bevy/crates/bevy_app/src/app.rs
MichiRecRoom 2a66bf0909
Clarify that bevy_app::App.world() (and mut variant) returns the main SubApp's World (#16527)
# Objective
The documentation for `bevy_app::App.world()` (and its mut variant)
could confuse some into thinking that this is the only World that the
App will contain.

## Solution
Clarify the documentation for `bevy_app::App.world()` (and its mut
variant), to say that it returns the main subapp's world. This helps
imply that Apps can contain more than one world (albeit, only one per
SubApp).

## Testing
This is a documentation change, with no changes to doctests. Thus,
testing is not necessary beyond ensuring the link syntax is correct.
2024-11-27 16:09:09 +00:00

1787 lines
61 KiB
Rust

use crate::{
First, Main, MainSchedulePlugin, PlaceholderPlugin, Plugin, Plugins, PluginsState, SubApp,
SubApps,
};
pub use bevy_derive::AppLabel;
use bevy_ecs::{
component::RequiredComponentsError,
event::{event_update_system, EventCursor},
intern::Interned,
prelude::*,
schedule::{ScheduleBuildSettings, ScheduleLabel},
system::{IntoObserverSystem, SystemId, SystemInput},
};
#[cfg(feature = "trace")]
use bevy_utils::tracing::info_span;
use bevy_utils::{tracing::debug, HashMap};
use core::{fmt::Debug, num::NonZero, panic::AssertUnwindSafe};
use derive_more::derive::{Display, Error};
use std::{
panic::{catch_unwind, resume_unwind},
process::{ExitCode, Termination},
};
bevy_ecs::define_label!(
/// A strongly-typed class of labels used to identify an [`App`].
AppLabel,
APP_LABEL_INTERNER
);
pub use bevy_ecs::label::DynEq;
/// A shorthand for `Interned<dyn AppLabel>`.
pub type InternedAppLabel = Interned<dyn AppLabel>;
#[derive(Debug, Error, Display)]
pub(crate) enum AppError {
#[display("duplicate plugin {plugin_name:?}")]
DuplicatePlugin { plugin_name: String },
}
/// [`App`] is the primary API for writing user applications. It automates the setup of a
/// [standard lifecycle](Main) and provides interface glue for [plugins](`Plugin`).
///
/// A single [`App`] can contain multiple [`SubApp`] instances, but [`App`] methods only affect
/// the "main" one. To access a particular [`SubApp`], use [`get_sub_app`](App::get_sub_app)
/// or [`get_sub_app_mut`](App::get_sub_app_mut).
///
///
/// # Examples
///
/// Here is a simple "Hello World" Bevy app:
///
/// ```
/// # use bevy_app::prelude::*;
/// # use bevy_ecs::prelude::*;
/// #
/// fn main() {
/// App::new()
/// .add_systems(Update, hello_world_system)
/// .run();
/// }
///
/// fn hello_world_system() {
/// println!("hello world");
/// }
/// ```
pub struct App {
pub(crate) sub_apps: SubApps,
/// The function that will manage the app's lifecycle.
///
/// Bevy provides the [`WinitPlugin`] and [`ScheduleRunnerPlugin`] for windowed and headless
/// applications, respectively.
///
/// [`WinitPlugin`]: https://docs.rs/bevy/latest/bevy/winit/struct.WinitPlugin.html
/// [`ScheduleRunnerPlugin`]: https://docs.rs/bevy/latest/bevy/app/struct.ScheduleRunnerPlugin.html
pub(crate) runner: RunnerFn,
}
impl Debug for App {
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
write!(f, "App {{ sub_apps: ")?;
f.debug_map()
.entries(self.sub_apps.sub_apps.iter())
.finish()?;
write!(f, "}}")
}
}
impl Default for App {
fn default() -> Self {
let mut app = App::empty();
app.sub_apps.main.update_schedule = Some(Main.intern());
#[cfg(feature = "bevy_reflect")]
app.init_resource::<AppTypeRegistry>();
#[cfg(feature = "reflect_functions")]
app.init_resource::<AppFunctionRegistry>();
app.add_plugins(MainSchedulePlugin);
app.add_systems(
First,
event_update_system
.in_set(bevy_ecs::event::EventUpdates)
.run_if(bevy_ecs::event::event_update_condition),
);
app.add_event::<AppExit>();
app
}
}
impl App {
/// Creates a new [`App`] with some default structure to enable core engine features.
/// This is the preferred constructor for most use cases.
pub fn new() -> App {
App::default()
}
/// Creates a new empty [`App`] with minimal default configuration.
///
/// Use this constructor if you want to customize scheduling, exit handling, cleanup, etc.
pub fn empty() -> App {
Self {
sub_apps: SubApps {
main: SubApp::new(),
sub_apps: HashMap::new(),
},
runner: Box::new(run_once),
}
}
/// Runs the default schedules of all sub-apps (starting with the "main" app) once.
pub fn update(&mut self) {
if self.is_building_plugins() {
panic!("App::update() was called while a plugin was building.");
}
self.sub_apps.update();
}
/// Runs the [`App`] by calling its [runner](Self::set_runner).
///
/// This will (re)build the [`App`] first. For general usage, see the example on the item
/// level documentation.
///
/// # Caveats
///
/// Calls to [`App::run()`] will never return on iOS and Web.
///
/// Headless apps can generally expect this method to return control to the caller when
/// it completes, but that is not the case for windowed apps. Windowed apps are typically
/// driven by an event loop and some platforms expect the program to terminate when the
/// event loop ends.
///
/// By default, *Bevy* uses the `winit` crate for window creation.
///
/// # Panics
///
/// Panics if not all plugins have been built.
pub fn run(&mut self) -> AppExit {
#[cfg(feature = "trace")]
let _bevy_app_run_span = info_span!("bevy_app").entered();
if self.is_building_plugins() {
panic!("App::run() was called while a plugin was building.");
}
let runner = core::mem::replace(&mut self.runner, Box::new(run_once));
let app = core::mem::replace(self, App::empty());
(runner)(app)
}
/// Sets the function that will be called when the app is run.
///
/// The runner function `f` is called only once by [`App::run`]. If the
/// presence of a main loop in the app is desired, it is the responsibility of the runner
/// function to provide it.
///
/// The runner function is usually not set manually, but by Bevy integrated plugins
/// (e.g. `WinitPlugin`).
///
/// # Examples
///
/// ```
/// # use bevy_app::prelude::*;
/// #
/// fn my_runner(mut app: App) -> AppExit {
/// loop {
/// println!("In main loop");
/// app.update();
/// if let Some(exit) = app.should_exit() {
/// return exit;
/// }
/// }
/// }
///
/// App::new()
/// .set_runner(my_runner);
/// ```
pub fn set_runner(&mut self, f: impl FnOnce(App) -> AppExit + 'static) -> &mut Self {
self.runner = Box::new(f);
self
}
/// Returns the state of all plugins. This is usually called by the event loop, but can be
/// useful for situations where you want to use [`App::update`].
// TODO: &mut self -> &self
#[inline]
pub fn plugins_state(&mut self) -> PluginsState {
let mut overall_plugins_state = match self.main_mut().plugins_state {
PluginsState::Adding => {
let mut state = PluginsState::Ready;
let plugins = core::mem::take(&mut self.main_mut().plugin_registry);
for plugin in &plugins {
// plugins installed to main need to see all sub-apps
if !plugin.ready(self) {
state = PluginsState::Adding;
break;
}
}
self.main_mut().plugin_registry = plugins;
state
}
state => state,
};
// overall state is the earliest state of any sub-app
self.sub_apps.iter_mut().skip(1).for_each(|s| {
overall_plugins_state = overall_plugins_state.min(s.plugins_state());
});
overall_plugins_state
}
/// Runs [`Plugin::finish`] for each plugin. This is usually called by the event loop once all
/// plugins are ready, but can be useful for situations where you want to use [`App::update`].
pub fn finish(&mut self) {
// plugins installed to main should see all sub-apps
let plugins = core::mem::take(&mut self.main_mut().plugin_registry);
for plugin in &plugins {
plugin.finish(self);
}
let main = self.main_mut();
main.plugin_registry = plugins;
main.plugins_state = PluginsState::Finished;
self.sub_apps.iter_mut().skip(1).for_each(SubApp::finish);
}
/// Runs [`Plugin::cleanup`] for each plugin. This is usually called by the event loop after
/// [`App::finish`], but can be useful for situations where you want to use [`App::update`].
pub fn cleanup(&mut self) {
// plugins installed to main should see all sub-apps
let plugins = core::mem::take(&mut self.main_mut().plugin_registry);
for plugin in &plugins {
plugin.cleanup(self);
}
let main = self.main_mut();
main.plugin_registry = plugins;
main.plugins_state = PluginsState::Cleaned;
self.sub_apps.iter_mut().skip(1).for_each(SubApp::cleanup);
}
/// Returns `true` if any of the sub-apps are building plugins.
pub(crate) fn is_building_plugins(&self) -> bool {
self.sub_apps.iter().any(SubApp::is_building_plugins)
}
/// Adds one or more systems to the given schedule in this app's [`Schedules`].
///
/// # Examples
///
/// ```
/// # use bevy_app::prelude::*;
/// # use bevy_ecs::prelude::*;
/// #
/// # let mut app = App::new();
/// # fn system_a() {}
/// # fn system_b() {}
/// # fn system_c() {}
/// # fn should_run() -> bool { true }
/// #
/// app.add_systems(Update, (system_a, system_b, system_c));
/// app.add_systems(Update, (system_a, system_b).run_if(should_run));
/// ```
pub fn add_systems<M>(
&mut self,
schedule: impl ScheduleLabel,
systems: impl IntoSystemConfigs<M>,
) -> &mut Self {
self.main_mut().add_systems(schedule, systems);
self
}
/// Registers a system and returns a [`SystemId`] so it can later be called by [`World::run_system`].
///
/// It's possible to register the same systems more than once, they'll be stored separately.
///
/// This is different from adding systems to a [`Schedule`] with [`App::add_systems`],
/// because the [`SystemId`] that is returned can be used anywhere in the [`World`] to run the associated system.
/// This allows for running systems in a push-based fashion.
/// Using a [`Schedule`] is still preferred for most cases
/// due to its better performance and ability to run non-conflicting systems simultaneously.
pub fn register_system<I, O, M>(
&mut self,
system: impl IntoSystem<I, O, M> + 'static,
) -> SystemId<I, O>
where
I: SystemInput + 'static,
O: 'static,
{
self.main_mut().register_system(system)
}
/// Configures a collection of system sets in the provided schedule, adding any sets that do not exist.
#[track_caller]
pub fn configure_sets(
&mut self,
schedule: impl ScheduleLabel,
sets: impl IntoSystemSetConfigs,
) -> &mut Self {
self.main_mut().configure_sets(schedule, sets);
self
}
/// Initializes `T` event handling by inserting an event queue resource ([`Events::<T>`])
/// and scheduling an [`event_update_system`] in [`First`].
///
/// See [`Events`] for information on how to define events.
///
/// # Examples
///
/// ```
/// # use bevy_app::prelude::*;
/// # use bevy_ecs::prelude::*;
/// #
/// # #[derive(Event)]
/// # struct MyEvent;
/// # let mut app = App::new();
/// #
/// app.add_event::<MyEvent>();
/// ```
pub fn add_event<T>(&mut self) -> &mut Self
where
T: Event,
{
self.main_mut().add_event::<T>();
self
}
/// Inserts the [`Resource`] into the app, overwriting any existing resource of the same type.
///
/// There is also an [`init_resource`](Self::init_resource) for resources that have
/// [`Default`] or [`FromWorld`] implementations.
///
/// # Examples
///
/// ```
/// # use bevy_app::prelude::*;
/// # use bevy_ecs::prelude::*;
/// #
/// #[derive(Resource)]
/// struct MyCounter {
/// counter: usize,
/// }
///
/// App::new()
/// .insert_resource(MyCounter { counter: 0 });
/// ```
pub fn insert_resource<R: Resource>(&mut self, resource: R) -> &mut Self {
self.main_mut().insert_resource(resource);
self
}
/// Inserts the [`Resource`], initialized with its default value, into the app,
/// if there is no existing instance of `R`.
///
/// `R` must implement [`FromWorld`].
/// If `R` implements [`Default`], [`FromWorld`] will be automatically implemented and
/// initialize the [`Resource`] with [`Default::default`].
///
/// # Examples
///
/// ```
/// # use bevy_app::prelude::*;
/// # use bevy_ecs::prelude::*;
/// #
/// #[derive(Resource)]
/// struct MyCounter {
/// counter: usize,
/// }
///
/// impl Default for MyCounter {
/// fn default() -> MyCounter {
/// MyCounter {
/// counter: 100
/// }
/// }
/// }
///
/// App::new()
/// .init_resource::<MyCounter>();
/// ```
pub fn init_resource<R: Resource + FromWorld>(&mut self) -> &mut Self {
self.main_mut().init_resource::<R>();
self
}
/// Inserts the [`!Send`](Send) resource into the app, overwriting any existing resource
/// of the same type.
///
/// There is also an [`init_non_send_resource`](Self::init_non_send_resource) for
/// resources that implement [`Default`]
///
/// # Examples
///
/// ```
/// # use bevy_app::prelude::*;
/// # use bevy_ecs::prelude::*;
/// #
/// struct MyCounter {
/// counter: usize,
/// }
///
/// App::new()
/// .insert_non_send_resource(MyCounter { counter: 0 });
/// ```
pub fn insert_non_send_resource<R: 'static>(&mut self, resource: R) -> &mut Self {
self.world_mut().insert_non_send_resource(resource);
self
}
/// Inserts the [`!Send`](Send) resource into the app if there is no existing instance of `R`.
///
/// `R` must implement [`FromWorld`].
/// If `R` implements [`Default`], [`FromWorld`] will be automatically implemented and
/// initialize the [`Resource`] with [`Default::default`].
pub fn init_non_send_resource<R: 'static + FromWorld>(&mut self) -> &mut Self {
self.world_mut().init_non_send_resource::<R>();
self
}
pub(crate) fn add_boxed_plugin(
&mut self,
plugin: Box<dyn Plugin>,
) -> Result<&mut Self, AppError> {
debug!("added plugin: {}", plugin.name());
if plugin.is_unique() && self.main_mut().plugin_names.contains(plugin.name()) {
Err(AppError::DuplicatePlugin {
plugin_name: plugin.name().to_string(),
})?;
}
// Reserve position in the plugin registry. If the plugin adds more plugins,
// they'll all end up in insertion order.
let index = self.main().plugin_registry.len();
self.main_mut()
.plugin_registry
.push(Box::new(PlaceholderPlugin));
self.main_mut().plugin_build_depth += 1;
let result = catch_unwind(AssertUnwindSafe(|| plugin.build(self)));
self.main_mut()
.plugin_names
.insert(plugin.name().to_string());
self.main_mut().plugin_build_depth -= 1;
if let Err(payload) = result {
resume_unwind(payload);
}
self.main_mut().plugin_registry[index] = plugin;
Ok(self)
}
/// Returns `true` if the [`Plugin`] has already been added.
pub fn is_plugin_added<T>(&self) -> bool
where
T: Plugin,
{
self.main().is_plugin_added::<T>()
}
/// Returns a vector of references to all plugins of type `T` that have been added.
///
/// This can be used to read the settings of any existing plugins.
/// This vector will be empty if no plugins of that type have been added.
/// If multiple copies of the same plugin are added to the [`App`], they will be listed in insertion order in this vector.
///
/// ```
/// # use bevy_app::prelude::*;
/// # #[derive(Default)]
/// # struct ImagePlugin {
/// # default_sampler: bool,
/// # }
/// # impl Plugin for ImagePlugin {
/// # fn build(&self, app: &mut App) {}
/// # }
/// # let mut app = App::new();
/// # app.add_plugins(ImagePlugin::default());
/// let default_sampler = app.get_added_plugins::<ImagePlugin>()[0].default_sampler;
/// ```
pub fn get_added_plugins<T>(&self) -> Vec<&T>
where
T: Plugin,
{
self.main().get_added_plugins::<T>()
}
/// Installs a [`Plugin`] collection.
///
/// Bevy prioritizes modularity as a core principle. **All** engine features are implemented
/// as plugins, even the complex ones like rendering.
///
/// [`Plugin`]s can be grouped into a set by using a [`PluginGroup`].
///
/// There are built-in [`PluginGroup`]s that provide core engine functionality.
/// The [`PluginGroup`]s available by default are `DefaultPlugins` and `MinimalPlugins`.
///
/// To customize the plugins in the group (reorder, disable a plugin, add a new plugin
/// before / after another plugin), call [`build()`](super::PluginGroup::build) on the group,
/// which will convert it to a [`PluginGroupBuilder`](crate::PluginGroupBuilder).
///
/// You can also specify a group of [`Plugin`]s by using a tuple over [`Plugin`]s and
/// [`PluginGroup`]s. See [`Plugins`] for more details.
///
/// ## Examples
/// ```
/// # use bevy_app::{prelude::*, PluginGroupBuilder, NoopPluginGroup as MinimalPlugins};
/// #
/// # // Dummies created to avoid using `bevy_log`,
/// # // which pulls in too many dependencies and breaks rust-analyzer
/// # pub struct LogPlugin;
/// # impl Plugin for LogPlugin {
/// # fn build(&self, app: &mut App) {}
/// # }
/// App::new()
/// .add_plugins(MinimalPlugins);
/// App::new()
/// .add_plugins((MinimalPlugins, LogPlugin));
/// ```
///
/// # Panics
///
/// Panics if one of the plugins had already been added to the application.
///
/// [`PluginGroup`]:super::PluginGroup
#[track_caller]
pub fn add_plugins<M>(&mut self, plugins: impl Plugins<M>) -> &mut Self {
if matches!(
self.plugins_state(),
PluginsState::Cleaned | PluginsState::Finished
) {
panic!(
"Plugins cannot be added after App::cleanup() or App::finish() has been called."
);
}
plugins.add_to_app(self);
self
}
/// Registers the type `T` in the [`AppTypeRegistry`] resource,
/// adding reflect data as specified in the [`Reflect`](bevy_reflect::Reflect) derive:
/// ```ignore (No serde "derive" feature)
/// #[derive(Component, Serialize, Deserialize, Reflect)]
/// #[reflect(Component, Serialize, Deserialize)] // will register ReflectComponent, ReflectSerialize, ReflectDeserialize
/// ```
///
/// See [`bevy_reflect::TypeRegistry::register`] for more information.
#[cfg(feature = "bevy_reflect")]
pub fn register_type<T: bevy_reflect::GetTypeRegistration>(&mut self) -> &mut Self {
self.main_mut().register_type::<T>();
self
}
/// Associates type data `D` with type `T` in the [`AppTypeRegistry`] resource.
///
/// Most of the time [`register_type`](Self::register_type) can be used instead to register a
/// type you derived [`Reflect`](bevy_reflect::Reflect) for. However, in cases where you want to
/// add a piece of type data that was not included in the list of `#[reflect(...)]` type data in
/// the derive, or where the type is generic and cannot register e.g. `ReflectSerialize`
/// unconditionally without knowing the specific type parameters, this method can be used to
/// insert additional type data.
///
/// # Example
/// ```
/// use bevy_app::App;
/// use bevy_reflect::{ReflectSerialize, ReflectDeserialize};
///
/// App::new()
/// .register_type::<Option<String>>()
/// .register_type_data::<Option<String>, ReflectSerialize>()
/// .register_type_data::<Option<String>, ReflectDeserialize>();
/// ```
///
/// See [`bevy_reflect::TypeRegistry::register_type_data`].
#[cfg(feature = "bevy_reflect")]
pub fn register_type_data<
T: bevy_reflect::Reflect + bevy_reflect::TypePath,
D: bevy_reflect::TypeData + bevy_reflect::FromType<T>,
>(
&mut self,
) -> &mut Self {
self.main_mut().register_type_data::<T, D>();
self
}
/// Registers the given function into the [`AppFunctionRegistry`] resource.
///
/// The given function will internally be stored as a [`DynamicFunction`]
/// and mapped according to its [name].
///
/// Because the function must have a name,
/// anonymous functions (e.g. `|a: i32, b: i32| { a + b }`) and closures must instead
/// be registered using [`register_function_with_name`] or converted to a [`DynamicFunction`]
/// and named using [`DynamicFunction::with_name`].
/// Failure to do so will result in a panic.
///
/// Only types that implement [`IntoFunction`] may be registered via this method.
///
/// See [`FunctionRegistry::register`] for more information.
///
/// # Panics
///
/// Panics if a function has already been registered with the given name
/// or if the function is missing a name (such as when it is an anonymous function).
///
/// # Examples
///
/// ```
/// use bevy_app::App;
///
/// fn add(a: i32, b: i32) -> i32 {
/// a + b
/// }
///
/// App::new().register_function(add);
/// ```
///
/// Functions cannot be registered more than once.
///
/// ```should_panic
/// use bevy_app::App;
///
/// fn add(a: i32, b: i32) -> i32 {
/// a + b
/// }
///
/// App::new()
/// .register_function(add)
/// // Panic! A function has already been registered with the name "my_function"
/// .register_function(add);
/// ```
///
/// Anonymous functions and closures should be registered using [`register_function_with_name`] or given a name using [`DynamicFunction::with_name`].
///
/// ```should_panic
/// use bevy_app::App;
///
/// // Panic! Anonymous functions cannot be registered using `register_function`
/// App::new().register_function(|a: i32, b: i32| a + b);
/// ```
///
/// [`register_function_with_name`]: Self::register_function_with_name
/// [`DynamicFunction`]: bevy_reflect::func::DynamicFunction
/// [name]: bevy_reflect::func::FunctionInfo::name
/// [`DynamicFunction::with_name`]: bevy_reflect::func::DynamicFunction::with_name
/// [`IntoFunction`]: bevy_reflect::func::IntoFunction
/// [`FunctionRegistry::register`]: bevy_reflect::func::FunctionRegistry::register
#[cfg(feature = "reflect_functions")]
pub fn register_function<F, Marker>(&mut self, function: F) -> &mut Self
where
F: bevy_reflect::func::IntoFunction<'static, Marker> + 'static,
{
self.main_mut().register_function(function);
self
}
/// Registers the given function or closure into the [`AppFunctionRegistry`] resource using the given name.
///
/// To avoid conflicts, it's recommended to use a unique name for the function.
/// This can be achieved by "namespacing" the function with a unique identifier,
/// such as the name of your crate.
///
/// For example, to register a function, `add`, from a crate, `my_crate`,
/// you could use the name, `"my_crate::add"`.
///
/// Another approach could be to use the [type name] of the function,
/// however, it should be noted that anonymous functions do _not_ have unique type names.
///
/// For named functions (e.g. `fn add(a: i32, b: i32) -> i32 { a + b }`) where a custom name is not needed,
/// it's recommended to use [`register_function`] instead as the generated name is guaranteed to be unique.
///
/// Only types that implement [`IntoFunction`] may be registered via this method.
///
/// See [`FunctionRegistry::register_with_name`] for more information.
///
/// # Panics
///
/// Panics if a function has already been registered with the given name.
///
/// # Examples
///
/// ```
/// use bevy_app::App;
///
/// fn mul(a: i32, b: i32) -> i32 {
/// a * b
/// }
///
/// let div = |a: i32, b: i32| a / b;
///
/// App::new()
/// // Registering an anonymous function with a unique name
/// .register_function_with_name("my_crate::add", |a: i32, b: i32| {
/// a + b
/// })
/// // Registering an existing function with its type name
/// .register_function_with_name(std::any::type_name_of_val(&mul), mul)
/// // Registering an existing function with a custom name
/// .register_function_with_name("my_crate::mul", mul)
/// // Be careful not to register anonymous functions with their type name.
/// // This code works but registers the function with a non-unique name like `foo::bar::{{closure}}`
/// .register_function_with_name(std::any::type_name_of_val(&div), div);
/// ```
///
/// Names must be unique.
///
/// ```should_panic
/// use bevy_app::App;
///
/// fn one() {}
/// fn two() {}
///
/// App::new()
/// .register_function_with_name("my_function", one)
/// // Panic! A function has already been registered with the name "my_function"
/// .register_function_with_name("my_function", two);
/// ```
///
/// [type name]: std::any::type_name
/// [`register_function`]: Self::register_function
/// [`IntoFunction`]: bevy_reflect::func::IntoFunction
/// [`FunctionRegistry::register_with_name`]: bevy_reflect::func::FunctionRegistry::register_with_name
#[cfg(feature = "reflect_functions")]
pub fn register_function_with_name<F, Marker>(
&mut self,
name: impl Into<alloc::borrow::Cow<'static, str>>,
function: F,
) -> &mut Self
where
F: bevy_reflect::func::IntoFunction<'static, Marker> + 'static,
{
self.main_mut().register_function_with_name(name, function);
self
}
/// Registers the given component `R` as a [required component] for `T`.
///
/// When `T` is added to an entity, `R` and its own required components will also be added
/// if `R` was not already provided. The [`Default`] `constructor` will be used for the creation of `R`.
/// If a custom constructor is desired, use [`App::register_required_components_with`] instead.
///
/// For the non-panicking version, see [`App::try_register_required_components`].
///
/// Note that requirements must currently be registered before `T` is inserted into the world
/// for the first time. Commonly, this is done in plugins. This limitation may be fixed in the future.
///
/// [required component]: Component#required-components
///
/// # Panics
///
/// Panics if `R` is already a directly required component for `T`, or if `T` has ever been added
/// on an entity before the registration.
///
/// Indirect requirements through other components are allowed. In those cases, any existing requirements
/// will only be overwritten if the new requirement is more specific.
///
/// # Example
///
/// ```
/// # use bevy_app::{App, NoopPluginGroup as MinimalPlugins, Startup};
/// # use bevy_ecs::prelude::*;
/// #[derive(Component)]
/// struct A;
///
/// #[derive(Component, Default, PartialEq, Eq, Debug)]
/// struct B(usize);
///
/// #[derive(Component, Default, PartialEq, Eq, Debug)]
/// struct C(u32);
///
/// # let mut app = App::new();
/// # app.add_plugins(MinimalPlugins).add_systems(Startup, setup);
/// // Register B as required by A and C as required by B.
/// app.register_required_components::<A, B>();
/// app.register_required_components::<B, C>();
///
/// fn setup(mut commands: Commands) {
/// // This will implicitly also insert B and C with their Default constructors.
/// commands.spawn(A);
/// }
///
/// fn validate(query: Option<Single<(&A, &B, &C)>>) {
/// let (a, b, c) = query.unwrap().into_inner();
/// assert_eq!(b, &B(0));
/// assert_eq!(c, &C(0));
/// }
/// # app.update();
/// ```
pub fn register_required_components<T: Component, R: Component + Default>(
&mut self,
) -> &mut Self {
self.world_mut().register_required_components::<T, R>();
self
}
/// Registers the given component `R` as a [required component] for `T`.
///
/// When `T` is added to an entity, `R` and its own required components will also be added
/// if `R` was not already provided. The given `constructor` will be used for the creation of `R`.
/// If a [`Default`] constructor is desired, use [`App::register_required_components`] instead.
///
/// For the non-panicking version, see [`App::try_register_required_components_with`].
///
/// Note that requirements must currently be registered before `T` is inserted into the world
/// for the first time. Commonly, this is done in plugins. This limitation may be fixed in the future.
///
/// [required component]: Component#required-components
///
/// # Panics
///
/// Panics if `R` is already a directly required component for `T`, or if `T` has ever been added
/// on an entity before the registration.
///
/// Indirect requirements through other components are allowed. In those cases, any existing requirements
/// will only be overwritten if the new requirement is more specific.
///
/// # Example
///
/// ```
/// # use bevy_app::{App, NoopPluginGroup as MinimalPlugins, Startup};
/// # use bevy_ecs::prelude::*;
/// #[derive(Component)]
/// struct A;
///
/// #[derive(Component, Default, PartialEq, Eq, Debug)]
/// struct B(usize);
///
/// #[derive(Component, Default, PartialEq, Eq, Debug)]
/// struct C(u32);
///
/// # let mut app = App::new();
/// # app.add_plugins(MinimalPlugins).add_systems(Startup, setup);
/// // Register B and C as required by A and C as required by B.
/// // A requiring C directly will overwrite the indirect requirement through B.
/// app.register_required_components::<A, B>();
/// app.register_required_components_with::<B, C>(|| C(1));
/// app.register_required_components_with::<A, C>(|| C(2));
///
/// fn setup(mut commands: Commands) {
/// // This will implicitly also insert B with its Default constructor and C
/// // with the custom constructor defined by A.
/// commands.spawn(A);
/// }
///
/// fn validate(query: Option<Single<(&A, &B, &C)>>) {
/// let (a, b, c) = query.unwrap().into_inner();
/// assert_eq!(b, &B(0));
/// assert_eq!(c, &C(2));
/// }
/// # app.update();
/// ```
pub fn register_required_components_with<T: Component, R: Component>(
&mut self,
constructor: fn() -> R,
) -> &mut Self {
self.world_mut()
.register_required_components_with::<T, R>(constructor);
self
}
/// Tries to register the given component `R` as a [required component] for `T`.
///
/// When `T` is added to an entity, `R` and its own required components will also be added
/// if `R` was not already provided. The [`Default`] `constructor` will be used for the creation of `R`.
/// If a custom constructor is desired, use [`App::register_required_components_with`] instead.
///
/// For the panicking version, see [`App::register_required_components`].
///
/// Note that requirements must currently be registered before `T` is inserted into the world
/// for the first time. Commonly, this is done in plugins. This limitation may be fixed in the future.
///
/// [required component]: Component#required-components
///
/// # Errors
///
/// Returns a [`RequiredComponentsError`] if `R` is already a directly required component for `T`, or if `T` has ever been added
/// on an entity before the registration.
///
/// Indirect requirements through other components are allowed. In those cases, any existing requirements
/// will only be overwritten if the new requirement is more specific.
///
/// # Example
///
/// ```
/// # use bevy_app::{App, NoopPluginGroup as MinimalPlugins, Startup};
/// # use bevy_ecs::prelude::*;
/// #[derive(Component)]
/// struct A;
///
/// #[derive(Component, Default, PartialEq, Eq, Debug)]
/// struct B(usize);
///
/// #[derive(Component, Default, PartialEq, Eq, Debug)]
/// struct C(u32);
///
/// # let mut app = App::new();
/// # app.add_plugins(MinimalPlugins).add_systems(Startup, setup);
/// // Register B as required by A and C as required by B.
/// app.register_required_components::<A, B>();
/// app.register_required_components::<B, C>();
///
/// // Duplicate registration! This will fail.
/// assert!(app.try_register_required_components::<A, B>().is_err());
///
/// fn setup(mut commands: Commands) {
/// // This will implicitly also insert B and C with their Default constructors.
/// commands.spawn(A);
/// }
///
/// fn validate(query: Option<Single<(&A, &B, &C)>>) {
/// let (a, b, c) = query.unwrap().into_inner();
/// assert_eq!(b, &B(0));
/// assert_eq!(c, &C(0));
/// }
/// # app.update();
/// ```
pub fn try_register_required_components<T: Component, R: Component + Default>(
&mut self,
) -> Result<(), RequiredComponentsError> {
self.world_mut().try_register_required_components::<T, R>()
}
/// Tries to register the given component `R` as a [required component] for `T`.
///
/// When `T` is added to an entity, `R` and its own required components will also be added
/// if `R` was not already provided. The given `constructor` will be used for the creation of `R`.
/// If a [`Default`] constructor is desired, use [`App::register_required_components`] instead.
///
/// For the panicking version, see [`App::register_required_components_with`].
///
/// Note that requirements must currently be registered before `T` is inserted into the world
/// for the first time. Commonly, this is done in plugins. This limitation may be fixed in the future.
///
/// [required component]: Component#required-components
///
/// # Errors
///
/// Returns a [`RequiredComponentsError`] if `R` is already a directly required component for `T`, or if `T` has ever been added
/// on an entity before the registration.
///
/// Indirect requirements through other components are allowed. In those cases, any existing requirements
/// will only be overwritten if the new requirement is more specific.
///
/// # Example
///
/// ```
/// # use bevy_app::{App, NoopPluginGroup as MinimalPlugins, Startup};
/// # use bevy_ecs::prelude::*;
/// #[derive(Component)]
/// struct A;
///
/// #[derive(Component, Default, PartialEq, Eq, Debug)]
/// struct B(usize);
///
/// #[derive(Component, Default, PartialEq, Eq, Debug)]
/// struct C(u32);
///
/// # let mut app = App::new();
/// # app.add_plugins(MinimalPlugins).add_systems(Startup, setup);
/// // Register B and C as required by A and C as required by B.
/// // A requiring C directly will overwrite the indirect requirement through B.
/// app.register_required_components::<A, B>();
/// app.register_required_components_with::<B, C>(|| C(1));
/// app.register_required_components_with::<A, C>(|| C(2));
///
/// // Duplicate registration! Even if the constructors were different, this would fail.
/// assert!(app.try_register_required_components_with::<B, C>(|| C(1)).is_err());
///
/// fn setup(mut commands: Commands) {
/// // This will implicitly also insert B with its Default constructor and C
/// // with the custom constructor defined by A.
/// commands.spawn(A);
/// }
///
/// fn validate(query: Option<Single<(&A, &B, &C)>>) {
/// let (a, b, c) = query.unwrap().into_inner();
/// assert_eq!(b, &B(0));
/// assert_eq!(c, &C(2));
/// }
/// # app.update();
/// ```
pub fn try_register_required_components_with<T: Component, R: Component>(
&mut self,
constructor: fn() -> R,
) -> Result<(), RequiredComponentsError> {
self.world_mut()
.try_register_required_components_with::<T, R>(constructor)
}
/// Returns a reference to the main [`SubApp`]'s [`World`]. This is the same as calling
/// [`app.main().world()`].
///
/// [`app.main().world()`]: SubApp::world
pub fn world(&self) -> &World {
self.main().world()
}
/// Returns a mutable reference to the main [`SubApp`]'s [`World`]. This is the same as calling
/// [`app.main_mut().world_mut()`].
///
/// [`app.main_mut().world_mut()`]: SubApp::world_mut
pub fn world_mut(&mut self) -> &mut World {
self.main_mut().world_mut()
}
/// Returns a reference to the main [`SubApp`].
pub fn main(&self) -> &SubApp {
&self.sub_apps.main
}
/// Returns a mutable reference to the main [`SubApp`].
pub fn main_mut(&mut self) -> &mut SubApp {
&mut self.sub_apps.main
}
/// Returns a reference to the [`SubApp`] with the given label.
///
/// # Panics
///
/// Panics if the [`SubApp`] doesn't exist.
pub fn sub_app(&self, label: impl AppLabel) -> &SubApp {
let str = label.intern();
self.get_sub_app(label).unwrap_or_else(|| {
panic!("No sub-app with label '{:?}' exists.", str);
})
}
/// Returns a reference to the [`SubApp`] with the given label.
///
/// # Panics
///
/// Panics if the [`SubApp`] doesn't exist.
pub fn sub_app_mut(&mut self, label: impl AppLabel) -> &mut SubApp {
let str = label.intern();
self.get_sub_app_mut(label).unwrap_or_else(|| {
panic!("No sub-app with label '{:?}' exists.", str);
})
}
/// Returns a reference to the [`SubApp`] with the given label, if it exists.
pub fn get_sub_app(&self, label: impl AppLabel) -> Option<&SubApp> {
self.sub_apps.sub_apps.get(&label.intern())
}
/// Returns a mutable reference to the [`SubApp`] with the given label, if it exists.
pub fn get_sub_app_mut(&mut self, label: impl AppLabel) -> Option<&mut SubApp> {
self.sub_apps.sub_apps.get_mut(&label.intern())
}
/// Inserts a [`SubApp`] with the given label.
pub fn insert_sub_app(&mut self, label: impl AppLabel, sub_app: SubApp) {
self.sub_apps.sub_apps.insert(label.intern(), sub_app);
}
/// Removes the [`SubApp`] with the given label, if it exists.
pub fn remove_sub_app(&mut self, label: impl AppLabel) -> Option<SubApp> {
self.sub_apps.sub_apps.remove(&label.intern())
}
/// Extract data from the main world into the [`SubApp`] with the given label and perform an update if it exists.
pub fn update_sub_app_by_label(&mut self, label: impl AppLabel) {
self.sub_apps.update_subapp_by_label(label);
}
/// Inserts a new `schedule` under the provided `label`, overwriting any existing
/// schedule with the same label.
pub fn add_schedule(&mut self, schedule: Schedule) -> &mut Self {
self.main_mut().add_schedule(schedule);
self
}
/// Initializes an empty `schedule` under the provided `label`, if it does not exist.
///
/// See [`add_schedule`](Self::add_schedule) to insert an existing schedule.
pub fn init_schedule(&mut self, label: impl ScheduleLabel) -> &mut Self {
self.main_mut().init_schedule(label);
self
}
/// Returns a reference to the [`Schedule`] with the provided `label` if it exists.
pub fn get_schedule(&self, label: impl ScheduleLabel) -> Option<&Schedule> {
self.main().get_schedule(label)
}
/// Returns a mutable reference to the [`Schedule`] with the provided `label` if it exists.
pub fn get_schedule_mut(&mut self, label: impl ScheduleLabel) -> Option<&mut Schedule> {
self.main_mut().get_schedule_mut(label)
}
/// Runs function `f` with the [`Schedule`] associated with `label`.
///
/// **Note:** This will create the schedule if it does not already exist.
pub fn edit_schedule(
&mut self,
label: impl ScheduleLabel,
f: impl FnMut(&mut Schedule),
) -> &mut Self {
self.main_mut().edit_schedule(label, f);
self
}
/// Applies the provided [`ScheduleBuildSettings`] to all schedules.
pub fn configure_schedules(
&mut self,
schedule_build_settings: ScheduleBuildSettings,
) -> &mut Self {
self.main_mut().configure_schedules(schedule_build_settings);
self
}
/// When doing [ambiguity checking](ScheduleBuildSettings) this
/// ignores systems that are ambiguous on [`Component`] T.
///
/// This settings only applies to the main world. To apply this to other worlds call the
/// [corresponding method](World::allow_ambiguous_component) on World
///
/// ## Example
///
/// ```
/// # use bevy_app::prelude::*;
/// # use bevy_ecs::prelude::*;
/// # use bevy_ecs::schedule::{LogLevel, ScheduleBuildSettings};
/// # use bevy_utils::default;
///
/// #[derive(Component)]
/// struct A;
///
/// // these systems are ambiguous on A
/// fn system_1(_: Query<&mut A>) {}
/// fn system_2(_: Query<&A>) {}
///
/// let mut app = App::new();
/// app.configure_schedules(ScheduleBuildSettings {
/// ambiguity_detection: LogLevel::Error,
/// ..default()
/// });
///
/// app.add_systems(Update, ( system_1, system_2 ));
/// app.allow_ambiguous_component::<A>();
///
/// // running the app does not error.
/// app.update();
/// ```
pub fn allow_ambiguous_component<T: Component>(&mut self) -> &mut Self {
self.main_mut().allow_ambiguous_component::<T>();
self
}
/// When doing [ambiguity checking](ScheduleBuildSettings) this
/// ignores systems that are ambiguous on [`Resource`] T.
///
/// This settings only applies to the main world. To apply this to other worlds call the
/// [corresponding method](World::allow_ambiguous_resource) on World
///
/// ## Example
///
/// ```
/// # use bevy_app::prelude::*;
/// # use bevy_ecs::prelude::*;
/// # use bevy_ecs::schedule::{LogLevel, ScheduleBuildSettings};
/// # use bevy_utils::default;
///
/// #[derive(Resource)]
/// struct R;
///
/// // these systems are ambiguous on R
/// fn system_1(_: ResMut<R>) {}
/// fn system_2(_: Res<R>) {}
///
/// let mut app = App::new();
/// app.configure_schedules(ScheduleBuildSettings {
/// ambiguity_detection: LogLevel::Error,
/// ..default()
/// });
/// app.insert_resource(R);
///
/// app.add_systems(Update, ( system_1, system_2 ));
/// app.allow_ambiguous_resource::<R>();
///
/// // running the app does not error.
/// app.update();
/// ```
pub fn allow_ambiguous_resource<T: Resource>(&mut self) -> &mut Self {
self.main_mut().allow_ambiguous_resource::<T>();
self
}
/// Suppress warnings and errors that would result from systems in these sets having ambiguities
/// (conflicting access but indeterminate order) with systems in `set`.
///
/// When possible, do this directly in the `.add_systems(Update, a.ambiguous_with(b))` call.
/// However, sometimes two independent plugins `A` and `B` are reported as ambiguous, which you
/// can only suppress as the consumer of both.
#[track_caller]
pub fn ignore_ambiguity<M1, M2, S1, S2>(
&mut self,
schedule: impl ScheduleLabel,
a: S1,
b: S2,
) -> &mut Self
where
S1: IntoSystemSet<M1>,
S2: IntoSystemSet<M2>,
{
self.main_mut().ignore_ambiguity(schedule, a, b);
self
}
/// Attempts to determine if an [`AppExit`] was raised since the last update.
///
/// Will attempt to return the first [`Error`](AppExit::Error) it encounters.
/// This should be called after every [`update()`](App::update) otherwise you risk
/// dropping possible [`AppExit`] events.
pub fn should_exit(&self) -> Option<AppExit> {
let mut reader = EventCursor::default();
let events = self.world().get_resource::<Events<AppExit>>()?;
let mut events = reader.read(events);
if events.len() != 0 {
return Some(
events
.find(|exit| exit.is_error())
.cloned()
.unwrap_or(AppExit::Success),
);
}
None
}
/// Spawns an [`Observer`] entity, which will watch for and respond to the given event.
///
/// # Examples
///
/// ```rust
/// # use bevy_app::prelude::*;
/// # use bevy_ecs::prelude::*;
/// # use bevy_utils::default;
/// #
/// # let mut app = App::new();
/// #
/// # #[derive(Event)]
/// # struct Party {
/// # friends_allowed: bool,
/// # };
/// #
/// # #[derive(Event)]
/// # struct Invite;
/// #
/// # #[derive(Component)]
/// # struct Friend;
/// #
/// // An observer system can be any system where the first parameter is a trigger
/// app.add_observer(|trigger: Trigger<Party>, friends: Query<Entity, With<Friend>>, mut commands: Commands| {
/// if trigger.event().friends_allowed {
/// for friend in friends.iter() {
/// commands.trigger_targets(Invite, friend);
/// }
/// }
/// });
/// ```
pub fn add_observer<E: Event, B: Bundle, M>(
&mut self,
observer: impl IntoObserverSystem<E, B, M>,
) -> &mut Self {
self.world_mut().add_observer(observer);
self
}
}
type RunnerFn = Box<dyn FnOnce(App) -> AppExit>;
fn run_once(mut app: App) -> AppExit {
while app.plugins_state() == PluginsState::Adding {
#[cfg(not(target_arch = "wasm32"))]
bevy_tasks::tick_global_task_pools_on_main_thread();
}
app.finish();
app.cleanup();
app.update();
app.should_exit().unwrap_or(AppExit::Success)
}
/// An event that indicates the [`App`] should exit. If one or more of these are present at the end of an update,
/// the [runner](App::set_runner) will end and ([maybe](App::run)) return control to the caller.
///
/// This event can be used to detect when an exit is requested. Make sure that systems listening
/// for this event run before the current update ends.
///
/// # Portability
/// This type is roughly meant to map to a standard definition of a process exit code (0 means success, not 0 means error). Due to portability concerns
/// (see [`ExitCode`](https://doc.rust-lang.org/std/process/struct.ExitCode.html) and [`process::exit`](https://doc.rust-lang.org/std/process/fn.exit.html#))
/// we only allow error codes between 1 and [255](u8::MAX).
#[derive(Event, Debug, Clone, Default, PartialEq, Eq)]
pub enum AppExit {
/// [`App`] exited without any problems.
#[default]
Success,
/// The [`App`] experienced an unhandleable error.
/// Holds the exit code we expect our app to return.
Error(NonZero<u8>),
}
impl AppExit {
/// Creates a [`AppExit::Error`] with a error code of 1.
#[must_use]
pub const fn error() -> Self {
Self::Error(NonZero::<u8>::MIN)
}
/// Returns `true` if `self` is a [`AppExit::Success`].
#[must_use]
pub const fn is_success(&self) -> bool {
matches!(self, AppExit::Success)
}
/// Returns `true` if `self` is a [`AppExit::Error`].
#[must_use]
pub const fn is_error(&self) -> bool {
matches!(self, AppExit::Error(_))
}
/// Creates a [`AppExit`] from a code.
///
/// When `code` is 0 a [`AppExit::Success`] is constructed otherwise a
/// [`AppExit::Error`] is constructed.
#[must_use]
pub const fn from_code(code: u8) -> Self {
match NonZero::<u8>::new(code) {
Some(code) => Self::Error(code),
None => Self::Success,
}
}
}
impl From<u8> for AppExit {
#[must_use]
fn from(value: u8) -> Self {
Self::from_code(value)
}
}
impl Termination for AppExit {
fn report(self) -> ExitCode {
match self {
AppExit::Success => ExitCode::SUCCESS,
// We leave logging an error to our users
AppExit::Error(value) => ExitCode::from(value.get()),
}
}
}
#[cfg(test)]
mod tests {
use core::{iter, marker::PhantomData};
use std::sync::Mutex;
use bevy_ecs::{
change_detection::{DetectChanges, ResMut},
component::Component,
entity::Entity,
event::{Event, EventWriter, Events},
query::With,
removal_detection::RemovedComponents,
schedule::{IntoSystemConfigs, ScheduleLabel},
system::{Commands, Query, Resource},
world::{FromWorld, World},
};
use crate::{App, AppExit, Plugin, SubApp, Update};
struct PluginA;
impl Plugin for PluginA {
fn build(&self, _app: &mut App) {}
}
struct PluginB;
impl Plugin for PluginB {
fn build(&self, _app: &mut App) {}
}
struct PluginC<T>(T);
impl<T: Send + Sync + 'static> Plugin for PluginC<T> {
fn build(&self, _app: &mut App) {}
}
struct PluginD;
impl Plugin for PluginD {
fn build(&self, _app: &mut App) {}
fn is_unique(&self) -> bool {
false
}
}
struct PluginE;
impl Plugin for PluginE {
fn build(&self, _app: &mut App) {}
fn finish(&self, app: &mut App) {
if app.is_plugin_added::<PluginA>() {
panic!("cannot run if PluginA is already registered");
}
}
}
#[test]
fn can_add_two_plugins() {
App::new().add_plugins((PluginA, PluginB));
}
#[test]
#[should_panic]
fn cant_add_twice_the_same_plugin() {
App::new().add_plugins((PluginA, PluginA));
}
#[test]
fn can_add_twice_the_same_plugin_with_different_type_param() {
App::new().add_plugins((PluginC(0), PluginC(true)));
}
#[test]
fn can_add_twice_the_same_plugin_not_unique() {
App::new().add_plugins((PluginD, PluginD));
}
#[test]
#[should_panic]
fn cant_call_app_run_from_plugin_build() {
struct PluginRun;
struct InnerPlugin;
impl Plugin for InnerPlugin {
fn build(&self, _: &mut App) {}
}
impl Plugin for PluginRun {
fn build(&self, app: &mut App) {
app.add_plugins(InnerPlugin).run();
}
}
App::new().add_plugins(PluginRun);
}
#[derive(ScheduleLabel, Hash, Clone, PartialEq, Eq, Debug)]
struct EnterMainMenu;
fn bar(mut commands: Commands) {
commands.spawn_empty();
}
fn foo(mut commands: Commands) {
commands.spawn_empty();
}
#[test]
fn add_systems_should_create_schedule_if_it_does_not_exist() {
let mut app = App::new();
app.add_systems(EnterMainMenu, (foo, bar));
app.world_mut().run_schedule(EnterMainMenu);
assert_eq!(app.world().entities().len(), 2);
}
#[test]
#[should_panic]
fn test_is_plugin_added_works_during_finish() {
let mut app = App::new();
app.add_plugins(PluginA);
app.add_plugins(PluginE);
app.finish();
}
#[test]
fn test_derive_app_label() {
use super::AppLabel;
use crate::{self as bevy_app};
#[derive(AppLabel, Debug, Default, Clone, Copy, PartialEq, Eq, Hash)]
struct UnitLabel;
#[derive(AppLabel, Debug, Default, Clone, Copy, PartialEq, Eq, Hash)]
struct TupleLabel(u32, u32);
#[derive(AppLabel, Debug, Default, Clone, Copy, PartialEq, Eq, Hash)]
struct StructLabel {
a: u32,
b: u32,
}
#[derive(AppLabel, Debug, Default, Clone, Copy, PartialEq, Eq, Hash)]
struct EmptyTupleLabel();
#[derive(AppLabel, Debug, Default, Clone, Copy, PartialEq, Eq, Hash)]
struct EmptyStructLabel {}
#[derive(AppLabel, Debug, Default, Clone, Copy, PartialEq, Eq, Hash)]
enum EnumLabel {
#[default]
Unit,
Tuple(u32, u32),
Struct {
a: u32,
b: u32,
},
}
#[derive(AppLabel, Debug, Default, Clone, Copy, PartialEq, Eq, Hash)]
struct GenericLabel<T>(PhantomData<T>);
assert_eq!(UnitLabel.intern(), UnitLabel.intern());
assert_eq!(EnumLabel::Unit.intern(), EnumLabel::Unit.intern());
assert_ne!(UnitLabel.intern(), EnumLabel::Unit.intern());
assert_ne!(UnitLabel.intern(), TupleLabel(0, 0).intern());
assert_ne!(EnumLabel::Unit.intern(), EnumLabel::Tuple(0, 0).intern());
assert_eq!(TupleLabel(0, 0).intern(), TupleLabel(0, 0).intern());
assert_eq!(
EnumLabel::Tuple(0, 0).intern(),
EnumLabel::Tuple(0, 0).intern()
);
assert_ne!(TupleLabel(0, 0).intern(), TupleLabel(0, 1).intern());
assert_ne!(
EnumLabel::Tuple(0, 0).intern(),
EnumLabel::Tuple(0, 1).intern()
);
assert_ne!(TupleLabel(0, 0).intern(), EnumLabel::Tuple(0, 0).intern());
assert_ne!(
TupleLabel(0, 0).intern(),
StructLabel { a: 0, b: 0 }.intern()
);
assert_ne!(
EnumLabel::Tuple(0, 0).intern(),
EnumLabel::Struct { a: 0, b: 0 }.intern()
);
assert_eq!(
StructLabel { a: 0, b: 0 }.intern(),
StructLabel { a: 0, b: 0 }.intern()
);
assert_eq!(
EnumLabel::Struct { a: 0, b: 0 }.intern(),
EnumLabel::Struct { a: 0, b: 0 }.intern()
);
assert_ne!(
StructLabel { a: 0, b: 0 }.intern(),
StructLabel { a: 0, b: 1 }.intern()
);
assert_ne!(
EnumLabel::Struct { a: 0, b: 0 }.intern(),
EnumLabel::Struct { a: 0, b: 1 }.intern()
);
assert_ne!(
StructLabel { a: 0, b: 0 }.intern(),
EnumLabel::Struct { a: 0, b: 0 }.intern()
);
assert_ne!(
StructLabel { a: 0, b: 0 }.intern(),
EnumLabel::Struct { a: 0, b: 0 }.intern()
);
assert_ne!(StructLabel { a: 0, b: 0 }.intern(), UnitLabel.intern(),);
assert_ne!(
EnumLabel::Struct { a: 0, b: 0 }.intern(),
EnumLabel::Unit.intern()
);
assert_eq!(
GenericLabel::<u32>(PhantomData).intern(),
GenericLabel::<u32>(PhantomData).intern()
);
assert_ne!(
GenericLabel::<u32>(PhantomData).intern(),
GenericLabel::<u64>(PhantomData).intern()
);
}
#[test]
fn test_update_clears_trackers_once() {
#[derive(Component, Copy, Clone)]
struct Foo;
let mut app = App::new();
app.world_mut().spawn_batch(iter::repeat(Foo).take(5));
fn despawn_one_foo(mut commands: Commands, foos: Query<Entity, With<Foo>>) {
if let Some(e) = foos.iter().next() {
commands.entity(e).despawn();
};
}
fn check_despawns(mut removed_foos: RemovedComponents<Foo>) {
let mut despawn_count = 0;
for _ in removed_foos.read() {
despawn_count += 1;
}
assert_eq!(despawn_count, 2);
}
app.add_systems(Update, despawn_one_foo);
app.update(); // Frame 0
app.update(); // Frame 1
app.add_systems(Update, check_despawns.after(despawn_one_foo));
app.update(); // Should see despawns from frames 1 & 2, but not frame 0
}
#[test]
fn test_extract_sees_changes() {
use super::AppLabel;
use crate::{self as bevy_app};
#[derive(AppLabel, Clone, Copy, Hash, PartialEq, Eq, Debug)]
struct MySubApp;
#[derive(Resource)]
struct Foo(usize);
let mut app = App::new();
app.world_mut().insert_resource(Foo(0));
app.add_systems(Update, |mut foo: ResMut<Foo>| {
foo.0 += 1;
});
let mut sub_app = SubApp::new();
sub_app.set_extract(|main_world, _sub_world| {
assert!(main_world.get_resource_ref::<Foo>().unwrap().is_changed());
});
app.insert_sub_app(MySubApp, sub_app);
app.update();
}
#[test]
fn runner_returns_correct_exit_code() {
fn raise_exits(mut exits: EventWriter<AppExit>) {
// Exit codes chosen by a fair dice roll.
// Unlikely to overlap with default values.
exits.send(AppExit::Success);
exits.send(AppExit::from_code(4));
exits.send(AppExit::from_code(73));
}
let exit = App::new().add_systems(Update, raise_exits).run();
assert_eq!(exit, AppExit::from_code(4));
}
/// Custom runners should be in charge of when `app::update` gets called as they may need to
/// coordinate some state.
/// bug: <https://github.com/bevyengine/bevy/issues/10385>
/// fix: <https://github.com/bevyengine/bevy/pull/10389>
#[test]
fn regression_test_10385() {
use super::{Res, Resource};
use crate::PreUpdate;
#[derive(Resource)]
struct MyState {}
fn my_runner(mut app: App) -> AppExit {
let my_state = MyState {};
app.world_mut().insert_resource(my_state);
for _ in 0..5 {
app.update();
}
AppExit::Success
}
fn my_system(_: Res<MyState>) {
// access state during app update
}
// Should not panic due to missing resource
App::new()
.set_runner(my_runner)
.add_systems(PreUpdate, my_system)
.run();
}
#[test]
fn app_exit_size() {
// There wont be many of them so the size isn't a issue but
// it's nice they're so small let's keep it that way.
assert_eq!(size_of::<AppExit>(), size_of::<u8>());
}
#[test]
fn initializing_resources_from_world() {
#[derive(Resource)]
struct TestResource;
impl FromWorld for TestResource {
fn from_world(_world: &mut World) -> Self {
TestResource
}
}
#[derive(Resource)]
struct NonSendTestResource {
_marker: PhantomData<Mutex<()>>,
}
impl FromWorld for NonSendTestResource {
fn from_world(_world: &mut World) -> Self {
NonSendTestResource {
_marker: PhantomData,
}
}
}
App::new()
.init_non_send_resource::<NonSendTestResource>()
.init_resource::<TestResource>();
}
#[test]
/// Plugin should not be considered inserted while it's being built
///
/// bug: <https://github.com/bevyengine/bevy/issues/13815>
fn plugin_should_not_be_added_during_build_time() {
pub struct Foo;
impl Plugin for Foo {
fn build(&self, app: &mut App) {
assert!(!app.is_plugin_added::<Self>());
}
}
App::new().add_plugins(Foo);
}
#[test]
fn events_should_be_updated_once_per_update() {
#[derive(Event, Clone)]
struct TestEvent;
let mut app = App::new();
app.add_event::<TestEvent>();
// Starts empty
let test_events = app.world().resource::<Events<TestEvent>>();
assert_eq!(test_events.len(), 0);
assert_eq!(test_events.iter_current_update_events().count(), 0);
app.update();
// Sending one event
app.world_mut().send_event(TestEvent);
let test_events = app.world().resource::<Events<TestEvent>>();
assert_eq!(test_events.len(), 1);
assert_eq!(test_events.iter_current_update_events().count(), 1);
app.update();
// Sending two events on the next frame
app.world_mut().send_event(TestEvent);
app.world_mut().send_event(TestEvent);
let test_events = app.world().resource::<Events<TestEvent>>();
assert_eq!(test_events.len(), 3); // Events are double-buffered, so we see 1 + 2 = 3
assert_eq!(test_events.iter_current_update_events().count(), 2);
app.update();
// Sending zero events
let test_events = app.world().resource::<Events<TestEvent>>();
assert_eq!(test_events.len(), 2); // Events are double-buffered, so we see 2 + 0 = 2
assert_eq!(test_events.iter_current_update_events().count(), 0);
}
}