Fix issue where renaming a file would not update imports in related files if they are not open (#36681)

Closes #34445

Now we open a multi-buffer consisting of buffers that have updated,
renamed file imports.

Only local is handled, for now.

Release Notes:

- Fixed an issue where renaming a file would not update imports in
related files if they are not already open.

crates/editor/src/editor.rs

@@ -1900,6 +1900,60 @@ impl Editor {
                             editor.update_lsp_data(false, Some(*buffer_id), window, cx);
                         }
                     }
+
+                    project::Event::EntryRenamed(transaction) => {
+                        let Some(workspace) = editor.workspace() else {
+                            return;
+                        };
+                        let Some(active_editor) = workspace.read(cx).active_item_as::<Self>(cx)
+                        else {
+                            return;
+                        };
+                        if active_editor.entity_id() == cx.entity_id() {
+                            let edited_buffers_already_open = {
+                                let other_editors: Vec<Entity<Editor>> = workspace
+                                    .read(cx)
+                                    .panes()
+                                    .iter()
+                                    .flat_map(|pane| pane.read(cx).items_of_type::<Editor>())
+                                    .filter(|editor| editor.entity_id() != cx.entity_id())
+                                    .collect();
+
+                                transaction.0.keys().all(|buffer| {
+                                    other_editors.iter().any(|editor| {
+                                        let multi_buffer = editor.read(cx).buffer();
+                                        multi_buffer.read(cx).is_singleton()
+                                            && multi_buffer.read(cx).as_singleton().map_or(
+                                                false,
+                                                |singleton| {
+                                                    singleton.entity_id() == buffer.entity_id()
+                                                },
+                                            )
+                                    })
+                                })
+                            };
+
+                            if !edited_buffers_already_open {
+                                let workspace = workspace.downgrade();
+                                let transaction = transaction.clone();
+                                cx.defer_in(window, move |_, window, cx| {
+                                    cx.spawn_in(window, async move |editor, cx| {
+                                        Self::open_project_transaction(
+                                            &editor,
+                                            workspace,
+                                            transaction,
+                                            "Rename".to_string(),
+                                            cx,
+                                        )
+                                        .await
+                                        .ok()
+                                    })
+                                    .detach();
+                                });
+                            }
+                        }
+                    }
+
                     _ => {}
                 },
             ));
@@ -6282,7 +6336,7 @@ impl Editor {
     }
 
     pub async fn open_project_transaction(
-        this: &WeakEntity<Editor>,
+        editor: &WeakEntity<Editor>,
         workspace: WeakEntity<Workspace>,
         transaction: ProjectTransaction,
         title: String,
@@ -6300,7 +6354,7 @@ impl Editor {
 
         if let Some((buffer, transaction)) = entries.first() {
             if entries.len() == 1 {
-                let excerpt = this.update(cx, |editor, cx| {
+                let excerpt = editor.update(cx, |editor, cx| {
                     editor
                         .buffer()
                         .read(cx)