Initial commit

src/sanitize.rs

@@ -0,0 +1,80 @@
+/// Characters that are invalid in filenames on common filesystems.
+const INVALID_CHARS: &[char] = &['/', '\\', ':', '*', '?', '"', '<', '>', '|', '\0'];
+
+/// Sanitize a single path component (filename or directory name) for filesystem safety.
+pub fn sanitize_component(s: &str) -> String {
+    let mut result: String = s
+        .chars()
+        .map(|c| if INVALID_CHARS.contains(&c) { '_' } else { c })
+        .collect();
+
+    // Trim leading/trailing dots and spaces (problematic on Windows and some Linux tools)
+    result = result.trim_matches(|c: char| c == '.' || c == ' ').to_string();
+
+    // Collapse consecutive underscores
+    while result.contains("__") {
+        result = result.replace("__", "_");
+    }
+
+    // Truncate to 255 bytes (common filesystem limit)
+    if result.len() > 255 {
+        result = result[..255].to_string();
+        // Don't leave a partial UTF-8 sequence
+        while !result.is_char_boundary(result.len()) {
+            result.pop();
+        }
+    }
+
+    // If empty after sanitization, return a placeholder
+    if result.is_empty() {
+        return "_".to_string();
+    }
+
+    result
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_sanitize_normal() {
+        assert_eq!(sanitize_component("Hello World"), "Hello World");
+    }
+
+    #[test]
+    fn test_sanitize_invalid_chars() {
+        assert_eq!(sanitize_component("AC/DC"), "AC_DC");
+        assert_eq!(sanitize_component("What?"), "What_");
+        assert_eq!(sanitize_component("a:b*c"), "a_b_c");
+    }
+
+    #[test]
+    fn test_sanitize_dots_and_spaces() {
+        assert_eq!(sanitize_component("..hidden"), "hidden");
+        assert_eq!(sanitize_component("  spaced  "), "spaced");
+        assert_eq!(sanitize_component("..."), "_");
+    }
+
+    #[test]
+    fn test_sanitize_collapse_underscores() {
+        assert_eq!(sanitize_component("a///b"), "a_b");
+    }
+
+    #[test]
+    fn test_sanitize_empty() {
+        assert_eq!(sanitize_component(""), "_");
+    }
+
+    #[test]
+    fn test_sanitize_null_bytes() {
+        assert_eq!(sanitize_component("a\0b"), "a_b");
+    }
+
+    #[test]
+    fn test_sanitize_long_string() {
+        let long = "a".repeat(300);
+        let result = sanitize_component(&long);
+        assert!(result.len() <= 255);
+    }
+}