Add fs2

Co-Authored-By: Max <max@zed.dev>
Co-Authored-By: Conrad <conrad.irwin@gmail.com>
Co-Authored-By: Kyle <kyle@zed.dev>

crates/gpui2/src/executor.rs

@@ -207,8 +207,8 @@ impl Executor {
     }
 
     #[cfg(any(test, feature = "test-support"))]
-    pub async fn simulate_random_delay(&self) {
-        todo!("simulate_random_delay")
+    pub fn simulate_random_delay(&self) -> impl Future<Output = ()> {
+        self.dispatcher.as_test().unwrap().simulate_random_delay()
     }
 
     pub fn num_cpus(&self) -> usize {

crates/gpui2/src/platform.rs

@@ -162,8 +162,11 @@ pub trait PlatformDispatcher: Send + Sync {
     fn dispatch_on_main_thread(&self, runnable: Runnable);
     fn dispatch_after(&self, duration: Duration, runnable: Runnable);
     fn poll(&self) -> bool;
+
     #[cfg(any(test, feature = "test-support"))]
-    fn advance_clock(&self, duration: Duration);
+    fn as_test(&self) -> Option<&TestDispatcher> {
+        None
+    }
 }
 
 pub trait PlatformTextSystem: Send + Sync {

crates/gpui2/src/platform/mac/dispatcher.rs

@@ -71,11 +71,6 @@ impl PlatformDispatcher for MacDispatcher {
     fn poll(&self) -> bool {
         false
     }
-
-    #[cfg(any(test, feature = "test-support"))]
-    fn advance_clock(&self, _: Duration) {
-        unimplemented!()
-    }
 }
 
 extern "C" fn trampoline(runnable: *mut c_void) {

crates/gpui2/src/platform/test/dispatcher.rs

@@ -4,7 +4,10 @@ use collections::{BTreeMap, HashMap, VecDeque};
 use parking_lot::Mutex;
 use rand::prelude::*;
 use std::{
+    future::Future,
+    pin::Pin,
     sync::Arc,
+    task::{Context, Poll},
     time::{Duration, Instant},
 };
 use util::post_inc;
@@ -44,6 +47,34 @@ impl TestDispatcher {
             state: Arc::new(Mutex::new(state)),
         }
     }
+
+    pub fn advance_clock(&self, by: Duration) {
+        self.state.lock().time += by;
+    }
+
+    pub fn simulate_random_delay(&self) -> impl Future<Output = ()> {
+        pub struct YieldNow {
+            count: usize,
+        }
+
+        impl Future for YieldNow {
+            type Output = ();
+
+            fn poll(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
+                if self.count > 0 {
+                    self.count -= 1;
+                    cx.waker().wake_by_ref();
+                    Poll::Pending
+                } else {
+                    Poll::Ready(())
+                }
+            }
+        }
+
+        YieldNow {
+            count: self.state.lock().random.gen_range(0..10),
+        }
+    }
 }
 
 impl Clone for TestDispatcher {
@@ -131,8 +162,8 @@ impl PlatformDispatcher for TestDispatcher {
         true
     }
 
-    fn advance_clock(&self, by: Duration) {
-        self.state.lock().time += by;
+    fn as_test(&self) -> Option<&TestDispatcher> {
+        Some(self)
     }
 }