check if game data is present

src/game.rs

@@ -67,8 +67,10 @@ impl Version {
     }
 }
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq)]
 pub enum NotFound {
+    /// no game data whatsoever
+    Anything,
     Avatar,
     Room,
     Sprite,
@@ -101,7 +103,14 @@ pub struct GameHasNoAvatar;
 // todo no tiles? no rooms? no palettes? turn this into an enum?
 
 impl Game {
+    // todo return (Result<Game, ?>, Vec<Box<dyn Error>>)?
+    // would be nice to *try* to parse a game, and catalogue any and all errors without crashing,
+    // for display purposes etc.
     pub fn from(string: String) -> Result<Game, NotFound> {
+        if string.clone().trim() == "".to_string() {
+            return Err(NotFound::Anything);
+        }
+
         let line_endings_crlf = string.contains("\r\n");
         let mut string = string;
         if line_endings_crlf {
@@ -834,7 +843,7 @@ impl Game {
 
 #[cfg(test)]
 mod test {
-    use crate::game::{Version, Game};
+    use crate::game::{Version, Game, NotFound};
     use crate::text::{TextDirection, Font};
     use crate::tile::Tile;
     use crate::image::Image;
@@ -1059,4 +1068,10 @@ mod test {
         let expected = Some(&game.tiles[0]);
         assert_eq!(output, expected);
     }
+
+    #[test]
+    fn empty_game_data_throws_error() {
+        assert_eq!(Game::from("".to_string()        ).err().unwrap(), NotFound::Anything);
+        assert_eq!(Game::from(" \n \r\n".to_string()).err().unwrap(), NotFound::Anything);
+    }
 }