coalesce error handler param into CommandError

Author: NathanSWard

crates/bevy_ecs/src/system/commands/config.rs

@@ -1,4 +1,3 @@
-use crate::world::World;
 use std::{
     fmt::Debug,
     ops::{Deref, DerefMut},
@@ -94,7 +93,7 @@ macro_rules! impl_fallible_commands {
         {
             pub fn on_failure<'this, H>(&'this mut self, error_handler: H) -> $returnty
             where
-                H: FnOnce(C::Error, &mut World) + Send + Sync + 'static,
+                H: FnOnce(CommandError<'_, C>) + Send + Sync + 'static,
             {
                 let command = self.command.take().unwrap();
                 self.inner.add_command(FallibleCommandWrapper {

crates/bevy_ecs/src/system/commands/fallible.rs

@@ -3,6 +3,11 @@ use crate::world::World;
 use bevy_utils::tracing::error;
 use std::fmt::Debug;
 
+pub struct CommandError<'a, C: FallibleCommand> {
+    pub error: C::Error,
+    pub world: &'a mut World,
+}
+
 pub trait FallibleCommand: Send + Sync + 'static {
     type Error;
 
@@ -55,7 +60,7 @@ where
 pub(crate) struct FallibleCommandWrapper<C, E>
 where
     C: FallibleCommand,
-    E: FnOnce(C::Error, &mut World) + Send + Sync + 'static,
+    E: FnOnce(CommandError<'_, C>) + Send + Sync + 'static,
 {
     pub(crate) command: C,
     pub(crate) error_handler: E,
@@ -64,16 +69,16 @@ where
 impl<C, E> Command for FallibleCommandWrapper<C, E>
 where
     C: FallibleCommand,
-    E: FnOnce(C::Error, &mut World) + Send + Sync + 'static,
+    E: FnOnce(CommandError<'_, C>) + Send + Sync + 'static,
 {
     fn write(self: Box<Self>, world: &mut World) {
         let FallibleCommandWrapper {
             command,
             error_handler,
         } = *self;
 
-        if let Err(e) = command.try_write(world) {
-            (error_handler)(e, world);
+        if let Err(error) = command.try_write(world) {
+            (error_handler)(CommandError { error, world });
         }
     }
 }

crates/bevy_ecs/src/system/commands/mod.rs

@@ -7,7 +7,6 @@ use crate::{
     entity::{Entities, Entity},
     world::World,
 };
-use config::*;
 use fallible::*;
 use std::{fmt::Debug, marker::PhantomData};
 
@@ -732,7 +731,7 @@ mod tests {
 
             let mut try_despawn = |e| {
                 let invoked_clone = invoked.clone();
-                commands.entity(e).despawn().on_failure(move |_, _| {
+                commands.entity(e).despawn().on_failure(move |_| {
                     invoked_clone.fetch_add(1, Ordering::Relaxed);
                 });
             };