lsp2.rs

   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 gpui2::{AsyncAppContext, Executor, Task};
   9use parking_lot::Mutex;
  10use postage::{barrier, prelude::Stream};
  11use serde::{de::DeserializeOwned, Deserialize, Serialize};
  12use serde_json::{json, value::RawValue, Value};
  13use smol::{
  14    channel,
  15    io::{AsyncBufReadExt, AsyncReadExt, AsyncWriteExt, BufReader},
  16    process::{self, Child},
  17};
  18use std::{
  19    ffi::OsString,
  20    fmt,
  21    future::Future,
  22    io::Write,
  23    path::PathBuf,
  24    str::{self, FromStr as _},
  25    sync::{
  26        atomic::{AtomicUsize, Ordering::SeqCst},
  27        Arc, Weak,
  28    },
  29    time::{Duration, Instant},
  30};
  31use std::{path::Path, process::Stdio};
  32use util::{ResultExt, TryFutureExt};
  33
  34const JSON_RPC_VERSION: &str = "2.0";
  35const CONTENT_LEN_HEADER: &str = "Content-Length: ";
  36const LSP_REQUEST_TIMEOUT: Duration = Duration::from_secs(60 * 2);
  37
  38type NotificationHandler = Box<dyn Send + FnMut(Option<usize>, &str, AsyncAppContext)>;
  39type ResponseHandler = Box<dyn Send + FnOnce(Result<String, Error>)>;
  40type IoHandler = Box<dyn Send + FnMut(IoKind, &str)>;
  41
  42#[derive(Debug, Clone, Copy)]
  43pub enum IoKind {
  44    StdOut,
  45    StdIn,
  46    StdErr,
  47}
  48
  49#[derive(Debug, Clone, Deserialize)]
  50pub struct LanguageServerBinary {
  51    pub path: PathBuf,
  52    pub arguments: Vec<OsString>,
  53}
  54
  55pub struct LanguageServer {
  56    server_id: LanguageServerId,
  57    next_id: AtomicUsize,
  58    outbound_tx: channel::Sender<String>,
  59    name: String,
  60    capabilities: ServerCapabilities,
  61    code_action_kinds: Option<Vec<CodeActionKind>>,
  62    notification_handlers: Arc<Mutex<HashMap<&'static str, NotificationHandler>>>,
  63    response_handlers: Arc<Mutex<Option<HashMap<usize, ResponseHandler>>>>,
  64    io_handlers: Arc<Mutex<HashMap<usize, IoHandler>>>,
  65    executor: Executor,
  66    #[allow(clippy::type_complexity)]
  67    io_tasks: Mutex<Option<(Task<Option<()>>, Task<Option<()>>)>>,
  68    output_done_rx: Mutex<Option<barrier::Receiver>>,
  69    root_path: PathBuf,
  70    _server: Option<Mutex<Child>>,
  71}
  72
  73#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
  74#[repr(transparent)]
  75pub struct LanguageServerId(pub usize);
  76
  77pub enum Subscription {
  78    Notification {
  79        method: &'static str,
  80        notification_handlers: Option<Arc<Mutex<HashMap<&'static str, NotificationHandler>>>>,
  81    },
  82    Io {
  83        id: usize,
  84        io_handlers: Option<Weak<Mutex<HashMap<usize, IoHandler>>>>,
  85    },
  86}
  87
  88#[derive(Serialize, Deserialize)]
  89pub struct Request<'a, T> {
  90    jsonrpc: &'static str,
  91    id: usize,
  92    method: &'a str,
  93    params: T,
  94}
  95
  96#[derive(Serialize, Deserialize)]
  97struct AnyResponse<'a> {
  98    jsonrpc: &'a str,
  99    id: usize,
 100    #[serde(default)]
 101    error: Option<Error>,
 102    #[serde(borrow)]
 103    result: Option<&'a RawValue>,
 104}
 105
 106#[derive(Serialize)]
 107struct Response<T> {
 108    jsonrpc: &'static str,
 109    id: usize,
 110    result: Option<T>,
 111    error: Option<Error>,
 112}
 113
 114#[derive(Serialize, Deserialize)]
 115struct Notification<'a, T> {
 116    jsonrpc: &'static str,
 117    #[serde(borrow)]
 118    method: &'a str,
 119    params: T,
 120}
 121
 122#[derive(Debug, Clone, Deserialize)]
 123struct AnyNotification<'a> {
 124    #[serde(default)]
 125    id: Option<usize>,
 126    #[serde(borrow)]
 127    method: &'a str,
 128    #[serde(borrow, default)]
 129    params: Option<&'a RawValue>,
 130}
 131
 132#[derive(Debug, Serialize, Deserialize)]
 133struct Error {
 134    message: String,
 135}
 136
 137impl LanguageServer {
 138    pub fn new(
 139        server_id: LanguageServerId,
 140        binary: LanguageServerBinary,
 141        root_path: &Path,
 142        code_action_kinds: Option<Vec<CodeActionKind>>,
 143        cx: AsyncAppContext,
 144    ) -> Result<Self> {
 145        let working_dir = if root_path.is_dir() {
 146            root_path
 147        } else {
 148            root_path.parent().unwrap_or_else(|| Path::new("/"))
 149        };
 150
 151        let mut server = process::Command::new(&binary.path)
 152            .current_dir(working_dir)
 153            .args(binary.arguments)
 154            .stdin(Stdio::piped())
 155            .stdout(Stdio::piped())
 156            .stderr(Stdio::piped())
 157            .kill_on_drop(true)
 158            .spawn()?;
 159
 160        let stdin = server.stdin.take().unwrap();
 161        let stdout = server.stdout.take().unwrap();
 162        let stderr = server.stderr.take().unwrap();
 163        let mut server = Self::new_internal(
 164            server_id.clone(),
 165            stdin,
 166            stdout,
 167            Some(stderr),
 168            Some(server),
 169            root_path,
 170            code_action_kinds,
 171            cx,
 172            move |notification| {
 173                log::info!(
 174                    "{} unhandled notification {}:\n{}",
 175                    server_id,
 176                    notification.method,
 177                    serde_json::to_string_pretty(
 178                        &notification
 179                            .params
 180                            .and_then(|params| Value::from_str(params.get()).ok())
 181                            .unwrap_or(Value::Null)
 182                    )
 183                    .unwrap(),
 184                );
 185            },
 186        );
 187
 188        if let Some(name) = binary.path.file_name() {
 189            server.name = name.to_string_lossy().to_string();
 190        }
 191
 192        Ok(server)
 193    }
 194
 195    fn new_internal<Stdin, Stdout, Stderr, F>(
 196        server_id: LanguageServerId,
 197        stdin: Stdin,
 198        stdout: Stdout,
 199        stderr: Option<Stderr>,
 200        server: Option<Child>,
 201        root_path: &Path,
 202        code_action_kinds: Option<Vec<CodeActionKind>>,
 203        cx: AsyncAppContext,
 204        on_unhandled_notification: F,
 205    ) -> Self
 206    where
 207        Stdin: AsyncWrite + Unpin + Send + 'static,
 208        Stdout: AsyncRead + Unpin + Send + 'static,
 209        Stderr: AsyncRead + Unpin + Send + 'static,
 210        F: FnMut(AnyNotification) + 'static + Send + Sync + Clone,
 211    {
 212        let (outbound_tx, outbound_rx) = channel::unbounded::<String>();
 213        let (output_done_tx, output_done_rx) = barrier::channel();
 214        let notification_handlers =
 215            Arc::new(Mutex::new(HashMap::<_, NotificationHandler>::default()));
 216        let response_handlers =
 217            Arc::new(Mutex::new(Some(HashMap::<_, ResponseHandler>::default())));
 218        let io_handlers = Arc::new(Mutex::new(HashMap::default()));
 219
 220        let stdout_input_task = cx.spawn({
 221            let on_unhandled_notification = on_unhandled_notification.clone();
 222            let notification_handlers = notification_handlers.clone();
 223            let response_handlers = response_handlers.clone();
 224            let io_handlers = io_handlers.clone();
 225            move |cx| {
 226                Self::handle_input(
 227                    stdout,
 228                    on_unhandled_notification,
 229                    notification_handlers,
 230                    response_handlers,
 231                    io_handlers,
 232                    cx,
 233                )
 234                .log_err()
 235            }
 236        });
 237        let stderr_input_task = stderr
 238            .map(|stderr| {
 239                let io_handlers = io_handlers.clone();
 240                cx.spawn(|_| Self::handle_stderr(stderr, io_handlers).log_err())
 241            })
 242            .unwrap_or_else(|| Task::Ready(Some(None)));
 243        let input_task = cx.spawn(|_| async move {
 244            let (stdout, stderr) = futures::join!(stdout_input_task, stderr_input_task);
 245            stdout.or(stderr)
 246        });
 247        let output_task = cx.executor().spawn({
 248            Self::handle_output(
 249                stdin,
 250                outbound_rx,
 251                output_done_tx,
 252                response_handlers.clone(),
 253                io_handlers.clone(),
 254            )
 255            .log_err()
 256        });
 257
 258        Self {
 259            server_id,
 260            notification_handlers,
 261            response_handlers,
 262            io_handlers,
 263            name: Default::default(),
 264            capabilities: Default::default(),
 265            code_action_kinds,
 266            next_id: Default::default(),
 267            outbound_tx,
 268            executor: cx.executor().clone(),
 269            io_tasks: Mutex::new(Some((input_task, output_task))),
 270            output_done_rx: Mutex::new(Some(output_done_rx)),
 271            root_path: root_path.to_path_buf(),
 272            _server: server.map(|server| Mutex::new(server)),
 273        }
 274    }
 275
 276    pub fn code_action_kinds(&self) -> Option<Vec<CodeActionKind>> {
 277        self.code_action_kinds.clone()
 278    }
 279
 280    async fn handle_input<Stdout, F>(
 281        stdout: Stdout,
 282        mut on_unhandled_notification: F,
 283        notification_handlers: Arc<Mutex<HashMap<&'static str, NotificationHandler>>>,
 284        response_handlers: Arc<Mutex<Option<HashMap<usize, ResponseHandler>>>>,
 285        io_handlers: Arc<Mutex<HashMap<usize, IoHandler>>>,
 286        cx: AsyncAppContext,
 287    ) -> anyhow::Result<()>
 288    where
 289        Stdout: AsyncRead + Unpin + Send + 'static,
 290        F: FnMut(AnyNotification) + 'static + Send,
 291    {
 292        let mut stdout = BufReader::new(stdout);
 293        let _clear_response_handlers = util::defer({
 294            let response_handlers = response_handlers.clone();
 295            move || {
 296                response_handlers.lock().take();
 297            }
 298        });
 299        let mut buffer = Vec::new();
 300        loop {
 301            buffer.clear();
 302            stdout.read_until(b'\n', &mut buffer).await?;
 303            stdout.read_until(b'\n', &mut buffer).await?;
 304            let header = std::str::from_utf8(&buffer)?;
 305            let message_len: usize = header
 306                .strip_prefix(CONTENT_LEN_HEADER)
 307                .ok_or_else(|| anyhow!("invalid LSP message header {header:?}"))?
 308                .trim_end()
 309                .parse()?;
 310
 311            buffer.resize(message_len, 0);
 312            stdout.read_exact(&mut buffer).await?;
 313
 314            if let Ok(message) = str::from_utf8(&buffer) {
 315                log::trace!("incoming message: {}", message);
 316                for handler in io_handlers.lock().values_mut() {
 317                    handler(IoKind::StdOut, message);
 318                }
 319            }
 320
 321            if let Ok(msg) = serde_json::from_slice::<AnyNotification>(&buffer) {
 322                if let Some(handler) = notification_handlers.lock().get_mut(msg.method) {
 323                    handler(
 324                        msg.id,
 325                        &msg.params.map(|params| params.get()).unwrap_or("null"),
 326                        cx.clone(),
 327                    );
 328                } else {
 329                    on_unhandled_notification(msg);
 330                }
 331            } else if let Ok(AnyResponse {
 332                id, error, result, ..
 333            }) = serde_json::from_slice(&buffer)
 334            {
 335                if let Some(handler) = response_handlers
 336                    .lock()
 337                    .as_mut()
 338                    .and_then(|handlers| handlers.remove(&id))
 339                {
 340                    if let Some(error) = error {
 341                        handler(Err(error));
 342                    } else if let Some(result) = result {
 343                        handler(Ok(result.get().into()));
 344                    } else {
 345                        handler(Ok("null".into()));
 346                    }
 347                }
 348            } else {
 349                warn!(
 350                    "failed to deserialize LSP message:\n{}",
 351                    std::str::from_utf8(&buffer)?
 352                );
 353            }
 354
 355            // Don't starve the main thread when receiving lots of messages at once.
 356            smol::future::yield_now().await;
 357        }
 358    }
 359
 360    async fn handle_stderr<Stderr>(
 361        stderr: Stderr,
 362        io_handlers: Arc<Mutex<HashMap<usize, IoHandler>>>,
 363    ) -> anyhow::Result<()>
 364    where
 365        Stderr: AsyncRead + Unpin + Send + 'static,
 366    {
 367        let mut stderr = BufReader::new(stderr);
 368        let mut buffer = Vec::new();
 369        loop {
 370            buffer.clear();
 371            stderr.read_until(b'\n', &mut buffer).await?;
 372            if let Ok(message) = str::from_utf8(&buffer) {
 373                log::trace!("incoming stderr message:{message}");
 374                for handler in io_handlers.lock().values_mut() {
 375                    handler(IoKind::StdErr, message);
 376                }
 377            }
 378
 379            // Don't starve the main thread when receiving lots of messages at once.
 380            smol::future::yield_now().await;
 381        }
 382    }
 383
 384    async fn handle_output<Stdin>(
 385        stdin: Stdin,
 386        outbound_rx: channel::Receiver<String>,
 387        output_done_tx: barrier::Sender,
 388        response_handlers: Arc<Mutex<Option<HashMap<usize, ResponseHandler>>>>,
 389        io_handlers: Arc<Mutex<HashMap<usize, IoHandler>>>,
 390    ) -> anyhow::Result<()>
 391    where
 392        Stdin: AsyncWrite + Unpin + Send + 'static,
 393    {
 394        let mut stdin = BufWriter::new(stdin);
 395        let _clear_response_handlers = util::defer({
 396            let response_handlers = response_handlers.clone();
 397            move || {
 398                response_handlers.lock().take();
 399            }
 400        });
 401        let mut content_len_buffer = Vec::new();
 402        while let Ok(message) = outbound_rx.recv().await {
 403            log::trace!("outgoing message:{}", message);
 404            for handler in io_handlers.lock().values_mut() {
 405                handler(IoKind::StdIn, &message);
 406            }
 407
 408            content_len_buffer.clear();
 409            write!(content_len_buffer, "{}", message.len()).unwrap();
 410            stdin.write_all(CONTENT_LEN_HEADER.as_bytes()).await?;
 411            stdin.write_all(&content_len_buffer).await?;
 412            stdin.write_all("\r\n\r\n".as_bytes()).await?;
 413            stdin.write_all(message.as_bytes()).await?;
 414            stdin.flush().await?;
 415        }
 416        drop(output_done_tx);
 417        Ok(())
 418    }
 419
 420    /// Initializes a language server.
 421    /// Note that `options` is used directly to construct [`InitializeParams`],
 422    /// which is why it is owned.
 423    pub async fn initialize(mut self, options: Option<Value>) -> Result<Arc<Self>> {
 424        let root_uri = Url::from_file_path(&self.root_path).unwrap();
 425        #[allow(deprecated)]
 426        let params = InitializeParams {
 427            process_id: Default::default(),
 428            root_path: Default::default(),
 429            root_uri: Some(root_uri.clone()),
 430            initialization_options: options,
 431            capabilities: ClientCapabilities {
 432                workspace: Some(WorkspaceClientCapabilities {
 433                    configuration: Some(true),
 434                    did_change_watched_files: Some(DidChangeWatchedFilesClientCapabilities {
 435                        dynamic_registration: Some(true),
 436                        relative_pattern_support: Some(true),
 437                    }),
 438                    did_change_configuration: Some(DynamicRegistrationClientCapabilities {
 439                        dynamic_registration: Some(true),
 440                    }),
 441                    workspace_folders: Some(true),
 442                    symbol: Some(WorkspaceSymbolClientCapabilities {
 443                        resolve_support: None,
 444                        ..WorkspaceSymbolClientCapabilities::default()
 445                    }),
 446                    inlay_hint: Some(InlayHintWorkspaceClientCapabilities {
 447                        refresh_support: Some(true),
 448                    }),
 449                    ..Default::default()
 450                }),
 451                text_document: Some(TextDocumentClientCapabilities {
 452                    definition: Some(GotoCapability {
 453                        link_support: Some(true),
 454                        ..Default::default()
 455                    }),
 456                    code_action: Some(CodeActionClientCapabilities {
 457                        code_action_literal_support: Some(CodeActionLiteralSupport {
 458                            code_action_kind: CodeActionKindLiteralSupport {
 459                                value_set: vec![
 460                                    CodeActionKind::REFACTOR.as_str().into(),
 461                                    CodeActionKind::QUICKFIX.as_str().into(),
 462                                    CodeActionKind::SOURCE.as_str().into(),
 463                                ],
 464                            },
 465                        }),
 466                        data_support: Some(true),
 467                        resolve_support: Some(CodeActionCapabilityResolveSupport {
 468                            properties: vec!["edit".to_string(), "command".to_string()],
 469                        }),
 470                        ..Default::default()
 471                    }),
 472                    completion: Some(CompletionClientCapabilities {
 473                        completion_item: Some(CompletionItemCapability {
 474                            snippet_support: Some(true),
 475                            resolve_support: Some(CompletionItemCapabilityResolveSupport {
 476                                properties: vec!["additionalTextEdits".to_string()],
 477                            }),
 478                            ..Default::default()
 479                        }),
 480                        completion_list: Some(CompletionListCapability {
 481                            item_defaults: Some(vec![
 482                                "commitCharacters".to_owned(),
 483                                "editRange".to_owned(),
 484                                "insertTextMode".to_owned(),
 485                                "data".to_owned(),
 486                            ]),
 487                        }),
 488                        ..Default::default()
 489                    }),
 490                    rename: Some(RenameClientCapabilities {
 491                        prepare_support: Some(true),
 492                        ..Default::default()
 493                    }),
 494                    hover: Some(HoverClientCapabilities {
 495                        content_format: Some(vec![MarkupKind::Markdown]),
 496                        ..Default::default()
 497                    }),
 498                    inlay_hint: Some(InlayHintClientCapabilities {
 499                        resolve_support: Some(InlayHintResolveClientCapabilities {
 500                            properties: vec![
 501                                "textEdits".to_string(),
 502                                "tooltip".to_string(),
 503                                "label.tooltip".to_string(),
 504                                "label.location".to_string(),
 505                                "label.command".to_string(),
 506                            ],
 507                        }),
 508                        dynamic_registration: Some(false),
 509                    }),
 510                    ..Default::default()
 511                }),
 512                experimental: Some(json!({
 513                    "serverStatusNotification": true,
 514                })),
 515                window: Some(WindowClientCapabilities {
 516                    work_done_progress: Some(true),
 517                    ..Default::default()
 518                }),
 519                ..Default::default()
 520            },
 521            trace: Default::default(),
 522            workspace_folders: Some(vec![WorkspaceFolder {
 523                uri: root_uri,
 524                name: Default::default(),
 525            }]),
 526            client_info: Default::default(),
 527            locale: Default::default(),
 528        };
 529
 530        let response = self.request::<request::Initialize>(params).await?;
 531        if let Some(info) = response.server_info {
 532            self.name = info.name;
 533        }
 534        self.capabilities = response.capabilities;
 535
 536        self.notify::<notification::Initialized>(InitializedParams {})?;
 537        Ok(Arc::new(self))
 538    }
 539
 540    pub fn shutdown(&self) -> Option<impl 'static + Send + Future<Output = Option<()>>> {
 541        if let Some(tasks) = self.io_tasks.lock().take() {
 542            let response_handlers = self.response_handlers.clone();
 543            let next_id = AtomicUsize::new(self.next_id.load(SeqCst));
 544            let outbound_tx = self.outbound_tx.clone();
 545            let executor = self.executor.clone();
 546            let mut output_done = self.output_done_rx.lock().take().unwrap();
 547            let shutdown_request = Self::request_internal::<request::Shutdown>(
 548                &next_id,
 549                &response_handlers,
 550                &outbound_tx,
 551                &executor,
 552                (),
 553            );
 554            let exit = Self::notify_internal::<notification::Exit>(&outbound_tx, ());
 555            outbound_tx.close();
 556            Some(
 557                async move {
 558                    log::debug!("language server shutdown started");
 559                    shutdown_request.await?;
 560                    response_handlers.lock().take();
 561                    exit?;
 562                    output_done.recv().await;
 563                    log::debug!("language server shutdown finished");
 564                    drop(tasks);
 565                    anyhow::Ok(())
 566                }
 567                .log_err(),
 568            )
 569        } else {
 570            None
 571        }
 572    }
 573
 574    #[must_use]
 575    pub fn on_notification<T, F>(&self, f: F) -> Subscription
 576    where
 577        T: notification::Notification,
 578        F: 'static + Send + FnMut(T::Params, AsyncAppContext),
 579    {
 580        self.on_custom_notification(T::METHOD, f)
 581    }
 582
 583    #[must_use]
 584    pub fn on_request<T, F, Fut>(&self, f: F) -> Subscription
 585    where
 586        T: request::Request,
 587        T::Params: 'static + Send,
 588        F: 'static + Send + FnMut(T::Params, AsyncAppContext) -> Fut,
 589        Fut: 'static + Future<Output = Result<T::Result>> + Send,
 590    {
 591        self.on_custom_request(T::METHOD, f)
 592    }
 593
 594    #[must_use]
 595    pub fn on_io<F>(&self, f: F) -> Subscription
 596    where
 597        F: 'static + Send + FnMut(IoKind, &str),
 598    {
 599        let id = self.next_id.fetch_add(1, SeqCst);
 600        self.io_handlers.lock().insert(id, Box::new(f));
 601        Subscription::Io {
 602            id,
 603            io_handlers: Some(Arc::downgrade(&self.io_handlers)),
 604        }
 605    }
 606
 607    pub fn remove_request_handler<T: request::Request>(&self) {
 608        self.notification_handlers.lock().remove(T::METHOD);
 609    }
 610
 611    pub fn remove_notification_handler<T: notification::Notification>(&self) {
 612        self.notification_handlers.lock().remove(T::METHOD);
 613    }
 614
 615    pub fn has_notification_handler<T: notification::Notification>(&self) -> bool {
 616        self.notification_handlers.lock().contains_key(T::METHOD)
 617    }
 618
 619    #[must_use]
 620    pub fn on_custom_notification<Params, F>(&self, method: &'static str, mut f: F) -> Subscription
 621    where
 622        F: 'static + Send + FnMut(Params, AsyncAppContext),
 623        Params: DeserializeOwned,
 624    {
 625        let prev_handler = self.notification_handlers.lock().insert(
 626            method,
 627            Box::new(move |_, params, cx| {
 628                if let Some(params) = serde_json::from_str(params).log_err() {
 629                    f(params, cx);
 630                }
 631            }),
 632        );
 633        assert!(
 634            prev_handler.is_none(),
 635            "registered multiple handlers for the same LSP method"
 636        );
 637        Subscription::Notification {
 638            method,
 639            notification_handlers: Some(self.notification_handlers.clone()),
 640        }
 641    }
 642
 643    #[must_use]
 644    pub fn on_custom_request<Params, Res, Fut, F>(
 645        &self,
 646        method: &'static str,
 647        mut f: F,
 648    ) -> Subscription
 649    where
 650        F: 'static + Send + FnMut(Params, AsyncAppContext) -> Fut,
 651        Fut: 'static + Future<Output = Result<Res>> + Send,
 652        Params: DeserializeOwned + Send + 'static,
 653        Res: Serialize,
 654    {
 655        let outbound_tx = self.outbound_tx.clone();
 656        let prev_handler = self.notification_handlers.lock().insert(
 657            method,
 658            Box::new(move |id, params, cx| {
 659                if let Some(id) = id {
 660                    match serde_json::from_str(params) {
 661                        Ok(params) => {
 662                            let response = f(params, cx.clone());
 663                            cx.executor()
 664                                .spawn_on_main({
 665                                    let outbound_tx = outbound_tx.clone();
 666                                    move || async move {
 667                                        let response = match response.await {
 668                                            Ok(result) => Response {
 669                                                jsonrpc: JSON_RPC_VERSION,
 670                                                id,
 671                                                result: Some(result),
 672                                                error: None,
 673                                            },
 674                                            Err(error) => Response {
 675                                                jsonrpc: JSON_RPC_VERSION,
 676                                                id,
 677                                                result: None,
 678                                                error: Some(Error {
 679                                                    message: error.to_string(),
 680                                                }),
 681                                            },
 682                                        };
 683                                        if let Some(response) =
 684                                            serde_json::to_string(&response).log_err()
 685                                        {
 686                                            outbound_tx.try_send(response).ok();
 687                                        }
 688                                    }
 689                                })
 690                                .detach();
 691                        }
 692
 693                        Err(error) => {
 694                            log::error!(
 695                                "error deserializing {} request: {:?}, message: {:?}",
 696                                method,
 697                                error,
 698                                params
 699                            );
 700                            let response = AnyResponse {
 701                                jsonrpc: JSON_RPC_VERSION,
 702                                id,
 703                                result: None,
 704                                error: Some(Error {
 705                                    message: error.to_string(),
 706                                }),
 707                            };
 708                            if let Some(response) = serde_json::to_string(&response).log_err() {
 709                                outbound_tx.try_send(response).ok();
 710                            }
 711                        }
 712                    }
 713                }
 714            }),
 715        );
 716        assert!(
 717            prev_handler.is_none(),
 718            "registered multiple handlers for the same LSP method"
 719        );
 720        Subscription::Notification {
 721            method,
 722            notification_handlers: Some(self.notification_handlers.clone()),
 723        }
 724    }
 725
 726    pub fn name(&self) -> &str {
 727        &self.name
 728    }
 729
 730    pub fn capabilities(&self) -> &ServerCapabilities {
 731        &self.capabilities
 732    }
 733
 734    pub fn server_id(&self) -> LanguageServerId {
 735        self.server_id
 736    }
 737
 738    pub fn root_path(&self) -> &PathBuf {
 739        &self.root_path
 740    }
 741
 742    pub fn request<T: request::Request>(
 743        &self,
 744        params: T::Params,
 745    ) -> impl Future<Output = Result<T::Result>>
 746    where
 747        T::Result: 'static + Send,
 748    {
 749        Self::request_internal::<T>(
 750            &self.next_id,
 751            &self.response_handlers,
 752            &self.outbound_tx,
 753            &self.executor,
 754            params,
 755        )
 756    }
 757
 758    fn request_internal<T: request::Request>(
 759        next_id: &AtomicUsize,
 760        response_handlers: &Mutex<Option<HashMap<usize, ResponseHandler>>>,
 761        outbound_tx: &channel::Sender<String>,
 762        executor: &Executor,
 763        params: T::Params,
 764    ) -> impl 'static + Future<Output = anyhow::Result<T::Result>>
 765    where
 766        T::Result: 'static + Send,
 767    {
 768        let id = next_id.fetch_add(1, SeqCst);
 769        let message = serde_json::to_string(&Request {
 770            jsonrpc: JSON_RPC_VERSION,
 771            id,
 772            method: T::METHOD,
 773            params,
 774        })
 775        .unwrap();
 776
 777        let (tx, rx) = oneshot::channel();
 778        let handle_response = response_handlers
 779            .lock()
 780            .as_mut()
 781            .ok_or_else(|| anyhow!("server shut down"))
 782            .map(|handlers| {
 783                let executor = executor.clone();
 784                handlers.insert(
 785                    id,
 786                    Box::new(move |result| {
 787                        executor
 788                            .spawn(async move {
 789                                let response = match result {
 790                                    Ok(response) => serde_json::from_str(&response)
 791                                        .context("failed to deserialize response"),
 792                                    Err(error) => Err(anyhow!("{}", error.message)),
 793                                };
 794                                _ = tx.send(response);
 795                            })
 796                            .detach();
 797                    }),
 798                );
 799            });
 800
 801        let send = outbound_tx
 802            .try_send(message)
 803            .context("failed to write to language server's stdin");
 804
 805        let mut timeout = executor.timer(LSP_REQUEST_TIMEOUT).fuse();
 806        let started = Instant::now();
 807        async move {
 808            handle_response?;
 809            send?;
 810
 811            let method = T::METHOD;
 812            futures::select! {
 813                response = rx.fuse() => {
 814                    let elapsed = started.elapsed();
 815                    log::trace!("Took {elapsed:?} to recieve response to {method:?} id {id}");
 816                    response?
 817                }
 818
 819                _ = timeout => {
 820                    log::error!("Cancelled LSP request task for {method:?} id {id} which took over {LSP_REQUEST_TIMEOUT:?}");
 821                    anyhow::bail!("LSP request timeout");
 822                }
 823            }
 824        }
 825    }
 826
 827    pub fn notify<T: notification::Notification>(&self, params: T::Params) -> Result<()> {
 828        Self::notify_internal::<T>(&self.outbound_tx, params)
 829    }
 830
 831    fn notify_internal<T: notification::Notification>(
 832        outbound_tx: &channel::Sender<String>,
 833        params: T::Params,
 834    ) -> Result<()> {
 835        let message = serde_json::to_string(&Notification {
 836            jsonrpc: JSON_RPC_VERSION,
 837            method: T::METHOD,
 838            params,
 839        })
 840        .unwrap();
 841        outbound_tx.try_send(message)?;
 842        Ok(())
 843    }
 844}
 845
 846impl Drop for LanguageServer {
 847    fn drop(&mut self) {
 848        if let Some(shutdown) = self.shutdown() {
 849            self.executor.spawn(shutdown).detach();
 850        }
 851    }
 852}
 853
 854impl Subscription {
 855    pub fn detach(&mut self) {
 856        match self {
 857            Subscription::Notification {
 858                notification_handlers,
 859                ..
 860            } => *notification_handlers = None,
 861            Subscription::Io { io_handlers, .. } => *io_handlers = None,
 862        }
 863    }
 864}
 865
 866impl fmt::Display for LanguageServerId {
 867    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 868        self.0.fmt(f)
 869    }
 870}
 871
 872impl fmt::Debug for LanguageServer {
 873    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 874        f.debug_struct("LanguageServer")
 875            .field("id", &self.server_id.0)
 876            .field("name", &self.name)
 877            .finish_non_exhaustive()
 878    }
 879}
 880
 881impl Drop for Subscription {
 882    fn drop(&mut self) {
 883        match self {
 884            Subscription::Notification {
 885                method,
 886                notification_handlers,
 887            } => {
 888                if let Some(handlers) = notification_handlers {
 889                    handlers.lock().remove(method);
 890                }
 891            }
 892            Subscription::Io { id, io_handlers } => {
 893                if let Some(io_handlers) = io_handlers.as_ref().and_then(|h| h.upgrade()) {
 894                    io_handlers.lock().remove(id);
 895                }
 896            }
 897        }
 898    }
 899}
 900
 901#[cfg(any(test, feature = "test-support"))]
 902#[derive(Clone)]
 903pub struct FakeLanguageServer {
 904    pub server: Arc<LanguageServer>,
 905    notifications_rx: channel::Receiver<(String, String)>,
 906}
 907
 908#[cfg(any(test, feature = "test-support"))]
 909impl LanguageServer {
 910    pub fn full_capabilities() -> ServerCapabilities {
 911        ServerCapabilities {
 912            document_highlight_provider: Some(OneOf::Left(true)),
 913            code_action_provider: Some(CodeActionProviderCapability::Simple(true)),
 914            document_formatting_provider: Some(OneOf::Left(true)),
 915            document_range_formatting_provider: Some(OneOf::Left(true)),
 916            definition_provider: Some(OneOf::Left(true)),
 917            type_definition_provider: Some(TypeDefinitionProviderCapability::Simple(true)),
 918            ..Default::default()
 919        }
 920    }
 921
 922    pub fn fake(
 923        name: String,
 924        capabilities: ServerCapabilities,
 925        cx: AsyncAppContext,
 926    ) -> (Self, FakeLanguageServer) {
 927        let (stdin_writer, stdin_reader) = async_pipe::pipe();
 928        let (stdout_writer, stdout_reader) = async_pipe::pipe();
 929        let (notifications_tx, notifications_rx) = channel::unbounded();
 930
 931        let server = Self::new_internal(
 932            LanguageServerId(0),
 933            stdin_writer,
 934            stdout_reader,
 935            None::<async_pipe::PipeReader>,
 936            None,
 937            Path::new("/"),
 938            None,
 939            cx.clone(),
 940            |_| {},
 941        );
 942        let fake = FakeLanguageServer {
 943            server: Arc::new(Self::new_internal(
 944                LanguageServerId(0),
 945                stdout_writer,
 946                stdin_reader,
 947                None::<async_pipe::PipeReader>,
 948                None,
 949                Path::new("/"),
 950                None,
 951                cx,
 952                move |msg| {
 953                    notifications_tx
 954                        .try_send((
 955                            msg.method.to_string(),
 956                            msg.params
 957                                .map(|raw_value| raw_value.get())
 958                                .unwrap_or("null")
 959                                .to_string(),
 960                        ))
 961                        .ok();
 962                },
 963            )),
 964            notifications_rx,
 965        };
 966        fake.handle_request::<request::Initialize, _, _>({
 967            let capabilities = capabilities;
 968            move |_, _| {
 969                let capabilities = capabilities.clone();
 970                let name = name.clone();
 971                async move {
 972                    Ok(InitializeResult {
 973                        capabilities,
 974                        server_info: Some(ServerInfo {
 975                            name,
 976                            ..Default::default()
 977                        }),
 978                    })
 979                }
 980            }
 981        });
 982
 983        (server, fake)
 984    }
 985}
 986
 987#[cfg(any(test, feature = "test-support"))]
 988impl FakeLanguageServer {
 989    pub fn notify<T: notification::Notification>(&self, params: T::Params) {
 990        self.server.notify::<T>(params).ok();
 991    }
 992
 993    pub async fn request<T>(&self, params: T::Params) -> Result<T::Result>
 994    where
 995        T: request::Request,
 996        T::Result: 'static + Send,
 997    {
 998        self.server.executor.start_waiting();
 999        self.server.request::<T>(params).await
1000    }
1001
1002    pub async fn receive_notification<T: notification::Notification>(&mut self) -> T::Params {
1003        self.server.executor.start_waiting();
1004        self.try_receive_notification::<T>().await.unwrap()
1005    }
1006
1007    pub async fn try_receive_notification<T: notification::Notification>(
1008        &mut self,
1009    ) -> Option<T::Params> {
1010        use futures::StreamExt as _;
1011
1012        loop {
1013            let (method, params) = self.notifications_rx.next().await?;
1014            if method == T::METHOD {
1015                return Some(serde_json::from_str::<T::Params>(&params).unwrap());
1016            } else {
1017                log::info!("skipping message in fake language server {:?}", params);
1018            }
1019        }
1020    }
1021
1022    pub fn handle_request<T, F, Fut>(
1023        &self,
1024        mut handler: F,
1025    ) -> futures::channel::mpsc::UnboundedReceiver<()>
1026    where
1027        T: 'static + request::Request,
1028        T::Params: 'static + Send,
1029        F: 'static + Send + FnMut(T::Params, gpui2::AsyncAppContext) -> Fut,
1030        Fut: 'static + Send + Future<Output = Result<T::Result>>,
1031    {
1032        let (responded_tx, responded_rx) = futures::channel::mpsc::unbounded();
1033        self.server.remove_request_handler::<T>();
1034        self.server
1035            .on_request::<T, _, _>(move |params, cx| {
1036                let result = handler(params, cx.clone());
1037                let responded_tx = responded_tx.clone();
1038                async move {
1039                    cx.executor().simulate_random_delay().await;
1040                    let result = result.await;
1041                    responded_tx.unbounded_send(()).ok();
1042                    result
1043                }
1044            })
1045            .detach();
1046        responded_rx
1047    }
1048
1049    pub fn handle_notification<T, F>(
1050        &self,
1051        mut handler: F,
1052    ) -> futures::channel::mpsc::UnboundedReceiver<()>
1053    where
1054        T: 'static + notification::Notification,
1055        T::Params: 'static + Send,
1056        F: 'static + Send + FnMut(T::Params, gpui2::AsyncAppContext),
1057    {
1058        let (handled_tx, handled_rx) = futures::channel::mpsc::unbounded();
1059        self.server.remove_notification_handler::<T>();
1060        self.server
1061            .on_notification::<T, _>(move |params, cx| {
1062                handler(params, cx.clone());
1063                handled_tx.unbounded_send(()).ok();
1064            })
1065            .detach();
1066        handled_rx
1067    }
1068
1069    pub fn remove_request_handler<T>(&mut self)
1070    where
1071        T: 'static + request::Request,
1072    {
1073        self.server.remove_request_handler::<T>();
1074    }
1075
1076    pub async fn start_progress(&self, token: impl Into<String>) {
1077        let token = token.into();
1078        self.request::<request::WorkDoneProgressCreate>(WorkDoneProgressCreateParams {
1079            token: NumberOrString::String(token.clone()),
1080        })
1081        .await
1082        .unwrap();
1083        self.notify::<notification::Progress>(ProgressParams {
1084            token: NumberOrString::String(token),
1085            value: ProgressParamsValue::WorkDone(WorkDoneProgress::Begin(Default::default())),
1086        });
1087    }
1088
1089    pub fn end_progress(&self, token: impl Into<String>) {
1090        self.notify::<notification::Progress>(ProgressParams {
1091            token: NumberOrString::String(token.into()),
1092            value: ProgressParamsValue::WorkDone(WorkDoneProgress::End(Default::default())),
1093        });
1094    }
1095}
1096
1097// #[cfg(test)]
1098// mod tests {
1099//     use super::*;
1100//     use gpui::TestAppContext;
1101
1102//     #[ctor::ctor]
1103//     fn init_logger() {
1104//         if std::env::var("RUST_LOG").is_ok() {
1105//             env_logger::init();
1106//         }
1107//     }
1108
1109//     #[gpui::test]
1110//     async fn test_fake(cx: &mut TestAppContext) {
1111//         let (server, mut fake) =
1112//             LanguageServer::fake("the-lsp".to_string(), Default::default(), cx.to_async());
1113
1114//         let (message_tx, message_rx) = channel::unbounded();
1115//         let (diagnostics_tx, diagnostics_rx) = channel::unbounded();
1116//         server
1117//             .on_notification::<notification::ShowMessage, _>(move |params, _| {
1118//                 message_tx.try_send(params).unwrap()
1119//             })
1120//             .detach();
1121//         server
1122//             .on_notification::<notification::PublishDiagnostics, _>(move |params, _| {
1123//                 diagnostics_tx.try_send(params).unwrap()
1124//             })
1125//             .detach();
1126
1127//         let server = server.initialize(None).await.unwrap();
1128//         server
1129//             .notify::<notification::DidOpenTextDocument>(DidOpenTextDocumentParams {
1130//                 text_document: TextDocumentItem::new(
1131//                     Url::from_str("file://a/b").unwrap(),
1132//                     "rust".to_string(),
1133//                     0,
1134//                     "".to_string(),
1135//                 ),
1136//             })
1137//             .unwrap();
1138//         assert_eq!(
1139//             fake.receive_notification::<notification::DidOpenTextDocument>()
1140//                 .await
1141//                 .text_document
1142//                 .uri
1143//                 .as_str(),
1144//             "file://a/b"
1145//         );
1146
1147//         fake.notify::<notification::ShowMessage>(ShowMessageParams {
1148//             typ: MessageType::ERROR,
1149//             message: "ok".to_string(),
1150//         });
1151//         fake.notify::<notification::PublishDiagnostics>(PublishDiagnosticsParams {
1152//             uri: Url::from_str("file://b/c").unwrap(),
1153//             version: Some(5),
1154//             diagnostics: vec![],
1155//         });
1156//         assert_eq!(message_rx.recv().await.unwrap().message, "ok");
1157//         assert_eq!(
1158//             diagnostics_rx.recv().await.unwrap().uri.as_str(),
1159//             "file://b/c"
1160//         );
1161
1162//         fake.handle_request::<request::Shutdown, _, _>(|_, _| async move { Ok(()) });
1163
1164//         drop(server);
1165//         fake.receive_notification::<notification::Exit>().await;
1166//     }
1167// }