Make test_terminal_eof less flaky and faster (#39281)

Release Notes:

- N/A

crates/gpui/src/util.rs

@@ -115,6 +115,7 @@ impl<T: Future> Future for WithTimeout<T> {
 
 #[cfg(any(test, feature = "test-support"))]
 /// Uses smol executor to run a given future no longer than the timeout specified.
+/// Note that this won't "rewind" on `cx.executor().advance_clock` call, truly waiting for the timeout to elapse.
 pub async fn smol_timeout<F, T>(timeout: Duration, f: F) -> Result<T, ()>
 where
     F: Future<Output = T>,

crates/terminal/src/terminal.rs

@@ -2308,8 +2308,9 @@ mod tests {
         })
         .detach();
 
+        let first_event = Event::Wakeup;
         let wakeup = event_rx.recv().await.expect("No wakeup event received");
-        assert_eq!(wakeup, Event::Wakeup, "Expected wakeup, got {wakeup:?}");
+        assert_eq!(wakeup, first_event, "Expected wakeup, got {wakeup:?}");
 
         terminal.update(cx, |terminal, _| {
             let success = terminal.try_keystroke(&Keystroke::parse("ctrl-c").unwrap(), false);
@@ -2320,13 +2321,13 @@ mod tests {
             assert!(success, "Should have registered ctrl-d sequence");
         });
 
-        let mut all_events = vec![Event::Wakeup];
-        while let Ok(Ok(new_event)) =
-            smol_timeout(Duration::from_millis(500), event_rx.recv()).await
-        {
+        let mut all_events = vec![first_event];
+        while let Ok(Ok(new_event)) = smol_timeout(Duration::from_secs(1), event_rx.recv()).await {
             all_events.push(new_event.clone());
+            if new_event == Event::CloseTerminal {
+                break;
+            }
         }
-
         assert!(
             all_events.contains(&Event::CloseTerminal),
             "EOF command sequence should have triggered a TTY terminal exit, but got events: {all_events:?}",
@@ -2375,6 +2376,10 @@ mod tests {
             {
                 let exit_status = completion_rx.recv().await.ok().flatten();
                 if let Some(exit_status) = exit_status {
+                    assert!(
+                        !exit_status.success(),
+                        "Wrong shell command should result in a failure"
+                    );
                     assert_eq!(exit_status.code(), Some(1));
                 }
             }