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(DynamicRegistrationClientCapabilities {
365 dynamic_registration: Some(true),
366 }),
367 did_change_configuration: Some(DynamicRegistrationClientCapabilities {
368 dynamic_registration: Some(true),
369 }),
370 workspace_folders: Some(true),
371 ..Default::default()
372 }),
373 text_document: Some(TextDocumentClientCapabilities {
374 definition: Some(GotoCapability {
375 link_support: Some(true),
376 ..Default::default()
377 }),
378 code_action: Some(CodeActionClientCapabilities {
379 code_action_literal_support: Some(CodeActionLiteralSupport {
380 code_action_kind: CodeActionKindLiteralSupport {
381 value_set: vec![
382 CodeActionKind::REFACTOR.as_str().into(),
383 CodeActionKind::QUICKFIX.as_str().into(),
384 CodeActionKind::SOURCE.as_str().into(),
385 ],
386 },
387 }),
388 data_support: Some(true),
389 resolve_support: Some(CodeActionCapabilityResolveSupport {
390 properties: vec!["edit".to_string(), "command".to_string()],
391 }),
392 ..Default::default()
393 }),
394 completion: Some(CompletionClientCapabilities {
395 completion_item: Some(CompletionItemCapability {
396 snippet_support: Some(true),
397 resolve_support: Some(CompletionItemCapabilityResolveSupport {
398 properties: vec!["additionalTextEdits".to_string()],
399 }),
400 ..Default::default()
401 }),
402 ..Default::default()
403 }),
404 rename: Some(RenameClientCapabilities {
405 prepare_support: Some(true),
406 ..Default::default()
407 }),
408 hover: Some(HoverClientCapabilities {
409 content_format: Some(vec![MarkupKind::Markdown]),
410 ..Default::default()
411 }),
412 ..Default::default()
413 }),
414 experimental: Some(json!({
415 "serverStatusNotification": true,
416 })),
417 window: Some(WindowClientCapabilities {
418 work_done_progress: Some(true),
419 ..Default::default()
420 }),
421 ..Default::default()
422 },
423 trace: Default::default(),
424 workspace_folders: Some(vec![WorkspaceFolder {
425 uri: root_uri,
426 name: Default::default(),
427 }]),
428 client_info: Default::default(),
429 locale: Default::default(),
430 };
431
432 let response = self.request::<request::Initialize>(params).await?;
433 if let Some(info) = response.server_info {
434 self.name = info.name;
435 }
436 self.capabilities = response.capabilities;
437
438 self.notify::<notification::Initialized>(InitializedParams {})?;
439 Ok(Arc::new(self))
440 }
441
442 pub fn shutdown(&self) -> Option<impl 'static + Send + Future<Output = Option<()>>> {
443 if let Some(tasks) = self.io_tasks.lock().take() {
444 let response_handlers = self.response_handlers.clone();
445 let next_id = AtomicUsize::new(self.next_id.load(SeqCst));
446 let outbound_tx = self.outbound_tx.clone();
447 let mut output_done = self.output_done_rx.lock().take().unwrap();
448 let shutdown_request = Self::request_internal::<request::Shutdown>(
449 &next_id,
450 &response_handlers,
451 &outbound_tx,
452 (),
453 );
454 let exit = Self::notify_internal::<notification::Exit>(&outbound_tx, ());
455 outbound_tx.close();
456 Some(
457 async move {
458 log::debug!("language server shutdown started");
459 shutdown_request.await?;
460 response_handlers.lock().take();
461 exit?;
462 output_done.recv().await;
463 log::debug!("language server shutdown finished");
464 drop(tasks);
465 anyhow::Ok(())
466 }
467 .log_err(),
468 )
469 } else {
470 None
471 }
472 }
473
474 #[must_use]
475 pub fn on_notification<T, F>(&self, f: F) -> Subscription
476 where
477 T: notification::Notification,
478 F: 'static + Send + FnMut(T::Params, AsyncAppContext),
479 {
480 self.on_custom_notification(T::METHOD, f)
481 }
482
483 #[must_use]
484 pub fn on_request<T, F, Fut>(&self, f: F) -> Subscription
485 where
486 T: request::Request,
487 T::Params: 'static + Send,
488 F: 'static + Send + FnMut(T::Params, AsyncAppContext) -> Fut,
489 Fut: 'static + Future<Output = Result<T::Result>>,
490 {
491 self.on_custom_request(T::METHOD, f)
492 }
493
494 #[must_use]
495 pub fn on_io<F>(&self, f: F) -> Subscription
496 where
497 F: 'static + Send + FnMut(bool, &str),
498 {
499 let id = self.next_id.fetch_add(1, SeqCst);
500 self.io_handlers.lock().insert(id, Box::new(f));
501 Subscription::Io {
502 id,
503 io_handlers: Some(Arc::downgrade(&self.io_handlers)),
504 }
505 }
506
507 pub fn remove_request_handler<T: request::Request>(&self) {
508 self.notification_handlers.lock().remove(T::METHOD);
509 }
510
511 pub fn remove_notification_handler<T: notification::Notification>(&self) {
512 self.notification_handlers.lock().remove(T::METHOD);
513 }
514
515 #[must_use]
516 pub fn on_custom_notification<Params, F>(&self, method: &'static str, mut f: F) -> Subscription
517 where
518 F: 'static + Send + FnMut(Params, AsyncAppContext),
519 Params: DeserializeOwned,
520 {
521 let prev_handler = self.notification_handlers.lock().insert(
522 method,
523 Box::new(move |_, params, cx| {
524 if let Some(params) = serde_json::from_str(params).log_err() {
525 f(params, cx);
526 }
527 }),
528 );
529 assert!(
530 prev_handler.is_none(),
531 "registered multiple handlers for the same LSP method"
532 );
533 Subscription::Notification {
534 method,
535 notification_handlers: Some(self.notification_handlers.clone()),
536 }
537 }
538
539 #[must_use]
540 pub fn on_custom_request<Params, Res, Fut, F>(
541 &self,
542 method: &'static str,
543 mut f: F,
544 ) -> Subscription
545 where
546 F: 'static + Send + FnMut(Params, AsyncAppContext) -> Fut,
547 Fut: 'static + Future<Output = Result<Res>>,
548 Params: DeserializeOwned + Send + 'static,
549 Res: Serialize,
550 {
551 let outbound_tx = self.outbound_tx.clone();
552 let prev_handler = self.notification_handlers.lock().insert(
553 method,
554 Box::new(move |id, params, cx| {
555 if let Some(id) = id {
556 match serde_json::from_str(params) {
557 Ok(params) => {
558 let response = f(params, cx.clone());
559 cx.foreground()
560 .spawn({
561 let outbound_tx = outbound_tx.clone();
562 async move {
563 let response = match response.await {
564 Ok(result) => Response {
565 jsonrpc: JSON_RPC_VERSION,
566 id,
567 result: Some(result),
568 error: None,
569 },
570 Err(error) => Response {
571 jsonrpc: JSON_RPC_VERSION,
572 id,
573 result: None,
574 error: Some(Error {
575 message: error.to_string(),
576 }),
577 },
578 };
579 if let Some(response) =
580 serde_json::to_string(&response).log_err()
581 {
582 outbound_tx.try_send(response).ok();
583 }
584 }
585 })
586 .detach();
587 }
588 Err(error) => {
589 log::error!(
590 "error deserializing {} request: {:?}, message: {:?}",
591 method,
592 error,
593 params
594 );
595 let response = AnyResponse {
596 jsonrpc: JSON_RPC_VERSION,
597 id,
598 result: None,
599 error: Some(Error {
600 message: error.to_string(),
601 }),
602 };
603 if let Some(response) = serde_json::to_string(&response).log_err() {
604 outbound_tx.try_send(response).ok();
605 }
606 }
607 }
608 }
609 }),
610 );
611 assert!(
612 prev_handler.is_none(),
613 "registered multiple handlers for the same LSP method"
614 );
615 Subscription::Notification {
616 method,
617 notification_handlers: Some(self.notification_handlers.clone()),
618 }
619 }
620
621 pub fn name<'a>(self: &'a Arc<Self>) -> &'a str {
622 &self.name
623 }
624
625 pub fn capabilities<'a>(self: &'a Arc<Self>) -> &'a ServerCapabilities {
626 &self.capabilities
627 }
628
629 pub fn server_id(&self) -> LanguageServerId {
630 self.server_id
631 }
632
633 pub fn root_path(&self) -> &PathBuf {
634 &self.root_path
635 }
636
637 pub fn request<T: request::Request>(
638 &self,
639 params: T::Params,
640 ) -> impl Future<Output = Result<T::Result>>
641 where
642 T::Result: 'static + Send,
643 {
644 Self::request_internal::<T>(
645 &self.next_id,
646 &self.response_handlers,
647 &self.outbound_tx,
648 params,
649 )
650 }
651
652 fn request_internal<T: request::Request>(
653 next_id: &AtomicUsize,
654 response_handlers: &Mutex<Option<HashMap<usize, ResponseHandler>>>,
655 outbound_tx: &channel::Sender<String>,
656 params: T::Params,
657 ) -> impl 'static + Future<Output = Result<T::Result>>
658 where
659 T::Result: 'static + Send,
660 {
661 let id = next_id.fetch_add(1, SeqCst);
662 let message = serde_json::to_string(&Request {
663 jsonrpc: JSON_RPC_VERSION,
664 id,
665 method: T::METHOD,
666 params,
667 })
668 .unwrap();
669
670 let (tx, rx) = oneshot::channel();
671 let handle_response = response_handlers
672 .lock()
673 .as_mut()
674 .ok_or_else(|| anyhow!("server shut down"))
675 .map(|handlers| {
676 handlers.insert(
677 id,
678 Box::new(move |result| {
679 let response = match result {
680 Ok(response) => serde_json::from_str(response)
681 .context("failed to deserialize response"),
682 Err(error) => Err(anyhow!("{}", error.message)),
683 };
684 let _ = tx.send(response);
685 }),
686 );
687 });
688
689 let send = outbound_tx
690 .try_send(message)
691 .context("failed to write to language server's stdin");
692
693 async move {
694 handle_response?;
695 send?;
696 rx.await?
697 }
698 }
699
700 pub fn notify<T: notification::Notification>(&self, params: T::Params) -> Result<()> {
701 Self::notify_internal::<T>(&self.outbound_tx, params)
702 }
703
704 fn notify_internal<T: notification::Notification>(
705 outbound_tx: &channel::Sender<String>,
706 params: T::Params,
707 ) -> Result<()> {
708 let message = serde_json::to_string(&Notification {
709 jsonrpc: JSON_RPC_VERSION,
710 method: T::METHOD,
711 params,
712 })
713 .unwrap();
714 outbound_tx.try_send(message)?;
715 Ok(())
716 }
717}
718
719impl Drop for LanguageServer {
720 fn drop(&mut self) {
721 if let Some(shutdown) = self.shutdown() {
722 self.executor.spawn(shutdown).detach();
723 }
724 }
725}
726
727impl Subscription {
728 pub fn detach(&mut self) {
729 match self {
730 Subscription::Notification {
731 notification_handlers,
732 ..
733 } => *notification_handlers = None,
734 Subscription::Io { io_handlers, .. } => *io_handlers = None,
735 }
736 }
737}
738
739impl fmt::Display for LanguageServerId {
740 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
741 self.0.fmt(f)
742 }
743}
744
745impl Drop for Subscription {
746 fn drop(&mut self) {
747 match self {
748 Subscription::Notification {
749 method,
750 notification_handlers,
751 } => {
752 if let Some(handlers) = notification_handlers {
753 handlers.lock().remove(method);
754 }
755 }
756 Subscription::Io { id, io_handlers } => {
757 if let Some(io_handlers) = io_handlers.as_ref().and_then(|h| h.upgrade()) {
758 io_handlers.lock().remove(id);
759 }
760 }
761 }
762 }
763}
764
765#[cfg(any(test, feature = "test-support"))]
766#[derive(Clone)]
767pub struct FakeLanguageServer {
768 pub server: Arc<LanguageServer>,
769 notifications_rx: channel::Receiver<(String, String)>,
770}
771
772#[cfg(any(test, feature = "test-support"))]
773impl LanguageServer {
774 pub fn full_capabilities() -> ServerCapabilities {
775 ServerCapabilities {
776 document_highlight_provider: Some(OneOf::Left(true)),
777 code_action_provider: Some(CodeActionProviderCapability::Simple(true)),
778 document_formatting_provider: Some(OneOf::Left(true)),
779 document_range_formatting_provider: Some(OneOf::Left(true)),
780 ..Default::default()
781 }
782 }
783
784 pub fn fake(
785 name: String,
786 capabilities: ServerCapabilities,
787 cx: AsyncAppContext,
788 ) -> (Self, FakeLanguageServer) {
789 let (stdin_writer, stdin_reader) = async_pipe::pipe();
790 let (stdout_writer, stdout_reader) = async_pipe::pipe();
791 let (notifications_tx, notifications_rx) = channel::unbounded();
792
793 let server = Self::new_internal(
794 LanguageServerId(0),
795 stdin_writer,
796 stdout_reader,
797 None,
798 Path::new("/"),
799 None,
800 cx.clone(),
801 |_| {},
802 );
803 let fake = FakeLanguageServer {
804 server: Arc::new(Self::new_internal(
805 LanguageServerId(0),
806 stdout_writer,
807 stdin_reader,
808 None,
809 Path::new("/"),
810 None,
811 cx,
812 move |msg| {
813 notifications_tx
814 .try_send((msg.method.to_string(), msg.params.get().to_string()))
815 .ok();
816 },
817 )),
818 notifications_rx,
819 };
820 fake.handle_request::<request::Initialize, _, _>({
821 let capabilities = capabilities;
822 move |_, _| {
823 let capabilities = capabilities.clone();
824 let name = name.clone();
825 async move {
826 Ok(InitializeResult {
827 capabilities,
828 server_info: Some(ServerInfo {
829 name,
830 ..Default::default()
831 }),
832 })
833 }
834 }
835 });
836
837 (server, fake)
838 }
839}
840
841#[cfg(any(test, feature = "test-support"))]
842impl FakeLanguageServer {
843 pub fn notify<T: notification::Notification>(&self, params: T::Params) {
844 self.server.notify::<T>(params).ok();
845 }
846
847 pub async fn request<T>(&self, params: T::Params) -> Result<T::Result>
848 where
849 T: request::Request,
850 T::Result: 'static + Send,
851 {
852 self.server.request::<T>(params).await
853 }
854
855 pub async fn receive_notification<T: notification::Notification>(&mut self) -> T::Params {
856 self.try_receive_notification::<T>().await.unwrap()
857 }
858
859 pub async fn try_receive_notification<T: notification::Notification>(
860 &mut self,
861 ) -> Option<T::Params> {
862 use futures::StreamExt as _;
863
864 loop {
865 let (method, params) = self.notifications_rx.next().await?;
866 if method == T::METHOD {
867 return Some(serde_json::from_str::<T::Params>(¶ms).unwrap());
868 } else {
869 log::info!("skipping message in fake language server {:?}", params);
870 }
871 }
872 }
873
874 pub fn handle_request<T, F, Fut>(
875 &self,
876 mut handler: F,
877 ) -> futures::channel::mpsc::UnboundedReceiver<()>
878 where
879 T: 'static + request::Request,
880 T::Params: 'static + Send,
881 F: 'static + Send + FnMut(T::Params, gpui::AsyncAppContext) -> Fut,
882 Fut: 'static + Send + Future<Output = Result<T::Result>>,
883 {
884 let (responded_tx, responded_rx) = futures::channel::mpsc::unbounded();
885 self.server.remove_request_handler::<T>();
886 self.server
887 .on_request::<T, _, _>(move |params, cx| {
888 let result = handler(params, cx.clone());
889 let responded_tx = responded_tx.clone();
890 async move {
891 cx.background().simulate_random_delay().await;
892 let result = result.await;
893 responded_tx.unbounded_send(()).ok();
894 result
895 }
896 })
897 .detach();
898 responded_rx
899 }
900
901 pub fn handle_notification<T, F>(
902 &self,
903 mut handler: F,
904 ) -> futures::channel::mpsc::UnboundedReceiver<()>
905 where
906 T: 'static + notification::Notification,
907 T::Params: 'static + Send,
908 F: 'static + Send + FnMut(T::Params, gpui::AsyncAppContext),
909 {
910 let (handled_tx, handled_rx) = futures::channel::mpsc::unbounded();
911 self.server.remove_notification_handler::<T>();
912 self.server
913 .on_notification::<T, _>(move |params, cx| {
914 handler(params, cx.clone());
915 handled_tx.unbounded_send(()).ok();
916 })
917 .detach();
918 handled_rx
919 }
920
921 pub fn remove_request_handler<T>(&mut self)
922 where
923 T: 'static + request::Request,
924 {
925 self.server.remove_request_handler::<T>();
926 }
927
928 pub async fn start_progress(&self, token: impl Into<String>) {
929 let token = token.into();
930 self.request::<request::WorkDoneProgressCreate>(WorkDoneProgressCreateParams {
931 token: NumberOrString::String(token.clone()),
932 })
933 .await
934 .unwrap();
935 self.notify::<notification::Progress>(ProgressParams {
936 token: NumberOrString::String(token),
937 value: ProgressParamsValue::WorkDone(WorkDoneProgress::Begin(Default::default())),
938 });
939 }
940
941 pub fn end_progress(&self, token: impl Into<String>) {
942 self.notify::<notification::Progress>(ProgressParams {
943 token: NumberOrString::String(token.into()),
944 value: ProgressParamsValue::WorkDone(WorkDoneProgress::End(Default::default())),
945 });
946 }
947}
948
949#[cfg(test)]
950mod tests {
951 use super::*;
952 use gpui::TestAppContext;
953
954 #[ctor::ctor]
955 fn init_logger() {
956 if std::env::var("RUST_LOG").is_ok() {
957 env_logger::init();
958 }
959 }
960
961 #[gpui::test]
962 async fn test_fake(cx: &mut TestAppContext) {
963 let (server, mut fake) =
964 LanguageServer::fake("the-lsp".to_string(), Default::default(), cx.to_async());
965
966 let (message_tx, message_rx) = channel::unbounded();
967 let (diagnostics_tx, diagnostics_rx) = channel::unbounded();
968 server
969 .on_notification::<notification::ShowMessage, _>(move |params, _| {
970 message_tx.try_send(params).unwrap()
971 })
972 .detach();
973 server
974 .on_notification::<notification::PublishDiagnostics, _>(move |params, _| {
975 diagnostics_tx.try_send(params).unwrap()
976 })
977 .detach();
978
979 let server = server.initialize(None).await.unwrap();
980 server
981 .notify::<notification::DidOpenTextDocument>(DidOpenTextDocumentParams {
982 text_document: TextDocumentItem::new(
983 Url::from_str("file://a/b").unwrap(),
984 "rust".to_string(),
985 0,
986 "".to_string(),
987 ),
988 })
989 .unwrap();
990 assert_eq!(
991 fake.receive_notification::<notification::DidOpenTextDocument>()
992 .await
993 .text_document
994 .uri
995 .as_str(),
996 "file://a/b"
997 );
998
999 fake.notify::<notification::ShowMessage>(ShowMessageParams {
1000 typ: MessageType::ERROR,
1001 message: "ok".to_string(),
1002 });
1003 fake.notify::<notification::PublishDiagnostics>(PublishDiagnosticsParams {
1004 uri: Url::from_str("file://b/c").unwrap(),
1005 version: Some(5),
1006 diagnostics: vec![],
1007 });
1008 assert_eq!(message_rx.recv().await.unwrap().message, "ok");
1009 assert_eq!(
1010 diagnostics_rx.recv().await.unwrap().uri.as_str(),
1011 "file://b/c"
1012 );
1013
1014 fake.handle_request::<request::Shutdown, _, _>(|_, _| async move { Ok(()) });
1015
1016 drop(server);
1017 fake.receive_notification::<notification::Exit>().await;
1018 }
1019}