557ab9897a
# Objective - In the large majority of cases, users were calling `.unwrap()` immediately after `.get_resource`. - Attempting to add more helpful error messages here resulted in endless manual boilerplate (see #3899 and the linked PRs). ## Solution - Add an infallible variant named `.resource` and so on. - Use these infallible variants over `.get_resource().unwrap()` across the code base. ## Notes I did not provide equivalent methods on `WorldCell`, in favor of removing it entirely in #3939. ## Migration Guide Infallible variants of `.get_resource` have been added that implicitly panic, rather than needing to be unwrapped. Replace `world.get_resource::<Foo>().unwrap()` with `world.resource::<Foo>()`. ## Impact - `.unwrap` search results before: 1084 - `.unwrap` search results after: 942 - internal `unwrap_or_else` calls added: 4 - trivial unwrap calls removed from tests and code: 146 - uses of the new `try_get_resource` API: 11 - percentage of the time the unwrapping API was used internally: 93%
98 lines
2.6 KiB
Rust
98 lines
2.6 KiB
Rust
use bevy::prelude::*;
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#[derive(Component, Default)]
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struct Enemy {
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hit_points: u32,
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}
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fn despawn_dead_enemies(mut commands: Commands, enemies: Query<(Entity, &Enemy)>) {
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for (entity, enemy) in enemies.iter() {
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if enemy.hit_points == 0 {
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commands.entity(entity).despawn_recursive();
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}
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}
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}
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fn hurt_enemies(mut enemies: Query<&mut Enemy>) {
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for mut enemy in enemies.iter_mut() {
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enemy.hit_points -= 1;
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}
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}
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fn spawn_enemy(mut commands: Commands, keyboard_input: Res<Input<KeyCode>>) {
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if keyboard_input.just_pressed(KeyCode::Space) {
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commands.spawn().insert(Enemy { hit_points: 5 });
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}
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}
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#[test]
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fn did_hurt_enemy() {
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// Setup world
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let mut world = World::default();
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// Setup stage with our two systems
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let mut update_stage = SystemStage::parallel();
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update_stage.add_system(hurt_enemies.before("death"));
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update_stage.add_system(despawn_dead_enemies.label("death"));
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// Setup test entities
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let enemy_id = world.spawn().insert(Enemy { hit_points: 5 }).id();
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// Run systems
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update_stage.run(&mut world);
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// Check resulting changes
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assert!(world.get::<Enemy>(enemy_id).is_some());
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assert_eq!(world.get::<Enemy>(enemy_id).unwrap().hit_points, 4);
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}
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#[test]
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fn did_despawn_enemy() {
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// Setup world
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let mut world = World::default();
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// Setup stage with our two systems
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let mut update_stage = SystemStage::parallel();
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update_stage.add_system(hurt_enemies.before("death"));
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update_stage.add_system(despawn_dead_enemies.label("death"));
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// Setup test entities
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let enemy_id = world.spawn().insert(Enemy { hit_points: 1 }).id();
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// Run systems
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update_stage.run(&mut world);
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// Check resulting changes
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assert!(world.get::<Enemy>(enemy_id).is_none());
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}
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#[test]
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fn spawn_enemy_using_input_resource() {
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// Setup world
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let mut world = World::default();
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// Setup stage with a system
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let mut update_stage = SystemStage::parallel();
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update_stage.add_system(spawn_enemy);
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// Setup test resource
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let mut input = Input::<KeyCode>::default();
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input.press(KeyCode::Space);
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world.insert_resource(input);
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// Run systems
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update_stage.run(&mut world);
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// Check resulting changes, one entity has been spawned with `Enemy` component
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assert_eq!(world.query::<&Enemy>().iter(&world).len(), 1);
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// Clear the `just_pressed` status for all `KeyCode`s
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world.resource_mut::<Input<KeyCode>>().clear();
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// Run systems
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update_stage.run(&mut world);
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// Check resulting changes, no new entity has been spawned
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assert_eq!(world.query::<&Enemy>().iter(&world).len(), 1);
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}
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