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::{AppContext, AsyncAppContext, BackgroundExecutor, Task};
9use parking_lot::Mutex;
10use postage::{barrier, prelude::Stream};
11use serde::{de::DeserializeOwned, Deserialize, Serialize};
12use serde_json::{json, value::RawValue, Value};
13use smol::{
14 channel,
15 io::{AsyncBufReadExt, AsyncReadExt, AsyncWriteExt, BufReader},
16 process::{self, Child},
17};
18use std::{
19 ffi::OsString,
20 fmt,
21 future::Future,
22 io::Write,
23 path::PathBuf,
24 str::{self, FromStr as _},
25 sync::{
26 atomic::{AtomicUsize, Ordering::SeqCst},
27 Arc, Weak,
28 },
29 time::{Duration, Instant},
30};
31use std::{path::Path, process::Stdio};
32use util::{ResultExt, TryFutureExt};
33
34const JSON_RPC_VERSION: &str = "2.0";
35const CONTENT_LEN_HEADER: &str = "Content-Length: ";
36const LSP_REQUEST_TIMEOUT: Duration = Duration::from_secs(60 * 2);
37
38type NotificationHandler = Box<dyn Send + FnMut(Option<usize>, &str, AsyncAppContext)>;
39type ResponseHandler = Box<dyn Send + FnOnce(Result<String, Error>)>;
40type IoHandler = Box<dyn Send + FnMut(IoKind, &str)>;
41
42/// Kind of language server stdio given to an IO handler.
43#[derive(Debug, Clone, Copy)]
44pub enum IoKind {
45 StdOut,
46 StdIn,
47 StdErr,
48}
49
50/// Represents a launchable language server. This can either be a standalone binary or the path
51/// to a runtime with arguments to instruct it to launch the actual language server file.
52#[derive(Debug, Clone, Deserialize)]
53pub struct LanguageServerBinary {
54 pub path: PathBuf,
55 pub arguments: Vec<OsString>,
56}
57
58/// A running language server process.
59pub struct LanguageServer {
60 server_id: LanguageServerId,
61 next_id: AtomicUsize,
62 outbound_tx: channel::Sender<String>,
63 name: String,
64 capabilities: ServerCapabilities,
65 code_action_kinds: Option<Vec<CodeActionKind>>,
66 notification_handlers: Arc<Mutex<HashMap<&'static str, NotificationHandler>>>,
67 response_handlers: Arc<Mutex<Option<HashMap<usize, ResponseHandler>>>>,
68 io_handlers: Arc<Mutex<HashMap<usize, IoHandler>>>,
69 executor: BackgroundExecutor,
70 #[allow(clippy::type_complexity)]
71 io_tasks: Mutex<Option<(Task<Option<()>>, Task<Option<()>>)>>,
72 output_done_rx: Mutex<Option<barrier::Receiver>>,
73 root_path: PathBuf,
74 _server: Option<Mutex<Child>>,
75}
76
77/// Identifies a running language server.
78#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
79#[repr(transparent)]
80pub struct LanguageServerId(pub usize);
81
82/// Handle to a language server RPC activity subscription.
83pub enum Subscription {
84 Notification {
85 method: &'static str,
86 notification_handlers: Option<Arc<Mutex<HashMap<&'static str, NotificationHandler>>>>,
87 },
88 Io {
89 id: usize,
90 io_handlers: Option<Weak<Mutex<HashMap<usize, IoHandler>>>>,
91 },
92}
93
94/// Language server protocol RPC request message.
95///
96/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
97#[derive(Serialize, Deserialize)]
98pub struct Request<'a, T> {
99 jsonrpc: &'static str,
100 id: usize,
101 method: &'a str,
102 params: T,
103}
104
105/// Language server protocol RPC request response message before it is deserialized into a concrete type.
106#[derive(Serialize, Deserialize)]
107struct AnyResponse<'a> {
108 jsonrpc: &'a str,
109 id: usize,
110 #[serde(default)]
111 error: Option<Error>,
112 #[serde(borrow)]
113 result: Option<&'a RawValue>,
114}
115
116/// Language server protocol RPC request response message.
117///
118/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#responseMessage)
119#[derive(Serialize)]
120struct Response<T> {
121 jsonrpc: &'static str,
122 id: usize,
123 result: Option<T>,
124 error: Option<Error>,
125}
126
127/// Language server protocol RPC notification message.
128///
129/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
130#[derive(Serialize, Deserialize)]
131struct Notification<'a, T> {
132 jsonrpc: &'static str,
133 #[serde(borrow)]
134 method: &'a str,
135 params: T,
136}
137
138/// Language server RPC notification message before it is deserialized into a concrete type.
139#[derive(Debug, Clone, Deserialize)]
140struct AnyNotification<'a> {
141 #[serde(default)]
142 id: Option<usize>,
143 #[serde(borrow)]
144 method: &'a str,
145 #[serde(borrow, default)]
146 params: Option<&'a RawValue>,
147}
148
149#[derive(Debug, Serialize, Deserialize)]
150struct Error {
151 message: String,
152}
153
154impl LanguageServer {
155 /// Starts a language server process.
156 pub fn new(
157 stderr_capture: Arc<Mutex<Option<String>>>,
158 server_id: LanguageServerId,
159 binary: LanguageServerBinary,
160 root_path: &Path,
161 code_action_kinds: Option<Vec<CodeActionKind>>,
162 cx: AsyncAppContext,
163 ) -> Result<Self> {
164 let working_dir = if root_path.is_dir() {
165 root_path
166 } else {
167 root_path.parent().unwrap_or_else(|| Path::new("/"))
168 };
169
170 let mut server = process::Command::new(&binary.path)
171 .current_dir(working_dir)
172 .args(binary.arguments)
173 .stdin(Stdio::piped())
174 .stdout(Stdio::piped())
175 .stderr(Stdio::piped())
176 .kill_on_drop(true)
177 .spawn()?;
178
179 let stdin = server.stdin.take().unwrap();
180 let stdout = server.stdout.take().unwrap();
181 let stderr = server.stderr.take().unwrap();
182 let mut server = Self::new_internal(
183 server_id.clone(),
184 stdin,
185 stdout,
186 Some(stderr),
187 stderr_capture,
188 Some(server),
189 root_path,
190 code_action_kinds,
191 cx,
192 move |notification| {
193 log::info!(
194 "{} unhandled notification {}:\n{}",
195 server_id,
196 notification.method,
197 serde_json::to_string_pretty(
198 ¬ification
199 .params
200 .and_then(|params| Value::from_str(params.get()).ok())
201 .unwrap_or(Value::Null)
202 )
203 .unwrap(),
204 );
205 },
206 );
207
208 if let Some(name) = binary.path.file_name() {
209 server.name = name.to_string_lossy().to_string();
210 }
211
212 Ok(server)
213 }
214
215 fn new_internal<Stdin, Stdout, Stderr, F>(
216 server_id: LanguageServerId,
217 stdin: Stdin,
218 stdout: Stdout,
219 stderr: Option<Stderr>,
220 stderr_capture: Arc<Mutex<Option<String>>>,
221 server: Option<Child>,
222 root_path: &Path,
223 code_action_kinds: Option<Vec<CodeActionKind>>,
224 cx: AsyncAppContext,
225 on_unhandled_notification: F,
226 ) -> Self
227 where
228 Stdin: AsyncWrite + Unpin + Send + 'static,
229 Stdout: AsyncRead + Unpin + Send + 'static,
230 Stderr: AsyncRead + Unpin + Send + 'static,
231 F: FnMut(AnyNotification) + 'static + Send + Sync + Clone,
232 {
233 let (outbound_tx, outbound_rx) = channel::unbounded::<String>();
234 let (output_done_tx, output_done_rx) = barrier::channel();
235 let notification_handlers =
236 Arc::new(Mutex::new(HashMap::<_, NotificationHandler>::default()));
237 let response_handlers =
238 Arc::new(Mutex::new(Some(HashMap::<_, ResponseHandler>::default())));
239 let io_handlers = Arc::new(Mutex::new(HashMap::default()));
240
241 let stdout_input_task = cx.spawn({
242 let on_unhandled_notification = on_unhandled_notification.clone();
243 let notification_handlers = notification_handlers.clone();
244 let response_handlers = response_handlers.clone();
245 let io_handlers = io_handlers.clone();
246 move |cx| {
247 Self::handle_input(
248 stdout,
249 on_unhandled_notification,
250 notification_handlers,
251 response_handlers,
252 io_handlers,
253 cx,
254 )
255 .log_err()
256 }
257 });
258 let stderr_input_task = stderr
259 .map(|stderr| {
260 let io_handlers = io_handlers.clone();
261 let stderr_captures = stderr_capture.clone();
262 cx.spawn(|_| Self::handle_stderr(stderr, io_handlers, stderr_captures).log_err())
263 })
264 .unwrap_or_else(|| Task::Ready(Some(None)));
265 let input_task = cx.spawn(|_| async move {
266 let (stdout, stderr) = futures::join!(stdout_input_task, stderr_input_task);
267 stdout.or(stderr)
268 });
269 let output_task = cx.background_executor().spawn({
270 Self::handle_output(
271 stdin,
272 outbound_rx,
273 output_done_tx,
274 response_handlers.clone(),
275 io_handlers.clone(),
276 )
277 .log_err()
278 });
279
280 Self {
281 server_id,
282 notification_handlers,
283 response_handlers,
284 io_handlers,
285 name: Default::default(),
286 capabilities: Default::default(),
287 code_action_kinds,
288 next_id: Default::default(),
289 outbound_tx,
290 executor: cx.background_executor().clone(),
291 io_tasks: Mutex::new(Some((input_task, output_task))),
292 output_done_rx: Mutex::new(Some(output_done_rx)),
293 root_path: root_path.to_path_buf(),
294 _server: server.map(|server| Mutex::new(server)),
295 }
296 }
297
298 /// List of code action kinds this language server reports being able to emit.
299 pub fn code_action_kinds(&self) -> Option<Vec<CodeActionKind>> {
300 self.code_action_kinds.clone()
301 }
302
303 async fn handle_input<Stdout, F>(
304 stdout: Stdout,
305 mut on_unhandled_notification: F,
306 notification_handlers: Arc<Mutex<HashMap<&'static str, NotificationHandler>>>,
307 response_handlers: Arc<Mutex<Option<HashMap<usize, ResponseHandler>>>>,
308 io_handlers: Arc<Mutex<HashMap<usize, IoHandler>>>,
309 cx: AsyncAppContext,
310 ) -> anyhow::Result<()>
311 where
312 Stdout: AsyncRead + Unpin + Send + 'static,
313 F: FnMut(AnyNotification) + 'static + Send,
314 {
315 let mut stdout = BufReader::new(stdout);
316 let _clear_response_handlers = util::defer({
317 let response_handlers = response_handlers.clone();
318 move || {
319 response_handlers.lock().take();
320 }
321 });
322 let mut buffer = Vec::new();
323 loop {
324 buffer.clear();
325
326 if stdout.read_until(b'\n', &mut buffer).await? == 0 {
327 break;
328 };
329
330 if stdout.read_until(b'\n', &mut buffer).await? == 0 {
331 break;
332 };
333
334 let header = std::str::from_utf8(&buffer)?;
335 let mut segments = header.lines();
336
337 let message_len: usize = segments
338 .next()
339 .with_context(|| {
340 format!("unable to find the first line of the LSP message header `{header}`")
341 })?
342 .strip_prefix(CONTENT_LEN_HEADER)
343 .with_context(|| format!("invalid LSP message header `{header}`"))?
344 .parse()
345 .with_context(|| {
346 format!("failed to parse Content-Length of LSP message header: `{header}`")
347 })?;
348
349 if let Some(second_segment) = segments.next() {
350 match second_segment {
351 "" => (), // Header end
352 header_field => {
353 if header_field.starts_with("Content-Type:") {
354 stdout.read_until(b'\n', &mut buffer).await?;
355 } else {
356 anyhow::bail!(
357 "inside `{header}`, expected a Content-Type header field or a header ending CRLF, got `{second_segment:?}`"
358 )
359 }
360 }
361 }
362 } else {
363 anyhow::bail!(
364 "unable to find the second line of the LSP message header `{header}`"
365 );
366 }
367
368 buffer.resize(message_len, 0);
369 stdout.read_exact(&mut buffer).await?;
370
371 if let Ok(message) = str::from_utf8(&buffer) {
372 log::trace!("incoming message: {message}");
373 for handler in io_handlers.lock().values_mut() {
374 handler(IoKind::StdOut, message);
375 }
376 }
377
378 if let Ok(msg) = serde_json::from_slice::<AnyNotification>(&buffer) {
379 if let Some(handler) = notification_handlers.lock().get_mut(msg.method) {
380 handler(
381 msg.id,
382 msg.params.map(|params| params.get()).unwrap_or("null"),
383 cx.clone(),
384 );
385 } else {
386 on_unhandled_notification(msg);
387 }
388 } else if let Ok(AnyResponse {
389 id, error, result, ..
390 }) = serde_json::from_slice(&buffer)
391 {
392 if let Some(handler) = response_handlers
393 .lock()
394 .as_mut()
395 .and_then(|handlers| handlers.remove(&id))
396 {
397 if let Some(error) = error {
398 handler(Err(error));
399 } else if let Some(result) = result {
400 handler(Ok(result.get().into()));
401 } else {
402 handler(Ok("null".into()));
403 }
404 }
405 } else {
406 warn!(
407 "failed to deserialize LSP message:\n{}",
408 std::str::from_utf8(&buffer)?
409 );
410 }
411
412 // Don't starve the main thread when receiving lots of messages at once.
413 smol::future::yield_now().await;
414 }
415
416 Ok(())
417 }
418
419 async fn handle_stderr<Stderr>(
420 stderr: Stderr,
421 io_handlers: Arc<Mutex<HashMap<usize, IoHandler>>>,
422 stderr_capture: Arc<Mutex<Option<String>>>,
423 ) -> anyhow::Result<()>
424 where
425 Stderr: AsyncRead + Unpin + Send + 'static,
426 {
427 let mut stderr = BufReader::new(stderr);
428 let mut buffer = Vec::new();
429
430 loop {
431 buffer.clear();
432
433 let bytes_read = stderr.read_until(b'\n', &mut buffer).await?;
434 if bytes_read == 0 {
435 return Ok(());
436 }
437
438 if let Ok(message) = str::from_utf8(&buffer) {
439 log::trace!("incoming stderr message:{message}");
440 for handler in io_handlers.lock().values_mut() {
441 handler(IoKind::StdErr, message);
442 }
443
444 if let Some(stderr) = stderr_capture.lock().as_mut() {
445 stderr.push_str(message);
446 }
447 }
448
449 // Don't starve the main thread when receiving lots of messages at once.
450 smol::future::yield_now().await;
451 }
452 }
453
454 async fn handle_output<Stdin>(
455 stdin: Stdin,
456 outbound_rx: channel::Receiver<String>,
457 output_done_tx: barrier::Sender,
458 response_handlers: Arc<Mutex<Option<HashMap<usize, ResponseHandler>>>>,
459 io_handlers: Arc<Mutex<HashMap<usize, IoHandler>>>,
460 ) -> anyhow::Result<()>
461 where
462 Stdin: AsyncWrite + Unpin + Send + 'static,
463 {
464 let mut stdin = BufWriter::new(stdin);
465 let _clear_response_handlers = util::defer({
466 let response_handlers = response_handlers.clone();
467 move || {
468 response_handlers.lock().take();
469 }
470 });
471 let mut content_len_buffer = Vec::new();
472 while let Ok(message) = outbound_rx.recv().await {
473 log::trace!("outgoing message:{}", message);
474 for handler in io_handlers.lock().values_mut() {
475 handler(IoKind::StdIn, &message);
476 }
477
478 content_len_buffer.clear();
479 write!(content_len_buffer, "{}", message.len()).unwrap();
480 stdin.write_all(CONTENT_LEN_HEADER.as_bytes()).await?;
481 stdin.write_all(&content_len_buffer).await?;
482 stdin.write_all("\r\n\r\n".as_bytes()).await?;
483 stdin.write_all(message.as_bytes()).await?;
484 stdin.flush().await?;
485 }
486 drop(output_done_tx);
487 Ok(())
488 }
489
490 /// Initializes a language server by sending the `Initialize` request.
491 /// Note that `options` is used directly to construct [`InitializeParams`], which is why it is owned.
492 ///
493 /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#initialize)
494 pub fn initialize(
495 mut self,
496 options: Option<Value>,
497 cx: &AppContext,
498 ) -> Task<Result<Arc<Self>>> {
499 let root_uri = Url::from_file_path(&self.root_path).unwrap();
500 #[allow(deprecated)]
501 let params = InitializeParams {
502 process_id: None,
503 root_path: None,
504 root_uri: Some(root_uri.clone()),
505 initialization_options: options,
506 capabilities: ClientCapabilities {
507 workspace: Some(WorkspaceClientCapabilities {
508 configuration: Some(true),
509 did_change_watched_files: Some(DidChangeWatchedFilesClientCapabilities {
510 dynamic_registration: Some(true),
511 relative_pattern_support: Some(true),
512 }),
513 did_change_configuration: Some(DynamicRegistrationClientCapabilities {
514 dynamic_registration: Some(true),
515 }),
516 workspace_folders: Some(true),
517 symbol: Some(WorkspaceSymbolClientCapabilities {
518 resolve_support: None,
519 ..WorkspaceSymbolClientCapabilities::default()
520 }),
521 inlay_hint: Some(InlayHintWorkspaceClientCapabilities {
522 refresh_support: Some(true),
523 }),
524 diagnostic: Some(DiagnosticWorkspaceClientCapabilities {
525 refresh_support: None,
526 }),
527 workspace_edit: Some(WorkspaceEditClientCapabilities {
528 resource_operations: Some(vec![
529 ResourceOperationKind::Create,
530 ResourceOperationKind::Rename,
531 ResourceOperationKind::Delete,
532 ]),
533 document_changes: Some(true),
534 ..WorkspaceEditClientCapabilities::default()
535 }),
536 ..Default::default()
537 }),
538 text_document: Some(TextDocumentClientCapabilities {
539 definition: Some(GotoCapability {
540 link_support: Some(true),
541 dynamic_registration: None,
542 }),
543 code_action: Some(CodeActionClientCapabilities {
544 code_action_literal_support: Some(CodeActionLiteralSupport {
545 code_action_kind: CodeActionKindLiteralSupport {
546 value_set: vec![
547 CodeActionKind::REFACTOR.as_str().into(),
548 CodeActionKind::QUICKFIX.as_str().into(),
549 CodeActionKind::SOURCE.as_str().into(),
550 ],
551 },
552 }),
553 data_support: Some(true),
554 resolve_support: Some(CodeActionCapabilityResolveSupport {
555 properties: vec!["edit".to_string(), "command".to_string()],
556 }),
557 ..Default::default()
558 }),
559 completion: Some(CompletionClientCapabilities {
560 completion_item: Some(CompletionItemCapability {
561 snippet_support: Some(true),
562 resolve_support: Some(CompletionItemCapabilityResolveSupport {
563 properties: vec![
564 "documentation".to_string(),
565 "additionalTextEdits".to_string(),
566 ],
567 }),
568 ..Default::default()
569 }),
570 completion_list: Some(CompletionListCapability {
571 item_defaults: Some(vec![
572 "commitCharacters".to_owned(),
573 "editRange".to_owned(),
574 "insertTextMode".to_owned(),
575 "data".to_owned(),
576 ]),
577 }),
578 ..Default::default()
579 }),
580 rename: Some(RenameClientCapabilities {
581 prepare_support: Some(true),
582 ..Default::default()
583 }),
584 hover: Some(HoverClientCapabilities {
585 content_format: Some(vec![MarkupKind::Markdown]),
586 dynamic_registration: None,
587 }),
588 inlay_hint: Some(InlayHintClientCapabilities {
589 resolve_support: Some(InlayHintResolveClientCapabilities {
590 properties: vec![
591 "textEdits".to_string(),
592 "tooltip".to_string(),
593 "label.tooltip".to_string(),
594 "label.location".to_string(),
595 "label.command".to_string(),
596 ],
597 }),
598 dynamic_registration: Some(false),
599 }),
600 publish_diagnostics: Some(PublishDiagnosticsClientCapabilities {
601 related_information: Some(true),
602 ..Default::default()
603 }),
604 formatting: Some(DynamicRegistrationClientCapabilities {
605 dynamic_registration: None,
606 }),
607 on_type_formatting: Some(DynamicRegistrationClientCapabilities {
608 dynamic_registration: None,
609 }),
610 diagnostic: Some(DiagnosticClientCapabilities {
611 related_document_support: Some(true),
612 dynamic_registration: None,
613 }),
614 ..Default::default()
615 }),
616 experimental: Some(json!({
617 "serverStatusNotification": true,
618 })),
619 window: Some(WindowClientCapabilities {
620 work_done_progress: Some(true),
621 ..Default::default()
622 }),
623 general: None,
624 },
625 trace: None,
626 workspace_folders: Some(vec![WorkspaceFolder {
627 uri: root_uri,
628 name: Default::default(),
629 }]),
630 client_info: Some(ClientInfo {
631 name: release_channel::ReleaseChannel::global(cx)
632 .display_name()
633 .to_string(),
634 version: Some(release_channel::AppVersion::global(cx).to_string()),
635 }),
636 locale: None,
637 };
638
639 cx.spawn(|_| async move {
640 let response = self.request::<request::Initialize>(params).await?;
641 if let Some(info) = response.server_info {
642 self.name = info.name;
643 }
644 self.capabilities = response.capabilities;
645
646 self.notify::<notification::Initialized>(InitializedParams {})?;
647 Ok(Arc::new(self))
648 })
649 }
650
651 /// Sends a shutdown request to the language server process and prepares the [`LanguageServer`] to be dropped.
652 pub fn shutdown(&self) -> Option<impl 'static + Send + Future<Output = Option<()>>> {
653 if let Some(tasks) = self.io_tasks.lock().take() {
654 let response_handlers = self.response_handlers.clone();
655 let next_id = AtomicUsize::new(self.next_id.load(SeqCst));
656 let outbound_tx = self.outbound_tx.clone();
657 let executor = self.executor.clone();
658 let mut output_done = self.output_done_rx.lock().take().unwrap();
659 let shutdown_request = Self::request_internal::<request::Shutdown>(
660 &next_id,
661 &response_handlers,
662 &outbound_tx,
663 &executor,
664 (),
665 );
666 let exit = Self::notify_internal::<notification::Exit>(&outbound_tx, ());
667 outbound_tx.close();
668 Some(
669 async move {
670 log::debug!("language server shutdown started");
671 shutdown_request.await?;
672 response_handlers.lock().take();
673 exit?;
674 output_done.recv().await;
675 log::debug!("language server shutdown finished");
676 drop(tasks);
677 anyhow::Ok(())
678 }
679 .log_err(),
680 )
681 } else {
682 None
683 }
684 }
685
686 /// Register a handler to handle incoming LSP notifications.
687 ///
688 /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
689 #[must_use]
690 pub fn on_notification<T, F>(&self, f: F) -> Subscription
691 where
692 T: notification::Notification,
693 F: 'static + Send + FnMut(T::Params, AsyncAppContext),
694 {
695 self.on_custom_notification(T::METHOD, f)
696 }
697
698 /// Register a handler to handle incoming LSP requests.
699 ///
700 /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
701 #[must_use]
702 pub fn on_request<T, F, Fut>(&self, f: F) -> Subscription
703 where
704 T: request::Request,
705 T::Params: 'static + Send,
706 F: 'static + FnMut(T::Params, AsyncAppContext) -> Fut + Send,
707 Fut: 'static + Future<Output = Result<T::Result>>,
708 {
709 self.on_custom_request(T::METHOD, f)
710 }
711
712 /// Registers a handler to inspect all language server process stdio.
713 #[must_use]
714 pub fn on_io<F>(&self, f: F) -> Subscription
715 where
716 F: 'static + Send + FnMut(IoKind, &str),
717 {
718 let id = self.next_id.fetch_add(1, SeqCst);
719 self.io_handlers.lock().insert(id, Box::new(f));
720 Subscription::Io {
721 id,
722 io_handlers: Some(Arc::downgrade(&self.io_handlers)),
723 }
724 }
725
726 /// Removes a request handler registers via [`Self::on_request`].
727 pub fn remove_request_handler<T: request::Request>(&self) {
728 self.notification_handlers.lock().remove(T::METHOD);
729 }
730
731 /// Removes a notification handler registers via [`Self::on_notification`].
732 pub fn remove_notification_handler<T: notification::Notification>(&self) {
733 self.notification_handlers.lock().remove(T::METHOD);
734 }
735
736 /// Checks if a notification handler has been registered via [`Self::on_notification`].
737 pub fn has_notification_handler<T: notification::Notification>(&self) -> bool {
738 self.notification_handlers.lock().contains_key(T::METHOD)
739 }
740
741 #[must_use]
742 fn on_custom_notification<Params, F>(&self, method: &'static str, mut f: F) -> Subscription
743 where
744 F: 'static + FnMut(Params, AsyncAppContext) + Send,
745 Params: DeserializeOwned,
746 {
747 let prev_handler = self.notification_handlers.lock().insert(
748 method,
749 Box::new(move |_, params, cx| {
750 if let Some(params) = serde_json::from_str(params).log_err() {
751 f(params, cx);
752 }
753 }),
754 );
755 assert!(
756 prev_handler.is_none(),
757 "registered multiple handlers for the same LSP method"
758 );
759 Subscription::Notification {
760 method,
761 notification_handlers: Some(self.notification_handlers.clone()),
762 }
763 }
764
765 #[must_use]
766 fn on_custom_request<Params, Res, Fut, F>(&self, method: &'static str, mut f: F) -> Subscription
767 where
768 F: 'static + FnMut(Params, AsyncAppContext) -> Fut + Send,
769 Fut: 'static + Future<Output = Result<Res>>,
770 Params: DeserializeOwned + Send + 'static,
771 Res: Serialize,
772 {
773 let outbound_tx = self.outbound_tx.clone();
774 let prev_handler = self.notification_handlers.lock().insert(
775 method,
776 Box::new(move |id, params, cx| {
777 if let Some(id) = id {
778 match serde_json::from_str(params) {
779 Ok(params) => {
780 let response = f(params, cx.clone());
781 cx.foreground_executor()
782 .spawn({
783 let outbound_tx = outbound_tx.clone();
784 async move {
785 let response = match response.await {
786 Ok(result) => Response {
787 jsonrpc: JSON_RPC_VERSION,
788 id,
789 result: Some(result),
790 error: None,
791 },
792 Err(error) => Response {
793 jsonrpc: JSON_RPC_VERSION,
794 id,
795 result: None,
796 error: Some(Error {
797 message: error.to_string(),
798 }),
799 },
800 };
801 if let Some(response) =
802 serde_json::to_string(&response).log_err()
803 {
804 outbound_tx.try_send(response).ok();
805 }
806 }
807 })
808 .detach();
809 }
810
811 Err(error) => {
812 log::error!(
813 "error deserializing {} request: {:?}, message: {:?}",
814 method,
815 error,
816 params
817 );
818 let response = AnyResponse {
819 jsonrpc: JSON_RPC_VERSION,
820 id,
821 result: None,
822 error: Some(Error {
823 message: error.to_string(),
824 }),
825 };
826 if let Some(response) = serde_json::to_string(&response).log_err() {
827 outbound_tx.try_send(response).ok();
828 }
829 }
830 }
831 }
832 }),
833 );
834 assert!(
835 prev_handler.is_none(),
836 "registered multiple handlers for the same LSP method"
837 );
838 Subscription::Notification {
839 method,
840 notification_handlers: Some(self.notification_handlers.clone()),
841 }
842 }
843
844 /// Get the name of the running language server.
845 pub fn name(&self) -> &str {
846 &self.name
847 }
848
849 /// Get the reported capabilities of the running language server.
850 pub fn capabilities(&self) -> &ServerCapabilities {
851 &self.capabilities
852 }
853
854 /// Get the id of the running language server.
855 pub fn server_id(&self) -> LanguageServerId {
856 self.server_id
857 }
858
859 /// Get the root path of the project the language server is running against.
860 pub fn root_path(&self) -> &PathBuf {
861 &self.root_path
862 }
863
864 /// Sends a RPC request to the language server.
865 ///
866 /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
867 pub fn request<T: request::Request>(
868 &self,
869 params: T::Params,
870 ) -> impl Future<Output = Result<T::Result>>
871 where
872 T::Result: 'static + Send,
873 {
874 Self::request_internal::<T>(
875 &self.next_id,
876 &self.response_handlers,
877 &self.outbound_tx,
878 &self.executor,
879 params,
880 )
881 }
882
883 fn request_internal<T: request::Request>(
884 next_id: &AtomicUsize,
885 response_handlers: &Mutex<Option<HashMap<usize, ResponseHandler>>>,
886 outbound_tx: &channel::Sender<String>,
887 executor: &BackgroundExecutor,
888 params: T::Params,
889 ) -> impl 'static + Future<Output = anyhow::Result<T::Result>>
890 where
891 T::Result: 'static + Send,
892 {
893 let id = next_id.fetch_add(1, SeqCst);
894 let message = serde_json::to_string(&Request {
895 jsonrpc: JSON_RPC_VERSION,
896 id,
897 method: T::METHOD,
898 params,
899 })
900 .unwrap();
901
902 let (tx, rx) = oneshot::channel();
903 let handle_response = response_handlers
904 .lock()
905 .as_mut()
906 .ok_or_else(|| anyhow!("server shut down"))
907 .map(|handlers| {
908 let executor = executor.clone();
909 handlers.insert(
910 id,
911 Box::new(move |result| {
912 executor
913 .spawn(async move {
914 let response = match result {
915 Ok(response) => serde_json::from_str(&response)
916 .context("failed to deserialize response"),
917 Err(error) => Err(anyhow!("{}", error.message)),
918 };
919 _ = tx.send(response);
920 })
921 .detach();
922 }),
923 );
924 });
925
926 let send = outbound_tx
927 .try_send(message)
928 .context("failed to write to language server's stdin");
929
930 let outbound_tx = outbound_tx.downgrade();
931 let mut timeout = executor.timer(LSP_REQUEST_TIMEOUT).fuse();
932 let started = Instant::now();
933 async move {
934 handle_response?;
935 send?;
936
937 let cancel_on_drop = util::defer(move || {
938 if let Some(outbound_tx) = outbound_tx.upgrade() {
939 Self::notify_internal::<notification::Cancel>(
940 &outbound_tx,
941 CancelParams {
942 id: NumberOrString::Number(id as i32),
943 },
944 )
945 .log_err();
946 }
947 });
948
949 let method = T::METHOD;
950 futures::select! {
951 response = rx.fuse() => {
952 let elapsed = started.elapsed();
953 log::trace!("Took {elapsed:?} to receive response to {method:?} id {id}");
954 cancel_on_drop.abort();
955 response?
956 }
957
958 _ = timeout => {
959 log::error!("Cancelled LSP request task for {method:?} id {id} which took over {LSP_REQUEST_TIMEOUT:?}");
960 anyhow::bail!("LSP request timeout");
961 }
962 }
963 }
964 }
965
966 /// Sends a RPC notification to the language server.
967 ///
968 /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
969 pub fn notify<T: notification::Notification>(&self, params: T::Params) -> Result<()> {
970 Self::notify_internal::<T>(&self.outbound_tx, params)
971 }
972
973 fn notify_internal<T: notification::Notification>(
974 outbound_tx: &channel::Sender<String>,
975 params: T::Params,
976 ) -> Result<()> {
977 let message = serde_json::to_string(&Notification {
978 jsonrpc: JSON_RPC_VERSION,
979 method: T::METHOD,
980 params,
981 })
982 .unwrap();
983 outbound_tx.try_send(message)?;
984 Ok(())
985 }
986}
987
988impl Drop for LanguageServer {
989 fn drop(&mut self) {
990 if let Some(shutdown) = self.shutdown() {
991 self.executor.spawn(shutdown).detach();
992 }
993 }
994}
995
996impl Subscription {
997 /// Detaching a subscription handle prevents it from unsubscribing on drop.
998 pub fn detach(&mut self) {
999 match self {
1000 Subscription::Notification {
1001 notification_handlers,
1002 ..
1003 } => *notification_handlers = None,
1004 Subscription::Io { io_handlers, .. } => *io_handlers = None,
1005 }
1006 }
1007}
1008
1009impl fmt::Display for LanguageServerId {
1010 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1011 self.0.fmt(f)
1012 }
1013}
1014
1015impl fmt::Debug for LanguageServer {
1016 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1017 f.debug_struct("LanguageServer")
1018 .field("id", &self.server_id.0)
1019 .field("name", &self.name)
1020 .finish_non_exhaustive()
1021 }
1022}
1023
1024impl Drop for Subscription {
1025 fn drop(&mut self) {
1026 match self {
1027 Subscription::Notification {
1028 method,
1029 notification_handlers,
1030 } => {
1031 if let Some(handlers) = notification_handlers {
1032 handlers.lock().remove(method);
1033 }
1034 }
1035 Subscription::Io { id, io_handlers } => {
1036 if let Some(io_handlers) = io_handlers.as_ref().and_then(|h| h.upgrade()) {
1037 io_handlers.lock().remove(id);
1038 }
1039 }
1040 }
1041 }
1042}
1043
1044/// Mock language server for use in tests.
1045#[cfg(any(test, feature = "test-support"))]
1046#[derive(Clone)]
1047pub struct FakeLanguageServer {
1048 pub server: Arc<LanguageServer>,
1049 notifications_rx: channel::Receiver<(String, String)>,
1050}
1051
1052#[cfg(any(test, feature = "test-support"))]
1053impl FakeLanguageServer {
1054 /// Construct a fake language server.
1055 pub fn new(
1056 name: String,
1057 capabilities: ServerCapabilities,
1058 cx: AsyncAppContext,
1059 ) -> (LanguageServer, FakeLanguageServer) {
1060 let (stdin_writer, stdin_reader) = async_pipe::pipe();
1061 let (stdout_writer, stdout_reader) = async_pipe::pipe();
1062 let (notifications_tx, notifications_rx) = channel::unbounded();
1063
1064 let server = LanguageServer::new_internal(
1065 LanguageServerId(0),
1066 stdin_writer,
1067 stdout_reader,
1068 None::<async_pipe::PipeReader>,
1069 Arc::new(Mutex::new(None)),
1070 None,
1071 Path::new("/"),
1072 None,
1073 cx.clone(),
1074 |_| {},
1075 );
1076 let fake = FakeLanguageServer {
1077 server: Arc::new(LanguageServer::new_internal(
1078 LanguageServerId(0),
1079 stdout_writer,
1080 stdin_reader,
1081 None::<async_pipe::PipeReader>,
1082 Arc::new(Mutex::new(None)),
1083 None,
1084 Path::new("/"),
1085 None,
1086 cx,
1087 move |msg| {
1088 notifications_tx
1089 .try_send((
1090 msg.method.to_string(),
1091 msg.params
1092 .map(|raw_value| raw_value.get())
1093 .unwrap_or("null")
1094 .to_string(),
1095 ))
1096 .ok();
1097 },
1098 )),
1099 notifications_rx,
1100 };
1101 fake.handle_request::<request::Initialize, _, _>({
1102 let capabilities = capabilities;
1103 move |_, _| {
1104 let capabilities = capabilities.clone();
1105 let name = name.clone();
1106 async move {
1107 Ok(InitializeResult {
1108 capabilities,
1109 server_info: Some(ServerInfo {
1110 name,
1111 ..Default::default()
1112 }),
1113 })
1114 }
1115 }
1116 });
1117
1118 (server, fake)
1119 }
1120}
1121
1122#[cfg(any(test, feature = "test-support"))]
1123impl LanguageServer {
1124 pub fn full_capabilities() -> ServerCapabilities {
1125 ServerCapabilities {
1126 document_highlight_provider: Some(OneOf::Left(true)),
1127 code_action_provider: Some(CodeActionProviderCapability::Simple(true)),
1128 document_formatting_provider: Some(OneOf::Left(true)),
1129 document_range_formatting_provider: Some(OneOf::Left(true)),
1130 definition_provider: Some(OneOf::Left(true)),
1131 type_definition_provider: Some(TypeDefinitionProviderCapability::Simple(true)),
1132 ..Default::default()
1133 }
1134 }
1135}
1136
1137#[cfg(any(test, feature = "test-support"))]
1138impl FakeLanguageServer {
1139 /// See [`LanguageServer::notify`].
1140 pub fn notify<T: notification::Notification>(&self, params: T::Params) {
1141 self.server.notify::<T>(params).ok();
1142 }
1143
1144 /// See [`LanguageServer::request`].
1145 pub async fn request<T>(&self, params: T::Params) -> Result<T::Result>
1146 where
1147 T: request::Request,
1148 T::Result: 'static + Send,
1149 {
1150 self.server.executor.start_waiting();
1151 self.server.request::<T>(params).await
1152 }
1153
1154 /// Attempts [`Self::try_receive_notification`], unwrapping if it has not received the specified type yet.
1155 pub async fn receive_notification<T: notification::Notification>(&mut self) -> T::Params {
1156 self.server.executor.start_waiting();
1157 self.try_receive_notification::<T>().await.unwrap()
1158 }
1159
1160 /// Consumes the notification channel until it finds a notification for the specified type.
1161 pub async fn try_receive_notification<T: notification::Notification>(
1162 &mut self,
1163 ) -> Option<T::Params> {
1164 use futures::StreamExt as _;
1165
1166 loop {
1167 let (method, params) = self.notifications_rx.next().await?;
1168 if method == T::METHOD {
1169 return Some(serde_json::from_str::<T::Params>(¶ms).unwrap());
1170 } else {
1171 log::info!("skipping message in fake language server {:?}", params);
1172 }
1173 }
1174 }
1175
1176 /// Registers a handler for a specific kind of request. Removes any existing handler for specified request type.
1177 pub fn handle_request<T, F, Fut>(
1178 &self,
1179 mut handler: F,
1180 ) -> futures::channel::mpsc::UnboundedReceiver<()>
1181 where
1182 T: 'static + request::Request,
1183 T::Params: 'static + Send,
1184 F: 'static + Send + FnMut(T::Params, gpui::AsyncAppContext) -> Fut,
1185 Fut: 'static + Send + Future<Output = Result<T::Result>>,
1186 {
1187 let (responded_tx, responded_rx) = futures::channel::mpsc::unbounded();
1188 self.server.remove_request_handler::<T>();
1189 self.server
1190 .on_request::<T, _, _>(move |params, cx| {
1191 let result = handler(params, cx.clone());
1192 let responded_tx = responded_tx.clone();
1193 let executor = cx.background_executor().clone();
1194 async move {
1195 executor.simulate_random_delay().await;
1196 let result = result.await;
1197 responded_tx.unbounded_send(()).ok();
1198 result
1199 }
1200 })
1201 .detach();
1202 responded_rx
1203 }
1204
1205 /// Registers a handler for a specific kind of notification. Removes any existing handler for specified notification type.
1206 pub fn handle_notification<T, F>(
1207 &self,
1208 mut handler: F,
1209 ) -> futures::channel::mpsc::UnboundedReceiver<()>
1210 where
1211 T: 'static + notification::Notification,
1212 T::Params: 'static + Send,
1213 F: 'static + Send + FnMut(T::Params, gpui::AsyncAppContext),
1214 {
1215 let (handled_tx, handled_rx) = futures::channel::mpsc::unbounded();
1216 self.server.remove_notification_handler::<T>();
1217 self.server
1218 .on_notification::<T, _>(move |params, cx| {
1219 handler(params, cx.clone());
1220 handled_tx.unbounded_send(()).ok();
1221 })
1222 .detach();
1223 handled_rx
1224 }
1225
1226 /// Removes any existing handler for specified notification type.
1227 pub fn remove_request_handler<T>(&mut self)
1228 where
1229 T: 'static + request::Request,
1230 {
1231 self.server.remove_request_handler::<T>();
1232 }
1233
1234 /// Simulate that the server has started work and notifies about its progress with the specified token.
1235 pub async fn start_progress(&self, token: impl Into<String>) {
1236 let token = token.into();
1237 self.request::<request::WorkDoneProgressCreate>(WorkDoneProgressCreateParams {
1238 token: NumberOrString::String(token.clone()),
1239 })
1240 .await
1241 .unwrap();
1242 self.notify::<notification::Progress>(ProgressParams {
1243 token: NumberOrString::String(token),
1244 value: ProgressParamsValue::WorkDone(WorkDoneProgress::Begin(Default::default())),
1245 });
1246 }
1247
1248 /// Simulate that the server has completed work and notifies about that with the specified token.
1249 pub fn end_progress(&self, token: impl Into<String>) {
1250 self.notify::<notification::Progress>(ProgressParams {
1251 token: NumberOrString::String(token.into()),
1252 value: ProgressParamsValue::WorkDone(WorkDoneProgress::End(Default::default())),
1253 });
1254 }
1255}
1256
1257#[cfg(test)]
1258mod tests {
1259 use super::*;
1260 use gpui::TestAppContext;
1261
1262 #[ctor::ctor]
1263 fn init_logger() {
1264 if std::env::var("RUST_LOG").is_ok() {
1265 env_logger::init();
1266 }
1267 }
1268
1269 #[gpui::test]
1270 async fn test_fake(cx: &mut TestAppContext) {
1271 cx.update(|cx| {
1272 release_channel::init("0.0.0", cx);
1273 });
1274 let (server, mut fake) =
1275 FakeLanguageServer::new("the-lsp".to_string(), Default::default(), cx.to_async());
1276
1277 let (message_tx, message_rx) = channel::unbounded();
1278 let (diagnostics_tx, diagnostics_rx) = channel::unbounded();
1279 server
1280 .on_notification::<notification::ShowMessage, _>(move |params, _| {
1281 message_tx.try_send(params).unwrap()
1282 })
1283 .detach();
1284 server
1285 .on_notification::<notification::PublishDiagnostics, _>(move |params, _| {
1286 diagnostics_tx.try_send(params).unwrap()
1287 })
1288 .detach();
1289
1290 let server = cx.update(|cx| server.initialize(None, cx)).await.unwrap();
1291 server
1292 .notify::<notification::DidOpenTextDocument>(DidOpenTextDocumentParams {
1293 text_document: TextDocumentItem::new(
1294 Url::from_str("file://a/b").unwrap(),
1295 "rust".to_string(),
1296 0,
1297 "".to_string(),
1298 ),
1299 })
1300 .unwrap();
1301 assert_eq!(
1302 fake.receive_notification::<notification::DidOpenTextDocument>()
1303 .await
1304 .text_document
1305 .uri
1306 .as_str(),
1307 "file://a/b"
1308 );
1309
1310 fake.notify::<notification::ShowMessage>(ShowMessageParams {
1311 typ: MessageType::ERROR,
1312 message: "ok".to_string(),
1313 });
1314 fake.notify::<notification::PublishDiagnostics>(PublishDiagnosticsParams {
1315 uri: Url::from_str("file://b/c").unwrap(),
1316 version: Some(5),
1317 diagnostics: vec![],
1318 });
1319 assert_eq!(message_rx.recv().await.unwrap().message, "ok");
1320 assert_eq!(
1321 diagnostics_rx.recv().await.unwrap().uri.as_str(),
1322 "file://b/c"
1323 );
1324
1325 fake.handle_request::<request::Shutdown, _, _>(|_, _| async move { Ok(()) });
1326
1327 drop(server);
1328 fake.receive_notification::<notification::Exit>().await;
1329 }
1330}