fix: issue 12 edit_file tool panics (#14)

* fix: improve edit file logic to prevent negative indentation

* test: add more tests

* chore: update tests

* feat: preserve line ending

* cleanup

* chore: fix clippy warnings

Author: hashemix

src/fs_service.rs

@@ -62,11 +62,11 @@ impl FileSystemService {
         let expanded_path = expand_home(requested_path.to_path_buf());
 
         // Resolve the absolute path
-        let absolute_path = expanded_path
-            .as_path()
-            .is_absolute()
-            .then(|| expanded_path.clone())
-            .unwrap_or_else(|| env::current_dir().unwrap().join(&expanded_path));
+        let absolute_path = if expanded_path.as_path().is_absolute() {
+            expanded_path.clone()
+        } else {
+            env::current_dir().unwrap().join(&expanded_path)
+        };
 
         // Normalize the path
         let normalized_requested = normalize_path(&absolute_path);
@@ -121,6 +121,16 @@ impl FileSystemService {
         })
     }
 
+    fn detect_line_ending(&self, text: &str) -> &str {
+        if text.contains("\r\n") {
+            "\r\n"
+        } else if text.contains('\r') {
+            "\r"
+        } else {
+            "\n"
+        }
+    }
+
     pub async fn zip_directory(
         &self,
         input_dir: String,
@@ -472,6 +482,7 @@ impl FileSystemService {
 
         // Read file content and normalize line endings
         let content_str = tokio::fs::read_to_string(&valid_path).await?;
+        let original_line_ending = self.detect_line_ending(&content_str);
         let content_str = normalize_line_endings(&content_str);
 
         // Apply edits sequentially
@@ -480,15 +491,13 @@ impl FileSystemService {
         for edit in edits {
             let normalized_old = normalize_line_endings(&edit.old_text);
             let normalized_new = normalize_line_endings(&edit.new_text);
-
             // If exact match exists, use it
             if modified_content.contains(&normalized_old) {
                 modified_content = modified_content.replacen(&normalized_old, &normalized_new, 1);
                 continue;
             }
 
             // Otherwise, try line-by-line matching with flexibility for whitespace
-            // trim ends help to avoid inconsistencies empty lines at the end that may break the comparison
             let old_lines: Vec<String> = normalized_old
                 .trim_end()
                 .split('\n')
@@ -514,7 +523,6 @@ impl FileSystemService {
 
                 if is_match {
                     // Preserve original indentation of first line
-                    // leading spaces
                     let original_indent = content_lines[i]
                         .chars()
                         .take_while(|&c| c.is_whitespace())
@@ -524,12 +532,12 @@ impl FileSystemService {
                         .split('\n')
                         .enumerate()
                         .map(|(j, line)| {
-                            // keep indentation of the first line
+                            // Keep indentation of the first line
                             if j == 0 {
                                 return format!("{}{}", original_indent, line.trim_start());
                             }
 
-                            // For subsequent lines, try to preserve relative indentation
+                            // For subsequent lines, preserve relative indentation and original whitespace type
                             let old_indent = old_lines
                                 .get(j)
                                 .map(|line| {
@@ -544,12 +552,22 @@ impl FileSystemService {
                                 .take_while(|&c| c.is_whitespace())
                                 .collect::<String>();
 
-                            let relative_indent = new_indent.len() - old_indent.len();
-
+                            // Use the same whitespace character as original_indent (tabs or spaces)
+                            let indent_char = if original_indent.contains('\t') {
+                                "\t"
+                            } else {
+                                " "
+                            };
+                            let relative_indent = if new_indent.len() >= old_indent.len() {
+                                new_indent.len() - old_indent.len()
+                            } else {
+                                0 // Don't reduce indentation below original
+                            };
                             format!(
-                                "{}{}",
-                                original_indent,
-                                " ".repeat(relative_indent.max(0)) + line.trim_start()
+                                "{}{}{}",
+                                &original_indent,
+                                &indent_char.repeat(relative_indent),
+                                line.trim_start()
                             )
                         })
                         .collect();
@@ -593,6 +611,7 @@ impl FileSystemService {
 
         if !is_dry_run {
             let target = save_to.unwrap_or(valid_path.as_path());
+            let modified_content = modified_content.replace("\n", original_line_ending);
             tokio::fs::write(target, modified_content).await?;
         }
 

src/fs_service/utils.rs

@@ -103,7 +103,7 @@ pub async fn write_zip_entry(
 }
 
 pub fn normalize_line_endings(text: &str) -> String {
-    text.replace("\r\n", "\n")
+    text.replace("\r\n", "\n").replace('\r', "\n")
 }
 
 // checks if path component is a  Prefix::VerbatimDisk