Change HandleUntyped::typed to not panic

crates/bevy_asset/src/asset_server.rs

@@ -230,7 +230,9 @@ impl AssetServer {
     /// `"assets"`.
     #[must_use = "not using the returned strong handle may result in the unexpected release of the asset"]
     pub fn load<'a, T: Asset, P: Into<AssetPath<'a>>>(&self, path: P) -> Handle<T> {
-        self.load_untyped(path).typed()
+        self.load_untyped(path).typed().expect(
+            "Failed to convert untyped handle from asset to typed, this should never happen. Report a bug!",
+        )
     }
 
     async fn load_async(

crates/bevy_asset/src/handle.rs

@@ -275,23 +275,26 @@ impl HandleUntyped {
         matches!(self.handle_type, HandleType::Strong(_))
     }
 
-    pub fn typed<T: Asset>(mut self) -> Handle<T> {
+    pub fn typed<T: Asset>(mut self) -> Result<Handle<T>, Self> {
         if let HandleId::Id(type_uuid, _) = self.id {
             if T::TYPE_UUID != type_uuid {
-                panic!("Attempted to convert handle to invalid type.");
+                return Err(self);
             }
         }
+
         let handle_type = match &self.handle_type {
             HandleType::Strong(sender) => HandleType::Strong(sender.clone()),
             HandleType::Weak => HandleType::Weak,
         };
+
         // ensure we don't send the RefChange event when "self" is dropped
         self.handle_type = HandleType::Weak;
-        Handle {
+
+        Ok(Handle {
             handle_type,
             id: self.id,
             marker: PhantomData::default(),
-        }
+        })
     }
 }
 

crates/bevy_pbr/src/entity.rs

@@ -27,7 +27,7 @@ impl Default for PbrBundle {
     fn default() -> Self {
         Self {
             render_pipelines: RenderPipelines::from_pipelines(vec![RenderPipeline::new(
-                PBR_PIPELINE_HANDLE.typed(),
+                PBR_PIPELINE_HANDLE.typed().unwrap(),
             )]),
             mesh: Default::default(),
             visible: Default::default(),

crates/bevy_pbr/src/render_graph/pbr_pipeline/mod.rs

@@ -10,6 +10,7 @@ use bevy_render::{
     texture::TextureFormat,
 };
 
+// FIXME: Handle is always converted to typed, see discussion in PR #2536
 pub const PBR_PIPELINE_HANDLE: HandleUntyped =
     HandleUntyped::weak_from_u64(PipelineDescriptor::TYPE_UUID, 13148362314012771389);
 

crates/bevy_render/src/wireframe/mod.rs

@@ -18,6 +18,7 @@ use bevy_utils::HashSet;
 
 mod pipeline;
 
+// FIXME: Handle is always converted to typed, see discussion in PR #2536
 pub const WIREFRAME_PIPELINE_HANDLE: HandleUntyped =
     HandleUntyped::weak_from_u64(PipelineDescriptor::TYPE_UUID, 0x137c75ab7e9ad7f5);
 
@@ -84,7 +85,7 @@ pub fn draw_wireframes_system(
         };
 
         let mut render_pipeline = RenderPipeline::specialized(
-            WIREFRAME_PIPELINE_HANDLE.typed(),
+            WIREFRAME_PIPELINE_HANDLE.typed().unwrap(),
             PipelineSpecialization {
                 sample_count: msaa.samples,
                 strip_index_format: None,

crates/bevy_sprite/src/entity.rs

@@ -28,9 +28,9 @@ pub struct SpriteBundle {
 impl Default for SpriteBundle {
     fn default() -> Self {
         Self {
-            mesh: QUAD_HANDLE.typed(),
+            mesh: QUAD_HANDLE.typed().unwrap(),
             render_pipelines: RenderPipelines::from_pipelines(vec![RenderPipeline::new(
-                SPRITE_PIPELINE_HANDLE.typed(),
+                SPRITE_PIPELINE_HANDLE.typed().unwrap(),
             )]),
             visible: Visible {
                 is_transparent: true,
@@ -68,14 +68,14 @@ impl Default for SpriteSheetBundle {
     fn default() -> Self {
         Self {
             render_pipelines: RenderPipelines::from_pipelines(vec![RenderPipeline::new(
-                SPRITE_SHEET_PIPELINE_HANDLE.typed(),
+                SPRITE_SHEET_PIPELINE_HANDLE.typed().unwrap(),
             )]),
             visible: Visible {
                 is_transparent: true,
                 ..Default::default()
             },
             main_pass: MainPass,
-            mesh: QUAD_HANDLE.typed(),
+            mesh: QUAD_HANDLE.typed().unwrap(),
             draw: Default::default(),
             sprite: Default::default(),
             texture_atlas: Default::default(),

crates/bevy_sprite/src/lib.rs

@@ -63,6 +63,7 @@ impl Default for SpriteSettings {
 #[derive(Default)]
 pub struct SpritePlugin;
 
+// FIXME: Handle is always converted to typed, see discussion in PR #2536
 pub const QUAD_HANDLE: HandleUntyped =
     HandleUntyped::weak_from_u64(Mesh::TYPE_UUID, 14240461981130137526);
 

crates/bevy_sprite/src/render/mod.rs

@@ -12,9 +12,11 @@ use bevy_render::{
     texture::TextureFormat,
 };
 
+// FIXME: Handle is always converted to typed, see discussion in PR #2536
 pub const SPRITE_PIPELINE_HANDLE: HandleUntyped =
     HandleUntyped::weak_from_u64(PipelineDescriptor::TYPE_UUID, 2785347840338765446);
 
+// FIXME: Handle is always converted to typed, see discussion in PR #2536
 pub const SPRITE_SHEET_PIPELINE_HANDLE: HandleUntyped =
     HandleUntyped::weak_from_u64(PipelineDescriptor::TYPE_UUID, 9016885805180281612);
 

crates/bevy_text/src/draw.rs

@@ -28,7 +28,7 @@ impl<'a> Drawable for DrawableText<'a> {
     fn draw(&mut self, draw: &mut Draw, context: &mut DrawContext) -> Result<(), DrawError> {
         context.set_pipeline(
             draw,
-            &bevy_sprite::SPRITE_SHEET_PIPELINE_HANDLE.typed(),
+            &bevy_sprite::SPRITE_SHEET_PIPELINE_HANDLE.typed().unwrap(),
             &PipelineSpecialization {
                 sample_count: self.msaa.samples,
                 vertex_buffer_layout: self.font_quad_vertex_layout.clone(),
@@ -40,7 +40,7 @@ impl<'a> Drawable for DrawableText<'a> {
 
         if let Some(RenderResourceId::Buffer(vertex_attribute_buffer_id)) = render_resource_context
             .get_asset_resource(
-                &bevy_sprite::QUAD_HANDLE.typed::<Mesh>(),
+                &bevy_sprite::QUAD_HANDLE.typed::<Mesh>().unwrap(),
                 mesh::VERTEX_ATTRIBUTE_BUFFER_ID,
             )
         {
@@ -52,7 +52,7 @@ impl<'a> Drawable for DrawableText<'a> {
         let mut indices = 0..0;
         if let Some(RenderResourceId::Buffer(quad_index_buffer)) = render_resource_context
             .get_asset_resource(
-                &bevy_sprite::QUAD_HANDLE.typed::<Mesh>(),
+                &bevy_sprite::QUAD_HANDLE.typed::<Mesh>().unwrap(),
                 mesh::INDEX_BUFFER_ASSET_INDEX,
             )
         {

crates/bevy_ui/src/entity.rs

@@ -33,9 +33,9 @@ pub struct NodeBundle {
 impl Default for NodeBundle {
     fn default() -> Self {
         NodeBundle {
-            mesh: QUAD_HANDLE.typed(),
+            mesh: QUAD_HANDLE.typed().unwrap(),
             render_pipelines: RenderPipelines::from_pipelines(vec![RenderPipeline::new(
-                UI_PIPELINE_HANDLE.typed(),
+                UI_PIPELINE_HANDLE.typed().unwrap(),
             )]),
             visible: Visible {
                 is_transparent: true,
@@ -69,9 +69,9 @@ pub struct ImageBundle {
 impl Default for ImageBundle {
     fn default() -> Self {
         ImageBundle {
-            mesh: QUAD_HANDLE.typed(),
+            mesh: QUAD_HANDLE.typed().unwrap(),
             render_pipelines: RenderPipelines::from_pipelines(vec![RenderPipeline::new(
-                UI_PIPELINE_HANDLE.typed(),
+                UI_PIPELINE_HANDLE.typed().unwrap(),
             )]),
             node: Default::default(),
             image: Default::default(),
@@ -143,9 +143,9 @@ impl Default for ButtonBundle {
     fn default() -> Self {
         ButtonBundle {
             button: Button,
-            mesh: QUAD_HANDLE.typed(),
+            mesh: QUAD_HANDLE.typed().unwrap(),
             render_pipelines: RenderPipelines::from_pipelines(vec![RenderPipeline::new(
-                UI_PIPELINE_HANDLE.typed(),
+                UI_PIPELINE_HANDLE.typed().unwrap(),
             )]),
             interaction: Default::default(),
             focus_policy: Default::default(),

crates/bevy_ui/src/render/mod.rs

@@ -17,6 +17,7 @@ use bevy_render::{
     texture::TextureFormat,
 };
 
+// FIXME: Handle is always converted to typed, see discussion in PR #2536
 pub const UI_PIPELINE_HANDLE: HandleUntyped =
     HandleUntyped::weak_from_u64(PipelineDescriptor::TYPE_UUID, 3234320022263993878);
 

examples/2d/texture_atlas.rs

@@ -21,11 +21,16 @@ enum AppState {
 
 #[derive(Default)]
 struct RpgSpriteHandles {
-    handles: Vec<HandleUntyped>,
+    handles: Vec<Handle<Texture>>,
 }
 
 fn load_textures(mut rpg_sprite_handles: ResMut<RpgSpriteHandles>, asset_server: Res<AssetServer>) {
-    rpg_sprite_handles.handles = asset_server.load_folder("textures/rpg").unwrap();
+    if let Ok(handles) = asset_server.load_folder("textures/rpg") {
+        rpg_sprite_handles.handles = handles
+            .into_iter()
+            .flat_map(|handle| handle.typed::<Texture>())
+            .collect();
+    }
 }
 
 fn check_textures(
@@ -51,7 +56,7 @@ fn setup(
     let mut texture_atlas_builder = TextureAtlasBuilder::default();
     for handle in rpg_sprite_handles.handles.iter() {
         let texture = textures.get(handle).unwrap();
-        texture_atlas_builder.add_texture(handle.clone_weak().typed::<Texture>(), texture);
+        texture_atlas_builder.add_texture(handle.clone_weak(), texture);
     }
 
     let texture_atlas = texture_atlas_builder.finish(&mut textures).unwrap();

examples/3d/render_to_texture.rs

@@ -21,6 +21,7 @@ use bevy::{
 
 pub struct FirstPass;
 
+// FIXME: Handle is always converted to typed, see discussion in PR #2536
 pub const RENDER_TEXTURE_HANDLE: HandleUntyped =
     HandleUntyped::weak_from_u64(Texture::TYPE_UUID, 13378939762009864029);
 
@@ -186,7 +187,7 @@ fn setup(
 
     commands.spawn_bundle(first_pass_camera);
 
-    let texture_handle = RENDER_TEXTURE_HANDLE.typed();
+    let texture_handle = RENDER_TEXTURE_HANDLE.typed().unwrap();
 
     let cube_size = 4.0;
     let cube_handle = meshes.add(Mesh::from(shape::Box::new(cube_size, cube_size, cube_size)));