Struct TestRuntime 

pub struct TestRuntime { /* private fields */ }

A test runtime with virtual time for deterministic testing.

Unlike real runtimes, time only advances when you call advance_by() or advance_to(). This allows instant, reproducible tests for time-based operators.

Example

use agent_rex::TestRuntime;
 
#[tokio::test]
async fn test_debounce() {
  let runtime = TestRuntime::new();
   
  // Create a debounced stream using this runtime
  let source = futures::stream::iter(vec![1, 2, 3]);
  let debounced = debounce_with::<TestRuntime>(Duration::from_millis(100), source);
   
  // Advance virtual time to trigger debounce
  runtime.advance_by(Duration::from_millis(150)).await;
   
  // Collect results - happens instantly!
}

Implementations

impl TestRuntime

pub fn new() -> Self

Create a new test runtime starting at time zero.

pub fn now(&self) -> Duration

Get the current virtual time.

pub async fn advance_by(&self, duration: Duration)

Advance virtual time by the given duration.

This will wake any timers whose target time has been reached.

pub async fn advance_to(&self, target: Duration)

Advance virtual time to a specific point.

Fires all timers between the current time and target time.

impl TestRuntime

pub fn test_sleep(&self, duration: Duration) -> TestSleep

Create a sleep future tied to this runtime instance.

pub fn test_interval(&self, period: Duration) -> TestInterval

Create an interval stream tied to this runtime instance.

impl TestRuntime

pub async fn run_timed_test<T, F, Fut>(&self, steps: Vec<Duration>, f: F) -> T

where F: FnMut() -> Fut, Fut: Future<Output = T>,

Run a test with controlled time, returning the result.

This is a convenience method that advances time in steps, useful for testing debounce/throttle behavior.

pub async fn assert_completes_within<T, Fut>( &self, timeout: Duration, fut: Fut, ) -> T

where Fut: Future<Output = T>,

Assert that a future completes within a virtual time budget.

Trait Implementations

impl Clone for TestRuntime

fn clone(&self) -> TestRuntime

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Default for TestRuntime

fn default() -> Self

Returns the “default value” for a type.

impl Runtime for TestRuntime

fn sleep(duration: Duration) -> Pin<Box<dyn Future<Output = ()> + Send>>

Sleep for the given duration

fn interval(period: Duration) -> Pin<Box<dyn Stream<Item = ()> + Send>>

Create an interval that yields at regular intervals

fn spawn<F>(_future: F)

where F: Future<Output = ()> + Send + 'static,

Spawn a future as a background task