Removed panic sources from server event handling

CHANGELOG.md

@@ -23,6 +23,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- Fixed a bug that would cause a server crash when a player levelled up or fired
+  a projectile in very specific circumstances
+
 ## [0.8.0] - 2020-11-28
 
 ### Added

server/src/events/entity_creation.rs

@@ -118,12 +118,11 @@ pub fn handle_shoot(
 ) {
     let state = server.state_mut();
 
-    let mut pos = state
-        .ecs()
-        .read_storage::<Pos>()
-        .get(entity)
-        .expect("Failed to fetch entity")
-        .0;
+    let mut pos = if let Some(pos) = state.ecs().read_storage::<Pos>().get(entity) {
+        pos.0
+    } else {
+        return;
+    };
 
     let vel = *dir * speed;
 

server/src/events/entity_manipulation.rs

@@ -721,23 +721,18 @@ pub fn handle_explosion(
 
 pub fn handle_level_up(server: &mut Server, entity: EcsEntity, new_level: u32) {
     let ecs = &server.state.ecs();
-    let uids = server.state.ecs().read_storage::<Uid>();
-    let uid = uids
+    if let Some((uid, pos)) = ecs
+        .read_storage::<Uid>()
         .get(entity)
-        .expect("Failed to fetch uid component for entity.");
-    let pos = server
-        .state
-        .ecs()
-        .read_storage::<Pos>()
-        .get(entity)
-        .expect("Failed to fetch position component for the entity.")
-        .0;
-
-    server.state.notify_players(ServerGeneral::PlayerListUpdate(
-        PlayerListUpdate::LevelChange(*uid, new_level),
-    ));
+        .copied()
+        .zip(ecs.read_storage::<Pos>().get(entity).map(|p| p.0))
+    {
         ecs.write_resource::<Vec<Outcome>>()
             .push(Outcome::LevelUp { pos });
+        server.state.notify_players(ServerGeneral::PlayerListUpdate(
+            PlayerListUpdate::LevelChange(uid, new_level),
+        ));
+    }
 }
 
 pub fn handle_aura(server: &mut Server, entity: EcsEntity, aura_change: aura::AuraChange) {