Allow disk-based diagnostic progress begin/end events to interleave

When multiple saves occur, we can have multiple start events followed by multiple end events. We don't want to update our project diagnostics view until all pending progress is finished.

Co-Authored-By: Antonio Scandurra <me@as-cii.com>

crates/editor/src/display_map/wrap_map.rs

@@ -1014,11 +1014,12 @@ mod tests {
     use super::*;
     use crate::{
         display_map::{fold_map::FoldMap, tab_map::TabMap},
-        test::Observer,
         MultiBuffer,
     };
+    use gpui::test::observe;
     use language::RandomCharIter;
     use rand::prelude::*;
+    use smol::stream::StreamExt;
     use std::{cmp, env};
     use text::Rope;
 
@@ -1072,10 +1073,10 @@ mod tests {
 
         let (wrap_map, _) =
             cx.update(|cx| WrapMap::new(tabs_snapshot.clone(), font_id, font_size, wrap_width, cx));
-        let (_observer, notifications) = Observer::new(&wrap_map, &mut cx);
+        let mut notifications = observe(&wrap_map, &mut cx);
 
         if wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
-            notifications.recv().await.unwrap();
+            notifications.next().await.unwrap();
         }
 
         let (initial_snapshot, _) = wrap_map.update(&mut cx, |map, cx| {
@@ -1148,7 +1149,7 @@ mod tests {
             if wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) && rng.gen_bool(0.4) {
                 log::info!("Waiting for wrapping to finish");
                 while wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
-                    notifications.recv().await.unwrap();
+                    notifications.next().await.unwrap();
                 }
                 wrap_map.read_with(&cx, |map, _| assert!(map.pending_edits.is_empty()));
             }
@@ -1236,7 +1237,7 @@ mod tests {
         if wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
             log::info!("Waiting for wrapping to finish");
             while wrap_map.read_with(&cx, |map, _| map.is_rewrapping()) {
-                notifications.recv().await.unwrap();
+                notifications.next().await.unwrap();
             }
         }
         wrap_map.read_with(&cx, |map, _| assert!(map.pending_edits.is_empty()));