From 4d33a0a2843d39c237f1c75363baf772aff68d06 Mon Sep 17 00:00:00 2001
From: Max Bradbury <max@tinybird.info>
Date: Tue, 23 Jun 2020 13:01:04 +0100
Subject: [PATCH] handle errors on sprite parsing

---
 src/game.rs   |  5 ++++-
 src/sprite.rs | 15 +++++++++------
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/src/game.rs b/src/game.rs
index 8126cf1..d29284b 100644
--- a/src/game.rs
+++ b/src/game.rs
@@ -186,7 +186,10 @@ impl Game {
             } else if segment.starts_with("TIL ") {
                 tiles.push(Tile::from(segment));
             } else if segment.starts_with("SPR ") {
-                sprites.push(Sprite::from(segment));
+                let sprite = Sprite::from(segment);
+                if sprite.is_ok() {
+                    sprites.push(sprite.unwrap());
+                }
             } else if segment.starts_with("ITM ") {
                 items.push(Item::from(segment));
             } else if segment.starts_with("DLG ") {
diff --git a/src/sprite.rs b/src/sprite.rs
index f42fd2e..c8bae13 100644
--- a/src/sprite.rs
+++ b/src/sprite.rs
@@ -54,9 +54,12 @@ impl Sprite {
     }
 }
 
-impl From<String> for Sprite {
+#[derive(Debug)]
+pub struct SpriteMissingRoomPosition;
+
+impl Sprite {
     #[inline]
-    fn from(string: String) -> Sprite {
+    pub(crate) fn from(string: String) -> Result<Sprite, SpriteMissingRoomPosition> {
         let mut lines: Vec<&str> = string.lines().collect();
 
         let id = lines[0].replace("SPR ", "");
@@ -80,7 +83,7 @@ impl From<String> for Sprite {
                 room_id = Some(room_position[0].to_string());
 
                 if room_position.len() < 2 {
-                    panic!("Bad room/position for sprite: {}", string);
+                    return Err(SpriteMissingRoomPosition);
                 }
 
                 position = Some(Position::from_str(room_position[1]).unwrap());
@@ -100,7 +103,7 @@ impl From<String> for Sprite {
             lines[1..].join("\n")
         );
 
-        Sprite {
+        Ok(Sprite {
             id,
             name,
             animation_frames,
@@ -109,7 +112,7 @@ impl From<String> for Sprite {
             position,
             colour_id,
             items
-        }
+        })
     }
 }
 
@@ -136,7 +139,7 @@ mod test {
 
     #[test]
     fn test_sprite_from_string() {
-        let output = Sprite::from(include_str!("test-resources/sprite").to_string());
+        let output = Sprite::from(include_str!("test-resources/sprite").to_string()).unwrap();
         let expected = mock::sprite();
 
         assert_eq!(output, expected);