lsp: Do not notify all language servers on file save (#17756)

This is not an ideal solution to
https://github.com/fasterthanlime/zed-diags-readme, but current status
quo is not great either; we were just going through all of the language
servers and notifying them, whereas we should ideally do it based on a
glob.
/cc @fasterthanlime

Release Notes:

- N/A

crates/project/src/lsp_store.rs

@@ -2892,11 +2892,27 @@ impl LspStore {
         let file = File::from_dyn(buffer.read(cx).file())?;
         let worktree_id = file.worktree_id(cx);
         let abs_path = file.as_local()?.abs_path(cx);
+        let worktree_path = file.as_local()?.path();
         let text_document = lsp::TextDocumentIdentifier {
             uri: lsp::Url::from_file_path(abs_path).log_err()?,
         };
 
+        let watched_paths_for_server = &self.as_local()?.language_server_watched_paths;
         for server in self.language_servers_for_worktree(worktree_id) {
+            let should_notify = maybe!({
+                Some(
+                    watched_paths_for_server
+                        .get(&server.server_id())?
+                        .read(cx)
+                        .worktree_paths
+                        .get(&worktree_id)?
+                        .is_match(worktree_path),
+                )
+            })
+            .unwrap_or_default();
+            if !should_notify {
+                continue;
+            }
             if let Some(include_text) = include_text(server.as_ref()) {
                 let text = if include_text {
                     Some(buffer.read(cx).text())

crates/project/src/project_tests.rs

@@ -386,6 +386,34 @@ async fn test_managing_language_servers(cx: &mut gpui::TestAppContext) {
 
     // A server is started up, and it is notified about Rust files.
     let mut fake_rust_server = fake_rust_servers.next().await.unwrap();
+    fake_rust_server
+        .request::<lsp::request::RegisterCapability>(lsp::RegistrationParams {
+            registrations: vec![lsp::Registration {
+                id: Default::default(),
+                method: "workspace/didChangeWatchedFiles".to_string(),
+                register_options: serde_json::to_value(
+                    lsp::DidChangeWatchedFilesRegistrationOptions {
+                        watchers: vec![
+                            lsp::FileSystemWatcher {
+                                glob_pattern: lsp::GlobPattern::String(
+                                    "/the-root/Cargo.toml".to_string(),
+                                ),
+                                kind: None,
+                            },
+                            lsp::FileSystemWatcher {
+                                glob_pattern: lsp::GlobPattern::String(
+                                    "/the-root/*.rs".to_string(),
+                                ),
+                                kind: None,
+                            },
+                        ],
+                    },
+                )
+                .ok(),
+            }],
+        })
+        .await
+        .unwrap();
     assert_eq!(
         fake_rust_server
             .receive_notification::<lsp::notification::DidOpenTextDocument>()
@@ -433,6 +461,24 @@ async fn test_managing_language_servers(cx: &mut gpui::TestAppContext) {
 
     // A json language server is started up and is only notified about the json buffer.
     let mut fake_json_server = fake_json_servers.next().await.unwrap();
+    fake_json_server
+        .request::<lsp::request::RegisterCapability>(lsp::RegistrationParams {
+            registrations: vec![lsp::Registration {
+                id: Default::default(),
+                method: "workspace/didChangeWatchedFiles".to_string(),
+                register_options: serde_json::to_value(
+                    lsp::DidChangeWatchedFilesRegistrationOptions {
+                        watchers: vec![lsp::FileSystemWatcher {
+                            glob_pattern: lsp::GlobPattern::String("/the-root/*.json".to_string()),
+                            kind: None,
+                        }],
+                    },
+                )
+                .ok(),
+            }],
+        })
+        .await
+        .unwrap();
     assert_eq!(
         fake_json_server
             .receive_notification::<lsp::notification::DidOpenTextDocument>()
@@ -483,7 +529,7 @@ async fn test_managing_language_servers(cx: &mut gpui::TestAppContext) {
         )
     );
 
-    // Save notifications are reported to all servers.
+    // Save notifications are reported only to servers that signed up for a given extension.
     project
         .update(cx, |project, cx| project.save_buffer(toml_buffer, cx))
         .await
@@ -495,13 +541,6 @@ async fn test_managing_language_servers(cx: &mut gpui::TestAppContext) {
             .text_document,
         lsp::TextDocumentIdentifier::new(lsp::Url::from_file_path("/the-root/Cargo.toml").unwrap())
     );
-    assert_eq!(
-        fake_json_server
-            .receive_notification::<lsp::notification::DidSaveTextDocument>()
-            .await
-            .text_document,
-        lsp::TextDocumentIdentifier::new(lsp::Url::from_file_path("/the-root/Cargo.toml").unwrap())
-    );
 
     // Renames are reported only to servers matching the buffer's language.
     fs.rename(