fix dedupe_tiles function and test

src/game.rs

@@ -675,6 +675,17 @@ impl Game {
         new_unique_id(self.variable_ids())
     }
 
+    /// todo refactor?
+    pub fn get_tile_id(&self, matching_tile: &Tile) -> Option<String> {
+        for tile in &self.tiles {
+            if tile == matching_tile {
+                return Some(tile.id.clone());
+            }
+        }
+
+        None
+    }
+
     /// adds a palette safely and returns the ID
     #[inline]
     pub fn add_palette(&mut self, mut palette: Palette) -> String {
@@ -774,8 +785,10 @@ impl Game {
             if tile == crate::mock::tile_background() {
                 tile_id_changes.insert(tile.id, "0".to_string());
             } else if tiles_temp.contains(&tile) {
-                // todo get the ID of the first matching tile
+                tile_id_changes.insert(
-                //tile_id_changes.insert(tile.id, tiles_temp);
+                    tile.id.clone(),
+                    self.get_tile_id(&tile).unwrap()
+                );
             } else {
                 unique_tiles.push(tile);
             }
@@ -785,6 +798,8 @@ impl Game {
             room.change_tile_ids(&tile_id_changes);
         }
 
+        unique_tiles.reverse();
+
         self.tiles = unique_tiles;
     }
 
@@ -849,6 +864,8 @@ mod test {
     use crate::game::{Version, Game};
     use crate::text::{TextDirection, Font};
     use crate::tile::Tile;
+    use std::sync::TryLockError;
+    use crate::image::Image;
 
     #[test]
     fn test_game_from_string() {
@@ -989,5 +1006,52 @@ mod test {
         game.add_tile(crate::mock::tile_background());
         game.dedupe_tiles();
         assert_eq!(game.tiles, vec![crate::mock::tile_default()]);
+
+        let tile_a = Tile {
+            id: "0".to_string(),
+            name: Some("apple".to_string()),
+            wall: Some(true),
+            animation_frames: vec![Image {
+                pixels: vec![
+                    0,1,1,0,1,1,0,1,
+                    0,1,1,0,1,1,0,1,
+                    1,0,1,0,1,0,0,1,
+                    1,0,1,0,1,0,0,1,
+                    0,0,0,0,1,1,1,1,
+                    0,0,0,0,1,1,1,1,
+                    1,1,0,1,1,0,1,1,
+                    1,1,0,1,1,0,1,1,
+                ]
+            }],
+            colour_id: Some(1)
+        };
+
+        let tile_b = Tile {
+            id: "1".to_string(),
+            name: Some("frogspawn".to_string()),
+            wall: Some(false),
+            animation_frames: vec![Image {
+                pixels: vec![
+                    1,0,1,0,1,0,0,1,
+                    0,1,1,0,1,1,0,1,
+                    0,1,1,0,1,1,0,1,
+                    1,1,0,1,1,0,1,1,
+                    1,0,1,0,1,0,0,1,
+                    0,0,0,0,1,1,1,1,
+                    0,0,0,0,1,1,1,1,
+                    1,1,0,1,1,0,1,1,
+                ]
+            }],
+            colour_id: None
+        };
+
+        game.add_tile(tile_a.clone());
+        game.add_tile(tile_b.clone());
+        game.add_tile(tile_a.clone());
+        game.add_tile(tile_b.clone());
+
+        game.dedupe_tiles();
+
+        assert_eq!(game.tiles, vec![crate::mock::tile_default(), tile_a, tile_b]);
     }
 }