1 files changed, 59 insertions, 0 deletions
diff --git a/tests/instrument.rs b/tests/instrument.rs
new file mode 100644
index 0000000..5247249
--- /dev/null
+++ b/tests/instrument.rs
@@ -0,0 +1,59 @@
+// These tests require the thread-local scoped dispatcher, which only works when
+// we have a standard library. The behaviour being tested should be the same
+// with the standard lib disabled.
+#![cfg(feature = "std")]
+
+use std::{future::Future, pin::Pin, task};
+
+use futures::FutureExt as _;
+use tracing::{subscriber::with_default, Instrument as _, Level};
+use tracing_mock::*;
+
+#[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
+#[test]
+fn span_on_drop() {
+    #[derive(Clone, Debug)]
+    struct AssertSpanOnDrop;
+
+    impl Drop for AssertSpanOnDrop {
+        fn drop(&mut self) {
+            tracing::info!("Drop");
+        }
+    }
+
+    struct Fut(Option<AssertSpanOnDrop>);
+
+    impl Future for Fut {
+        type Output = ();
+
+        fn poll(mut self: Pin<&mut Self>, _: &mut task::Context<'_>) -> task::Poll<Self::Output> {
+            self.set(Fut(None));
+            task::Poll::Ready(())
+        }
+    }
+
+    let subscriber = subscriber::mock()
+        .enter(expect::span().named("foo"))
+        .event(expect::event().at_level(Level::INFO))
+        .exit(expect::span().named("foo"))
+        .enter(expect::span().named("foo"))
+        .exit(expect::span().named("foo"))
+        .drop_span(expect::span().named("foo"))
+        .enter(expect::span().named("bar"))
+        .event(expect::event().at_level(Level::INFO))
+        .exit(expect::span().named("bar"))
+        .drop_span(expect::span().named("bar"))
+        .only()
+        .run();
+
+    with_default(subscriber, || {
+        // polled once
+        Fut(Some(AssertSpanOnDrop))
+            .instrument(tracing::span!(Level::TRACE, "foo"))
+            .now_or_never()
+            .unwrap();
+
+        // never polled
+        drop(Fut(Some(AssertSpanOnDrop)).instrument(tracing::span!(Level::TRACE, "bar")));
+    });
+}