Create parent directories when saving to a non-existent path

crates/edit/src/bin/edit/documents.rs

@@ -4,6 +4,7 @@
 use std::collections::LinkedList;
 use std::ffi::OsStr;
 use std::fs::File;
+use std::fs;
 use std::path::{Path, PathBuf};
 
 use edit::buffer::{RcTextBuffer, TextBuffer};
@@ -210,7 +211,26 @@ impl DocumentManager {
     }
 
     pub fn open_for_writing(path: &Path) -> apperr::Result<File> {
-        File::create(path).map_err(apperr::Error::from)
+        // Error handling for directory creation and file writing
+        if let Some(parent) = path.parent() {
+            if !parent.exists() {
+                match fs::create_dir_all(parent) {
+                    Ok(_) => {},
+                    Err(e) => {
+                        // Log or handle the error as needed
+                        eprintln!("[Error] Failed to create parent directories for {:?}: {}", parent, e);
+                        return Err(apperr::Error::from(e));
+                    }
+                }
+            }
+        }
+        match File::create(path) {
+            Ok(f) => Ok(f),
+            Err(e) => {
+                eprintln!("[Error] Failed to create file {:?}: {}", path, e);
+                Err(apperr::Error::from(e))
+            }
+        }
     }
 
     fn create_buffer() -> apperr::Result<RcTextBuffer> {
@@ -312,4 +332,25 @@ mod tests {
         assert_eq!(parse("file.txt:10"), ("file.txt", Some(Point { x: 0, y: 9 })));
         assert_eq!(parse("file.txt:10:5"), ("file.txt", Some(Point { x: 4, y: 9 })));
     }
+
+    #[test]
+    fn test_open_for_writing_error() {
+        // It is not possible to reliably trigger a file creation error on all systems/environments.
+        // Instead, we check that the function works for a valid temp path.
+        use std::env;
+        use std::fs;
+        use std::path::PathBuf;
+
+        let mut temp_path = env::temp_dir();
+        temp_path.push("test_open_for_writing_should_succeed.txt");
+
+        // Clean up before test
+        let _ = fs::remove_file(&temp_path);
+
+        let result = DocumentManager::open_for_writing(&temp_path);
+        assert!(result.is_ok(), "Expected to be able to create a file in temp dir");
+
+        // Clean up after test
+        let _ = fs::remove_file(&temp_path);
+    }
 }