
}
let mut result = String::new();
for d in &dirs {
result.push_str(d);
result.push('\n');
}
let mut line_buf = String::new();
for f in &files {
if line_buf.len() + f.len() + 2 > 70 {
result.push_str(&line_buf);
result.push('\n');
line_buf.clear();
}
if !line_buf.is_empty() {
line_buf.push_str(" ");
}
line_buf.push_str(f);
}
if !line_buf.is_empty() {
result.push_str(&line_buf);
result.push('\n');
}
result.push_str(&format!("\n{} items", dirs.len() + files.len()));
Some(result)
}
fn format_size(size_str: &str) -> String {
let last = size_str.as_bytes().last().copied().unwrap_or(b'0');
if matches!(last, b'K' | b'M' | b'G' | b'T') {
return size_str.to_string();
}
let bytes: u64 = size_str.parse().unwrap_or(0);
if bytes >= 1_048_576 {
format!("{:.1}M", bytes as f64 / 1_048_576.0)
} else if bytes >= 1024 {
format!("{:.1}K", bytes as f64 / 1024.0)
} else {
format!("{bytes}B")
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn format_size_raw_small() {
assert_eq!(format_size("512"), "512B");
}
#[test]
fn format_size_raw_kb() {
assert_eq!(format_size("4096"), "4.0K");
}
#[test]
fn format_size_raw_mb() {
assert_eq!(format_size("1048576"), "1.0M");
}
#[test]
fn format_size_human_k_passthrough() {
assert_eq!(format_size("4.0K"), "4.0K");
}
#[test]
fn format_size_human_m_passthrough() {
assert_eq!(format_size("1.2M"), "1.2M");
}
#[test]
fn format_size_human_g_passthrough() {
assert_eq!(format_size("2.5G"), "2.5G");
}
#[test]
fn format_size_zero_and_empty() {
assert_eq!(format_size("0"), "0B");
assert_eq!(format_size(""), "0B");
}
#[test]
fn format_size_integer_k_passthrough() {
assert_eq!(format_size("15K"), "15K");
}
#[test]
fn compress_long_ls_l_raw_bytes() {
let output = "total 32\n\
drwxr-xr-x 5 user staff 160 May 20 10:00 src\n\
drwxr-xr-x 3 user staff 96 May 20 10:00 tests\n\
-rw-r--r-- 1 user staff 4096 May 20 10:00 Cargo.toml\n\
-rw-r--r-- 1 user staff 12288 May 20 10:00 Cargo.lock\n\
-rw-r--r-- 1 user staff 512 May 20 10:00 README.md\n\
-rw-r--r-- 1 user staff 100 May 20 10:00 .gitignore\n\
-rw-r--r-- 1 user staff 42 May 20 10:00 .env\n";
let result = compress(output).expect("should compress");
assert!(result.contains("4.0K"), "4096 should become 4.0K: {result}");
assert!(
result.contains("12.0K"),
"12288 should become 12.0K: {result}"
);
assert!(result.contains("512B"), "512 should become 512B: {result}");
assert!(
result.contains("src/"),
"dirs should have trailing /: {result}"
);
}
#[test]
fn compress_long_ls_lah_human_readable() {
let output = "total 32K\n\
drwxr-xr-x 5 user staff 160 May 20 10:00 src\n\
drwxr-xr-x 3 user staff 96 May 20 10:00 tests\n\
-rw-r--r-- 1 user staff 4.0K May 20 10:00 Cargo.toml\n\
-rw-r--r-- 1 user staff 12K May 20 10:00 Cargo.lock\n\
-rw-r--r-- 1 user staff 1.2M May 20 10:00 big-file.bin\n\
-rw-r--r-- 1 user staff 512 May 20 10:00 README.md\n\
-rw-r--r-- 1 user staff 100 May 20 10:00 .gitignore\n";
let result = compress(output).expect("should compress");
assert!(
result.contains("4.0K"),
"human 4.0K should pass through: {result}"
);
assert!(
result.contains("12K"),
"human 12K should pass through: {result}"
);
assert!(
result.contains("1.2M"),
"human 1.2M should pass through: {result}"
);
assert!(
!result.contains(" 0B"),
"should NOT show 0B for human-readable sizes: {result}"
);
}
#[test]
fn compress_long_ls_lh_same_as_lah() {
let output = "total 16K\n\
drwxr-xr-x 2 user staff 64 May 20 10:00 docs\n\
-rw-r--r-- 1 user staff 2.5G May 20 10:00 database.db\n\
-rw-r--r-- 1 user staff 330K May 20 10:00 image.png\n\
-rw-r--r-- 1 user staff 15T May 20 10:00 huge.tar\n\
-rw-r--r-- 1 user staff 42 May 20 10:00 tiny.txt\n\
-rw-r--r-- 1 user staff 0 May 20 10:00 empty.log\n";
let result = compress(output).expect("should compress");
assert!(result.contains("2.5G"), "G suffix: {result}");
assert!(result.contains("15T"), "T suffix: {result}");
}
#[test]
fn compress_long_mixed_dirs_and_files() {
let output = "total 8\n\
drwxr-xr-x 2 user staff 64 May 20 10:00 .git\n\
drwxr-xr-x 2 user staff 64 May 20 10:00 node_modules\n\
drwxr-xr-x 2 user staff 64 May 20 10:00 src\n\
-rw-r--r-- 1 user staff 256 May 20 10:00 package.json\n\
-rw-r--r-- 1 user staff 100 May 20 10:00 .env\n";
let result = compress(output).expect("should compress");
assert!(result.contains(".git/"));
assert!(result.contains(".env"));
assert!(result.contains("3 dirs"));
assert!(result.contains("2 files"));
}
#[test]
fn compress_long_dotfiles_preserved() {
let output = "total 4\n\
-rw-r--r-- 1 user staff 100 May 20 10:00 .env\n\
-rw-r--r-- 1 user staff 200 May 20 10:00 .gitignore\n\
-rw-r--r-- 1 user staff 300 May 20 10:00 .dockerignore\n\
-rw-r--r-- 1 user staff 400 May 20 10:00 .eslintrc\n\
-rw-r--r-- 1 user staff 500 May 20 10:00 .prettierrc\n";
let result = compress(output).expect("should compress");
assert!(result.contains(".env"), "dotfiles must appear: {result}");
assert!(result.contains(".gitignore"));
}
}