1 files changed, 36 insertions, 0 deletions
diff --git a/third_party/rust/async-trait/tests/executor/mod.rs b/third_party/rust/async-trait/tests/executor/mod.rs
new file mode 100644
index 0000000000..912fb79844
--- /dev/null
+++ b/third_party/rust/async-trait/tests/executor/mod.rs
@@ -0,0 +1,36 @@
+use std::future::Future;
+use std::pin::Pin;
+use std::ptr;
+use std::task::{Context, Poll, RawWaker, RawWakerVTable, Waker};
+
+// Executor for a future that resolves immediately (test only).
+#[allow(clippy::missing_panics_doc)]
+pub fn block_on_simple<F: Future>(mut fut: F) -> F::Output {
+    unsafe fn clone(_null: *const ()) -> RawWaker {
+        unimplemented!()
+    }
+
+    unsafe fn wake(_null: *const ()) {
+        unimplemented!()
+    }
+
+    unsafe fn wake_by_ref(_null: *const ()) {
+        unimplemented!()
+    }
+
+    unsafe fn drop(_null: *const ()) {}
+
+    let data = ptr::null();
+    let vtable = &RawWakerVTable::new(clone, wake, wake_by_ref, drop);
+    let raw_waker = RawWaker::new(data, vtable);
+    let waker = unsafe { Waker::from_raw(raw_waker) };
+    let mut cx = Context::from_waker(&waker);
+
+    // fut does not move until it gets dropped.
+    let fut = unsafe { Pin::new_unchecked(&mut fut) };
+
+    match fut.poll(&mut cx) {
+        Poll::Ready(output) => output,
+        Poll::Pending => panic!("future did not resolve immediately"),
+    }
+}