1use log::warn;
2pub use lsp_types::request::*;
3pub use lsp_types::*;
4
5use anyhow::{anyhow, Context, Result};
6use collections::HashMap;
7use futures::{channel::oneshot, io::BufWriter, AsyncRead, AsyncWrite, FutureExt};
8use gpui::{AppContext, AsyncAppContext, BackgroundExecutor, Task};
9use parking_lot::Mutex;
10use postage::{barrier, prelude::Stream};
11use serde::{de::DeserializeOwned, Deserialize, Serialize};
12use serde_json::{json, value::RawValue, Value};
13use smol::{
14 channel,
15 io::{AsyncBufReadExt, AsyncReadExt, AsyncWriteExt, BufReader},
16 process::{self, Child},
17};
18use std::{
19 ffi::OsString,
20 fmt,
21 future::Future,
22 io::Write,
23 path::PathBuf,
24 str::{self, FromStr as _},
25 sync::{
26 atomic::{AtomicUsize, Ordering::SeqCst},
27 Arc, Weak,
28 },
29 time::{Duration, Instant},
30};
31use std::{path::Path, process::Stdio};
32use util::{ResultExt, TryFutureExt};
33
34const JSON_RPC_VERSION: &str = "2.0";
35const CONTENT_LEN_HEADER: &str = "Content-Length: ";
36const LSP_REQUEST_TIMEOUT: Duration = Duration::from_secs(60 * 2);
37
38type NotificationHandler = Box<dyn Send + FnMut(Option<usize>, &str, AsyncAppContext)>;
39type ResponseHandler = Box<dyn Send + FnOnce(Result<String, Error>)>;
40type IoHandler = Box<dyn Send + FnMut(IoKind, &str)>;
41
42/// Kind of language server stdio given to an IO handler.
43#[derive(Debug, Clone, Copy)]
44pub enum IoKind {
45 StdOut,
46 StdIn,
47 StdErr,
48}
49
50/// Represents a launchable language server. This can either be a standalone binary or the path
51/// to a runtime with arguments to instruct it to launch the actual language server file.
52#[derive(Debug, Clone, Deserialize)]
53pub struct LanguageServerBinary {
54 pub path: PathBuf,
55 pub arguments: Vec<OsString>,
56}
57
58/// A running language server process.
59pub struct LanguageServer {
60 server_id: LanguageServerId,
61 next_id: AtomicUsize,
62 outbound_tx: channel::Sender<String>,
63 name: String,
64 capabilities: ServerCapabilities,
65 code_action_kinds: Option<Vec<CodeActionKind>>,
66 notification_handlers: Arc<Mutex<HashMap<&'static str, NotificationHandler>>>,
67 response_handlers: Arc<Mutex<Option<HashMap<usize, ResponseHandler>>>>,
68 io_handlers: Arc<Mutex<HashMap<usize, IoHandler>>>,
69 executor: BackgroundExecutor,
70 #[allow(clippy::type_complexity)]
71 io_tasks: Mutex<Option<(Task<Option<()>>, Task<Option<()>>)>>,
72 output_done_rx: Mutex<Option<barrier::Receiver>>,
73 root_path: PathBuf,
74 _server: Option<Mutex<Child>>,
75}
76
77/// Identifies a running language server.
78#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
79#[repr(transparent)]
80pub struct LanguageServerId(pub usize);
81
82/// Handle to a language server RPC activity subscription.
83pub enum Subscription {
84 Notification {
85 method: &'static str,
86 notification_handlers: Option<Arc<Mutex<HashMap<&'static str, NotificationHandler>>>>,
87 },
88 Io {
89 id: usize,
90 io_handlers: Option<Weak<Mutex<HashMap<usize, IoHandler>>>>,
91 },
92}
93
94/// Language server protocol RPC request message.
95///
96/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
97#[derive(Serialize, Deserialize)]
98pub struct Request<'a, T> {
99 jsonrpc: &'static str,
100 id: usize,
101 method: &'a str,
102 params: T,
103}
104
105/// Language server protocol RPC request response message before it is deserialized into a concrete type.
106#[derive(Serialize, Deserialize)]
107struct AnyResponse<'a> {
108 jsonrpc: &'a str,
109 id: usize,
110 #[serde(default)]
111 error: Option<Error>,
112 #[serde(borrow)]
113 result: Option<&'a RawValue>,
114}
115
116/// Language server protocol RPC request response message.
117///
118/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#responseMessage)
119#[derive(Serialize)]
120struct Response<T> {
121 jsonrpc: &'static str,
122 id: usize,
123 result: Option<T>,
124 error: Option<Error>,
125}
126
127/// Language server protocol RPC notification message.
128///
129/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
130#[derive(Serialize, Deserialize)]
131struct Notification<'a, T> {
132 jsonrpc: &'static str,
133 #[serde(borrow)]
134 method: &'a str,
135 params: T,
136}
137
138/// Language server RPC notification message before it is deserialized into a concrete type.
139#[derive(Debug, Clone, Deserialize)]
140struct AnyNotification<'a> {
141 #[serde(default)]
142 id: Option<usize>,
143 #[serde(borrow)]
144 method: &'a str,
145 #[serde(borrow, default)]
146 params: Option<&'a RawValue>,
147}
148
149#[derive(Debug, Serialize, Deserialize)]
150struct Error {
151 message: String,
152}
153
154impl LanguageServer {
155 /// Starts a language server process.
156 pub fn new(
157 stderr_capture: Arc<Mutex<Option<String>>>,
158 server_id: LanguageServerId,
159 binary: LanguageServerBinary,
160 root_path: &Path,
161 code_action_kinds: Option<Vec<CodeActionKind>>,
162 cx: AsyncAppContext,
163 ) -> Result<Self> {
164 let working_dir = if root_path.is_dir() {
165 root_path
166 } else {
167 root_path.parent().unwrap_or_else(|| Path::new("/"))
168 };
169
170 let mut server = process::Command::new(&binary.path)
171 .current_dir(working_dir)
172 .args(binary.arguments)
173 .stdin(Stdio::piped())
174 .stdout(Stdio::piped())
175 .stderr(Stdio::piped())
176 .kill_on_drop(true)
177 .spawn()?;
178
179 let stdin = server.stdin.take().unwrap();
180 let stdout = server.stdout.take().unwrap();
181 let stderr = server.stderr.take().unwrap();
182 let mut server = Self::new_internal(
183 server_id.clone(),
184 stdin,
185 stdout,
186 Some(stderr),
187 stderr_capture,
188 Some(server),
189 root_path,
190 code_action_kinds,
191 cx,
192 move |notification| {
193 log::info!(
194 "{} unhandled notification {}:\n{}",
195 server_id,
196 notification.method,
197 serde_json::to_string_pretty(
198 ¬ification
199 .params
200 .and_then(|params| Value::from_str(params.get()).ok())
201 .unwrap_or(Value::Null)
202 )
203 .unwrap(),
204 );
205 },
206 );
207
208 if let Some(name) = binary.path.file_name() {
209 server.name = name.to_string_lossy().to_string();
210 }
211
212 Ok(server)
213 }
214
215 fn new_internal<Stdin, Stdout, Stderr, F>(
216 server_id: LanguageServerId,
217 stdin: Stdin,
218 stdout: Stdout,
219 stderr: Option<Stderr>,
220 stderr_capture: Arc<Mutex<Option<String>>>,
221 server: Option<Child>,
222 root_path: &Path,
223 code_action_kinds: Option<Vec<CodeActionKind>>,
224 cx: AsyncAppContext,
225 on_unhandled_notification: F,
226 ) -> Self
227 where
228 Stdin: AsyncWrite + Unpin + Send + 'static,
229 Stdout: AsyncRead + Unpin + Send + 'static,
230 Stderr: AsyncRead + Unpin + Send + 'static,
231 F: FnMut(AnyNotification) + 'static + Send + Sync + Clone,
232 {
233 let (outbound_tx, outbound_rx) = channel::unbounded::<String>();
234 let (output_done_tx, output_done_rx) = barrier::channel();
235 let notification_handlers =
236 Arc::new(Mutex::new(HashMap::<_, NotificationHandler>::default()));
237 let response_handlers =
238 Arc::new(Mutex::new(Some(HashMap::<_, ResponseHandler>::default())));
239 let io_handlers = Arc::new(Mutex::new(HashMap::default()));
240
241 let stdout_input_task = cx.spawn({
242 let on_unhandled_notification = on_unhandled_notification.clone();
243 let notification_handlers = notification_handlers.clone();
244 let response_handlers = response_handlers.clone();
245 let io_handlers = io_handlers.clone();
246 move |cx| {
247 Self::handle_input(
248 stdout,
249 on_unhandled_notification,
250 notification_handlers,
251 response_handlers,
252 io_handlers,
253 cx,
254 )
255 .log_err()
256 }
257 });
258 let stderr_input_task = stderr
259 .map(|stderr| {
260 let io_handlers = io_handlers.clone();
261 let stderr_captures = stderr_capture.clone();
262 cx.spawn(|_| Self::handle_stderr(stderr, io_handlers, stderr_captures).log_err())
263 })
264 .unwrap_or_else(|| Task::Ready(Some(None)));
265 let input_task = cx.spawn(|_| async move {
266 let (stdout, stderr) = futures::join!(stdout_input_task, stderr_input_task);
267 stdout.or(stderr)
268 });
269 let output_task = cx.background_executor().spawn({
270 Self::handle_output(
271 stdin,
272 outbound_rx,
273 output_done_tx,
274 response_handlers.clone(),
275 io_handlers.clone(),
276 )
277 .log_err()
278 });
279
280 Self {
281 server_id,
282 notification_handlers,
283 response_handlers,
284 io_handlers,
285 name: Default::default(),
286 capabilities: Default::default(),
287 code_action_kinds,
288 next_id: Default::default(),
289 outbound_tx,
290 executor: cx.background_executor().clone(),
291 io_tasks: Mutex::new(Some((input_task, output_task))),
292 output_done_rx: Mutex::new(Some(output_done_rx)),
293 root_path: root_path.to_path_buf(),
294 _server: server.map(|server| Mutex::new(server)),
295 }
296 }
297
298 /// List of code action kinds this language server reports being able to emit.
299 pub fn code_action_kinds(&self) -> Option<Vec<CodeActionKind>> {
300 self.code_action_kinds.clone()
301 }
302
303 async fn handle_input<Stdout, F>(
304 stdout: Stdout,
305 mut on_unhandled_notification: F,
306 notification_handlers: Arc<Mutex<HashMap<&'static str, NotificationHandler>>>,
307 response_handlers: Arc<Mutex<Option<HashMap<usize, ResponseHandler>>>>,
308 io_handlers: Arc<Mutex<HashMap<usize, IoHandler>>>,
309 cx: AsyncAppContext,
310 ) -> anyhow::Result<()>
311 where
312 Stdout: AsyncRead + Unpin + Send + 'static,
313 F: FnMut(AnyNotification) + 'static + Send,
314 {
315 let mut stdout = BufReader::new(stdout);
316 let _clear_response_handlers = util::defer({
317 let response_handlers = response_handlers.clone();
318 move || {
319 response_handlers.lock().take();
320 }
321 });
322 let mut buffer = Vec::new();
323 loop {
324 buffer.clear();
325
326 if stdout.read_until(b'\n', &mut buffer).await? == 0 {
327 break;
328 };
329
330 if stdout.read_until(b'\n', &mut buffer).await? == 0 {
331 break;
332 };
333
334 let header = std::str::from_utf8(&buffer)?;
335 let message_len: usize = header
336 .strip_prefix(CONTENT_LEN_HEADER)
337 .ok_or_else(|| anyhow!("invalid LSP message header {header:?}"))?
338 .trim_end()
339 .parse()?;
340
341 buffer.resize(message_len, 0);
342 stdout.read_exact(&mut buffer).await?;
343
344 if let Ok(message) = str::from_utf8(&buffer) {
345 log::trace!("incoming message: {}", message);
346 for handler in io_handlers.lock().values_mut() {
347 handler(IoKind::StdOut, message);
348 }
349 }
350
351 if let Ok(msg) = serde_json::from_slice::<AnyNotification>(&buffer) {
352 if let Some(handler) = notification_handlers.lock().get_mut(msg.method) {
353 handler(
354 msg.id,
355 msg.params.map(|params| params.get()).unwrap_or("null"),
356 cx.clone(),
357 );
358 } else {
359 on_unhandled_notification(msg);
360 }
361 } else if let Ok(AnyResponse {
362 id, error, result, ..
363 }) = serde_json::from_slice(&buffer)
364 {
365 if let Some(handler) = response_handlers
366 .lock()
367 .as_mut()
368 .and_then(|handlers| handlers.remove(&id))
369 {
370 if let Some(error) = error {
371 handler(Err(error));
372 } else if let Some(result) = result {
373 handler(Ok(result.get().into()));
374 } else {
375 handler(Ok("null".into()));
376 }
377 }
378 } else {
379 warn!(
380 "failed to deserialize LSP message:\n{}",
381 std::str::from_utf8(&buffer)?
382 );
383 }
384
385 // Don't starve the main thread when receiving lots of messages at once.
386 smol::future::yield_now().await;
387 }
388
389 Ok(())
390 }
391
392 async fn handle_stderr<Stderr>(
393 stderr: Stderr,
394 io_handlers: Arc<Mutex<HashMap<usize, IoHandler>>>,
395 stderr_capture: Arc<Mutex<Option<String>>>,
396 ) -> anyhow::Result<()>
397 where
398 Stderr: AsyncRead + Unpin + Send + 'static,
399 {
400 let mut stderr = BufReader::new(stderr);
401 let mut buffer = Vec::new();
402
403 loop {
404 buffer.clear();
405
406 let bytes_read = stderr.read_until(b'\n', &mut buffer).await?;
407 if bytes_read == 0 {
408 return Ok(());
409 }
410
411 if let Ok(message) = str::from_utf8(&buffer) {
412 log::trace!("incoming stderr message:{message}");
413 for handler in io_handlers.lock().values_mut() {
414 handler(IoKind::StdErr, message);
415 }
416
417 if let Some(stderr) = stderr_capture.lock().as_mut() {
418 stderr.push_str(message);
419 }
420 }
421
422 // Don't starve the main thread when receiving lots of messages at once.
423 smol::future::yield_now().await;
424 }
425 }
426
427 async fn handle_output<Stdin>(
428 stdin: Stdin,
429 outbound_rx: channel::Receiver<String>,
430 output_done_tx: barrier::Sender,
431 response_handlers: Arc<Mutex<Option<HashMap<usize, ResponseHandler>>>>,
432 io_handlers: Arc<Mutex<HashMap<usize, IoHandler>>>,
433 ) -> anyhow::Result<()>
434 where
435 Stdin: AsyncWrite + Unpin + Send + 'static,
436 {
437 let mut stdin = BufWriter::new(stdin);
438 let _clear_response_handlers = util::defer({
439 let response_handlers = response_handlers.clone();
440 move || {
441 response_handlers.lock().take();
442 }
443 });
444 let mut content_len_buffer = Vec::new();
445 while let Ok(message) = outbound_rx.recv().await {
446 log::trace!("outgoing message:{}", message);
447 for handler in io_handlers.lock().values_mut() {
448 handler(IoKind::StdIn, &message);
449 }
450
451 content_len_buffer.clear();
452 write!(content_len_buffer, "{}", message.len()).unwrap();
453 stdin.write_all(CONTENT_LEN_HEADER.as_bytes()).await?;
454 stdin.write_all(&content_len_buffer).await?;
455 stdin.write_all("\r\n\r\n".as_bytes()).await?;
456 stdin.write_all(message.as_bytes()).await?;
457 stdin.flush().await?;
458 }
459 drop(output_done_tx);
460 Ok(())
461 }
462
463 /// Initializes a language server by sending the `Initialize` request.
464 /// Note that `options` is used directly to construct [`InitializeParams`], which is why it is owned.
465 ///
466 /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#initialize)
467 pub fn initialize(
468 mut self,
469 options: Option<Value>,
470 cx: &AppContext,
471 ) -> Task<Result<Arc<Self>>> {
472 let root_uri = Url::from_file_path(&self.root_path).unwrap();
473 #[allow(deprecated)]
474 let params = InitializeParams {
475 process_id: None,
476 root_path: None,
477 root_uri: Some(root_uri.clone()),
478 initialization_options: options,
479 capabilities: ClientCapabilities {
480 workspace: Some(WorkspaceClientCapabilities {
481 configuration: Some(true),
482 did_change_watched_files: Some(DidChangeWatchedFilesClientCapabilities {
483 dynamic_registration: Some(true),
484 relative_pattern_support: Some(true),
485 }),
486 did_change_configuration: Some(DynamicRegistrationClientCapabilities {
487 dynamic_registration: Some(true),
488 }),
489 workspace_folders: Some(true),
490 symbol: Some(WorkspaceSymbolClientCapabilities {
491 resolve_support: None,
492 ..WorkspaceSymbolClientCapabilities::default()
493 }),
494 inlay_hint: Some(InlayHintWorkspaceClientCapabilities {
495 refresh_support: Some(true),
496 }),
497 diagnostic: Some(DiagnosticWorkspaceClientCapabilities {
498 refresh_support: None,
499 }),
500 workspace_edit: Some(WorkspaceEditClientCapabilities {
501 resource_operations: Some(vec![
502 ResourceOperationKind::Create,
503 ResourceOperationKind::Rename,
504 ResourceOperationKind::Delete,
505 ]),
506 document_changes: Some(true),
507 ..WorkspaceEditClientCapabilities::default()
508 }),
509 ..Default::default()
510 }),
511 text_document: Some(TextDocumentClientCapabilities {
512 definition: Some(GotoCapability {
513 link_support: Some(true),
514 dynamic_registration: None,
515 }),
516 code_action: Some(CodeActionClientCapabilities {
517 code_action_literal_support: Some(CodeActionLiteralSupport {
518 code_action_kind: CodeActionKindLiteralSupport {
519 value_set: vec![
520 CodeActionKind::REFACTOR.as_str().into(),
521 CodeActionKind::QUICKFIX.as_str().into(),
522 CodeActionKind::SOURCE.as_str().into(),
523 ],
524 },
525 }),
526 data_support: Some(true),
527 resolve_support: Some(CodeActionCapabilityResolveSupport {
528 properties: vec!["edit".to_string(), "command".to_string()],
529 }),
530 ..Default::default()
531 }),
532 completion: Some(CompletionClientCapabilities {
533 completion_item: Some(CompletionItemCapability {
534 snippet_support: Some(true),
535 resolve_support: Some(CompletionItemCapabilityResolveSupport {
536 properties: vec!["additionalTextEdits".to_string()],
537 }),
538 ..Default::default()
539 }),
540 completion_list: Some(CompletionListCapability {
541 item_defaults: Some(vec![
542 "commitCharacters".to_owned(),
543 "editRange".to_owned(),
544 "insertTextMode".to_owned(),
545 "data".to_owned(),
546 ]),
547 }),
548 ..Default::default()
549 }),
550 rename: Some(RenameClientCapabilities {
551 prepare_support: Some(true),
552 ..Default::default()
553 }),
554 hover: Some(HoverClientCapabilities {
555 content_format: Some(vec![MarkupKind::Markdown]),
556 dynamic_registration: None,
557 }),
558 inlay_hint: Some(InlayHintClientCapabilities {
559 resolve_support: Some(InlayHintResolveClientCapabilities {
560 properties: vec![
561 "textEdits".to_string(),
562 "tooltip".to_string(),
563 "label.tooltip".to_string(),
564 "label.location".to_string(),
565 "label.command".to_string(),
566 ],
567 }),
568 dynamic_registration: Some(false),
569 }),
570 publish_diagnostics: Some(PublishDiagnosticsClientCapabilities {
571 related_information: Some(true),
572 ..Default::default()
573 }),
574 formatting: Some(DynamicRegistrationClientCapabilities {
575 dynamic_registration: None,
576 }),
577 on_type_formatting: Some(DynamicRegistrationClientCapabilities {
578 dynamic_registration: None,
579 }),
580 diagnostic: Some(DiagnosticClientCapabilities {
581 related_document_support: Some(true),
582 dynamic_registration: None,
583 }),
584 ..Default::default()
585 }),
586 experimental: Some(json!({
587 "serverStatusNotification": true,
588 })),
589 window: Some(WindowClientCapabilities {
590 work_done_progress: Some(true),
591 ..Default::default()
592 }),
593 general: None,
594 },
595 trace: None,
596 workspace_folders: Some(vec![WorkspaceFolder {
597 uri: root_uri,
598 name: Default::default(),
599 }]),
600 client_info: Some(ClientInfo {
601 name: release_channel::ReleaseChannel::global(cx)
602 .display_name()
603 .to_string(),
604 version: Some(release_channel::AppVersion::global(cx).to_string()),
605 }),
606 locale: None,
607 };
608
609 cx.spawn(|_| async move {
610 let response = self.request::<request::Initialize>(params).await?;
611 if let Some(info) = response.server_info {
612 self.name = info.name;
613 }
614 self.capabilities = response.capabilities;
615
616 self.notify::<notification::Initialized>(InitializedParams {})?;
617 Ok(Arc::new(self))
618 })
619 }
620
621 /// Sends a shutdown request to the language server process and prepares the [`LanguageServer`] to be dropped.
622 pub fn shutdown(&self) -> Option<impl 'static + Send + Future<Output = Option<()>>> {
623 if let Some(tasks) = self.io_tasks.lock().take() {
624 let response_handlers = self.response_handlers.clone();
625 let next_id = AtomicUsize::new(self.next_id.load(SeqCst));
626 let outbound_tx = self.outbound_tx.clone();
627 let executor = self.executor.clone();
628 let mut output_done = self.output_done_rx.lock().take().unwrap();
629 let shutdown_request = Self::request_internal::<request::Shutdown>(
630 &next_id,
631 &response_handlers,
632 &outbound_tx,
633 &executor,
634 (),
635 );
636 let exit = Self::notify_internal::<notification::Exit>(&outbound_tx, ());
637 outbound_tx.close();
638 Some(
639 async move {
640 log::debug!("language server shutdown started");
641 shutdown_request.await?;
642 response_handlers.lock().take();
643 exit?;
644 output_done.recv().await;
645 log::debug!("language server shutdown finished");
646 drop(tasks);
647 anyhow::Ok(())
648 }
649 .log_err(),
650 )
651 } else {
652 None
653 }
654 }
655
656 /// Register a handler to handle incoming LSP notifications.
657 ///
658 /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
659 #[must_use]
660 pub fn on_notification<T, F>(&self, f: F) -> Subscription
661 where
662 T: notification::Notification,
663 F: 'static + Send + FnMut(T::Params, AsyncAppContext),
664 {
665 self.on_custom_notification(T::METHOD, f)
666 }
667
668 /// Register a handler to handle incoming LSP requests.
669 ///
670 /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
671 #[must_use]
672 pub fn on_request<T, F, Fut>(&self, f: F) -> Subscription
673 where
674 T: request::Request,
675 T::Params: 'static + Send,
676 F: 'static + FnMut(T::Params, AsyncAppContext) -> Fut + Send,
677 Fut: 'static + Future<Output = Result<T::Result>>,
678 {
679 self.on_custom_request(T::METHOD, f)
680 }
681
682 /// Registers a handler to inspect all language server process stdio.
683 #[must_use]
684 pub fn on_io<F>(&self, f: F) -> Subscription
685 where
686 F: 'static + Send + FnMut(IoKind, &str),
687 {
688 let id = self.next_id.fetch_add(1, SeqCst);
689 self.io_handlers.lock().insert(id, Box::new(f));
690 Subscription::Io {
691 id,
692 io_handlers: Some(Arc::downgrade(&self.io_handlers)),
693 }
694 }
695
696 /// Removes a request handler registers via [`Self::on_request`].
697 pub fn remove_request_handler<T: request::Request>(&self) {
698 self.notification_handlers.lock().remove(T::METHOD);
699 }
700
701 /// Removes a notification handler registers via [`Self::on_notification`].
702 pub fn remove_notification_handler<T: notification::Notification>(&self) {
703 self.notification_handlers.lock().remove(T::METHOD);
704 }
705
706 /// Checks if a notification handler has been registered via [`Self::on_notification`].
707 pub fn has_notification_handler<T: notification::Notification>(&self) -> bool {
708 self.notification_handlers.lock().contains_key(T::METHOD)
709 }
710
711 #[must_use]
712 fn on_custom_notification<Params, F>(&self, method: &'static str, mut f: F) -> Subscription
713 where
714 F: 'static + FnMut(Params, AsyncAppContext) + Send,
715 Params: DeserializeOwned,
716 {
717 let prev_handler = self.notification_handlers.lock().insert(
718 method,
719 Box::new(move |_, params, cx| {
720 if let Some(params) = serde_json::from_str(params).log_err() {
721 f(params, cx);
722 }
723 }),
724 );
725 assert!(
726 prev_handler.is_none(),
727 "registered multiple handlers for the same LSP method"
728 );
729 Subscription::Notification {
730 method,
731 notification_handlers: Some(self.notification_handlers.clone()),
732 }
733 }
734
735 #[must_use]
736 fn on_custom_request<Params, Res, Fut, F>(&self, method: &'static str, mut f: F) -> Subscription
737 where
738 F: 'static + FnMut(Params, AsyncAppContext) -> Fut + Send,
739 Fut: 'static + Future<Output = Result<Res>>,
740 Params: DeserializeOwned + Send + 'static,
741 Res: Serialize,
742 {
743 let outbound_tx = self.outbound_tx.clone();
744 let prev_handler = self.notification_handlers.lock().insert(
745 method,
746 Box::new(move |id, params, cx| {
747 if let Some(id) = id {
748 match serde_json::from_str(params) {
749 Ok(params) => {
750 let response = f(params, cx.clone());
751 cx.foreground_executor()
752 .spawn({
753 let outbound_tx = outbound_tx.clone();
754 async move {
755 let response = match response.await {
756 Ok(result) => Response {
757 jsonrpc: JSON_RPC_VERSION,
758 id,
759 result: Some(result),
760 error: None,
761 },
762 Err(error) => Response {
763 jsonrpc: JSON_RPC_VERSION,
764 id,
765 result: None,
766 error: Some(Error {
767 message: error.to_string(),
768 }),
769 },
770 };
771 if let Some(response) =
772 serde_json::to_string(&response).log_err()
773 {
774 outbound_tx.try_send(response).ok();
775 }
776 }
777 })
778 .detach();
779 }
780
781 Err(error) => {
782 log::error!(
783 "error deserializing {} request: {:?}, message: {:?}",
784 method,
785 error,
786 params
787 );
788 let response = AnyResponse {
789 jsonrpc: JSON_RPC_VERSION,
790 id,
791 result: None,
792 error: Some(Error {
793 message: error.to_string(),
794 }),
795 };
796 if let Some(response) = serde_json::to_string(&response).log_err() {
797 outbound_tx.try_send(response).ok();
798 }
799 }
800 }
801 }
802 }),
803 );
804 assert!(
805 prev_handler.is_none(),
806 "registered multiple handlers for the same LSP method"
807 );
808 Subscription::Notification {
809 method,
810 notification_handlers: Some(self.notification_handlers.clone()),
811 }
812 }
813
814 /// Get the name of the running language server.
815 pub fn name(&self) -> &str {
816 &self.name
817 }
818
819 /// Get the reported capabilities of the running language server.
820 pub fn capabilities(&self) -> &ServerCapabilities {
821 &self.capabilities
822 }
823
824 /// Get the id of the running language server.
825 pub fn server_id(&self) -> LanguageServerId {
826 self.server_id
827 }
828
829 /// Get the root path of the project the language server is running against.
830 pub fn root_path(&self) -> &PathBuf {
831 &self.root_path
832 }
833
834 /// Sends a RPC request to the language server.
835 ///
836 /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
837 pub fn request<T: request::Request>(
838 &self,
839 params: T::Params,
840 ) -> impl Future<Output = Result<T::Result>>
841 where
842 T::Result: 'static + Send,
843 {
844 Self::request_internal::<T>(
845 &self.next_id,
846 &self.response_handlers,
847 &self.outbound_tx,
848 &self.executor,
849 params,
850 )
851 }
852
853 fn request_internal<T: request::Request>(
854 next_id: &AtomicUsize,
855 response_handlers: &Mutex<Option<HashMap<usize, ResponseHandler>>>,
856 outbound_tx: &channel::Sender<String>,
857 executor: &BackgroundExecutor,
858 params: T::Params,
859 ) -> impl 'static + Future<Output = anyhow::Result<T::Result>>
860 where
861 T::Result: 'static + Send,
862 {
863 let id = next_id.fetch_add(1, SeqCst);
864 let message = serde_json::to_string(&Request {
865 jsonrpc: JSON_RPC_VERSION,
866 id,
867 method: T::METHOD,
868 params,
869 })
870 .unwrap();
871
872 let (tx, rx) = oneshot::channel();
873 let handle_response = response_handlers
874 .lock()
875 .as_mut()
876 .ok_or_else(|| anyhow!("server shut down"))
877 .map(|handlers| {
878 let executor = executor.clone();
879 handlers.insert(
880 id,
881 Box::new(move |result| {
882 executor
883 .spawn(async move {
884 let response = match result {
885 Ok(response) => serde_json::from_str(&response)
886 .context("failed to deserialize response"),
887 Err(error) => Err(anyhow!("{}", error.message)),
888 };
889 _ = tx.send(response);
890 })
891 .detach();
892 }),
893 );
894 });
895
896 let send = outbound_tx
897 .try_send(message)
898 .context("failed to write to language server's stdin");
899
900 let outbound_tx = outbound_tx.downgrade();
901 let mut timeout = executor.timer(LSP_REQUEST_TIMEOUT).fuse();
902 let started = Instant::now();
903 async move {
904 handle_response?;
905 send?;
906
907 let cancel_on_drop = util::defer(move || {
908 if let Some(outbound_tx) = outbound_tx.upgrade() {
909 Self::notify_internal::<notification::Cancel>(
910 &outbound_tx,
911 CancelParams {
912 id: NumberOrString::Number(id as i32),
913 },
914 )
915 .log_err();
916 }
917 });
918
919 let method = T::METHOD;
920 futures::select! {
921 response = rx.fuse() => {
922 let elapsed = started.elapsed();
923 log::trace!("Took {elapsed:?} to receive response to {method:?} id {id}");
924 cancel_on_drop.abort();
925 response?
926 }
927
928 _ = timeout => {
929 log::error!("Cancelled LSP request task for {method:?} id {id} which took over {LSP_REQUEST_TIMEOUT:?}");
930 anyhow::bail!("LSP request timeout");
931 }
932 }
933 }
934 }
935
936 /// Sends a RPC notification to the language server.
937 ///
938 /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
939 pub fn notify<T: notification::Notification>(&self, params: T::Params) -> Result<()> {
940 Self::notify_internal::<T>(&self.outbound_tx, params)
941 }
942
943 fn notify_internal<T: notification::Notification>(
944 outbound_tx: &channel::Sender<String>,
945 params: T::Params,
946 ) -> Result<()> {
947 let message = serde_json::to_string(&Notification {
948 jsonrpc: JSON_RPC_VERSION,
949 method: T::METHOD,
950 params,
951 })
952 .unwrap();
953 outbound_tx.try_send(message)?;
954 Ok(())
955 }
956}
957
958impl Drop for LanguageServer {
959 fn drop(&mut self) {
960 if let Some(shutdown) = self.shutdown() {
961 self.executor.spawn(shutdown).detach();
962 }
963 }
964}
965
966impl Subscription {
967 /// Detaching a subscription handle prevents it from unsubscribing on drop.
968 pub fn detach(&mut self) {
969 match self {
970 Subscription::Notification {
971 notification_handlers,
972 ..
973 } => *notification_handlers = None,
974 Subscription::Io { io_handlers, .. } => *io_handlers = None,
975 }
976 }
977}
978
979impl fmt::Display for LanguageServerId {
980 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
981 self.0.fmt(f)
982 }
983}
984
985impl fmt::Debug for LanguageServer {
986 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
987 f.debug_struct("LanguageServer")
988 .field("id", &self.server_id.0)
989 .field("name", &self.name)
990 .finish_non_exhaustive()
991 }
992}
993
994impl Drop for Subscription {
995 fn drop(&mut self) {
996 match self {
997 Subscription::Notification {
998 method,
999 notification_handlers,
1000 } => {
1001 if let Some(handlers) = notification_handlers {
1002 handlers.lock().remove(method);
1003 }
1004 }
1005 Subscription::Io { id, io_handlers } => {
1006 if let Some(io_handlers) = io_handlers.as_ref().and_then(|h| h.upgrade()) {
1007 io_handlers.lock().remove(id);
1008 }
1009 }
1010 }
1011 }
1012}
1013
1014/// Mock language server for use in tests.
1015#[cfg(any(test, feature = "test-support"))]
1016#[derive(Clone)]
1017pub struct FakeLanguageServer {
1018 pub server: Arc<LanguageServer>,
1019 notifications_rx: channel::Receiver<(String, String)>,
1020}
1021
1022#[cfg(any(test, feature = "test-support"))]
1023impl FakeLanguageServer {
1024 /// Construct a fake language server.
1025 pub fn new(
1026 name: String,
1027 capabilities: ServerCapabilities,
1028 cx: AsyncAppContext,
1029 ) -> (LanguageServer, FakeLanguageServer) {
1030 let (stdin_writer, stdin_reader) = async_pipe::pipe();
1031 let (stdout_writer, stdout_reader) = async_pipe::pipe();
1032 let (notifications_tx, notifications_rx) = channel::unbounded();
1033
1034 let server = LanguageServer::new_internal(
1035 LanguageServerId(0),
1036 stdin_writer,
1037 stdout_reader,
1038 None::<async_pipe::PipeReader>,
1039 Arc::new(Mutex::new(None)),
1040 None,
1041 Path::new("/"),
1042 None,
1043 cx.clone(),
1044 |_| {},
1045 );
1046 let fake = FakeLanguageServer {
1047 server: Arc::new(LanguageServer::new_internal(
1048 LanguageServerId(0),
1049 stdout_writer,
1050 stdin_reader,
1051 None::<async_pipe::PipeReader>,
1052 Arc::new(Mutex::new(None)),
1053 None,
1054 Path::new("/"),
1055 None,
1056 cx,
1057 move |msg| {
1058 notifications_tx
1059 .try_send((
1060 msg.method.to_string(),
1061 msg.params
1062 .map(|raw_value| raw_value.get())
1063 .unwrap_or("null")
1064 .to_string(),
1065 ))
1066 .ok();
1067 },
1068 )),
1069 notifications_rx,
1070 };
1071 fake.handle_request::<request::Initialize, _, _>({
1072 let capabilities = capabilities;
1073 move |_, _| {
1074 let capabilities = capabilities.clone();
1075 let name = name.clone();
1076 async move {
1077 Ok(InitializeResult {
1078 capabilities,
1079 server_info: Some(ServerInfo {
1080 name,
1081 ..Default::default()
1082 }),
1083 })
1084 }
1085 }
1086 });
1087
1088 (server, fake)
1089 }
1090}
1091
1092#[cfg(any(test, feature = "test-support"))]
1093impl LanguageServer {
1094 pub fn full_capabilities() -> ServerCapabilities {
1095 ServerCapabilities {
1096 document_highlight_provider: Some(OneOf::Left(true)),
1097 code_action_provider: Some(CodeActionProviderCapability::Simple(true)),
1098 document_formatting_provider: Some(OneOf::Left(true)),
1099 document_range_formatting_provider: Some(OneOf::Left(true)),
1100 definition_provider: Some(OneOf::Left(true)),
1101 type_definition_provider: Some(TypeDefinitionProviderCapability::Simple(true)),
1102 ..Default::default()
1103 }
1104 }
1105}
1106
1107#[cfg(any(test, feature = "test-support"))]
1108impl FakeLanguageServer {
1109 /// See [`LanguageServer::notify`].
1110 pub fn notify<T: notification::Notification>(&self, params: T::Params) {
1111 self.server.notify::<T>(params).ok();
1112 }
1113
1114 /// See [`LanguageServer::request`].
1115 pub async fn request<T>(&self, params: T::Params) -> Result<T::Result>
1116 where
1117 T: request::Request,
1118 T::Result: 'static + Send,
1119 {
1120 self.server.executor.start_waiting();
1121 self.server.request::<T>(params).await
1122 }
1123
1124 /// Attempts [`Self::try_receive_notification`], unwrapping if it has not received the specified type yet.
1125 pub async fn receive_notification<T: notification::Notification>(&mut self) -> T::Params {
1126 self.server.executor.start_waiting();
1127 self.try_receive_notification::<T>().await.unwrap()
1128 }
1129
1130 /// Consumes the notification channel until it finds a notification for the specified type.
1131 pub async fn try_receive_notification<T: notification::Notification>(
1132 &mut self,
1133 ) -> Option<T::Params> {
1134 use futures::StreamExt as _;
1135
1136 loop {
1137 let (method, params) = self.notifications_rx.next().await?;
1138 if method == T::METHOD {
1139 return Some(serde_json::from_str::<T::Params>(¶ms).unwrap());
1140 } else {
1141 log::info!("skipping message in fake language server {:?}", params);
1142 }
1143 }
1144 }
1145
1146 /// Registers a handler for a specific kind of request. Removes any existing handler for specified request type.
1147 pub fn handle_request<T, F, Fut>(
1148 &self,
1149 mut handler: F,
1150 ) -> futures::channel::mpsc::UnboundedReceiver<()>
1151 where
1152 T: 'static + request::Request,
1153 T::Params: 'static + Send,
1154 F: 'static + Send + FnMut(T::Params, gpui::AsyncAppContext) -> Fut,
1155 Fut: 'static + Send + Future<Output = Result<T::Result>>,
1156 {
1157 let (responded_tx, responded_rx) = futures::channel::mpsc::unbounded();
1158 self.server.remove_request_handler::<T>();
1159 self.server
1160 .on_request::<T, _, _>(move |params, cx| {
1161 let result = handler(params, cx.clone());
1162 let responded_tx = responded_tx.clone();
1163 let executor = cx.background_executor().clone();
1164 async move {
1165 executor.simulate_random_delay().await;
1166 let result = result.await;
1167 responded_tx.unbounded_send(()).ok();
1168 result
1169 }
1170 })
1171 .detach();
1172 responded_rx
1173 }
1174
1175 /// Registers a handler for a specific kind of notification. Removes any existing handler for specified notification type.
1176 pub fn handle_notification<T, F>(
1177 &self,
1178 mut handler: F,
1179 ) -> futures::channel::mpsc::UnboundedReceiver<()>
1180 where
1181 T: 'static + notification::Notification,
1182 T::Params: 'static + Send,
1183 F: 'static + Send + FnMut(T::Params, gpui::AsyncAppContext),
1184 {
1185 let (handled_tx, handled_rx) = futures::channel::mpsc::unbounded();
1186 self.server.remove_notification_handler::<T>();
1187 self.server
1188 .on_notification::<T, _>(move |params, cx| {
1189 handler(params, cx.clone());
1190 handled_tx.unbounded_send(()).ok();
1191 })
1192 .detach();
1193 handled_rx
1194 }
1195
1196 /// Removes any existing handler for specified notification type.
1197 pub fn remove_request_handler<T>(&mut self)
1198 where
1199 T: 'static + request::Request,
1200 {
1201 self.server.remove_request_handler::<T>();
1202 }
1203
1204 /// Simulate that the server has started work and notifies about its progress with the specified token.
1205 pub async fn start_progress(&self, token: impl Into<String>) {
1206 let token = token.into();
1207 self.request::<request::WorkDoneProgressCreate>(WorkDoneProgressCreateParams {
1208 token: NumberOrString::String(token.clone()),
1209 })
1210 .await
1211 .unwrap();
1212 self.notify::<notification::Progress>(ProgressParams {
1213 token: NumberOrString::String(token),
1214 value: ProgressParamsValue::WorkDone(WorkDoneProgress::Begin(Default::default())),
1215 });
1216 }
1217
1218 /// Simulate that the server has completed work and notifies about that with the specified token.
1219 pub fn end_progress(&self, token: impl Into<String>) {
1220 self.notify::<notification::Progress>(ProgressParams {
1221 token: NumberOrString::String(token.into()),
1222 value: ProgressParamsValue::WorkDone(WorkDoneProgress::End(Default::default())),
1223 });
1224 }
1225}
1226
1227#[cfg(test)]
1228mod tests {
1229 use super::*;
1230 use gpui::TestAppContext;
1231
1232 #[ctor::ctor]
1233 fn init_logger() {
1234 if std::env::var("RUST_LOG").is_ok() {
1235 env_logger::init();
1236 }
1237 }
1238
1239 #[gpui::test]
1240 async fn test_fake(cx: &mut TestAppContext) {
1241 cx.update(|cx| {
1242 release_channel::init("0.0.0", cx);
1243 });
1244 let (server, mut fake) =
1245 FakeLanguageServer::new("the-lsp".to_string(), Default::default(), cx.to_async());
1246
1247 let (message_tx, message_rx) = channel::unbounded();
1248 let (diagnostics_tx, diagnostics_rx) = channel::unbounded();
1249 server
1250 .on_notification::<notification::ShowMessage, _>(move |params, _| {
1251 message_tx.try_send(params).unwrap()
1252 })
1253 .detach();
1254 server
1255 .on_notification::<notification::PublishDiagnostics, _>(move |params, _| {
1256 diagnostics_tx.try_send(params).unwrap()
1257 })
1258 .detach();
1259
1260 let server = cx.update(|cx| server.initialize(None, cx)).await.unwrap();
1261 server
1262 .notify::<notification::DidOpenTextDocument>(DidOpenTextDocumentParams {
1263 text_document: TextDocumentItem::new(
1264 Url::from_str("file://a/b").unwrap(),
1265 "rust".to_string(),
1266 0,
1267 "".to_string(),
1268 ),
1269 })
1270 .unwrap();
1271 assert_eq!(
1272 fake.receive_notification::<notification::DidOpenTextDocument>()
1273 .await
1274 .text_document
1275 .uri
1276 .as_str(),
1277 "file://a/b"
1278 );
1279
1280 fake.notify::<notification::ShowMessage>(ShowMessageParams {
1281 typ: MessageType::ERROR,
1282 message: "ok".to_string(),
1283 });
1284 fake.notify::<notification::PublishDiagnostics>(PublishDiagnosticsParams {
1285 uri: Url::from_str("file://b/c").unwrap(),
1286 version: Some(5),
1287 diagnostics: vec![],
1288 });
1289 assert_eq!(message_rx.recv().await.unwrap().message, "ok");
1290 assert_eq!(
1291 diagnostics_rx.recv().await.unwrap().uri.as_str(),
1292 "file://b/c"
1293 );
1294
1295 fake.handle_request::<request::Shutdown, _, _>(|_, _| async move { Ok(()) });
1296
1297 drop(server);
1298 fake.receive_notification::<notification::Exit>().await;
1299 }
1300}