Struct TestHarness 

pub struct TestHarness { /* private fields */ }

Minimal test harness for handler dispatch.

Owns a World and auto-advances the sequence number before each dispatch. Designed for unit testing handlers without wiring up real drivers.

Examples

use nexus_rt::{WorldBuilder, ResMut, IntoHandler, Resource};
use nexus_rt::testing::TestHarness;

#[derive(Resource)]
struct Counter(u64);

fn accumulate(mut counter: ResMut<Counter>, event: u64) {
    counter.0 += event;
}

let mut builder = WorldBuilder::new();
builder.register(Counter(0));
let mut harness = TestHarness::new(builder);

let mut handler = accumulate.into_handler(harness.registry());
harness.dispatch(&mut handler, 10u64);
harness.dispatch(&mut handler, 5u64);

assert_eq!(harness.world().resource::<Counter>().0, 15);

Implementations

impl TestHarness

pub fn new(builder: WorldBuilder) -> Self

Build a test harness from a WorldBuilder.

pub fn registry(&self) -> &Registry

Registry access for creating handlers after build.

pub fn dispatch<E>(&mut self, handler: &mut impl Handler<E>, event: E)

Advance sequence and dispatch one event through a handler.

pub fn dispatch_many<E>( &mut self, handler: &mut impl Handler<E>, events: impl IntoIterator<Item = E>, )

Dispatch multiple events sequentially, advancing sequence per event.

pub fn world(&self) -> &World

Read-only world access for assertions.

pub fn world_mut(&mut self) -> &mut World

Mutable world access (e.g. to stamp resources manually).