Copy all components from an Entity to another in Bevy

cloneEntity.rs

// Bevy version: 0.10
use bevy::{prelude::*, ecs::system::Command};

// Copy all components from an entity to another.
// Using an entity with no components as the destination creates a copy of the source entity.
// panics if 
// - the components are not registered in the type registry, 
// - the world does not have a type registry
// - the source or destination entity do not exist
pub fn clone_entity_components(world: &mut World, source: Entity, destination: Entity) {
  let wc = world.as_unsafe_world_cell();
  unsafe {
    let registry = wc.world().get_resource::<AppTypeRegistry>().unwrap();
    let type_registry = registry.read();

    let entity_ref = wc.world().get_entity(source).unwrap();
    let archetype = entity_ref.archetype();
    let components = wc.world().components();

    for component_id in archetype.components() {
      let component_info = components.get_info(component_id).unwrap();
      let type_id = component_info.type_id().unwrap();
      let registration = type_registry.get(type_id).unwrap();
      // here is where the magic happens
      let reflect_component = registration.data::<ReflectComponent>().unwrap();
      reflect_component.copy(
        wc.world_mut(),
        wc.world_mut(),
        source,
        destination
      );
    }
  }
}

// this allows the command to be used in systems
pub struct CloneEntity(pub Entity, pub Entity);
impl Command for CloneEntity {
  fn write(self, world: &mut World) {
    clone_entity_components(world, self.0, self.1);
  }
}
      
// **********************************************************
// Adapt the code below to your needs 
// **********************************************************

// Components must derive Reflect and use reflect(Component)
// If your component includes some other structs, these have to derive from Reflect and FromReflect
#[derive(Component, Reflect, Default)]
#[reflect(Component)]
pub struct Foo {
  pub bar: i32,
  pub baz: bool,
}
      
// In your system, clone an entity like this:

fn clone_entity(mut commands: Commands, /* whatever you want that gets your entity */) {
  // your code here to fetch the source entity 
  // ...
  let copy = commands.spawn_empty().id();
  commands.add(CloneEntity(entity, copy));   
}
      
      
// Also, remember to register your components in the App Type Registry!
// Some predefined components are already registered (e.g. Name)
// You can write your own plugin where you put all your registrations
{
  let registry = app.world.resource_mut::<AppTypeRegistry>();
  let mut wr = registry.write();
  wr.register::<Foo>();
  // other structs...
}