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