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