Make sure trigger_ability spends resource costs

RELEASES.md

@@ -16,6 +16,11 @@
   - `ready_no_cost` and `trigger_no_cost` have been added to `Abilitylike`
   - when working with multiple resource pools, you should pass in `NullPool` as the type argument for `AbilityState`
 
+## Bugs (0.9)
+
+- `Actionlike::trigger` and friends now expends resource costs correctly
+  - if you were working around this bug, remember to remove your workaround to avoid double-spending!
+
 ## Version 0.8
 
 - now supports Bevy 0.14

src/lib.rs

@@ -231,7 +231,7 @@ pub fn trigger_ability<P: Pool>(
     ability_ready(
         charges.as_deref(),
         cooldown.as_deref(),
-        pool.map(|p| &*p),
+        pool.as_deref(),
         cost,
     )?;
 
@@ -241,6 +241,14 @@ pub fn trigger_ability<P: Pool>(
         cooldown.trigger()?;
     }
 
+    if let Some(pool) = pool {
+        if let Some(cost) = cost {
+            let _pool_result = pool.expend(cost);
+            // This is good to check, but panics in release mode are miserable
+            debug_assert!(_pool_result.is_ok());
+        }
+    }
+
     Ok(())
 }