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bevy/crates/bevy_reflect/src/lib.rs
Gino Valente 6e959db134
bevy_reflect: Type parameter bounds (#9046) 
# Objective

Fixes #8965.

#### Background

For convenience and to ensure everything is setup properly, we
automatically add certain bounds to the derived types. The current
implementation does this by taking the types from all active fields and
adding them to the where-clause of the generated impls. I believe this
method was chosen because it won't add bounds to types that are
otherwise ignored.

```rust
#[derive(Reflect)]
struct Foo<T, U: SomeTrait, V> {
  t: T,
  u: U::Assoc,
  #[reflect(ignore)]
  v: [V; 2]
}

// Generates something like:
impl<T, U: SomeTrait, V> for Foo<T, U, V>
where
  // Active:
  T: Reflect,
  U::Assoc: Reflect,

  // Ignored:
  [V; 2]: Send + Sync + Any
{
  // ...
}
```

The self-referential type fails because it ends up using _itself_ as a
type bound due to being one of its own active fields.

```rust
#[derive(Reflect)]
struct Foo {
  foo: Vec<Foo>
}

// Foo where Vec<Foo>: Reflect -> Vec<T> where T: Reflect -> Foo where Vec<Foo>: Reflect -> ...
```

## Solution

We can't simply parse all field types for the name of our type. That
would be both complex and prone to errors and false-positives. And even
if it wasn't, what would we replace the bound with?

Instead, I opted to go for a solution that only adds the bounds to what
really needs it: the type parameters. While the bounds on concrete types
make errors a bit cleaner, they aren't strictly necessary. This means we
can change our generated where-clause to only add bounds to generic type
parameters.

Doing this, though, returns us back to the problem of over-bounding
parameters that don't need to be bounded. To solve this, I added a new
container attribute (based on
[this](https://github.com/dtolnay/syn/issues/422#issuecomment-406882925)
comment and @nicopap's
[comment](https://github.com/bevyengine/bevy/pull/9046#issuecomment-1623593780))
that allows us to pass in a custom where clause to modify what bounds
are added to these type parameters.

This allows us to do stuff like:

```rust
trait Trait {
  type Assoc;
}

// We don't need `T` to be reflectable since we only care about `T::Assoc`.
#[derive(Reflect)]
#[reflect(where T::Assoc: FromReflect)]
struct Foo<T: Trait>(T::Assoc);

#[derive(TypePath)]
struct Bar;

impl Trait for Bar {
  type Assoc = usize;
}

#[derive(Reflect)]
struct Baz {
  a: Foo<Bar>,
}
```

> **Note**
> I also
[tried](dc139ea34c)
allowing `#[reflect(ignore)]` to be used on the type parameters
themselves, but that proved problematic since the derive macro does not
consume the attribute. This is why I went with the container attribute
approach.

### Alternatives

One alternative could possibly be to just not add reflection bounds
automatically (i.e. only add required bounds like `Send`, `Sync`, `Any`,
and `TypePath`).

The downside here is we add more friction to using reflection, which
already comes with its own set of considerations. This is a potentially
viable option, but we really need to consider whether or not the
ergonomics hit is worth it.

If we did decide to go the more manual route, we should at least
consider something like #5772 to make it easier for users to add the
right bounds (although, this could still become tricky with
`FromReflect` also being automatically derived).

### Open Questions

1. Should we go with this approach or the manual alternative?
2. ~~Should we add a `skip_params` attribute to avoid the `T: 'static`
trick?~~ ~~Decided to go with `custom_where()` as it's the simplest~~
Scratch that, went with a normal where clause
3. ~~`custom_where` bikeshedding?~~ No longer needed since we are using
a normal where clause

### TODO

- [x] Add compile-fail tests

---

## Changelog

- Fixed issue preventing recursive types from deriving `Reflect`
- Changed how where-clause bounds are generated by the `Reflect` derive
macro
- They are now only applied to the type parameters, not to all active
fields
- Added `#[reflect(where T: Trait, U::Assoc: Trait, ...)]` container
attribute

## Migration Guide

When deriving `Reflect`, generic type params that do not need the
automatic reflection bounds (such as `Reflect`) applied to them will
need to opt-out using a custom where clause like: `#[reflect(where T:
Trait, U::Assoc: Trait, ...)]`.

The attribute can define custom bounds only used by the reflection
impls. To simply opt-out all the type params, we can pass in an empty
where clause: `#[reflect(where)]`.

```rust
// BEFORE:
#[derive(Reflect)]
struct Foo<T>(#[reflect(ignore)] T);

// AFTER:
#[derive(Reflect)]
#[reflect(where)]
struct Foo<T>(#[reflect(ignore)] T);
```

---------

Co-authored-by: Nicola Papale <nicopap@users.noreply.github.com>
2024-01-28 16:24:03 +00:00

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//! Reflection in Rust.
//!
//! [Reflection] is a powerful tool provided within many programming languages
//! that allows for meta-programming: using information _about_ the program to
//! _affect_ the program.
//! In other words, reflection allows us to inspect the program itself, its
//! syntax, and its type information at runtime.
//!
//! This crate adds this missing reflection functionality to Rust.
//! Though it was made with the [Bevy] game engine in mind,
//! it's a general-purpose solution that can be used in any Rust project.
//!
//! At a very high level, this crate allows you to:
//! * Dynamically interact with Rust values
//! * Access type metadata at runtime
//! * Serialize and deserialize (i.e. save and load) data
//!
//! It's important to note that because of missing features in Rust,
//! there are some [limitations] with this crate.
//!
//! # The `Reflect` Trait
//!
//! At the core of [`bevy_reflect`] is the [`Reflect`] trait.
//!
//! One of its primary purposes is to allow all implementors to be passed around
//! as a `dyn Reflect` trait object.
//! This allows any such type to be operated upon completely dynamically (at a small [runtime cost]).
//!
//! Implementing the trait is easily done using the provided [derive macro]:
//!
//! ```
//! # use bevy_reflect::Reflect;
//! #[derive(Reflect)]
//! struct MyStruct {
//! foo: i32
//! }
//! ```
//!
//! This will automatically generate the implementation of `Reflect` for any struct or enum.
//!
//! It will also generate other very important trait implementations used for reflection:
//! * [`GetTypeRegistration`]
//! * [`Typed`]
//! * [`Struct`], [`TupleStruct`], or [`Enum`] depending on the type
//!
//! ## Requirements
//!
//! We can implement `Reflect` on any type that satisfies _both_ of the following conditions:
//! * The type implements `Any`.
//! This is true if and only if the type itself has a [`'static` lifetime].
//! * All fields and sub-elements themselves implement `Reflect`
//! (see the [derive macro documentation] for details on how to ignore certain fields when deriving).
//!
//! Additionally, using the derive macro on enums requires a third condition to be met:
//! * All fields and sub-elements must implement [`FromReflect`]—
//! another important reflection trait discussed in a later section.
//!
//! # The `Reflect` Subtraits
//!
//! Since [`Reflect`] is meant to cover any and every type, this crate also comes with a few
//! more traits to accompany `Reflect` and provide more specific interactions.
//! We refer to these traits as the _reflection subtraits_ since they all have `Reflect` as a supertrait.
//! The current list of reflection subtraits include:
//! * [`Tuple`]
//! * [`Array`]
//! * [`List`]
//! * [`Map`]
//! * [`Struct`]
//! * [`TupleStruct`]
//! * [`Enum`]
//!
//! As mentioned previously, the last three are automatically implemented by the [derive macro].
//!
//! Each of these traits come with their own methods specific to their respective category.
//! For example, we can access our struct's fields by name using the [`Struct::field`] method.
//!
//! ```
//! # use bevy_reflect::{Reflect, Struct};
//! # #[derive(Reflect)]
//! # struct MyStruct {
//! # foo: i32
//! # }
//! let my_struct: Box<dyn Struct> = Box::new(MyStruct {
//! foo: 123
//! });
//! let foo: &dyn Reflect = my_struct.field("foo").unwrap();
//! assert_eq!(Some(&123), foo.downcast_ref::<i32>());
//! ```
//!
//! Since most data is passed around as `dyn Reflect`,
//! the `Reflect` trait has methods for going to and from these subtraits.
//!
//! [`Reflect::reflect_ref`], [`Reflect::reflect_mut`], and [`Reflect::reflect_owned`] all return
//! an enum that respectively contains immutable, mutable, and owned access to the type as a subtrait object.
//!
//! For example, we can get out a `dyn Tuple` from our reflected tuple type using one of these methods.
//!
//! ```
//! # use bevy_reflect::{Reflect, ReflectRef};
//! let my_tuple: Box<dyn Reflect> = Box::new((1, 2, 3));
//! let ReflectRef::Tuple(my_tuple) = my_tuple.reflect_ref() else { unreachable!() };
//! assert_eq!(3, my_tuple.field_len());
//! ```
//!
//! And to go back to a general-purpose `dyn Reflect`,
//! we can just use the matching [`Reflect::as_reflect`], [`Reflect::as_reflect_mut`],
//! or [`Reflect::into_reflect`] methods.
//!
//! ## Value Types
//!
//! Types that do not fall under one of the above subtraits,
//! such as for primitives (e.g. `bool`, `usize`, etc.)
//! and simple types (e.g. `String`, `Duration`),
//! are referred to as _value_ types
//! since methods like [`Reflect::reflect_ref`] return a [`ReflectRef::Value`] variant.
//! While most other types contain their own `dyn Reflect` fields and data,
//! these types generally cannot be broken down any further.
//!
//! # Dynamic Types
//!
//! Each subtrait comes with a corresponding _dynamic_ type.
//!
//! The available dynamic types are:
//! * [`DynamicTuple`]
//! * [`DynamicArray`]
//! * [`DynamicList`]
//! * [`DynamicMap`]
//! * [`DynamicStruct`]
//! * [`DynamicTupleStruct`]
//! * [`DynamicEnum`]
//!
//! These dynamic types may contain any arbitrary reflected data.
//!
//! ```
//! # use bevy_reflect::{DynamicStruct, Struct};
//! let mut data = DynamicStruct::default();
//! data.insert("foo", 123_i32);
//! assert_eq!(Some(&123), data.field("foo").unwrap().downcast_ref::<i32>())
//! ```
//!
//! They are most commonly used as "proxies" for other types,
//! where they contain the same data as— and therefore, represent— a concrete type.
//! The [`Reflect::clone_value`] method will return a dynamic type for all non-value types,
//! allowing all types to essentially be "cloned".
//! And since dynamic types themselves implement [`Reflect`],
//! we may pass them around just like any other reflected type.
//!
//! ```
//! # use bevy_reflect::{DynamicStruct, Reflect};
//! # #[derive(Reflect)]
//! # struct MyStruct {
//! # foo: i32
//! # }
//! let original: Box<dyn Reflect> = Box::new(MyStruct {
//! foo: 123
//! });
//!
//! // `cloned` will be a `DynamicStruct` representing a `MyStruct`
//! let cloned: Box<dyn Reflect> = original.clone_value();
//! assert!(cloned.represents::<MyStruct>());
//! assert!(cloned.is::<DynamicStruct>());
//! ```
//!
//! ## Patching
//!
//! These dynamic types come in handy when needing to apply multiple changes to another type.
//! This is known as "patching" and is done using the [`Reflect::apply`] method.
//!
//! ```
//! # use bevy_reflect::{DynamicEnum, Reflect};
//! let mut value = Some(123_i32);
//! let patch = DynamicEnum::new("None", ());
//! value.apply(&patch);
//! assert_eq!(None, value);
//! ```
//!
//! ## `FromReflect`
//!
//! It's important to remember that dynamic types are _not_ the concrete type they may be representing.
//! A common mistake is to treat them like such when trying to cast back to the original type
//! or when trying to make use of a reflected trait which expects the actual type.
//!
//! ```should_panic
//! # use bevy_reflect::{DynamicStruct, Reflect};
//! # #[derive(Reflect)]
//! # struct MyStruct {
//! # foo: i32
//! # }
//! let original: Box<dyn Reflect> = Box::new(MyStruct {
//! foo: 123
//! });
//!
//! let cloned: Box<dyn Reflect> = original.clone_value();
//! let value = cloned.take::<MyStruct>().unwrap(); // PANIC!
//! ```
//!
//! To resolve this issue, we'll need to convert the dynamic type to the concrete one.
//! This is where [`FromReflect`] comes in.
//!
//! `FromReflect` is a trait that allows an instance of a type to be generated from a
//! dynamic representation— even partial ones.
//! And since the [`FromReflect::from_reflect`] method takes the data by reference,
//! this can be used to effectively clone data (to an extent).
//!
//! It is automatically implemented when [deriving `Reflect`] on a type unless opted out of
//! using `#[reflect(from_reflect = false)]` on the item.
//!
//! ```
//! # use bevy_reflect::{Reflect, FromReflect};
//! #[derive(Reflect)]
//! struct MyStruct {
//! foo: i32
//! }
//! let original: Box<dyn Reflect> = Box::new(MyStruct {
//! foo: 123
//! });
//!
//! let cloned: Box<dyn Reflect> = original.clone_value();
//! let value = <MyStruct as FromReflect>::from_reflect(&*cloned).unwrap(); // OK!
//! ```
//!
//! When deriving, all active fields and sub-elements must also implement `FromReflect`.
//!
//! Fields can be given default values for when a field is missing in the passed value or even ignored.
//! Ignored fields must either implement [`Default`] or have a default function specified
//! using `#[reflect(default = "path::to::function")]`.
//!
//! See the [derive macro documentation](derive@crate::FromReflect) for details.
//!
//! All primitives and simple types implement `FromReflect` by relying on their [`Default`] implementation.
//!
//! # Path navigation
//!
//! The [`GetPath`] trait allows accessing arbitrary nested fields of a [`Reflect`] type.
//!
//! Using `GetPath`, it is possible to use a path string to access a specific field
//! of a reflected type.
//!
//! ```
//! # use bevy_reflect::{Reflect, GetPath};
//! #[derive(Reflect)]
//! struct MyStruct {
//! value: Vec<Option<u32>>
//! }
//!
//! let my_struct = MyStruct {
//! value: vec![None, None, Some(123)],
//! };
//! assert_eq!(
//! my_struct.path::<u32>(".value[2].0").unwrap(),
//! &123,
//! );
//! ```
//!
//! # Type Registration
//!
//! This crate also comes with a [`TypeRegistry`] that can be used to store and retrieve additional type metadata at runtime,
//! such as helper types and trait implementations.
//!
//! The [derive macro] for [`Reflect`] also generates an implementation of the [`GetTypeRegistration`] trait,
//! which is used by the registry to generate a [`TypeRegistration`] struct for that type.
//! We can then register additional [type data] we want associated with that type.
//!
//! For example, we can register [`ReflectDefault`] on our type so that its `Default` implementation
//! may be used dynamically.
//!
//! ```
//! # use bevy_reflect::{Reflect, TypeRegistry, prelude::ReflectDefault};
//! #[derive(Reflect, Default)]
//! struct MyStruct {
//! foo: i32
//! }
//! let mut registry = TypeRegistry::empty();
//! registry.register::<MyStruct>();
//! registry.register_type_data::<MyStruct, ReflectDefault>();
//!
//! let registration = registry.get(std::any::TypeId::of::<MyStruct>()).unwrap();
//! let reflect_default = registration.data::<ReflectDefault>().unwrap();
//!
//! let new_value: Box<dyn Reflect> = reflect_default.default();
//! assert!(new_value.is::<MyStruct>());
//! ```
//!
//! Because this operation is so common, the derive macro actually has a shorthand for it.
//! By using the `#[reflect(Trait)]` attribute, the derive macro will automatically register a matching,
//! in-scope `ReflectTrait` type within the `GetTypeRegistration` implementation.
//!
//! ```
//! use bevy_reflect::prelude::{Reflect, ReflectDefault};
//!
//! #[derive(Reflect, Default)]
//! #[reflect(Default)]
//! struct MyStruct {
//! foo: i32
//! }
//! ```
//!
//! ## Reflecting Traits
//!
//! Type data doesn't have to be tied to a trait, but it's often extremely useful to create trait type data.
//! These allow traits to be used directly on a `dyn Reflect` while utilizing the underlying type's implementation.
//!
//! For any [object-safe] trait, we can easily generate a corresponding `ReflectTrait` type for our trait
//! using the [`#[reflect_trait]`](reflect_trait) macro.
//!
//! ```
//! # use bevy_reflect::{Reflect, reflect_trait, TypeRegistry};
//! #[reflect_trait] // Generates a `ReflectMyTrait` type
//! pub trait MyTrait {}
//! impl<T: Reflect> MyTrait for T {}
//!
//! let mut registry = TypeRegistry::new();
//! registry.register_type_data::<i32, ReflectMyTrait>();
//! ```
//!
//! The generated type data can be used to convert a valid `dyn Reflect` into a `dyn MyTrait`.
//! See the [trait reflection example](https://github.com/bevyengine/bevy/blob/latest/examples/reflection/trait_reflection.rs)
//! for more information and usage details.
//!
//! # Serialization
//!
//! By using reflection, we are also able to get serialization capabilities for free.
//! In fact, using [`bevy_reflect`] can result in faster compile times and reduced code generation over
//! directly deriving the [`serde`] traits.
//!
//! The way it works is by moving the serialization logic into common serializers and deserializers:
//! * [`ReflectSerializer`]
//! * [`TypedReflectSerializer`]
//! * [`UntypedReflectDeserializer`]
//! * [`TypedReflectDeserializer`]
//!
//! All of these structs require a reference to the [registry] so that [type information] can be retrieved,
//! as well as registered type data, such as [`ReflectSerialize`] and [`ReflectDeserialize`].
//!
//! The general entry point are the "untyped" versions of these structs.
//! These will automatically extract the type information and pass them into their respective "typed" version.
//!
//! The output of the `ReflectSerializer` will be a map, where the key is the [type path]
//! and the value is the serialized data.
//! The `TypedReflectSerializer` will simply output the serialized data.
//!
//! The `UntypedReflectDeserializer` can be used to deserialize this map and return a `Box<dyn Reflect>`,
//! where the underlying type will be a dynamic type representing some concrete type (except for value types).
//!
//! Again, it's important to remember that dynamic types may need to be converted to their concrete counterparts
//! in order to be used in certain cases.
//! This can be achieved using [`FromReflect`].
//!
//! ```
//! # use serde::de::DeserializeSeed;
//! # use bevy_reflect::{
//! # serde::{ReflectSerializer, UntypedReflectDeserializer},
//! # Reflect, FromReflect, TypeRegistry
//! # };
//! #[derive(Reflect, PartialEq, Debug)]
//! struct MyStruct {
//! foo: i32
//! }
//!
//! let original_value = MyStruct {
//! foo: 123
//! };
//!
//! // Register
//! let mut registry = TypeRegistry::new();
//! registry.register::<MyStruct>();
//!
//! // Serialize
//! let reflect_serializer = ReflectSerializer::new(&original_value, &registry);
//! let serialized_value: String = ron::to_string(&reflect_serializer).unwrap();
//!
//! // Deserialize
//! let reflect_deserializer = UntypedReflectDeserializer::new(&registry);
//! let deserialized_value: Box<dyn Reflect> = reflect_deserializer.deserialize(
//! &mut ron::Deserializer::from_str(&serialized_value).unwrap()
//! ).unwrap();
//!
//! // Convert
//! let converted_value = <MyStruct as FromReflect>::from_reflect(&*deserialized_value).unwrap();
//!
//! assert_eq!(original_value, converted_value);
//! ```
//!
//! # Limitations
//!
//! While this crate offers a lot in terms of adding reflection to Rust,
//! it does come with some limitations that don't make it as featureful as reflection
//! in other programming languages.
//!
//! ## Non-Static Lifetimes
//!
//! One of the most obvious limitations is the `'static` requirement.
//! Rust requires fields to define a lifetime for referenced data,
//! but [`Reflect`] requires all types to have a `'static` lifetime.
//! This makes it impossible to reflect any type with non-static borrowed data.
//!
//! ## Function Reflection
//!
//! Another limitation is the inability to fully reflect functions and methods.
//! Most languages offer some way of calling methods dynamically,
//! but Rust makes this very difficult to do.
//! For non-generic methods, this can be done by registering custom [type data] that
//! contains function pointers.
//! For generic methods, the same can be done but will typically require manual monomorphization
//! (i.e. manually specifying the types the generic method can take).
//!
//! ## Manual Registration
//!
//! Since Rust doesn't provide built-in support for running initialization code before `main`,
//! there is no way for `bevy_reflect` to automatically register types into the [type registry].
//! This means types must manually be registered, including their desired monomorphized
//! representations if generic.
//!
//! # Features
//!
//! ## `bevy`
//!
//! | Default | Dependencies |
//! | :-----: | :---------------------------------------: |
//! | ❌ | [`bevy_math`], [`glam`], [`smallvec`] |
//!
//! This feature makes it so that the appropriate reflection traits are implemented on all the types
//! necessary for the [Bevy] game engine.
//! enables the optional dependencies: [`bevy_math`], [`glam`], and [`smallvec`].
//! These dependencies are used by the [Bevy] game engine and must define their reflection implementations
//! within this crate due to Rust's [orphan rule].
//!
//! ## `documentation`
//!
//! | Default | Dependencies |
//! | :-----: | :-------------------------------------------: |
//! | ❌ | [`bevy_reflect_derive/documentation`] |
//!
//! This feature enables capturing doc comments as strings for items that [derive `Reflect`].
//! Documentation information can then be accessed at runtime on the [`TypeInfo`] of that item.
//!
//! This can be useful for generating documentation for scripting language interop or
//! for displaying tooltips in an editor.
//!
//! [Reflection]: https://en.wikipedia.org/wiki/Reflective_programming
//! [Bevy]: https://bevyengine.org/
//! [limitations]: #limitations
//! [`bevy_reflect`]: crate
//! [runtime cost]: https://doc.rust-lang.org/book/ch17-02-trait-objects.html#trait-objects-perform-dynamic-dispatch
//! [derive macro]: derive@crate::Reflect
//! [`'static` lifetime]: https://doc.rust-lang.org/rust-by-example/scope/lifetime/static_lifetime.html#trait-bound
//! [derive macro documentation]: derive@crate::Reflect
//! [deriving `Reflect`]: derive@crate::Reflect
//! [type data]: TypeData
//! [`ReflectDefault`]: std_traits::ReflectDefault
//! [object-safe]: https://doc.rust-lang.org/reference/items/traits.html#object-safety
//! [`serde`]: ::serde
//! [`ReflectSerializer`]: serde::ReflectSerializer
//! [`TypedReflectSerializer`]: serde::TypedReflectSerializer
//! [`UntypedReflectDeserializer`]: serde::UntypedReflectDeserializer
//! [`TypedReflectDeserializer`]: serde::TypedReflectDeserializer
//! [registry]: TypeRegistry
//! [type information]: TypeInfo
//! [type path]: TypePath
//! [type registry]: TypeRegistry
//! [`bevy_math`]: https://docs.rs/bevy_math/latest/bevy_math/
//! [`glam`]: https://docs.rs/glam/latest/glam/
//! [`smallvec`]: https://docs.rs/smallvec/latest/smallvec/
//! [orphan rule]: https://doc.rust-lang.org/book/ch10-02-traits.html#implementing-a-trait-on-a-type:~:text=But%20we%20can%E2%80%99t,implementation%20to%20use.
//! [`bevy_reflect_derive/documentation`]: bevy_reflect_derive
//! [derive `Reflect`]: derive@crate::Reflect
mod array;
mod fields;
mod from_reflect;
mod list;
mod map;
mod path;
mod reflect;
mod struct_trait;
mod tuple;
mod tuple_struct;
mod type_info;
mod type_path;
mod type_registry;
mod impls {
#[cfg(feature = "glam")]
mod glam;
#[cfg(feature = "bevy_math")]
mod math {
mod primitives2d;
mod primitives3d;
mod rect;
}
#[cfg(feature = "smallvec")]
mod smallvec;
#[cfg(feature = "smol_str")]
mod smol_str;
mod std;
mod uuid;
}
mod enums;
pub mod serde;
pub mod std_traits;
pub mod utility;
pub mod prelude {
pub use crate::std_traits::*;
#[doc(hidden)]
pub use crate::{
reflect_trait, FromReflect, GetField, GetPath, GetTupleStructField, Reflect,
ReflectDeserialize, ReflectFromReflect, ReflectPath, ReflectSerialize, Struct, TupleStruct,
TypePath,
};
}
pub use array::*;
pub use enums::*;
pub use fields::*;
pub use from_reflect::*;
pub use list::*;
pub use map::*;
pub use path::*;
pub use reflect::*;
pub use struct_trait::*;
pub use tuple::*;
pub use tuple_struct::*;
pub use type_info::*;
pub use type_path::*;
pub use type_registry::*;
pub use bevy_reflect_derive::*;
pub use erased_serde;
extern crate alloc;
#[doc(hidden)]
pub mod __macro_exports {
pub use bevy_utils::uuid::generate_composite_uuid;
}
#[cfg(test)]
#[allow(clippy::disallowed_types, clippy::approx_constant)]
mod tests {
use ::serde::{de::DeserializeSeed, Deserialize, Serialize};
use bevy_utils::HashMap;
use ron::{
ser::{to_string_pretty, PrettyConfig},
Deserializer,
};
use static_assertions::{assert_impl_all, assert_not_impl_all};
use std::{
any::TypeId,
borrow::Cow,
fmt::{Debug, Formatter},
marker::PhantomData,
};
use super::prelude::*;
use super::*;
use crate as bevy_reflect;
use crate::serde::{ReflectSerializer, UntypedReflectDeserializer};
use crate::utility::GenericTypePathCell;
#[test]
fn reflect_struct() {
#[derive(Reflect)]
struct Foo {
a: u32,
b: f32,
c: Bar,
}
#[derive(Reflect)]
struct Bar {
x: u32,
}
let mut foo = Foo {
a: 42,
b: 3.14,
c: Bar { x: 1 },
};
let a = *foo.get_field::<u32>("a").unwrap();
assert_eq!(a, 42);
*foo.get_field_mut::<u32>("a").unwrap() += 1;
assert_eq!(foo.a, 43);
let bar = foo.get_field::<Bar>("c").unwrap();
assert_eq!(bar.x, 1);
// nested retrieval
let c = foo.field("c").unwrap();
if let ReflectRef::Struct(value) = c.reflect_ref() {
assert_eq!(*value.get_field::<u32>("x").unwrap(), 1);
} else {
panic!("Expected a struct.");
}
// patch Foo with a dynamic struct
let mut dynamic_struct = DynamicStruct::default();
dynamic_struct.insert("a", 123u32);
dynamic_struct.insert("should_be_ignored", 456);
foo.apply(&dynamic_struct);
assert_eq!(foo.a, 123);
}
#[test]
fn reflect_map() {
#[derive(Reflect, Hash)]
#[reflect(Hash)]
struct Foo {
a: u32,
b: String,
}
let key_a = Foo {
a: 1,
b: "k1".to_string(),
};
let key_b = Foo {
a: 1,
b: "k1".to_string(),
};
let key_c = Foo {
a: 3,
b: "k3".to_string(),
};
let mut map = DynamicMap::default();
map.insert(key_a, 10u32);
assert_eq!(10, *map.get(&key_b).unwrap().downcast_ref::<u32>().unwrap());
assert!(map.get(&key_c).is_none());
*map.get_mut(&key_b).unwrap().downcast_mut::<u32>().unwrap() = 20;
assert_eq!(20, *map.get(&key_b).unwrap().downcast_ref::<u32>().unwrap());
}
#[test]
#[allow(clippy::disallowed_types)]
fn reflect_unit_struct() {
#[derive(Reflect)]
struct Foo(u32, u64);
let mut foo = Foo(1, 2);
assert_eq!(1, *foo.get_field::<u32>(0).unwrap());
assert_eq!(2, *foo.get_field::<u64>(1).unwrap());
let mut patch = DynamicTupleStruct::default();
patch.insert(3u32);
patch.insert(4u64);
assert_eq!(3, *patch.field(0).unwrap().downcast_ref::<u32>().unwrap());
assert_eq!(4, *patch.field(1).unwrap().downcast_ref::<u64>().unwrap());
foo.apply(&patch);
assert_eq!(3, foo.0);
assert_eq!(4, foo.1);
let mut iter = patch.iter_fields();
assert_eq!(3, *iter.next().unwrap().downcast_ref::<u32>().unwrap());
assert_eq!(4, *iter.next().unwrap().downcast_ref::<u64>().unwrap());
}
#[test]
#[should_panic(expected = "the given key does not support hashing")]
fn reflect_map_no_hash() {
#[derive(Reflect)]
struct Foo {
a: u32,
}
let foo = Foo { a: 1 };
let mut map = DynamicMap::default();
map.insert(foo, 10u32);
}
#[test]
fn reflect_ignore() {
#[derive(Reflect)]
struct Foo {
a: u32,
#[reflect(ignore)]
_b: u32,
}
let foo = Foo { a: 1, _b: 2 };
let values: Vec<u32> = foo
.iter_fields()
.map(|value| *value.downcast_ref::<u32>().unwrap())
.collect();
assert_eq!(values, vec![1]);
}
#[test]
fn should_call_from_reflect_dynamically() {
#[derive(Reflect)]
struct MyStruct {
foo: usize,
}
// Register
let mut registry = TypeRegistry::default();
registry.register::<MyStruct>();
// Get type data
let type_id = TypeId::of::<MyStruct>();
let rfr = registry
.get_type_data::<ReflectFromReflect>(type_id)
.expect("the FromReflect trait should be registered");
// Call from_reflect
let mut dynamic_struct = DynamicStruct::default();
dynamic_struct.insert("foo", 123usize);
let reflected = rfr
.from_reflect(&dynamic_struct)
.expect("the type should be properly reflected");
// Assert
let expected = MyStruct { foo: 123 };
assert!(expected
.reflect_partial_eq(reflected.as_ref())
.unwrap_or_default());
let not_expected = MyStruct { foo: 321 };
assert!(!not_expected
.reflect_partial_eq(reflected.as_ref())
.unwrap_or_default());
}
#[test]
fn from_reflect_should_allow_ignored_unnamed_fields() {
#[derive(Reflect, Eq, PartialEq, Debug)]
struct MyTupleStruct(i8, #[reflect(ignore)] i16, i32);
let expected = MyTupleStruct(1, 0, 3);
let mut dyn_tuple_struct = DynamicTupleStruct::default();
dyn_tuple_struct.insert(1_i8);
dyn_tuple_struct.insert(3_i32);
let my_tuple_struct = <MyTupleStruct as FromReflect>::from_reflect(&dyn_tuple_struct);
assert_eq!(Some(expected), my_tuple_struct);
#[derive(Reflect, Eq, PartialEq, Debug)]
enum MyEnum {
Tuple(i8, #[reflect(ignore)] i16, i32),
}
let expected = MyEnum::Tuple(1, 0, 3);
let mut dyn_tuple = DynamicTuple::default();
dyn_tuple.insert(1_i8);
dyn_tuple.insert(3_i32);
let mut dyn_enum = DynamicEnum::default();
dyn_enum.set_variant("Tuple", dyn_tuple);
let my_enum = <MyEnum as FromReflect>::from_reflect(&dyn_enum);
assert_eq!(Some(expected), my_enum);
}
#[test]
fn from_reflect_should_use_default_field_attributes() {
#[derive(Reflect, Eq, PartialEq, Debug)]
struct MyStruct {
// Use `Default::default()`
// Note that this isn't an ignored field
#[reflect(default)]
foo: String,
// Use `get_bar_default()`
#[reflect(ignore)]
#[reflect(default = "get_bar_default")]
bar: NotReflect,
// Ensure attributes can be combined
#[reflect(ignore, default = "get_bar_default")]
baz: NotReflect,
}
#[derive(Eq, PartialEq, Debug)]
struct NotReflect(usize);
fn get_bar_default() -> NotReflect {
NotReflect(123)
}
let expected = MyStruct {
foo: String::default(),
bar: NotReflect(123),
baz: NotReflect(123),
};
let dyn_struct = DynamicStruct::default();
let my_struct = <MyStruct as FromReflect>::from_reflect(&dyn_struct);
assert_eq!(Some(expected), my_struct);
}
#[test]
fn from_reflect_should_use_default_variant_field_attributes() {
#[derive(Reflect, Eq, PartialEq, Debug)]
enum MyEnum {
Foo(#[reflect(default)] String),
Bar {
#[reflect(default = "get_baz_default")]
#[reflect(ignore)]
baz: usize,
},
}
fn get_baz_default() -> usize {
123
}
let expected = MyEnum::Foo(String::default());
let dyn_enum = DynamicEnum::new("Foo", DynamicTuple::default());
let my_enum = <MyEnum as FromReflect>::from_reflect(&dyn_enum);
assert_eq!(Some(expected), my_enum);
let expected = MyEnum::Bar {
baz: get_baz_default(),
};
let dyn_enum = DynamicEnum::new("Bar", DynamicStruct::default());
let my_enum = <MyEnum as FromReflect>::from_reflect(&dyn_enum);
assert_eq!(Some(expected), my_enum);
}
#[test]
fn from_reflect_should_use_default_container_attribute() {
#[derive(Reflect, Eq, PartialEq, Debug)]
#[reflect(Default)]
struct MyStruct {
foo: String,
#[reflect(ignore)]
bar: usize,
}
impl Default for MyStruct {
fn default() -> Self {
Self {
foo: String::from("Hello"),
bar: 123,
}
}
}
let expected = MyStruct {
foo: String::from("Hello"),
bar: 123,
};
let dyn_struct = DynamicStruct::default();
let my_struct = <MyStruct as FromReflect>::from_reflect(&dyn_struct);
assert_eq!(Some(expected), my_struct);
}
#[test]
fn reflect_complex_patch() {
#[derive(Reflect, Eq, PartialEq, Debug)]
#[reflect(PartialEq)]
struct Foo {
a: u32,
#[reflect(ignore)]
_b: u32,
c: Vec<isize>,
d: HashMap<usize, i8>,
e: Bar,
f: (i32, Vec<isize>, Bar),
g: Vec<(Baz, HashMap<usize, Bar>)>,
h: [u32; 2],
}
#[derive(Reflect, Eq, PartialEq, Clone, Debug)]
#[reflect(PartialEq)]
struct Bar {
x: u32,
}
#[derive(Reflect, Eq, PartialEq, Debug)]
struct Baz(String);
let mut hash_map = HashMap::default();
hash_map.insert(1, 1);
hash_map.insert(2, 2);
let mut hash_map_baz = HashMap::default();
hash_map_baz.insert(1, Bar { x: 0 });
let mut foo = Foo {
a: 1,
_b: 1,
c: vec![1, 2],
d: hash_map,
e: Bar { x: 1 },
f: (1, vec![1, 2], Bar { x: 1 }),
g: vec![(Baz("string".to_string()), hash_map_baz)],
h: [2; 2],
};
let mut foo_patch = DynamicStruct::default();
foo_patch.insert("a", 2u32);
foo_patch.insert("b", 2u32); // this should be ignored
let mut list = DynamicList::default();
list.push(3isize);
list.push(4isize);
list.push(5isize);
foo_patch.insert("c", list.clone_dynamic());
let mut map = DynamicMap::default();
map.insert(2usize, 3i8);
map.insert(3usize, 4i8);
foo_patch.insert("d", map);
let mut bar_patch = DynamicStruct::default();
bar_patch.insert("x", 2u32);
foo_patch.insert("e", bar_patch.clone_dynamic());
let mut tuple = DynamicTuple::default();
tuple.insert(2i32);
tuple.insert(list);
tuple.insert(bar_patch);
foo_patch.insert("f", tuple);
let mut composite = DynamicList::default();
composite.push({
let mut tuple = DynamicTuple::default();
tuple.insert({
let mut tuple_struct = DynamicTupleStruct::default();
tuple_struct.insert("new_string".to_string());
tuple_struct
});
tuple.insert({
let mut map = DynamicMap::default();
map.insert(1usize, {
let mut struct_ = DynamicStruct::default();
struct_.insert("x", 7u32);
struct_
});
map
});
tuple
});
foo_patch.insert("g", composite);
let array = DynamicArray::from_vec(vec![2u32, 2u32]);
foo_patch.insert("h", array);
foo.apply(&foo_patch);
let mut hash_map = HashMap::default();
hash_map.insert(1, 1);
hash_map.insert(2, 3);
hash_map.insert(3, 4);
let mut hash_map_baz = HashMap::default();
hash_map_baz.insert(1, Bar { x: 7 });
let expected_foo = Foo {
a: 2,
_b: 1,
c: vec![3, 4, 5],
d: hash_map,
e: Bar { x: 2 },
f: (2, vec![3, 4, 5], Bar { x: 2 }),
g: vec![(Baz("new_string".to_string()), hash_map_baz.clone())],
h: [2; 2],
};
assert_eq!(foo, expected_foo);
let new_foo = Foo::from_reflect(&foo_patch)
.expect("error while creating a concrete type from a dynamic type");
let mut hash_map = HashMap::default();
hash_map.insert(2, 3);
hash_map.insert(3, 4);
let expected_new_foo = Foo {
a: 2,
_b: 0,
c: vec![3, 4, 5],
d: hash_map,
e: Bar { x: 2 },
f: (2, vec![3, 4, 5], Bar { x: 2 }),
g: vec![(Baz("new_string".to_string()), hash_map_baz)],
h: [2; 2],
};
assert_eq!(new_foo, expected_new_foo);
}
#[test]
fn reflect_serialize() {
#[derive(Reflect)]
struct Foo {
a: u32,
#[reflect(ignore)]
_b: u32,
c: Vec<isize>,
d: HashMap<usize, i8>,
e: Bar,
f: String,
g: (i32, Vec<isize>, Bar),
h: [u32; 2],
}
#[derive(Reflect, Serialize, Deserialize)]
#[reflect(Serialize, Deserialize)]
struct Bar {
x: u32,
}
let mut hash_map = HashMap::default();
hash_map.insert(1, 1);
hash_map.insert(2, 2);
let foo = Foo {
a: 1,
_b: 1,
c: vec![1, 2],
d: hash_map,
e: Bar { x: 1 },
f: "hi".to_string(),
g: (1, vec![1, 2], Bar { x: 1 }),
h: [2; 2],
};
let mut registry = TypeRegistry::default();
registry.register::<u32>();
registry.register::<i8>();
registry.register::<i32>();
registry.register::<usize>();
registry.register::<isize>();
registry.register::<Foo>();
registry.register::<Bar>();
registry.register::<String>();
registry.register::<Vec<isize>>();
registry.register::<HashMap<usize, i8>>();
registry.register::<(i32, Vec<isize>, Bar)>();
registry.register::<[u32; 2]>();
let serializer = ReflectSerializer::new(&foo, &registry);
let serialized = to_string_pretty(&serializer, PrettyConfig::default()).unwrap();
let mut deserializer = Deserializer::from_str(&serialized).unwrap();
let reflect_deserializer = UntypedReflectDeserializer::new(&registry);
let value = reflect_deserializer.deserialize(&mut deserializer).unwrap();
let dynamic_struct = value.take::<DynamicStruct>().unwrap();
assert!(foo.reflect_partial_eq(&dynamic_struct).unwrap());
}
#[test]
fn reflect_downcast() {
#[derive(Reflect, Clone, Debug, PartialEq)]
struct Bar {
y: u8,
}
#[derive(Reflect, Clone, Debug, PartialEq)]
struct Foo {
x: i32,
s: String,
b: Bar,
u: usize,
t: ([f32; 3], String),
v: Cow<'static, str>,
w: Cow<'static, [u8]>,
}
let foo = Foo {
x: 123,
s: "String".to_string(),
b: Bar { y: 255 },
u: 1111111111111,
t: ([3.0, 2.0, 1.0], "Tuple String".to_string()),
v: Cow::Owned("Cow String".to_string()),
w: Cow::Owned(vec![1, 2, 3]),
};
let foo2: Box<dyn Reflect> = Box::new(foo.clone());
assert_eq!(foo, *foo2.downcast::<Foo>().unwrap());
}
#[test]
fn should_drain_fields() {
let array_value: Box<dyn Array> = Box::new([123_i32, 321_i32]);
let fields = array_value.drain();
assert!(fields[0].reflect_partial_eq(&123_i32).unwrap_or_default());
assert!(fields[1].reflect_partial_eq(&321_i32).unwrap_or_default());
let list_value: Box<dyn List> = Box::new(vec![123_i32, 321_i32]);
let fields = list_value.drain();
assert!(fields[0].reflect_partial_eq(&123_i32).unwrap_or_default());
assert!(fields[1].reflect_partial_eq(&321_i32).unwrap_or_default());
let tuple_value: Box<dyn Tuple> = Box::new((123_i32, 321_i32));
let fields = tuple_value.drain();
assert!(fields[0].reflect_partial_eq(&123_i32).unwrap_or_default());
assert!(fields[1].reflect_partial_eq(&321_i32).unwrap_or_default());
let map_value: Box<dyn Map> = Box::new(HashMap::from([(123_i32, 321_i32)]));
let fields = map_value.drain();
assert!(fields[0].0.reflect_partial_eq(&123_i32).unwrap_or_default());
assert!(fields[0].1.reflect_partial_eq(&321_i32).unwrap_or_default());
}
#[test]
fn reflect_take() {
#[derive(Reflect, Debug, PartialEq)]
#[reflect(PartialEq)]
struct Bar {
x: u32,
}
let x: Box<dyn Reflect> = Box::new(Bar { x: 2 });
let y = x.take::<Bar>().unwrap();
assert_eq!(y, Bar { x: 2 });
}
#[test]
fn not_dynamic_names() {
let list = Vec::<usize>::new();
let dyn_list = list.clone_dynamic();
assert_ne!(dyn_list.reflect_type_path(), Vec::<usize>::type_path());
let array = [b'0'; 4];
let dyn_array = array.clone_dynamic();
assert_ne!(dyn_array.reflect_type_path(), <[u8; 4]>::type_path());
let map = HashMap::<usize, String>::default();
let dyn_map = map.clone_dynamic();
assert_ne!(
dyn_map.reflect_type_path(),
HashMap::<usize, String>::type_path()
);
let tuple = (0usize, "1".to_string(), 2.0f32);
let mut dyn_tuple = tuple.clone_dynamic();
dyn_tuple.insert::<usize>(3);
assert_ne!(
dyn_tuple.reflect_type_path(),
<(usize, String, f32, usize)>::type_path()
);
#[derive(Reflect)]
struct TestStruct {
a: usize,
}
let struct_ = TestStruct { a: 0 };
let dyn_struct = struct_.clone_dynamic();
assert_ne!(dyn_struct.reflect_type_path(), TestStruct::type_path());
#[derive(Reflect)]
struct TestTupleStruct(usize);
let tuple_struct = TestTupleStruct(0);
let dyn_tuple_struct = tuple_struct.clone_dynamic();
assert_ne!(
dyn_tuple_struct.reflect_type_path(),
TestTupleStruct::type_path()
);
}
macro_rules! assert_type_paths {
($($ty:ty => $long:literal, $short:literal,)*) => {
$(
assert_eq!(<$ty as TypePath>::type_path(), $long);
assert_eq!(<$ty as TypePath>::short_type_path(), $short);
)*
};
}
#[test]
fn reflect_type_path() {
#[derive(TypePath)]
struct Param;
#[derive(TypePath)]
struct Derive;
#[derive(TypePath)]
#[type_path = "my_alias"]
struct DerivePath;
#[derive(TypePath)]
#[type_path = "my_alias"]
#[type_name = "MyDerivePathName"]
struct DerivePathName;
#[derive(TypePath)]
struct DeriveG<T>(PhantomData<T>);
#[derive(TypePath)]
#[type_path = "my_alias"]
struct DerivePathG<T, const N: usize>(PhantomData<T>);
#[derive(TypePath)]
#[type_path = "my_alias"]
#[type_name = "MyDerivePathNameG"]
struct DerivePathNameG<T>(PhantomData<T>);
struct Macro;
impl_type_path!((in my_alias) Macro);
struct MacroName;
impl_type_path!((in my_alias as MyMacroName) MacroName);
struct MacroG<T, const N: usize>(PhantomData<T>);
impl_type_path!((in my_alias) MacroG<T, const N: usize>);
struct MacroNameG<T>(PhantomData<T>);
impl_type_path!((in my_alias as MyMacroNameG) MacroNameG<T>);
assert_type_paths! {
Derive => "bevy_reflect::tests::Derive", "Derive",
DerivePath => "my_alias::DerivePath", "DerivePath",
DerivePathName => "my_alias::MyDerivePathName", "MyDerivePathName",
DeriveG<Param> => "bevy_reflect::tests::DeriveG<bevy_reflect::tests::Param>", "DeriveG<Param>",
DerivePathG<Param, 10> => "my_alias::DerivePathG<bevy_reflect::tests::Param, 10>", "DerivePathG<Param, 10>",
DerivePathNameG<Param> => "my_alias::MyDerivePathNameG<bevy_reflect::tests::Param>", "MyDerivePathNameG<Param>",
Macro => "my_alias::Macro", "Macro",
MacroName => "my_alias::MyMacroName", "MyMacroName",
MacroG<Param, 10> => "my_alias::MacroG<bevy_reflect::tests::Param, 10>", "MacroG<Param, 10>",
MacroNameG<Param> => "my_alias::MyMacroNameG<bevy_reflect::tests::Param>", "MyMacroNameG<Param>",
}
}
#[test]
fn std_type_paths() {
#[derive(Clone)]
struct Type;
impl TypePath for Type {
fn type_path() -> &'static str {
// for brevity in tests
"Long"
}
fn short_type_path() -> &'static str {
"Short"
}
}
assert_type_paths! {
u8 => "u8", "u8",
Type => "Long", "Short",
&Type => "&Long", "&Short",
[Type] => "[Long]", "[Short]",
&[Type] => "&[Long]", "&[Short]",
[Type; 0] => "[Long; 0]", "[Short; 0]",
[Type; 100] => "[Long; 100]", "[Short; 100]",
() => "()", "()",
(Type,) => "(Long,)", "(Short,)",
(Type, Type) => "(Long, Long)", "(Short, Short)",
(Type, Type, Type) => "(Long, Long, Long)", "(Short, Short, Short)",
Cow<'static, Type> => "alloc::borrow::Cow<Long>", "Cow<Short>",
}
}
#[test]
fn reflect_type_info() {
// TypeInfo
let info = i32::type_info();
assert_eq!(i32::type_path(), info.type_path());
assert_eq!(TypeId::of::<i32>(), info.type_id());
// TypeInfo (unsized)
assert_eq!(
TypeId::of::<dyn Reflect>(),
<dyn Reflect as Typed>::type_info().type_id()
);
// TypeInfo (instance)
let value: &dyn Reflect = &123_i32;
let info = value.get_represented_type_info().unwrap();
assert!(info.is::<i32>());
// Struct
#[derive(Reflect)]
struct MyStruct {
foo: i32,
bar: usize,
}
let info = MyStruct::type_info();
if let TypeInfo::Struct(info) = info {
assert!(info.is::<MyStruct>());
assert_eq!(MyStruct::type_path(), info.type_path());
assert_eq!(i32::type_path(), info.field("foo").unwrap().type_path());
assert_eq!(TypeId::of::<i32>(), info.field("foo").unwrap().type_id());
assert!(info.field("foo").unwrap().is::<i32>());
assert_eq!("foo", info.field("foo").unwrap().name());
assert_eq!(usize::type_path(), info.field_at(1).unwrap().type_path());
} else {
panic!("Expected `TypeInfo::Struct`");
}
let value: &dyn Reflect = &MyStruct { foo: 123, bar: 321 };
let info = value.get_represented_type_info().unwrap();
assert!(info.is::<MyStruct>());
// Struct (generic)
#[derive(Reflect)]
struct MyGenericStruct<T> {
foo: T,
bar: usize,
}
let info = <MyGenericStruct<i32>>::type_info();
if let TypeInfo::Struct(info) = info {
assert!(info.is::<MyGenericStruct<i32>>());
assert_eq!(MyGenericStruct::<i32>::type_path(), info.type_path());
assert_eq!(i32::type_path(), info.field("foo").unwrap().type_path());
assert_eq!("foo", info.field("foo").unwrap().name());
assert_eq!(usize::type_path(), info.field_at(1).unwrap().type_path());
} else {
panic!("Expected `TypeInfo::Struct`");
}
let value: &dyn Reflect = &MyGenericStruct {
foo: String::from("Hello!"),
bar: 321,
};
let info = value.get_represented_type_info().unwrap();
assert!(info.is::<MyGenericStruct<String>>());
// Tuple Struct
#[derive(Reflect)]
struct MyTupleStruct(usize, i32, MyStruct);
let info = MyTupleStruct::type_info();
if let TypeInfo::TupleStruct(info) = info {
assert!(info.is::<MyTupleStruct>());
assert_eq!(MyTupleStruct::type_path(), info.type_path());
assert_eq!(i32::type_path(), info.field_at(1).unwrap().type_path());
assert!(info.field_at(1).unwrap().is::<i32>());
} else {
panic!("Expected `TypeInfo::TupleStruct`");
}
// Tuple
type MyTuple = (u32, f32, String);
let info = MyTuple::type_info();
if let TypeInfo::Tuple(info) = info {
assert!(info.is::<MyTuple>());
assert_eq!(MyTuple::type_path(), info.type_path());
assert_eq!(f32::type_path(), info.field_at(1).unwrap().type_path());
} else {
panic!("Expected `TypeInfo::Tuple`");
}
let value: &dyn Reflect = &(123_u32, 1.23_f32, String::from("Hello!"));
let info = value.get_represented_type_info().unwrap();
assert!(info.is::<MyTuple>());
// List
type MyList = Vec<usize>;
let info = MyList::type_info();
if let TypeInfo::List(info) = info {
assert!(info.is::<MyList>());
assert!(info.item_is::<usize>());
assert_eq!(MyList::type_path(), info.type_path());
assert_eq!(usize::type_path(), info.item_type_path_table().path());
} else {
panic!("Expected `TypeInfo::List`");
}
let value: &dyn Reflect = &vec![123_usize];
let info = value.get_represented_type_info().unwrap();
assert!(info.is::<MyList>());
// List (SmallVec)
#[cfg(feature = "smallvec")]
{
use bevy_utils::smallvec;
type MySmallVec = smallvec::SmallVec<[String; 2]>;
let info = MySmallVec::type_info();
if let TypeInfo::List(info) = info {
assert!(info.is::<MySmallVec>());
assert!(info.item_is::<String>());
assert_eq!(MySmallVec::type_path(), info.type_path());
assert_eq!(String::type_path(), info.item_type_path_table().path());
} else {
panic!("Expected `TypeInfo::List`");
}
let value: MySmallVec = smallvec::smallvec![String::default(); 2];
let value: &dyn Reflect = &value;
let info = value.get_represented_type_info().unwrap();
assert!(info.is::<MySmallVec>());
}
// Array
type MyArray = [usize; 3];
let info = MyArray::type_info();
if let TypeInfo::Array(info) = info {
assert!(info.is::<MyArray>());
assert!(info.item_is::<usize>());
assert_eq!(MyArray::type_path(), info.type_path());
assert_eq!(usize::type_path(), info.item_type_path_table().path());
assert_eq!(3, info.capacity());
} else {
panic!("Expected `TypeInfo::Array`");
}
let value: &dyn Reflect = &[1usize, 2usize, 3usize];
let info = value.get_represented_type_info().unwrap();
assert!(info.is::<MyArray>());
// Cow<'static, str>
type MyCowStr = Cow<'static, str>;
let info = MyCowStr::type_info();
if let TypeInfo::Value(info) = info {
assert!(info.is::<MyCowStr>());
assert_eq!(std::any::type_name::<MyCowStr>(), info.type_path());
} else {
panic!("Expected `TypeInfo::Value`");
}
let value: &dyn Reflect = &Cow::<'static, str>::Owned("Hello!".to_string());
let info = value.get_represented_type_info().unwrap();
assert!(info.is::<MyCowStr>());
// Cow<'static, [u8]>
type MyCowSlice = Cow<'static, [u8]>;
let info = MyCowSlice::type_info();
if let TypeInfo::List(info) = info {
assert!(info.is::<MyCowSlice>());
assert!(info.item_is::<u8>());
assert_eq!(std::any::type_name::<MyCowSlice>(), info.type_path());
assert_eq!(
std::any::type_name::<u8>(),
info.item_type_path_table().path()
);
} else {
panic!("Expected `TypeInfo::List`");
}
let value: &dyn Reflect = &Cow::<'static, [u8]>::Owned(vec![0, 1, 2, 3]);
let info = value.get_represented_type_info().unwrap();
assert!(info.is::<MyCowSlice>());
// Map
type MyMap = HashMap<usize, f32>;
let info = MyMap::type_info();
if let TypeInfo::Map(info) = info {
assert!(info.is::<MyMap>());
assert!(info.key_is::<usize>());
assert!(info.value_is::<f32>());
assert_eq!(MyMap::type_path(), info.type_path());
assert_eq!(usize::type_path(), info.key_type_path_table().path());
assert_eq!(f32::type_path(), info.value_type_path_table().path());
} else {
panic!("Expected `TypeInfo::Map`");
}
let value: &dyn Reflect = &MyMap::new();
let info = value.get_represented_type_info().unwrap();
assert!(info.is::<MyMap>());
// Value
type MyValue = String;
let info = MyValue::type_info();
if let TypeInfo::Value(info) = info {
assert!(info.is::<MyValue>());
assert_eq!(MyValue::type_path(), info.type_path());
} else {
panic!("Expected `TypeInfo::Value`");
}
let value: &dyn Reflect = &String::from("Hello!");
let info = value.get_represented_type_info().unwrap();
assert!(info.is::<MyValue>());
}
#[test]
fn should_permit_higher_ranked_lifetimes() {
#[derive(Reflect)]
#[reflect(from_reflect = false)]
struct TestStruct {
#[reflect(ignore)]
_hrl: for<'a> fn(&'a str) -> &'a str,
}
impl Default for TestStruct {
fn default() -> Self {
TestStruct {
_hrl: |input| input,
}
}
}
fn get_type_registration<T: GetTypeRegistration>() {}
get_type_registration::<TestStruct>();
}
#[test]
fn should_permit_valid_represented_type_for_dynamic() {
let type_info = <[i32; 2] as Typed>::type_info();
let mut dynamic_array = [123; 2].clone_dynamic();
dynamic_array.set_represented_type(Some(type_info));
}
#[test]
#[should_panic(expected = "expected TypeInfo::Array but received")]
fn should_prohibit_invalid_represented_type_for_dynamic() {
let type_info = <(i32, i32) as Typed>::type_info();
let mut dynamic_array = [123; 2].clone_dynamic();
dynamic_array.set_represented_type(Some(type_info));
}
#[cfg(feature = "documentation")]
mod docstrings {
use super::*;
#[test]
fn should_not_contain_docs() {
// Regular comments do not count as doc comments,
// and are therefore not reflected.
#[derive(Reflect)]
struct SomeStruct;
let info = <SomeStruct as Typed>::type_info();
assert_eq!(None, info.docs());
/*
* Block comments do not count as doc comments,
* and are therefore not reflected.
*/
#[derive(Reflect)]
struct SomeOtherStruct;
let info = <SomeOtherStruct as Typed>::type_info();
assert_eq!(None, info.docs());
}
#[test]
fn should_contain_docs() {
/// Some struct.
///
/// # Example
///
/// ```ignore (This is only used for a unit test, no need to doc test)
/// let some_struct = SomeStruct;
/// ```
#[derive(Reflect)]
struct SomeStruct;
let info = <SomeStruct as Typed>::type_info();
assert_eq!(
Some(" Some struct.\n\n # Example\n\n ```ignore\n let some_struct = SomeStruct;\n ```"),
info.docs()
);
#[doc = "The compiler automatically converts `///`-style comments into `#[doc]` attributes."]
#[doc = "Of course, you _could_ use the attribute directly if you wanted to."]
#[doc = "Both will be reflected."]
#[derive(Reflect)]
struct SomeOtherStruct;
let info = <SomeOtherStruct as Typed>::type_info();
assert_eq!(
Some("The compiler automatically converts `///`-style comments into `#[doc]` attributes.\nOf course, you _could_ use the attribute directly if you wanted to.\nBoth will be reflected."),
info.docs()
);
/// Some tuple struct.
#[derive(Reflect)]
struct SomeTupleStruct(usize);
let info = <SomeTupleStruct as Typed>::type_info();
assert_eq!(Some(" Some tuple struct."), info.docs());
/// Some enum.
#[derive(Reflect)]
enum SomeEnum {
Foo,
}
let info = <SomeEnum as Typed>::type_info();
assert_eq!(Some(" Some enum."), info.docs());
#[derive(Clone)]
struct SomePrimitive;
impl_reflect_value!(
/// Some primitive for which we have attributed custom documentation.
(in bevy_reflect::tests) SomePrimitive
);
let info = <SomePrimitive as Typed>::type_info();
assert_eq!(
Some(" Some primitive for which we have attributed custom documentation."),
info.docs()
);
}
#[test]
fn fields_should_contain_docs() {
#[derive(Reflect)]
struct SomeStruct {
/// The name
name: String,
/// The index
index: usize,
// Not documented...
data: Vec<i32>,
}
let info = <SomeStruct as Typed>::type_info();
if let TypeInfo::Struct(info) = info {
let mut fields = info.iter();
assert_eq!(Some(" The name"), fields.next().unwrap().docs());
assert_eq!(Some(" The index"), fields.next().unwrap().docs());
assert_eq!(None, fields.next().unwrap().docs());
} else {
panic!("expected struct info");
}
}
#[test]
fn variants_should_contain_docs() {
#[derive(Reflect)]
enum SomeEnum {
// Not documented...
Nothing,
/// Option A
A(
/// Index
usize,
),
/// Option B
B {
/// Name
name: String,
},
}
let info = <SomeEnum as Typed>::type_info();
if let TypeInfo::Enum(info) = info {
let mut variants = info.iter();
assert_eq!(None, variants.next().unwrap().docs());
let variant = variants.next().unwrap();
assert_eq!(Some(" Option A"), variant.docs());
if let VariantInfo::Tuple(variant) = variant {
let field = variant.field_at(0).unwrap();
assert_eq!(Some(" Index"), field.docs());
} else {
panic!("expected tuple variant")
}
let variant = variants.next().unwrap();
assert_eq!(Some(" Option B"), variant.docs());
if let VariantInfo::Struct(variant) = variant {
let field = variant.field_at(0).unwrap();
assert_eq!(Some(" Name"), field.docs());
} else {
panic!("expected struct variant")
}
} else {
panic!("expected enum info");
}
}
}
#[test]
fn into_reflect() {
trait TestTrait: Reflect {}
#[derive(Reflect)]
struct TestStruct;
impl TestTrait for TestStruct {}
let trait_object: Box<dyn TestTrait> = Box::new(TestStruct);
// Should compile:
let _ = trait_object.into_reflect();
}
#[test]
fn as_reflect() {
trait TestTrait: Reflect {}
#[derive(Reflect)]
struct TestStruct;
impl TestTrait for TestStruct {}
let trait_object: Box<dyn TestTrait> = Box::new(TestStruct);
// Should compile:
let _ = trait_object.as_reflect();
}
#[test]
fn should_reflect_debug() {
#[derive(Reflect)]
struct Test {
value: usize,
list: Vec<String>,
array: [f32; 3],
map: HashMap<i32, f32>,
a_struct: SomeStruct,
a_tuple_struct: SomeTupleStruct,
enum_unit: SomeEnum,
enum_tuple: SomeEnum,
enum_struct: SomeEnum,
custom: CustomDebug,
#[reflect(ignore)]
#[allow(dead_code)]
ignored: isize,
}
#[derive(Reflect)]
struct SomeStruct {
foo: String,
}
#[derive(Reflect)]
enum SomeEnum {
A,
B(usize),
C { value: i32 },
}
#[derive(Reflect)]
struct SomeTupleStruct(String);
#[derive(Reflect)]
#[reflect(Debug)]
struct CustomDebug;
impl Debug for CustomDebug {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
f.write_str("Cool debug!")
}
}
let mut map = HashMap::new();
map.insert(123, 1.23);
let test = Test {
value: 123,
list: vec![String::from("A"), String::from("B"), String::from("C")],
array: [1.0, 2.0, 3.0],
map,
a_struct: SomeStruct {
foo: String::from("A Struct!"),
},
a_tuple_struct: SomeTupleStruct(String::from("A Tuple Struct!")),
enum_unit: SomeEnum::A,
enum_tuple: SomeEnum::B(123),
enum_struct: SomeEnum::C { value: 321 },
custom: CustomDebug,
ignored: 321,
};
let reflected: &dyn Reflect = &test;
let expected = r#"
bevy_reflect::tests::Test {
value: 123,
list: [
"A",
"B",
"C",
],
array: [
1.0,
2.0,
3.0,
],
map: {
123: 1.23,
},
a_struct: bevy_reflect::tests::SomeStruct {
foo: "A Struct!",
},
a_tuple_struct: bevy_reflect::tests::SomeTupleStruct(
"A Tuple Struct!",
),
enum_unit: A,
enum_tuple: B(
123,
),
enum_struct: C {
value: 321,
},
custom: Cool debug!,
}"#;
assert_eq!(expected, format!("\n{reflected:#?}"));
}
#[test]
fn multiple_reflect_lists() {
#[derive(Hash, PartialEq, Reflect)]
#[reflect(Debug, Hash)]
#[reflect(PartialEq)]
struct Foo(i32);
impl Debug for Foo {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
write!(f, "Foo")
}
}
let foo = Foo(123);
let foo: &dyn Reflect = &foo;
assert!(foo.reflect_hash().is_some());
assert_eq!(Some(true), foo.reflect_partial_eq(foo));
assert_eq!("Foo".to_string(), format!("{foo:?}"));
}
#[test]
fn multiple_reflect_value_lists() {
#[derive(Clone, Hash, PartialEq, Reflect)]
#[reflect_value(Debug, Hash)]
#[reflect_value(PartialEq)]
struct Foo(i32);
impl Debug for Foo {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
write!(f, "Foo")
}
}
let foo = Foo(123);
let foo: &dyn Reflect = &foo;
assert!(foo.reflect_hash().is_some());
assert_eq!(Some(true), foo.reflect_partial_eq(foo));
assert_eq!("Foo".to_string(), format!("{foo:?}"));
}
#[test]
fn custom_debug_function() {
#[derive(Reflect)]
#[reflect(Debug(custom_debug))]
struct Foo {
a: u32,
}
fn custom_debug(_x: &Foo, f: &mut Formatter<'_>) -> std::fmt::Result {
write!(f, "123")
}
let foo = Foo { a: 1 };
let foo: &dyn Reflect = &foo;
assert_eq!("123", format!("{:?}", foo));
}
#[test]
fn should_allow_custom_where() {
#[derive(Reflect)]
#[reflect(where T: Default)]
struct Foo<T>(String, #[reflect(ignore)] PhantomData<T>);
#[derive(Default, TypePath)]
struct Bar;
#[derive(TypePath)]
struct Baz;
assert_impl_all!(Foo<Bar>: Reflect);
assert_not_impl_all!(Foo<Baz>: Reflect);
}
#[test]
fn should_allow_empty_custom_where() {
#[derive(Reflect)]
#[reflect(where)]
struct Foo<T>(String, #[reflect(ignore)] PhantomData<T>);
#[derive(TypePath)]
struct Bar;
assert_impl_all!(Foo<Bar>: Reflect);
}
#[test]
fn should_allow_multiple_custom_where() {
#[derive(Reflect)]
#[reflect(where T: Default + FromReflect)]
#[reflect(where U: std::ops::Add<T> + FromReflect)]
struct Foo<T, U>(T, U);
#[derive(Reflect)]
struct Baz {
a: Foo<i32, i32>,
b: Foo<u32, u32>,
}
assert_impl_all!(Foo<i32, i32>: Reflect);
assert_not_impl_all!(Foo<i32, usize>: Reflect);
}
#[test]
fn should_allow_custom_where_wtih_assoc_type() {
trait Trait {
type Assoc: FromReflect + TypePath;
}
// We don't need `T` to be `Reflect` since we only care about `T::Assoc`
#[derive(Reflect)]
#[reflect(where T::Assoc: FromReflect)]
struct Foo<T: Trait>(T::Assoc);
#[derive(TypePath)]
struct Bar;
impl Trait for Bar {
type Assoc = usize;
}
assert_impl_all!(Foo<Bar>: Reflect);
}
#[test]
fn recursive_typed_storage_does_not_hang() {
#[derive(Reflect)]
struct Recurse<T>(T);
let _ = <Recurse<Recurse<()>> as Typed>::type_info();
let _ = <Recurse<Recurse<()>> as TypePath>::type_path();
#[derive(Reflect)]
struct SelfRecurse {
recurse: Vec<SelfRecurse>,
}
let _ = <SelfRecurse as Typed>::type_info();
let _ = <SelfRecurse as TypePath>::type_path();
#[derive(Reflect)]
enum RecurseA {
Recurse(RecurseB),
}
#[derive(Reflect)]
struct RecurseB {
vector: Vec<RecurseA>,
}
let _ = <RecurseA as Typed>::type_info();
let _ = <RecurseA as TypePath>::type_path();
let _ = <RecurseB as Typed>::type_info();
let _ = <RecurseB as TypePath>::type_path();
}
#[test]
fn can_opt_out_type_path() {
#[derive(Reflect)]
#[reflect(type_path = false)]
#[reflect(where)]
struct Foo<T> {
#[reflect(ignore)]
_marker: PhantomData<T>,
}
struct NotTypePath;
impl<T: 'static> TypePath for Foo<T> {
fn type_path() -> &'static str {
std::any::type_name::<Self>()
}
fn short_type_path() -> &'static str {
static CELL: GenericTypePathCell = GenericTypePathCell::new();
CELL.get_or_insert::<Self, _>(|| {
bevy_utils::get_short_name(std::any::type_name::<Self>())
})
}
fn type_ident() -> Option<&'static str> {
Some("Foo")
}
fn crate_name() -> Option<&'static str> {
Some("bevy_reflect")
}
fn module_path() -> Option<&'static str> {
Some("bevy_reflect::tests")
}
}
// Can use `TypePath`
let path = <Foo<NotTypePath> as TypePath>::type_path();
assert_eq!("bevy_reflect::tests::can_opt_out_type_path::Foo<bevy_reflect::tests::can_opt_out_type_path::NotTypePath>", path);
// Can register the type
let mut registry = TypeRegistry::default();
registry.register::<Foo<NotTypePath>>();
let registration = registry.get(TypeId::of::<Foo<NotTypePath>>()).unwrap();
assert_eq!(
"Foo<NotTypePath>",
registration.type_info().type_path_table().short_path()
);
}
#[test]
fn dynamic_types_debug_format() {
#[derive(Debug, Reflect)]
struct TestTupleStruct(u32);
#[derive(Debug, Reflect)]
enum TestEnum {
A(u32),
B,
}
#[derive(Debug, Reflect)]
// test DynamicStruct
struct TestStruct {
// test DynamicTuple
tuple: (u32, u32),
// test DynamicTupleStruct
tuple_struct: TestTupleStruct,
// test DynamicList
list: Vec<u32>,
// test DynamicArray
array: [u32; 3],
// test DynamicEnum
e: TestEnum,
// test DynamicMap
map: HashMap<u32, u32>,
// test reflected value
value: u32,
}
let mut map = HashMap::new();
map.insert(9, 10);
let mut test_struct = TestStruct {
tuple: (0, 1),
list: vec![2, 3, 4],
array: [5, 6, 7],
tuple_struct: TestTupleStruct(8),
e: TestEnum::A(11),
map,
value: 12,
}
.clone_value();
let test_struct = test_struct.downcast_mut::<DynamicStruct>().unwrap();
// test unknown DynamicStruct
let mut test_unknown_struct = DynamicStruct::default();
test_unknown_struct.insert("a", 13);
test_struct.insert("unknown_struct", test_unknown_struct);
// test unknown DynamicTupleStruct
let mut test_unknown_tuple_struct = DynamicTupleStruct::default();
test_unknown_tuple_struct.insert(14);
test_struct.insert("unknown_tuplestruct", test_unknown_tuple_struct);
assert_eq!(
format!("{:?}", test_struct),
"DynamicStruct(bevy_reflect::tests::TestStruct { \
tuple: DynamicTuple((0, 1)), \
tuple_struct: DynamicTupleStruct(bevy_reflect::tests::TestTupleStruct(8)), \
list: DynamicList([2, 3, 4]), \
array: DynamicArray([5, 6, 7]), \
e: DynamicEnum(A(11)), \
map: DynamicMap({9: 10}), \
value: 12, \
unknown_struct: DynamicStruct(_ { a: 13 }), \
unknown_tuplestruct: DynamicTupleStruct(_(14)) \
})"
);
}
#[cfg(feature = "glam")]
mod glam {
use super::*;
use ::glam::{quat, vec3, Quat, Vec3};
#[test]
fn quat_serialization() {
let q = quat(1.0, 2.0, 3.0, 4.0);
let mut registry = TypeRegistry::default();
registry.register::<f32>();
registry.register::<Quat>();
let ser = ReflectSerializer::new(&q, &registry);
let config = PrettyConfig::default()
.new_line(String::from("\n"))
.indentor(String::from(" "));
let output = to_string_pretty(&ser, config).unwrap();
let expected = r#"
{
"glam::Quat": (
x: 1.0,
y: 2.0,
z: 3.0,
w: 4.0,
),
}"#;
assert_eq!(expected, format!("\n{output}"));
}
#[test]
fn quat_deserialization() {
let data = r#"
{
"glam::Quat": (
x: 1.0,
y: 2.0,
z: 3.0,
w: 4.0,
),
}"#;
let mut registry = TypeRegistry::default();
registry.register::<Quat>();
registry.register::<f32>();
let de = UntypedReflectDeserializer::new(&registry);
let mut deserializer =
Deserializer::from_str(data).expect("Failed to acquire deserializer");
let dynamic_struct = de
.deserialize(&mut deserializer)
.expect("Failed to deserialize");
let mut result = Quat::default();
result.apply(&*dynamic_struct);
assert_eq!(result, quat(1.0, 2.0, 3.0, 4.0));
}
#[test]
fn vec3_serialization() {
let v = vec3(12.0, 3.0, -6.9);
let mut registry = TypeRegistry::default();
registry.register::<f32>();
registry.register::<Vec3>();
let ser = ReflectSerializer::new(&v, &registry);
let config = PrettyConfig::default()
.new_line(String::from("\n"))
.indentor(String::from(" "));
let output = to_string_pretty(&ser, config).unwrap();
let expected = r#"
{
"glam::Vec3": (
x: 12.0,
y: 3.0,
z: -6.9,
),
}"#;
assert_eq!(expected, format!("\n{output}"));
}
#[test]
fn vec3_deserialization() {
let data = r#"
{
"glam::Vec3": (
x: 12.0,
y: 3.0,
z: -6.9,
),
}"#;
let mut registry = TypeRegistry::default();
registry.add_registration(Vec3::get_type_registration());
registry.add_registration(f32::get_type_registration());
let de = UntypedReflectDeserializer::new(&registry);
let mut deserializer =
Deserializer::from_str(data).expect("Failed to acquire deserializer");
let dynamic_struct = de
.deserialize(&mut deserializer)
.expect("Failed to deserialize");
let mut result = Vec3::default();
result.apply(&*dynamic_struct);
assert_eq!(result, vec3(12.0, 3.0, -6.9));
}
#[test]
fn vec3_field_access() {
let mut v = vec3(1.0, 2.0, 3.0);
assert_eq!(*v.get_field::<f32>("x").unwrap(), 1.0);
*v.get_field_mut::<f32>("y").unwrap() = 6.0;
assert_eq!(v.y, 6.0);
}
#[test]
fn vec3_path_access() {
let mut v = vec3(1.0, 2.0, 3.0);
assert_eq!(
*v.reflect_path("x").unwrap().downcast_ref::<f32>().unwrap(),
1.0
);
*v.reflect_path_mut("y")
.unwrap()
.downcast_mut::<f32>()
.unwrap() = 6.0;
assert_eq!(v.y, 6.0);
}
#[test]
fn vec3_apply_dynamic() {
let mut v = vec3(3.0, 3.0, 3.0);
let mut d = DynamicStruct::default();
d.insert("x", 4.0f32);
d.insert("y", 2.0f32);
d.insert("z", 1.0f32);
v.apply(&d);
assert_eq!(v, vec3(4.0, 2.0, 1.0));
}
}
}
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