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};
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 fmt,
20 future::Future,
21 io::Write,
22 path::PathBuf,
23 str::{self, FromStr as _},
24 sync::{
25 atomic::{AtomicUsize, Ordering::SeqCst},
26 Arc, Weak,
27 },
28};
29use std::{path::Path, process::Stdio};
30use util::{ResultExt, TryFutureExt};
31
32const JSON_RPC_VERSION: &str = "2.0";
33const CONTENT_LEN_HEADER: &str = "Content-Length: ";
34
35type NotificationHandler = Box<dyn Send + FnMut(Option<usize>, &str, AsyncAppContext)>;
36type ResponseHandler = Box<dyn Send + FnOnce(Result<String, Error>)>;
37type IoHandler = Box<dyn Send + FnMut(bool, &str)>;
38
39pub struct LanguageServer {
40 server_id: LanguageServerId,
41 next_id: AtomicUsize,
42 outbound_tx: channel::Sender<String>,
43 name: String,
44 capabilities: ServerCapabilities,
45 code_action_kinds: Option<Vec<CodeActionKind>>,
46 notification_handlers: Arc<Mutex<HashMap<&'static str, NotificationHandler>>>,
47 response_handlers: Arc<Mutex<Option<HashMap<usize, ResponseHandler>>>>,
48 io_handlers: Arc<Mutex<HashMap<usize, IoHandler>>>,
49 executor: Arc<executor::Background>,
50 #[allow(clippy::type_complexity)]
51 io_tasks: Mutex<Option<(Task<Option<()>>, Task<Option<()>>)>>,
52 output_done_rx: Mutex<Option<barrier::Receiver>>,
53 root_path: PathBuf,
54 _server: Option<Child>,
55}
56
57#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
58#[repr(transparent)]
59pub struct LanguageServerId(pub usize);
60
61pub enum Subscription {
62 Notification {
63 method: &'static str,
64 notification_handlers: Option<Arc<Mutex<HashMap<&'static str, NotificationHandler>>>>,
65 },
66 Io {
67 id: usize,
68 io_handlers: Option<Weak<Mutex<HashMap<usize, IoHandler>>>>,
69 },
70}
71
72#[derive(Serialize, Deserialize)]
73struct Request<'a, T> {
74 jsonrpc: &'static str,
75 id: usize,
76 method: &'a str,
77 params: T,
78}
79
80#[derive(Serialize, Deserialize)]
81struct AnyResponse<'a> {
82 jsonrpc: &'a str,
83 id: usize,
84 #[serde(default)]
85 error: Option<Error>,
86 #[serde(borrow)]
87 result: Option<&'a RawValue>,
88}
89
90#[derive(Serialize)]
91struct Response<T> {
92 jsonrpc: &'static str,
93 id: usize,
94 result: Option<T>,
95 error: Option<Error>,
96}
97
98#[derive(Serialize, Deserialize)]
99struct Notification<'a, T> {
100 jsonrpc: &'static str,
101 #[serde(borrow)]
102 method: &'a str,
103 params: T,
104}
105
106#[derive(Debug, Clone, Deserialize)]
107struct AnyNotification<'a> {
108 #[serde(default)]
109 id: Option<usize>,
110 #[serde(borrow)]
111 method: &'a str,
112 #[serde(borrow, default)]
113 params: Option<&'a RawValue>,
114}
115
116#[derive(Debug, Serialize, Deserialize)]
117struct Error {
118 message: String,
119}
120
121impl LanguageServer {
122 pub fn new<T: AsRef<std::ffi::OsStr>>(
123 server_id: LanguageServerId,
124 binary_path: &Path,
125 arguments: &[T],
126 root_path: &Path,
127 code_action_kinds: Option<Vec<CodeActionKind>>,
128 cx: AsyncAppContext,
129 ) -> Result<Self> {
130 let working_dir = if root_path.is_dir() {
131 root_path
132 } else {
133 root_path.parent().unwrap_or_else(|| Path::new("/"))
134 };
135
136 let mut server = process::Command::new(binary_path)
137 .current_dir(working_dir)
138 .args(arguments)
139 .stdin(Stdio::piped())
140 .stdout(Stdio::piped())
141 .stderr(Stdio::inherit())
142 .kill_on_drop(true)
143 .spawn()?;
144
145 let stdin = server.stdin.take().unwrap();
146 let stout = server.stdout.take().unwrap();
147 let mut server = Self::new_internal(
148 server_id,
149 stdin,
150 stout,
151 Some(server),
152 root_path,
153 code_action_kinds,
154 cx,
155 |notification| {
156 log::info!(
157 "unhandled notification {}:\n{}",
158 notification.method,
159 serde_json::to_string_pretty(
160 ¬ification
161 .params
162 .and_then(|params| Value::from_str(params.get()).ok())
163 .unwrap_or(Value::Null)
164 )
165 .unwrap(),
166 );
167 },
168 );
169
170 if let Some(name) = binary_path.file_name() {
171 server.name = name.to_string_lossy().to_string();
172 }
173 Ok(server)
174 }
175
176 fn new_internal<Stdin, Stdout, F>(
177 server_id: LanguageServerId,
178 stdin: Stdin,
179 stdout: Stdout,
180 server: Option<Child>,
181 root_path: &Path,
182 code_action_kinds: Option<Vec<CodeActionKind>>,
183 cx: AsyncAppContext,
184 on_unhandled_notification: F,
185 ) -> Self
186 where
187 Stdin: AsyncWrite + Unpin + Send + 'static,
188 Stdout: AsyncRead + Unpin + Send + 'static,
189 F: FnMut(AnyNotification) + 'static + Send,
190 {
191 let (outbound_tx, outbound_rx) = channel::unbounded::<String>();
192 let (output_done_tx, output_done_rx) = barrier::channel();
193 let notification_handlers =
194 Arc::new(Mutex::new(HashMap::<_, NotificationHandler>::default()));
195 let response_handlers =
196 Arc::new(Mutex::new(Some(HashMap::<_, ResponseHandler>::default())));
197 let io_handlers = Arc::new(Mutex::new(HashMap::default()));
198 let input_task = cx.spawn(|cx| {
199 Self::handle_input(
200 stdout,
201 on_unhandled_notification,
202 notification_handlers.clone(),
203 response_handlers.clone(),
204 io_handlers.clone(),
205 cx,
206 )
207 .log_err()
208 });
209 let output_task = cx.background().spawn({
210 Self::handle_output(
211 stdin,
212 outbound_rx,
213 output_done_tx,
214 response_handlers.clone(),
215 io_handlers.clone(),
216 )
217 .log_err()
218 });
219
220 Self {
221 server_id,
222 notification_handlers,
223 response_handlers,
224 io_handlers,
225 name: Default::default(),
226 capabilities: Default::default(),
227 code_action_kinds,
228 next_id: Default::default(),
229 outbound_tx,
230 executor: cx.background(),
231 io_tasks: Mutex::new(Some((input_task, output_task))),
232 output_done_rx: Mutex::new(Some(output_done_rx)),
233 root_path: root_path.to_path_buf(),
234 _server: server,
235 }
236 }
237
238 pub fn code_action_kinds(&self) -> Option<Vec<CodeActionKind>> {
239 self.code_action_kinds.clone()
240 }
241
242 async fn handle_input<Stdout, F>(
243 stdout: Stdout,
244 mut on_unhandled_notification: F,
245 notification_handlers: Arc<Mutex<HashMap<&'static str, NotificationHandler>>>,
246 response_handlers: Arc<Mutex<Option<HashMap<usize, ResponseHandler>>>>,
247 io_handlers: Arc<Mutex<HashMap<usize, IoHandler>>>,
248 cx: AsyncAppContext,
249 ) -> anyhow::Result<()>
250 where
251 Stdout: AsyncRead + Unpin + Send + 'static,
252 F: FnMut(AnyNotification) + 'static + Send,
253 {
254 let mut stdout = BufReader::new(stdout);
255 let _clear_response_handlers = util::defer({
256 let response_handlers = response_handlers.clone();
257 move || {
258 response_handlers.lock().take();
259 }
260 });
261 let mut buffer = Vec::new();
262 loop {
263 buffer.clear();
264 stdout.read_until(b'\n', &mut buffer).await?;
265 stdout.read_until(b'\n', &mut buffer).await?;
266 let header = std::str::from_utf8(&buffer)?;
267 let message_len: usize = header
268 .strip_prefix(CONTENT_LEN_HEADER)
269 .ok_or_else(|| anyhow!("invalid LSP message header {header:?}"))?
270 .trim_end()
271 .parse()?;
272
273 buffer.resize(message_len, 0);
274 stdout.read_exact(&mut buffer).await?;
275
276 if let Ok(message) = str::from_utf8(&buffer) {
277 log::trace!("incoming message:{}", message);
278 for handler in io_handlers.lock().values_mut() {
279 handler(true, message);
280 }
281 }
282
283 if let Ok(msg) = serde_json::from_slice::<AnyNotification>(&buffer) {
284 if let Some(handler) = notification_handlers.lock().get_mut(msg.method) {
285 handler(
286 msg.id,
287 &msg.params.map(|params| params.get()).unwrap_or("null"),
288 cx.clone(),
289 );
290 } else {
291 on_unhandled_notification(msg);
292 }
293 } else if let Ok(AnyResponse {
294 id, error, result, ..
295 }) = serde_json::from_slice(&buffer)
296 {
297 if let Some(handler) = response_handlers
298 .lock()
299 .as_mut()
300 .and_then(|handlers| handlers.remove(&id))
301 {
302 if let Some(error) = error {
303 handler(Err(error));
304 } else if let Some(result) = result {
305 handler(Ok(result.get().into()));
306 } else {
307 handler(Ok("null".into()));
308 }
309 }
310 } else {
311 warn!(
312 "failed to deserialize LSP message:\n{}",
313 std::str::from_utf8(&buffer)?
314 );
315 }
316
317 // Don't starve the main thread when receiving lots of messages at once.
318 smol::future::yield_now().await;
319 }
320 }
321
322 async fn handle_output<Stdin>(
323 stdin: Stdin,
324 outbound_rx: channel::Receiver<String>,
325 output_done_tx: barrier::Sender,
326 response_handlers: Arc<Mutex<Option<HashMap<usize, ResponseHandler>>>>,
327 io_handlers: Arc<Mutex<HashMap<usize, IoHandler>>>,
328 ) -> anyhow::Result<()>
329 where
330 Stdin: AsyncWrite + Unpin + Send + 'static,
331 {
332 let mut stdin = BufWriter::new(stdin);
333 let _clear_response_handlers = util::defer({
334 let response_handlers = response_handlers.clone();
335 move || {
336 response_handlers.lock().take();
337 }
338 });
339 let mut content_len_buffer = Vec::new();
340 while let Ok(message) = outbound_rx.recv().await {
341 log::trace!("outgoing message:{}", message);
342 for handler in io_handlers.lock().values_mut() {
343 handler(false, &message);
344 }
345
346 content_len_buffer.clear();
347 write!(content_len_buffer, "{}", message.len()).unwrap();
348 stdin.write_all(CONTENT_LEN_HEADER.as_bytes()).await?;
349 stdin.write_all(&content_len_buffer).await?;
350 stdin.write_all("\r\n\r\n".as_bytes()).await?;
351 stdin.write_all(message.as_bytes()).await?;
352 stdin.flush().await?;
353 }
354 drop(output_done_tx);
355 Ok(())
356 }
357
358 /// Initializes a language server.
359 /// Note that `options` is used directly to construct [`InitializeParams`],
360 /// which is why it is owned.
361 pub async fn initialize(mut self, options: Option<Value>) -> Result<Arc<Self>> {
362 let root_uri = Url::from_file_path(&self.root_path).unwrap();
363 #[allow(deprecated)]
364 let params = InitializeParams {
365 process_id: Default::default(),
366 root_path: Default::default(),
367 root_uri: Some(root_uri.clone()),
368 initialization_options: options,
369 capabilities: ClientCapabilities {
370 workspace: Some(WorkspaceClientCapabilities {
371 configuration: Some(true),
372 did_change_watched_files: Some(DidChangeWatchedFilesClientCapabilities {
373 dynamic_registration: Some(true),
374 relative_pattern_support: Some(true),
375 }),
376 did_change_configuration: Some(DynamicRegistrationClientCapabilities {
377 dynamic_registration: Some(true),
378 }),
379 workspace_folders: Some(true),
380 symbol: Some(WorkspaceSymbolClientCapabilities {
381 resolve_support: None,
382 ..WorkspaceSymbolClientCapabilities::default()
383 }),
384 ..Default::default()
385 }),
386 text_document: Some(TextDocumentClientCapabilities {
387 definition: Some(GotoCapability {
388 link_support: Some(true),
389 ..Default::default()
390 }),
391 code_action: Some(CodeActionClientCapabilities {
392 code_action_literal_support: Some(CodeActionLiteralSupport {
393 code_action_kind: CodeActionKindLiteralSupport {
394 value_set: vec![
395 CodeActionKind::REFACTOR.as_str().into(),
396 CodeActionKind::QUICKFIX.as_str().into(),
397 CodeActionKind::SOURCE.as_str().into(),
398 ],
399 },
400 }),
401 data_support: Some(true),
402 resolve_support: Some(CodeActionCapabilityResolveSupport {
403 properties: vec!["edit".to_string(), "command".to_string()],
404 }),
405 ..Default::default()
406 }),
407 completion: Some(CompletionClientCapabilities {
408 completion_item: Some(CompletionItemCapability {
409 snippet_support: Some(true),
410 resolve_support: Some(CompletionItemCapabilityResolveSupport {
411 properties: vec!["additionalTextEdits".to_string()],
412 }),
413 ..Default::default()
414 }),
415 ..Default::default()
416 }),
417 rename: Some(RenameClientCapabilities {
418 prepare_support: Some(true),
419 ..Default::default()
420 }),
421 hover: Some(HoverClientCapabilities {
422 content_format: Some(vec![MarkupKind::Markdown]),
423 ..Default::default()
424 }),
425 ..Default::default()
426 }),
427 experimental: Some(json!({
428 "serverStatusNotification": true,
429 })),
430 window: Some(WindowClientCapabilities {
431 work_done_progress: Some(true),
432 ..Default::default()
433 }),
434 ..Default::default()
435 },
436 trace: Default::default(),
437 workspace_folders: Some(vec![WorkspaceFolder {
438 uri: root_uri,
439 name: Default::default(),
440 }]),
441 client_info: Default::default(),
442 locale: Default::default(),
443 };
444
445 let response = self.request::<request::Initialize>(params).await?;
446 if let Some(info) = response.server_info {
447 self.name = info.name;
448 }
449 self.capabilities = response.capabilities;
450
451 self.notify::<notification::Initialized>(InitializedParams {})?;
452 Ok(Arc::new(self))
453 }
454
455 pub fn shutdown(&self) -> Option<impl 'static + Send + Future<Output = Option<()>>> {
456 if let Some(tasks) = self.io_tasks.lock().take() {
457 let response_handlers = self.response_handlers.clone();
458 let next_id = AtomicUsize::new(self.next_id.load(SeqCst));
459 let outbound_tx = self.outbound_tx.clone();
460 let executor = self.executor.clone();
461 let mut output_done = self.output_done_rx.lock().take().unwrap();
462 let shutdown_request = Self::request_internal::<request::Shutdown>(
463 &next_id,
464 &response_handlers,
465 &outbound_tx,
466 &executor,
467 (),
468 );
469 let exit = Self::notify_internal::<notification::Exit>(&outbound_tx, ());
470 outbound_tx.close();
471 Some(
472 async move {
473 log::debug!("language server shutdown started");
474 shutdown_request.await?;
475 response_handlers.lock().take();
476 exit?;
477 output_done.recv().await;
478 log::debug!("language server shutdown finished");
479 drop(tasks);
480 anyhow::Ok(())
481 }
482 .log_err(),
483 )
484 } else {
485 None
486 }
487 }
488
489 #[must_use]
490 pub fn on_notification<T, F>(&self, f: F) -> Subscription
491 where
492 T: notification::Notification,
493 F: 'static + Send + FnMut(T::Params, AsyncAppContext),
494 {
495 self.on_custom_notification(T::METHOD, f)
496 }
497
498 #[must_use]
499 pub fn on_request<T, F, Fut>(&self, f: F) -> Subscription
500 where
501 T: request::Request,
502 T::Params: 'static + Send,
503 F: 'static + Send + FnMut(T::Params, AsyncAppContext) -> Fut,
504 Fut: 'static + Future<Output = Result<T::Result>>,
505 {
506 self.on_custom_request(T::METHOD, f)
507 }
508
509 #[must_use]
510 pub fn on_io<F>(&self, f: F) -> Subscription
511 where
512 F: 'static + Send + FnMut(bool, &str),
513 {
514 let id = self.next_id.fetch_add(1, SeqCst);
515 self.io_handlers.lock().insert(id, Box::new(f));
516 Subscription::Io {
517 id,
518 io_handlers: Some(Arc::downgrade(&self.io_handlers)),
519 }
520 }
521
522 pub fn remove_request_handler<T: request::Request>(&self) {
523 self.notification_handlers.lock().remove(T::METHOD);
524 }
525
526 pub fn remove_notification_handler<T: notification::Notification>(&self) {
527 self.notification_handlers.lock().remove(T::METHOD);
528 }
529
530 #[must_use]
531 pub fn on_custom_notification<Params, F>(&self, method: &'static str, mut f: F) -> Subscription
532 where
533 F: 'static + Send + FnMut(Params, AsyncAppContext),
534 Params: DeserializeOwned,
535 {
536 let prev_handler = self.notification_handlers.lock().insert(
537 method,
538 Box::new(move |_, params, cx| {
539 if let Some(params) = serde_json::from_str(params).log_err() {
540 f(params, cx);
541 }
542 }),
543 );
544 assert!(
545 prev_handler.is_none(),
546 "registered multiple handlers for the same LSP method"
547 );
548 Subscription::Notification {
549 method,
550 notification_handlers: Some(self.notification_handlers.clone()),
551 }
552 }
553
554 #[must_use]
555 pub fn on_custom_request<Params, Res, Fut, F>(
556 &self,
557 method: &'static str,
558 mut f: F,
559 ) -> Subscription
560 where
561 F: 'static + Send + FnMut(Params, AsyncAppContext) -> Fut,
562 Fut: 'static + Future<Output = Result<Res>>,
563 Params: DeserializeOwned + Send + 'static,
564 Res: Serialize,
565 {
566 let outbound_tx = self.outbound_tx.clone();
567 let prev_handler = self.notification_handlers.lock().insert(
568 method,
569 Box::new(move |id, params, cx| {
570 if let Some(id) = id {
571 match serde_json::from_str(params) {
572 Ok(params) => {
573 let response = f(params, cx.clone());
574 cx.foreground()
575 .spawn({
576 let outbound_tx = outbound_tx.clone();
577 async move {
578 let response = match response.await {
579 Ok(result) => Response {
580 jsonrpc: JSON_RPC_VERSION,
581 id,
582 result: Some(result),
583 error: None,
584 },
585 Err(error) => Response {
586 jsonrpc: JSON_RPC_VERSION,
587 id,
588 result: None,
589 error: Some(Error {
590 message: error.to_string(),
591 }),
592 },
593 };
594 if let Some(response) =
595 serde_json::to_string(&response).log_err()
596 {
597 outbound_tx.try_send(response).ok();
598 }
599 }
600 })
601 .detach();
602 }
603 Err(error) => {
604 log::error!(
605 "error deserializing {} request: {:?}, message: {:?}",
606 method,
607 error,
608 params
609 );
610 let response = AnyResponse {
611 jsonrpc: JSON_RPC_VERSION,
612 id,
613 result: None,
614 error: Some(Error {
615 message: error.to_string(),
616 }),
617 };
618 if let Some(response) = serde_json::to_string(&response).log_err() {
619 outbound_tx.try_send(response).ok();
620 }
621 }
622 }
623 }
624 }),
625 );
626 assert!(
627 prev_handler.is_none(),
628 "registered multiple handlers for the same LSP method"
629 );
630 Subscription::Notification {
631 method,
632 notification_handlers: Some(self.notification_handlers.clone()),
633 }
634 }
635
636 pub fn name<'a>(self: &'a Arc<Self>) -> &'a str {
637 &self.name
638 }
639
640 pub fn capabilities<'a>(self: &'a Arc<Self>) -> &'a ServerCapabilities {
641 &self.capabilities
642 }
643
644 pub fn server_id(&self) -> LanguageServerId {
645 self.server_id
646 }
647
648 pub fn root_path(&self) -> &PathBuf {
649 &self.root_path
650 }
651
652 pub fn request<T: request::Request>(
653 &self,
654 params: T::Params,
655 ) -> impl Future<Output = Result<T::Result>>
656 where
657 T::Result: 'static + Send,
658 {
659 Self::request_internal::<T>(
660 &self.next_id,
661 &self.response_handlers,
662 &self.outbound_tx,
663 &self.executor,
664 params,
665 )
666 }
667
668 fn request_internal<T: request::Request>(
669 next_id: &AtomicUsize,
670 response_handlers: &Mutex<Option<HashMap<usize, ResponseHandler>>>,
671 outbound_tx: &channel::Sender<String>,
672 executor: &Arc<executor::Background>,
673 params: T::Params,
674 ) -> impl 'static + Future<Output = Result<T::Result>>
675 where
676 T::Result: 'static + Send,
677 {
678 let id = next_id.fetch_add(1, SeqCst);
679 let message = serde_json::to_string(&Request {
680 jsonrpc: JSON_RPC_VERSION,
681 id,
682 method: T::METHOD,
683 params,
684 })
685 .unwrap();
686
687 let (tx, rx) = oneshot::channel();
688 let handle_response = response_handlers
689 .lock()
690 .as_mut()
691 .ok_or_else(|| anyhow!("server shut down"))
692 .map(|handlers| {
693 let executor = executor.clone();
694 handlers.insert(
695 id,
696 Box::new(move |result| {
697 executor
698 .spawn(async move {
699 let response = match result {
700 Ok(response) => serde_json::from_str(&response)
701 .context("failed to deserialize response"),
702 Err(error) => Err(anyhow!("{}", error.message)),
703 };
704 let _ = tx.send(response);
705 })
706 .detach();
707 }),
708 );
709 });
710
711 let send = outbound_tx
712 .try_send(message)
713 .context("failed to write to language server's stdin");
714
715 async move {
716 handle_response?;
717 send?;
718 rx.await?
719 }
720 }
721
722 pub fn notify<T: notification::Notification>(&self, params: T::Params) -> Result<()> {
723 Self::notify_internal::<T>(&self.outbound_tx, params)
724 }
725
726 fn notify_internal<T: notification::Notification>(
727 outbound_tx: &channel::Sender<String>,
728 params: T::Params,
729 ) -> Result<()> {
730 let message = serde_json::to_string(&Notification {
731 jsonrpc: JSON_RPC_VERSION,
732 method: T::METHOD,
733 params,
734 })
735 .unwrap();
736 outbound_tx.try_send(message)?;
737 Ok(())
738 }
739}
740
741impl Drop for LanguageServer {
742 fn drop(&mut self) {
743 if let Some(shutdown) = self.shutdown() {
744 self.executor.spawn(shutdown).detach();
745 }
746 }
747}
748
749impl Subscription {
750 pub fn detach(&mut self) {
751 match self {
752 Subscription::Notification {
753 notification_handlers,
754 ..
755 } => *notification_handlers = None,
756 Subscription::Io { io_handlers, .. } => *io_handlers = None,
757 }
758 }
759}
760
761impl fmt::Display for LanguageServerId {
762 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
763 self.0.fmt(f)
764 }
765}
766
767impl fmt::Debug for LanguageServer {
768 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
769 f.debug_struct("LanguageServer")
770 .field("id", &self.server_id.0)
771 .field("name", &self.name)
772 .finish_non_exhaustive()
773 }
774}
775
776impl Drop for Subscription {
777 fn drop(&mut self) {
778 match self {
779 Subscription::Notification {
780 method,
781 notification_handlers,
782 } => {
783 if let Some(handlers) = notification_handlers {
784 handlers.lock().remove(method);
785 }
786 }
787 Subscription::Io { id, io_handlers } => {
788 if let Some(io_handlers) = io_handlers.as_ref().and_then(|h| h.upgrade()) {
789 io_handlers.lock().remove(id);
790 }
791 }
792 }
793 }
794}
795
796#[cfg(any(test, feature = "test-support"))]
797#[derive(Clone)]
798pub struct FakeLanguageServer {
799 pub server: Arc<LanguageServer>,
800 notifications_rx: channel::Receiver<(String, String)>,
801}
802
803#[cfg(any(test, feature = "test-support"))]
804impl LanguageServer {
805 pub fn full_capabilities() -> ServerCapabilities {
806 ServerCapabilities {
807 document_highlight_provider: Some(OneOf::Left(true)),
808 code_action_provider: Some(CodeActionProviderCapability::Simple(true)),
809 document_formatting_provider: Some(OneOf::Left(true)),
810 document_range_formatting_provider: Some(OneOf::Left(true)),
811 definition_provider: Some(OneOf::Left(true)),
812 type_definition_provider: Some(TypeDefinitionProviderCapability::Simple(true)),
813 ..Default::default()
814 }
815 }
816
817 pub fn fake(
818 name: String,
819 capabilities: ServerCapabilities,
820 cx: AsyncAppContext,
821 ) -> (Self, FakeLanguageServer) {
822 let (stdin_writer, stdin_reader) = async_pipe::pipe();
823 let (stdout_writer, stdout_reader) = async_pipe::pipe();
824 let (notifications_tx, notifications_rx) = channel::unbounded();
825
826 let server = Self::new_internal(
827 LanguageServerId(0),
828 stdin_writer,
829 stdout_reader,
830 None,
831 Path::new("/"),
832 None,
833 cx.clone(),
834 |_| {},
835 );
836 let fake = FakeLanguageServer {
837 server: Arc::new(Self::new_internal(
838 LanguageServerId(0),
839 stdout_writer,
840 stdin_reader,
841 None,
842 Path::new("/"),
843 None,
844 cx,
845 move |msg| {
846 notifications_tx
847 .try_send((
848 msg.method.to_string(),
849 msg.params
850 .map(|raw_value| raw_value.get())
851 .unwrap_or("null")
852 .to_string(),
853 ))
854 .ok();
855 },
856 )),
857 notifications_rx,
858 };
859 fake.handle_request::<request::Initialize, _, _>({
860 let capabilities = capabilities;
861 move |_, _| {
862 let capabilities = capabilities.clone();
863 let name = name.clone();
864 async move {
865 Ok(InitializeResult {
866 capabilities,
867 server_info: Some(ServerInfo {
868 name,
869 ..Default::default()
870 }),
871 })
872 }
873 }
874 });
875
876 (server, fake)
877 }
878}
879
880#[cfg(any(test, feature = "test-support"))]
881impl FakeLanguageServer {
882 pub fn notify<T: notification::Notification>(&self, params: T::Params) {
883 self.server.notify::<T>(params).ok();
884 }
885
886 pub async fn request<T>(&self, params: T::Params) -> Result<T::Result>
887 where
888 T: request::Request,
889 T::Result: 'static + Send,
890 {
891 self.server.executor.start_waiting();
892 self.server.request::<T>(params).await
893 }
894
895 pub async fn receive_notification<T: notification::Notification>(&mut self) -> T::Params {
896 self.server.executor.start_waiting();
897 self.try_receive_notification::<T>().await.unwrap()
898 }
899
900 pub async fn try_receive_notification<T: notification::Notification>(
901 &mut self,
902 ) -> Option<T::Params> {
903 use futures::StreamExt as _;
904
905 loop {
906 let (method, params) = self.notifications_rx.next().await?;
907 if method == T::METHOD {
908 return Some(serde_json::from_str::<T::Params>(¶ms).unwrap());
909 } else {
910 log::info!("skipping message in fake language server {:?}", params);
911 }
912 }
913 }
914
915 pub fn handle_request<T, F, Fut>(
916 &self,
917 mut handler: F,
918 ) -> futures::channel::mpsc::UnboundedReceiver<()>
919 where
920 T: 'static + request::Request,
921 T::Params: 'static + Send,
922 F: 'static + Send + FnMut(T::Params, gpui::AsyncAppContext) -> Fut,
923 Fut: 'static + Send + Future<Output = Result<T::Result>>,
924 {
925 let (responded_tx, responded_rx) = futures::channel::mpsc::unbounded();
926 self.server.remove_request_handler::<T>();
927 self.server
928 .on_request::<T, _, _>(move |params, cx| {
929 let result = handler(params, cx.clone());
930 let responded_tx = responded_tx.clone();
931 async move {
932 cx.background().simulate_random_delay().await;
933 let result = result.await;
934 responded_tx.unbounded_send(()).ok();
935 result
936 }
937 })
938 .detach();
939 responded_rx
940 }
941
942 pub fn handle_notification<T, F>(
943 &self,
944 mut handler: F,
945 ) -> futures::channel::mpsc::UnboundedReceiver<()>
946 where
947 T: 'static + notification::Notification,
948 T::Params: 'static + Send,
949 F: 'static + Send + FnMut(T::Params, gpui::AsyncAppContext),
950 {
951 let (handled_tx, handled_rx) = futures::channel::mpsc::unbounded();
952 self.server.remove_notification_handler::<T>();
953 self.server
954 .on_notification::<T, _>(move |params, cx| {
955 handler(params, cx.clone());
956 handled_tx.unbounded_send(()).ok();
957 })
958 .detach();
959 handled_rx
960 }
961
962 pub fn remove_request_handler<T>(&mut self)
963 where
964 T: 'static + request::Request,
965 {
966 self.server.remove_request_handler::<T>();
967 }
968
969 pub async fn start_progress(&self, token: impl Into<String>) {
970 let token = token.into();
971 self.request::<request::WorkDoneProgressCreate>(WorkDoneProgressCreateParams {
972 token: NumberOrString::String(token.clone()),
973 })
974 .await
975 .unwrap();
976 self.notify::<notification::Progress>(ProgressParams {
977 token: NumberOrString::String(token),
978 value: ProgressParamsValue::WorkDone(WorkDoneProgress::Begin(Default::default())),
979 });
980 }
981
982 pub fn end_progress(&self, token: impl Into<String>) {
983 self.notify::<notification::Progress>(ProgressParams {
984 token: NumberOrString::String(token.into()),
985 value: ProgressParamsValue::WorkDone(WorkDoneProgress::End(Default::default())),
986 });
987 }
988}
989
990#[cfg(test)]
991mod tests {
992 use super::*;
993 use gpui::TestAppContext;
994
995 #[ctor::ctor]
996 fn init_logger() {
997 if std::env::var("RUST_LOG").is_ok() {
998 env_logger::init();
999 }
1000 }
1001
1002 #[gpui::test]
1003 async fn test_fake(cx: &mut TestAppContext) {
1004 let (server, mut fake) =
1005 LanguageServer::fake("the-lsp".to_string(), Default::default(), cx.to_async());
1006
1007 let (message_tx, message_rx) = channel::unbounded();
1008 let (diagnostics_tx, diagnostics_rx) = channel::unbounded();
1009 server
1010 .on_notification::<notification::ShowMessage, _>(move |params, _| {
1011 message_tx.try_send(params).unwrap()
1012 })
1013 .detach();
1014 server
1015 .on_notification::<notification::PublishDiagnostics, _>(move |params, _| {
1016 diagnostics_tx.try_send(params).unwrap()
1017 })
1018 .detach();
1019
1020 let server = server.initialize(None).await.unwrap();
1021 server
1022 .notify::<notification::DidOpenTextDocument>(DidOpenTextDocumentParams {
1023 text_document: TextDocumentItem::new(
1024 Url::from_str("file://a/b").unwrap(),
1025 "rust".to_string(),
1026 0,
1027 "".to_string(),
1028 ),
1029 })
1030 .unwrap();
1031 assert_eq!(
1032 fake.receive_notification::<notification::DidOpenTextDocument>()
1033 .await
1034 .text_document
1035 .uri
1036 .as_str(),
1037 "file://a/b"
1038 );
1039
1040 fake.notify::<notification::ShowMessage>(ShowMessageParams {
1041 typ: MessageType::ERROR,
1042 message: "ok".to_string(),
1043 });
1044 fake.notify::<notification::PublishDiagnostics>(PublishDiagnosticsParams {
1045 uri: Url::from_str("file://b/c").unwrap(),
1046 version: Some(5),
1047 diagnostics: vec![],
1048 });
1049 assert_eq!(message_rx.recv().await.unwrap().message, "ok");
1050 assert_eq!(
1051 diagnostics_rx.recv().await.unwrap().uri.as_str(),
1052 "file://b/c"
1053 );
1054
1055 fake.handle_request::<request::Shutdown, _, _>(|_, _| async move { Ok(()) });
1056
1057 drop(server);
1058 fake.receive_notification::<notification::Exit>().await;
1059 }
1060}