diff --git a/pttodoer/src/main.rs b/pttodoer/src/main.rs
index 37a0b07..29b15e5 100644
--- a/pttodoer/src/main.rs
+++ b/pttodoer/src/main.rs
@@ -243,6 +243,148 @@ impl DB {
 mod test_db {
    use super::*;
 
+   #[test]
+   fn edit_append_duplicate_keeps_both() {
+      use std::io::Seek;
+
+      let db = new_test_db(1, 1);
+      let db_after = db._edit(|cwd| {
+         let files_in_dir = std::fs::read_dir(cwd).expect("failed to ls cwd").collect::<Vec<_>>();
+         assert_eq!(1, files_in_dir.len());
+         let mut f = std::fs::OpenOptions::new()
+            .write(true)
+            .append(true)
+            .open(files_in_dir[0].as_ref().expect("failed to get file in dir").path())
+            .expect("failed to open file for append");
+         f.seek(std::io::SeekFrom::End(0)).expect("failed to seek to end");
+         f.write_all(b"\n- f").expect("failed to append the file in cwd");
+         f.write_all(b"\n- f").expect("failed to append the file in cwd");
+      }).expect("failed to not edit");
+      assert_ne!(db, db_after);
+
+      assert_eq!(1, db_after.tasks_and_metadatas.len());
+      assert_eq!(3, db_after.tasks_and_metadatas[0].tasks.len());
+      assert_eq!(db.tasks_and_metadatas[0].tasks.0[0], db_after.tasks_and_metadatas[0].tasks.0[0]);
+      assert_eq!(Some("f".to_string()), db_after.tasks_and_metadatas[0].tasks.0[1].get("is".to_string()));
+      assert_eq!(Some("f".to_string()), db_after.tasks_and_metadatas[0].tasks.0[2].get("is".to_string()));
+   }
+
+   #[test]
+   fn edit_schedule_future() {
+      let db = new_test_db(0, 0);
+      let db_after = db._edit(|cwd| {
+         let mut task = Task::new();
+         task.set("k".to_string(), "v".to_string());
+         task.set("schedule".to_string(), "2101-02-03".to_string());
+
+         let mut tasks = Tasks::new();
+         tasks.0.push(task);
+
+         let temp = TasksAndMetadata::new_with(
+            format!("{}/only", cwd),
+            TS::now(),
+            tasks,
+         );
+         temp.save(false).expect("failed to save");
+      }).expect("failed to not edit");
+      assert_ne!(db, db_after);
+
+      assert_eq!(1, db_after.tasks_and_metadatas.len());
+      assert_eq!(1, db_after.tasks_and_metadatas[0].tasks.len());
+      assert_eq!(0, db_after.tasks_and_metadatas[0].due().tasks.len());
+      assert_eq!(1, db_after.tasks_and_metadatas[0].not_due().tasks.len());
+   }
+
+   #[test]
+   fn edit_schedule_past() {
+      let db = new_test_db(0, 0);
+      let db_after = db._edit(|cwd| {
+         let mut task = Task::new();
+         task.set("k".to_string(), "v".to_string());
+         task.set("schedule".to_string(), "2001-02-03".to_string());
+
+         let mut tasks = Tasks::new();
+         tasks.0.push(task);
+
+         let temp = TasksAndMetadata::new_with(
+            format!("{}/only", cwd),
+            TS::now(),
+            tasks,
+         );
+         temp.save(false).expect("failed to save");
+      }).expect("failed to not edit");
+      assert_ne!(db, db_after);
+
+      assert_eq!(1, db_after.tasks_and_metadatas.len());
+      assert_eq!(1, db_after.tasks_and_metadatas[0].tasks.len());
+      assert_eq!(1, db_after.tasks_and_metadatas[0].due().tasks.len());
+      assert_eq!(0, db_after.tasks_and_metadatas[0].not_due().tasks.len());
+   }
+
+
+   #[test]
+   fn edit_append_second_file() {
+      use std::io::Seek;
+
+      let db = new_test_db(2, 1);
+      let db_after = db._edit(|cwd| {
+         let files_in_dir = std::fs::read_dir(cwd).expect("failed to ls cwd").collect::<Vec<_>>();
+         assert_eq!(2, files_in_dir.len());
+         let mut f = std::fs::OpenOptions::new()
+            .write(true)
+            .append(true)
+            .open(files_in_dir[1].as_ref().expect("failed to get file in dir").path())
+            .expect("failed to open file for append");
+         f.seek(std::io::SeekFrom::End(0)).expect("failed to seek to end");
+         f.write_all(b"\n- f").expect("failed to append the file in cwd");
+      }).expect("failed to not edit");
+      assert_ne!(db, db_after);
+
+      assert_eq!(2, db_after.tasks_and_metadatas.len());
+      assert_eq!(1, db_after.tasks_and_metadatas[0].tasks.len());
+      assert_eq!(2, db_after.tasks_and_metadatas[1].tasks.len());
+      assert_eq!(db.tasks_and_metadatas[1].tasks.0[0], db_after.tasks_and_metadatas[1].tasks.0[0]);
+      assert_eq!(Some("f".to_string()), db_after.tasks_and_metadatas[1].tasks.0[1].get("is".to_string()));
+   }
+
+   #[test]
+   fn edit_append_current_file() {
+      use std::io::Seek;
+
+      let db = new_test_db(1, 1);
+      let db_after = db._edit(|cwd| {
+         let files_in_dir = std::fs::read_dir(cwd).expect("failed to ls cwd").collect::<Vec<_>>();
+         assert_eq!(1, files_in_dir.len());
+         let mut f = std::fs::OpenOptions::new()
+            .write(true)
+            .append(true)
+            .open(files_in_dir[0].as_ref().expect("failed to get file in dir").path())
+            .expect("failed to open file for append");
+         f.seek(std::io::SeekFrom::End(0)).expect("failed to seek to end");
+         f.write_all(b"\n- f").expect("failed to append the file in cwd");
+      }).expect("failed to not edit");
+      assert_ne!(db, db_after);
+
+      assert_eq!(1, db_after.tasks_and_metadatas.len());
+      assert_eq!(2, db_after.tasks_and_metadatas[0].tasks.len());
+      assert_eq!(db.tasks_and_metadatas[0].tasks.0[0], db_after.tasks_and_metadatas[0].tasks.0[0]);
+      assert_eq!(Some("f".to_string()), db_after.tasks_and_metadatas[0].tasks.0[1].get("is".to_string()));
+   }
+
+   #[test]
+   fn edit_insert_new_second_file() {
+      let db = new_test_db(1, 1);
+      let db_after = db._edit(|cwd| {
+         let mut f = std::fs::File::create(format!("{}/new_second_file", cwd)).expect("failed to open a file in cwd");
+         f.write_all(b"f").expect("failed to write a file in cwd");
+      }).expect("failed to not edit");
+      assert_ne!(db, db_after);
+
+      assert_eq!(2, db_after.tasks_and_metadatas.len());
+      assert_eq!(1, db_after.tasks_and_metadatas[1].tasks.len());
+      assert_eq!(1, db_after.tasks_and_metadatas[0].tasks.len());
+   }
+
    #[test]
    fn edit_insert_empty() {
       let db = new_test_db(0, 0);
@@ -354,7 +496,10 @@ impl TasksAndMetadata {
    }
 
    pub fn save(&self, dry_run: bool) -> Result<(), String> {
-      let version = file_version(self.file.clone())?;
+      let version = match file_version(self.file.clone()){
+         Ok(v) => v,
+         Err(_) => self.version.clone(),
+      };
       let mut file = self.file.clone();
       if version != self.version {
          file = format!("{}.{}", &self.file, TS::now().to_string());