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