feat: basic pr diff rendering

src/query.rs

@@ -137,13 +137,13 @@ where
         })?;
 
         match wait_state {
-            | WaitState::Cached => {
-                return Ok(ent);
-            }
-            | WaitState::Waiting { rx, sub } => {
-                _ = sub;
-                _ = rx.await;
-            }
+        | WaitState::Cached => {
+            return Ok(ent);
+        }
+        | WaitState::Waiting { rx, sub } => {
+            _ = sub;
+            _ = rx.await;
+        }
         }
     }
 }
@@ -181,12 +181,27 @@ where
     let state = query.raw.read(cx);
 
     match &state.data {
-        | QueryData::Loading | QueryData::Pending | QueryData::Stale => QueryStatus::Loading,
-        | QueryData::Some(data) => QueryStatus::Loaded(data.downcast_ref::<F::Data>().unwrap()),
-        | QueryData::Err(error) => QueryStatus::Err(error.downcast_ref::<F::Error>().unwrap()),
+    | QueryData::Loading | QueryData::Pending | QueryData::Stale => QueryStatus::Loading,
+    | QueryData::Some(data) => QueryStatus::Loaded(data.downcast_ref::<F::Data>().unwrap()),
+    | QueryData::Err(error) => QueryStatus::Err(error.downcast_ref::<F::Error>().unwrap()),
     }
 }
 
+pub fn observe_query<E, F>(
+    query: &Entity<F>,
+    mut on_notify: impl FnMut(&mut E, &Entity<F>, &mut gpui::Context<E>) + 'static,
+    cx: &mut gpui::Context<E>,
+) -> gpui::Subscription
+where
+    E: 'static,
+    F: QueryFn,
+{
+    let q = query.clone();
+    cx.observe(&query, move |this, _, cx| {
+        on_notify(this, &q, cx);
+    })
+}
+
 // ================= Store ==================
 
 pub(crate) trait Context: Clone {}
@@ -284,14 +299,14 @@ where
 
             entity.raw.update(cx, |state, cx| {
                 state.data = match result {
-                    | Ok(data) => {
-                        println!("[query] OK {}", q.key());
-                        QueryData::Some(Box::new(data))
-                    }
-                    | Err(err) => {
-                        println!("[query] ERR {:?}: {:?}", q.key(), err);
-                        QueryData::Err(Box::new(err))
-                    }
+                | Ok(data) => {
+                    println!("[query] OK {}", q.key());
+                    QueryData::Some(Box::new(data))
+                }
+                | Err(err) => {
+                    println!("[query] ERR {:?}: {:?}", q.key(), err);
+                    QueryData::Err(Box::new(err))
+                }
                 };
                 cx.notify();
             })?;
@@ -317,8 +332,8 @@ where
             .raw
             .update(cx, |query, cx| {
                 query.data = match result {
-                    | Ok(data) => QueryData::Some(Box::new(data)),
-                    | Err(err) => QueryData::Err(Box::new(err)),
+                | Ok(data) => QueryData::Some(Box::new(data)),
+                | Err(err) => QueryData::Err(Box::new(err)),
                 };
                 cx.notify();
                 true