lsp.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, select, AsyncRead, AsyncWrite, Future, 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};
  18
  19#[cfg(target_os = "windows")]
  20use smol::process::windows::CommandExt;
  21
  22use std::{
  23    ffi::OsString,
  24    fmt,
  25    io::Write,
  26    path::PathBuf,
  27    pin::Pin,
  28    str::{self, FromStr as _},
  29    sync::{
  30        atomic::{AtomicI32, Ordering::SeqCst},
  31        Arc, Weak,
  32    },
  33    task::Poll,
  34    time::{Duration, Instant},
  35};
  36use std::{path::Path, process::Stdio};
  37use util::{ResultExt, TryFutureExt};
  38
  39const HEADER_DELIMITER: &'static [u8; 4] = b"\r\n\r\n";
  40const JSON_RPC_VERSION: &str = "2.0";
  41const CONTENT_LEN_HEADER: &str = "Content-Length: ";
  42const LSP_REQUEST_TIMEOUT: Duration = Duration::from_secs(60 * 2);
  43const SERVER_SHUTDOWN_TIMEOUT: Duration = Duration::from_secs(5);
  44
  45type NotificationHandler = Box<dyn Send + FnMut(Option<RequestId>, &str, AsyncAppContext)>;
  46type ResponseHandler = Box<dyn Send + FnOnce(Result<String, Error>)>;
  47type IoHandler = Box<dyn Send + FnMut(IoKind, &str)>;
  48
  49/// Kind of language server stdio given to an IO handler.
  50#[derive(Debug, Clone, Copy)]
  51pub enum IoKind {
  52    StdOut,
  53    StdIn,
  54    StdErr,
  55}
  56
  57/// Represents a launchable language server. This can either be a standalone binary or the path
  58/// to a runtime with arguments to instruct it to launch the actual language server file.
  59#[derive(Debug, Clone, Deserialize)]
  60pub struct LanguageServerBinary {
  61    pub path: PathBuf,
  62    pub arguments: Vec<OsString>,
  63    pub env: Option<HashMap<String, String>>,
  64}
  65
  66/// A running language server process.
  67pub struct LanguageServer {
  68    server_id: LanguageServerId,
  69    next_id: AtomicI32,
  70    outbound_tx: channel::Sender<String>,
  71    name: Arc<str>,
  72    capabilities: ServerCapabilities,
  73    code_action_kinds: Option<Vec<CodeActionKind>>,
  74    notification_handlers: Arc<Mutex<HashMap<&'static str, NotificationHandler>>>,
  75    response_handlers: Arc<Mutex<Option<HashMap<RequestId, ResponseHandler>>>>,
  76    io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
  77    executor: BackgroundExecutor,
  78    #[allow(clippy::type_complexity)]
  79    io_tasks: Mutex<Option<(Task<Option<()>>, Task<Option<()>>)>>,
  80    output_done_rx: Mutex<Option<barrier::Receiver>>,
  81    root_path: PathBuf,
  82    server: Arc<Mutex<Option<Child>>>,
  83}
  84
  85/// Identifies a running language server.
  86#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
  87#[repr(transparent)]
  88pub struct LanguageServerId(pub usize);
  89
  90/// Handle to a language server RPC activity subscription.
  91pub enum Subscription {
  92    Notification {
  93        method: &'static str,
  94        notification_handlers: Option<Arc<Mutex<HashMap<&'static str, NotificationHandler>>>>,
  95    },
  96    Io {
  97        id: i32,
  98        io_handlers: Option<Weak<Mutex<HashMap<i32, IoHandler>>>>,
  99    },
 100}
 101
 102/// Language server protocol RPC request message ID.
 103///
 104/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
 105#[derive(Debug, Clone, Eq, PartialEq, Hash, Serialize, Deserialize)]
 106#[serde(untagged)]
 107pub enum RequestId {
 108    Int(i32),
 109    Str(String),
 110}
 111
 112/// Language server protocol RPC request message.
 113///
 114/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
 115#[derive(Serialize, Deserialize)]
 116pub struct Request<'a, T> {
 117    jsonrpc: &'static str,
 118    id: RequestId,
 119    method: &'a str,
 120    params: T,
 121}
 122
 123/// Language server protocol RPC request response message before it is deserialized into a concrete type.
 124#[derive(Serialize, Deserialize)]
 125struct AnyResponse<'a> {
 126    jsonrpc: &'a str,
 127    id: RequestId,
 128    #[serde(default)]
 129    error: Option<Error>,
 130    #[serde(borrow)]
 131    result: Option<&'a RawValue>,
 132}
 133
 134/// Language server protocol RPC request response message.
 135///
 136/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#responseMessage)
 137#[derive(Serialize)]
 138struct Response<T> {
 139    jsonrpc: &'static str,
 140    id: RequestId,
 141    #[serde(flatten)]
 142    value: LspResult<T>,
 143}
 144
 145#[derive(Serialize)]
 146#[serde(rename_all = "snake_case")]
 147enum LspResult<T> {
 148    #[serde(rename = "result")]
 149    Ok(Option<T>),
 150    Error(Option<Error>),
 151}
 152
 153/// Language server protocol RPC notification message.
 154///
 155/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
 156#[derive(Serialize, Deserialize)]
 157struct Notification<'a, T> {
 158    jsonrpc: &'static str,
 159    #[serde(borrow)]
 160    method: &'a str,
 161    params: T,
 162}
 163
 164/// Language server RPC notification message before it is deserialized into a concrete type.
 165#[derive(Debug, Clone, Deserialize)]
 166struct AnyNotification<'a> {
 167    #[serde(default)]
 168    id: Option<RequestId>,
 169    #[serde(borrow)]
 170    method: &'a str,
 171    #[serde(borrow, default)]
 172    params: Option<&'a RawValue>,
 173}
 174
 175#[derive(Debug, Serialize, Deserialize)]
 176struct Error {
 177    message: String,
 178}
 179
 180pub trait LspRequestFuture<O>: Future<Output = O> {
 181    fn id(&self) -> i32;
 182}
 183
 184struct LspRequest<F> {
 185    id: i32,
 186    request: F,
 187}
 188
 189impl<F> LspRequest<F> {
 190    pub fn new(id: i32, request: F) -> Self {
 191        Self { id, request }
 192    }
 193}
 194
 195impl<F: Future> Future for LspRequest<F> {
 196    type Output = F::Output;
 197
 198    fn poll(self: Pin<&mut Self>, cx: &mut std::task::Context<'_>) -> Poll<Self::Output> {
 199        // SAFETY: This is standard pin projection, we're pinned so our fields must be pinned.
 200        let inner = unsafe { Pin::new_unchecked(&mut self.get_unchecked_mut().request) };
 201        inner.poll(cx)
 202    }
 203}
 204
 205impl<F: Future> LspRequestFuture<F::Output> for LspRequest<F> {
 206    fn id(&self) -> i32 {
 207        self.id
 208    }
 209}
 210
 211/// Experimental: Informs the end user about the state of the server
 212///
 213/// [Rust Analyzer Specification](https://github.com/rust-lang/rust-analyzer/blob/master/docs/dev/lsp-extensions.md#server-status)
 214#[derive(Debug)]
 215pub enum ServerStatus {}
 216
 217/// Other(String) variant to handle unknown values due to this still being experimental
 218#[derive(Debug, PartialEq, Deserialize, Serialize, Clone)]
 219#[serde(rename_all = "camelCase")]
 220pub enum ServerHealthStatus {
 221    Ok,
 222    Warning,
 223    Error,
 224    Other(String),
 225}
 226
 227#[derive(Debug, PartialEq, Deserialize, Serialize, Clone)]
 228#[serde(rename_all = "camelCase")]
 229pub struct ServerStatusParams {
 230    pub health: ServerHealthStatus,
 231    pub message: Option<String>,
 232}
 233
 234impl lsp_types::notification::Notification for ServerStatus {
 235    type Params = ServerStatusParams;
 236    const METHOD: &'static str = "experimental/serverStatus";
 237}
 238
 239impl LanguageServer {
 240    /// Starts a language server process.
 241    pub fn new(
 242        stderr_capture: Arc<Mutex<Option<String>>>,
 243        server_id: LanguageServerId,
 244        binary: LanguageServerBinary,
 245        root_path: &Path,
 246        code_action_kinds: Option<Vec<CodeActionKind>>,
 247        cx: AsyncAppContext,
 248    ) -> Result<Self> {
 249        let working_dir = if root_path.is_dir() {
 250            root_path
 251        } else {
 252            root_path.parent().unwrap_or_else(|| Path::new("/"))
 253        };
 254
 255        log::info!(
 256            "starting language server. binary path: {:?}, working directory: {:?}, args: {:?}",
 257            binary.path,
 258            working_dir,
 259            &binary.arguments
 260        );
 261
 262        let mut command = process::Command::new(&binary.path);
 263        command
 264            .current_dir(working_dir)
 265            .args(binary.arguments)
 266            .envs(binary.env.unwrap_or_default())
 267            .stdin(Stdio::piped())
 268            .stdout(Stdio::piped())
 269            .stderr(Stdio::piped())
 270            .kill_on_drop(true);
 271        #[cfg(windows)]
 272        command.creation_flags(windows::Win32::System::Threading::CREATE_NO_WINDOW.0);
 273        let mut server = command.spawn()?;
 274
 275        let stdin = server.stdin.take().unwrap();
 276        let stdout = server.stdout.take().unwrap();
 277        let stderr = server.stderr.take().unwrap();
 278        let mut server = Self::new_internal(
 279            server_id,
 280            stdin,
 281            stdout,
 282            Some(stderr),
 283            stderr_capture,
 284            Some(server),
 285            root_path,
 286            code_action_kinds,
 287            cx,
 288            move |notification| {
 289                log::info!(
 290                    "Language server with id {} sent unhandled notification {}:\n{}",
 291                    server_id,
 292                    notification.method,
 293                    serde_json::to_string_pretty(
 294                        &notification
 295                            .params
 296                            .and_then(|params| Value::from_str(params.get()).ok())
 297                            .unwrap_or(Value::Null)
 298                    )
 299                    .unwrap(),
 300                );
 301            },
 302        );
 303
 304        if let Some(name) = binary.path.file_name() {
 305            server.name = name.to_string_lossy().into();
 306        }
 307
 308        Ok(server)
 309    }
 310
 311    #[allow(clippy::too_many_arguments)]
 312    fn new_internal<Stdin, Stdout, Stderr, F>(
 313        server_id: LanguageServerId,
 314        stdin: Stdin,
 315        stdout: Stdout,
 316        stderr: Option<Stderr>,
 317        stderr_capture: Arc<Mutex<Option<String>>>,
 318        server: Option<Child>,
 319        root_path: &Path,
 320        code_action_kinds: Option<Vec<CodeActionKind>>,
 321        cx: AsyncAppContext,
 322        on_unhandled_notification: F,
 323    ) -> Self
 324    where
 325        Stdin: AsyncWrite + Unpin + Send + 'static,
 326        Stdout: AsyncRead + Unpin + Send + 'static,
 327        Stderr: AsyncRead + Unpin + Send + 'static,
 328        F: FnMut(AnyNotification) + 'static + Send + Sync + Clone,
 329    {
 330        let (outbound_tx, outbound_rx) = channel::unbounded::<String>();
 331        let (output_done_tx, output_done_rx) = barrier::channel();
 332        let notification_handlers =
 333            Arc::new(Mutex::new(HashMap::<_, NotificationHandler>::default()));
 334        let response_handlers =
 335            Arc::new(Mutex::new(Some(HashMap::<_, ResponseHandler>::default())));
 336        let io_handlers = Arc::new(Mutex::new(HashMap::default()));
 337
 338        let stdout_input_task = cx.spawn({
 339            let on_unhandled_notification = on_unhandled_notification.clone();
 340            let notification_handlers = notification_handlers.clone();
 341            let response_handlers = response_handlers.clone();
 342            let io_handlers = io_handlers.clone();
 343            move |cx| {
 344                Self::handle_input(
 345                    stdout,
 346                    on_unhandled_notification,
 347                    notification_handlers,
 348                    response_handlers,
 349                    io_handlers,
 350                    cx,
 351                )
 352                .log_err()
 353            }
 354        });
 355        let stderr_input_task = stderr
 356            .map(|stderr| {
 357                let io_handlers = io_handlers.clone();
 358                let stderr_captures = stderr_capture.clone();
 359                cx.spawn(|_| Self::handle_stderr(stderr, io_handlers, stderr_captures).log_err())
 360            })
 361            .unwrap_or_else(|| Task::Ready(Some(None)));
 362        let input_task = cx.spawn(|_| async move {
 363            let (stdout, stderr) = futures::join!(stdout_input_task, stderr_input_task);
 364            stdout.or(stderr)
 365        });
 366        let output_task = cx.background_executor().spawn({
 367            Self::handle_output(
 368                stdin,
 369                outbound_rx,
 370                output_done_tx,
 371                response_handlers.clone(),
 372                io_handlers.clone(),
 373            )
 374            .log_err()
 375        });
 376
 377        Self {
 378            server_id,
 379            notification_handlers,
 380            response_handlers,
 381            io_handlers,
 382            name: "".into(),
 383            capabilities: Default::default(),
 384            code_action_kinds,
 385            next_id: Default::default(),
 386            outbound_tx,
 387            executor: cx.background_executor().clone(),
 388            io_tasks: Mutex::new(Some((input_task, output_task))),
 389            output_done_rx: Mutex::new(Some(output_done_rx)),
 390            root_path: root_path.to_path_buf(),
 391            server: Arc::new(Mutex::new(server)),
 392        }
 393    }
 394
 395    /// List of code action kinds this language server reports being able to emit.
 396    pub fn code_action_kinds(&self) -> Option<Vec<CodeActionKind>> {
 397        self.code_action_kinds.clone()
 398    }
 399
 400    async fn handle_input<Stdout, F>(
 401        stdout: Stdout,
 402        mut on_unhandled_notification: F,
 403        notification_handlers: Arc<Mutex<HashMap<&'static str, NotificationHandler>>>,
 404        response_handlers: Arc<Mutex<Option<HashMap<RequestId, ResponseHandler>>>>,
 405        io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
 406        cx: AsyncAppContext,
 407    ) -> anyhow::Result<()>
 408    where
 409        Stdout: AsyncRead + Unpin + Send + 'static,
 410        F: FnMut(AnyNotification) + 'static + Send,
 411    {
 412        let mut stdout = BufReader::new(stdout);
 413        let _clear_response_handlers = util::defer({
 414            let response_handlers = response_handlers.clone();
 415            move || {
 416                response_handlers.lock().take();
 417            }
 418        });
 419        let mut buffer = Vec::new();
 420        loop {
 421            buffer.clear();
 422
 423            read_headers(&mut stdout, &mut buffer).await?;
 424
 425            let headers = std::str::from_utf8(&buffer)?;
 426
 427            let message_len = headers
 428                .split('\n')
 429                .find(|line| line.starts_with(CONTENT_LEN_HEADER))
 430                .and_then(|line| line.strip_prefix(CONTENT_LEN_HEADER))
 431                .ok_or_else(|| anyhow!("invalid LSP message header {headers:?}"))?
 432                .trim_end()
 433                .parse()?;
 434
 435            buffer.resize(message_len, 0);
 436            stdout.read_exact(&mut buffer).await?;
 437
 438            if let Ok(message) = str::from_utf8(&buffer) {
 439                log::trace!("incoming message: {message}");
 440                for handler in io_handlers.lock().values_mut() {
 441                    handler(IoKind::StdOut, message);
 442                }
 443            }
 444
 445            if let Ok(msg) = serde_json::from_slice::<AnyNotification>(&buffer) {
 446                if let Some(handler) = notification_handlers.lock().get_mut(msg.method) {
 447                    handler(
 448                        msg.id,
 449                        msg.params.map(|params| params.get()).unwrap_or("null"),
 450                        cx.clone(),
 451                    );
 452                } else {
 453                    on_unhandled_notification(msg);
 454                }
 455            } else if let Ok(AnyResponse {
 456                id, error, result, ..
 457            }) = serde_json::from_slice(&buffer)
 458            {
 459                if let Some(handler) = response_handlers
 460                    .lock()
 461                    .as_mut()
 462                    .and_then(|handlers| handlers.remove(&id))
 463                {
 464                    if let Some(error) = error {
 465                        handler(Err(error));
 466                    } else if let Some(result) = result {
 467                        handler(Ok(result.get().into()));
 468                    } else {
 469                        handler(Ok("null".into()));
 470                    }
 471                }
 472            } else {
 473                warn!(
 474                    "failed to deserialize LSP message:\n{}",
 475                    std::str::from_utf8(&buffer)?
 476                );
 477            }
 478
 479            // Don't starve the main thread when receiving lots of messages at once.
 480            smol::future::yield_now().await;
 481        }
 482    }
 483
 484    async fn handle_stderr<Stderr>(
 485        stderr: Stderr,
 486        io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
 487        stderr_capture: Arc<Mutex<Option<String>>>,
 488    ) -> anyhow::Result<()>
 489    where
 490        Stderr: AsyncRead + Unpin + Send + 'static,
 491    {
 492        let mut stderr = BufReader::new(stderr);
 493        let mut buffer = Vec::new();
 494
 495        loop {
 496            buffer.clear();
 497
 498            let bytes_read = stderr.read_until(b'\n', &mut buffer).await?;
 499            if bytes_read == 0 {
 500                return Ok(());
 501            }
 502
 503            if let Ok(message) = str::from_utf8(&buffer) {
 504                log::trace!("incoming stderr message:{message}");
 505                for handler in io_handlers.lock().values_mut() {
 506                    handler(IoKind::StdErr, message);
 507                }
 508
 509                if let Some(stderr) = stderr_capture.lock().as_mut() {
 510                    stderr.push_str(message);
 511                }
 512            }
 513
 514            // Don't starve the main thread when receiving lots of messages at once.
 515            smol::future::yield_now().await;
 516        }
 517    }
 518
 519    async fn handle_output<Stdin>(
 520        stdin: Stdin,
 521        outbound_rx: channel::Receiver<String>,
 522        output_done_tx: barrier::Sender,
 523        response_handlers: Arc<Mutex<Option<HashMap<RequestId, ResponseHandler>>>>,
 524        io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
 525    ) -> anyhow::Result<()>
 526    where
 527        Stdin: AsyncWrite + Unpin + Send + 'static,
 528    {
 529        let mut stdin = BufWriter::new(stdin);
 530        let _clear_response_handlers = util::defer({
 531            let response_handlers = response_handlers.clone();
 532            move || {
 533                response_handlers.lock().take();
 534            }
 535        });
 536        let mut content_len_buffer = Vec::new();
 537        while let Ok(message) = outbound_rx.recv().await {
 538            log::trace!("outgoing message:{}", message);
 539            for handler in io_handlers.lock().values_mut() {
 540                handler(IoKind::StdIn, &message);
 541            }
 542
 543            content_len_buffer.clear();
 544            write!(content_len_buffer, "{}", message.len()).unwrap();
 545            stdin.write_all(CONTENT_LEN_HEADER.as_bytes()).await?;
 546            stdin.write_all(&content_len_buffer).await?;
 547            stdin.write_all("\r\n\r\n".as_bytes()).await?;
 548            stdin.write_all(message.as_bytes()).await?;
 549            stdin.flush().await?;
 550        }
 551        drop(output_done_tx);
 552        Ok(())
 553    }
 554
 555    /// Initializes a language server by sending the `Initialize` request.
 556    /// Note that `options` is used directly to construct [`InitializeParams`], which is why it is owned.
 557    ///
 558    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#initialize)
 559    pub fn initialize(
 560        mut self,
 561        options: Option<Value>,
 562        cx: &AppContext,
 563    ) -> Task<Result<Arc<Self>>> {
 564        let root_uri = Url::from_file_path(&self.root_path).unwrap();
 565        #[allow(deprecated)]
 566        let params = InitializeParams {
 567            process_id: None,
 568            root_path: None,
 569            root_uri: Some(root_uri.clone()),
 570            initialization_options: options,
 571            capabilities: ClientCapabilities {
 572                workspace: Some(WorkspaceClientCapabilities {
 573                    configuration: Some(true),
 574                    did_change_watched_files: Some(DidChangeWatchedFilesClientCapabilities {
 575                        dynamic_registration: Some(true),
 576                        relative_pattern_support: Some(true),
 577                    }),
 578                    did_change_configuration: Some(DynamicRegistrationClientCapabilities {
 579                        dynamic_registration: Some(true),
 580                    }),
 581                    workspace_folders: Some(true),
 582                    symbol: Some(WorkspaceSymbolClientCapabilities {
 583                        resolve_support: None,
 584                        ..WorkspaceSymbolClientCapabilities::default()
 585                    }),
 586                    inlay_hint: Some(InlayHintWorkspaceClientCapabilities {
 587                        refresh_support: Some(true),
 588                    }),
 589                    diagnostic: Some(DiagnosticWorkspaceClientCapabilities {
 590                        refresh_support: None,
 591                    }),
 592                    workspace_edit: Some(WorkspaceEditClientCapabilities {
 593                        resource_operations: Some(vec![
 594                            ResourceOperationKind::Create,
 595                            ResourceOperationKind::Rename,
 596                            ResourceOperationKind::Delete,
 597                        ]),
 598                        document_changes: Some(true),
 599                        ..WorkspaceEditClientCapabilities::default()
 600                    }),
 601                    ..Default::default()
 602                }),
 603                text_document: Some(TextDocumentClientCapabilities {
 604                    definition: Some(GotoCapability {
 605                        link_support: Some(true),
 606                        dynamic_registration: None,
 607                    }),
 608                    code_action: Some(CodeActionClientCapabilities {
 609                        code_action_literal_support: Some(CodeActionLiteralSupport {
 610                            code_action_kind: CodeActionKindLiteralSupport {
 611                                value_set: vec![
 612                                    CodeActionKind::REFACTOR.as_str().into(),
 613                                    CodeActionKind::QUICKFIX.as_str().into(),
 614                                    CodeActionKind::SOURCE.as_str().into(),
 615                                ],
 616                            },
 617                        }),
 618                        data_support: Some(true),
 619                        resolve_support: Some(CodeActionCapabilityResolveSupport {
 620                            properties: vec![
 621                                "kind".to_string(),
 622                                "diagnostics".to_string(),
 623                                "isPreferred".to_string(),
 624                                "disabled".to_string(),
 625                                "edit".to_string(),
 626                                "command".to_string(),
 627                            ],
 628                        }),
 629                        ..Default::default()
 630                    }),
 631                    completion: Some(CompletionClientCapabilities {
 632                        completion_item: Some(CompletionItemCapability {
 633                            snippet_support: Some(true),
 634                            resolve_support: Some(CompletionItemCapabilityResolveSupport {
 635                                properties: vec![
 636                                    "documentation".to_string(),
 637                                    "additionalTextEdits".to_string(),
 638                                ],
 639                            }),
 640                            insert_replace_support: Some(true),
 641                            ..Default::default()
 642                        }),
 643                        completion_list: Some(CompletionListCapability {
 644                            item_defaults: Some(vec![
 645                                "commitCharacters".to_owned(),
 646                                "editRange".to_owned(),
 647                                "insertTextMode".to_owned(),
 648                                "data".to_owned(),
 649                            ]),
 650                        }),
 651                        ..Default::default()
 652                    }),
 653                    rename: Some(RenameClientCapabilities {
 654                        prepare_support: Some(true),
 655                        ..Default::default()
 656                    }),
 657                    hover: Some(HoverClientCapabilities {
 658                        content_format: Some(vec![MarkupKind::Markdown]),
 659                        dynamic_registration: None,
 660                    }),
 661                    inlay_hint: Some(InlayHintClientCapabilities {
 662                        resolve_support: Some(InlayHintResolveClientCapabilities {
 663                            properties: vec![
 664                                "textEdits".to_string(),
 665                                "tooltip".to_string(),
 666                                "label.tooltip".to_string(),
 667                                "label.location".to_string(),
 668                                "label.command".to_string(),
 669                            ],
 670                        }),
 671                        dynamic_registration: Some(false),
 672                    }),
 673                    publish_diagnostics: Some(PublishDiagnosticsClientCapabilities {
 674                        related_information: Some(true),
 675                        ..Default::default()
 676                    }),
 677                    formatting: Some(DynamicRegistrationClientCapabilities {
 678                        dynamic_registration: None,
 679                    }),
 680                    on_type_formatting: Some(DynamicRegistrationClientCapabilities {
 681                        dynamic_registration: None,
 682                    }),
 683                    diagnostic: Some(DiagnosticClientCapabilities {
 684                        related_document_support: Some(true),
 685                        dynamic_registration: None,
 686                    }),
 687                    ..Default::default()
 688                }),
 689                experimental: Some(json!({
 690                    "serverStatusNotification": true,
 691                })),
 692                window: Some(WindowClientCapabilities {
 693                    work_done_progress: Some(true),
 694                    ..Default::default()
 695                }),
 696                general: None,
 697            },
 698            trace: None,
 699            workspace_folders: Some(vec![WorkspaceFolder {
 700                uri: root_uri,
 701                name: Default::default(),
 702            }]),
 703            client_info: release_channel::ReleaseChannel::try_global(cx).map(|release_channel| {
 704                ClientInfo {
 705                    name: release_channel.display_name().to_string(),
 706                    version: Some(release_channel::AppVersion::global(cx).to_string()),
 707                }
 708            }),
 709            locale: None,
 710        };
 711
 712        cx.spawn(|_| async move {
 713            let response = self.request::<request::Initialize>(params).await?;
 714            if let Some(info) = response.server_info {
 715                self.name = info.name.into();
 716            }
 717            self.capabilities = response.capabilities;
 718
 719            self.notify::<notification::Initialized>(InitializedParams {})?;
 720            Ok(Arc::new(self))
 721        })
 722    }
 723
 724    /// Sends a shutdown request to the language server process and prepares the [`LanguageServer`] to be dropped.
 725    pub fn shutdown(&self) -> Option<impl 'static + Send + Future<Output = Option<()>>> {
 726        if let Some(tasks) = self.io_tasks.lock().take() {
 727            let response_handlers = self.response_handlers.clone();
 728            let next_id = AtomicI32::new(self.next_id.load(SeqCst));
 729            let outbound_tx = self.outbound_tx.clone();
 730            let executor = self.executor.clone();
 731            let mut output_done = self.output_done_rx.lock().take().unwrap();
 732            let shutdown_request = Self::request_internal::<request::Shutdown>(
 733                &next_id,
 734                &response_handlers,
 735                &outbound_tx,
 736                &executor,
 737                (),
 738            );
 739            let exit = Self::notify_internal::<notification::Exit>(&outbound_tx, ());
 740            outbound_tx.close();
 741
 742            let server = self.server.clone();
 743            let name = self.name.clone();
 744            let mut timer = self.executor.timer(SERVER_SHUTDOWN_TIMEOUT).fuse();
 745            Some(
 746                async move {
 747                    log::debug!("language server shutdown started");
 748
 749                    select! {
 750                        request_result = shutdown_request.fuse() => {
 751                            request_result?;
 752                        }
 753
 754                        _ = timer => {
 755                            log::info!("timeout waiting for language server {name} to shutdown");
 756                        },
 757                    }
 758
 759                    response_handlers.lock().take();
 760                    exit?;
 761                    output_done.recv().await;
 762                    server.lock().take().map(|mut child| child.kill());
 763                    log::debug!("language server shutdown finished");
 764
 765                    drop(tasks);
 766                    anyhow::Ok(())
 767                }
 768                .log_err(),
 769            )
 770        } else {
 771            None
 772        }
 773    }
 774
 775    /// Register a handler to handle incoming LSP notifications.
 776    ///
 777    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
 778    #[must_use]
 779    pub fn on_notification<T, F>(&self, f: F) -> Subscription
 780    where
 781        T: notification::Notification,
 782        F: 'static + Send + FnMut(T::Params, AsyncAppContext),
 783    {
 784        self.on_custom_notification(T::METHOD, f)
 785    }
 786
 787    /// Register a handler to handle incoming LSP requests.
 788    ///
 789    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
 790    #[must_use]
 791    pub fn on_request<T, F, Fut>(&self, f: F) -> Subscription
 792    where
 793        T: request::Request,
 794        T::Params: 'static + Send,
 795        F: 'static + FnMut(T::Params, AsyncAppContext) -> Fut + Send,
 796        Fut: 'static + Future<Output = Result<T::Result>>,
 797    {
 798        self.on_custom_request(T::METHOD, f)
 799    }
 800
 801    /// Registers a handler to inspect all language server process stdio.
 802    #[must_use]
 803    pub fn on_io<F>(&self, f: F) -> Subscription
 804    where
 805        F: 'static + Send + FnMut(IoKind, &str),
 806    {
 807        let id = self.next_id.fetch_add(1, SeqCst);
 808        self.io_handlers.lock().insert(id, Box::new(f));
 809        Subscription::Io {
 810            id,
 811            io_handlers: Some(Arc::downgrade(&self.io_handlers)),
 812        }
 813    }
 814
 815    /// Removes a request handler registers via [`Self::on_request`].
 816    pub fn remove_request_handler<T: request::Request>(&self) {
 817        self.notification_handlers.lock().remove(T::METHOD);
 818    }
 819
 820    /// Removes a notification handler registers via [`Self::on_notification`].
 821    pub fn remove_notification_handler<T: notification::Notification>(&self) {
 822        self.notification_handlers.lock().remove(T::METHOD);
 823    }
 824
 825    /// Checks if a notification handler has been registered via [`Self::on_notification`].
 826    pub fn has_notification_handler<T: notification::Notification>(&self) -> bool {
 827        self.notification_handlers.lock().contains_key(T::METHOD)
 828    }
 829
 830    #[must_use]
 831    fn on_custom_notification<Params, F>(&self, method: &'static str, mut f: F) -> Subscription
 832    where
 833        F: 'static + FnMut(Params, AsyncAppContext) + Send,
 834        Params: DeserializeOwned,
 835    {
 836        let prev_handler = self.notification_handlers.lock().insert(
 837            method,
 838            Box::new(move |_, params, cx| {
 839                if let Some(params) = serde_json::from_str(params).log_err() {
 840                    f(params, cx);
 841                }
 842            }),
 843        );
 844        assert!(
 845            prev_handler.is_none(),
 846            "registered multiple handlers for the same LSP method"
 847        );
 848        Subscription::Notification {
 849            method,
 850            notification_handlers: Some(self.notification_handlers.clone()),
 851        }
 852    }
 853
 854    #[must_use]
 855    fn on_custom_request<Params, Res, Fut, F>(&self, method: &'static str, mut f: F) -> Subscription
 856    where
 857        F: 'static + FnMut(Params, AsyncAppContext) -> Fut + Send,
 858        Fut: 'static + Future<Output = Result<Res>>,
 859        Params: DeserializeOwned + Send + 'static,
 860        Res: Serialize,
 861    {
 862        let outbound_tx = self.outbound_tx.clone();
 863        let prev_handler = self.notification_handlers.lock().insert(
 864            method,
 865            Box::new(move |id, params, cx| {
 866                if let Some(id) = id {
 867                    match serde_json::from_str(params) {
 868                        Ok(params) => {
 869                            let response = f(params, cx.clone());
 870                            cx.foreground_executor()
 871                                .spawn({
 872                                    let outbound_tx = outbound_tx.clone();
 873                                    async move {
 874                                        let response = match response.await {
 875                                            Ok(result) => Response {
 876                                                jsonrpc: JSON_RPC_VERSION,
 877                                                id,
 878                                                value: LspResult::Ok(Some(result)),
 879                                            },
 880                                            Err(error) => Response {
 881                                                jsonrpc: JSON_RPC_VERSION,
 882                                                id,
 883                                                value: LspResult::Error(Some(Error {
 884                                                    message: error.to_string(),
 885                                                })),
 886                                            },
 887                                        };
 888                                        if let Some(response) =
 889                                            serde_json::to_string(&response).log_err()
 890                                        {
 891                                            outbound_tx.try_send(response).ok();
 892                                        }
 893                                    }
 894                                })
 895                                .detach();
 896                        }
 897
 898                        Err(error) => {
 899                            log::error!(
 900                                "error deserializing {} request: {:?}, message: {:?}",
 901                                method,
 902                                error,
 903                                params
 904                            );
 905                            let response = AnyResponse {
 906                                jsonrpc: JSON_RPC_VERSION,
 907                                id,
 908                                result: None,
 909                                error: Some(Error {
 910                                    message: error.to_string(),
 911                                }),
 912                            };
 913                            if let Some(response) = serde_json::to_string(&response).log_err() {
 914                                outbound_tx.try_send(response).ok();
 915                            }
 916                        }
 917                    }
 918                }
 919            }),
 920        );
 921        assert!(
 922            prev_handler.is_none(),
 923            "registered multiple handlers for the same LSP method"
 924        );
 925        Subscription::Notification {
 926            method,
 927            notification_handlers: Some(self.notification_handlers.clone()),
 928        }
 929    }
 930
 931    /// Get the name of the running language server.
 932    pub fn name(&self) -> &str {
 933        &self.name
 934    }
 935
 936    /// Get the reported capabilities of the running language server.
 937    pub fn capabilities(&self) -> &ServerCapabilities {
 938        &self.capabilities
 939    }
 940
 941    /// Get the id of the running language server.
 942    pub fn server_id(&self) -> LanguageServerId {
 943        self.server_id
 944    }
 945
 946    /// Get the root path of the project the language server is running against.
 947    pub fn root_path(&self) -> &PathBuf {
 948        &self.root_path
 949    }
 950
 951    /// Sends a RPC request to the language server.
 952    ///
 953    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
 954    pub fn request<T: request::Request>(
 955        &self,
 956        params: T::Params,
 957    ) -> impl LspRequestFuture<Result<T::Result>>
 958    where
 959        T::Result: 'static + Send,
 960    {
 961        Self::request_internal::<T>(
 962            &self.next_id,
 963            &self.response_handlers,
 964            &self.outbound_tx,
 965            &self.executor,
 966            params,
 967        )
 968    }
 969
 970    fn request_internal<T: request::Request>(
 971        next_id: &AtomicI32,
 972        response_handlers: &Mutex<Option<HashMap<RequestId, ResponseHandler>>>,
 973        outbound_tx: &channel::Sender<String>,
 974        executor: &BackgroundExecutor,
 975        params: T::Params,
 976    ) -> impl LspRequestFuture<Result<T::Result>>
 977    where
 978        T::Result: 'static + Send,
 979    {
 980        let id = next_id.fetch_add(1, SeqCst);
 981        let message = serde_json::to_string(&Request {
 982            jsonrpc: JSON_RPC_VERSION,
 983            id: RequestId::Int(id),
 984            method: T::METHOD,
 985            params,
 986        })
 987        .unwrap();
 988
 989        let (tx, rx) = oneshot::channel();
 990        let handle_response = response_handlers
 991            .lock()
 992            .as_mut()
 993            .ok_or_else(|| anyhow!("server shut down"))
 994            .map(|handlers| {
 995                let executor = executor.clone();
 996                handlers.insert(
 997                    RequestId::Int(id),
 998                    Box::new(move |result| {
 999                        executor
1000                            .spawn(async move {
1001                                let response = match result {
1002                                    Ok(response) => match serde_json::from_str(&response) {
1003                                        Ok(deserialized) => Ok(deserialized),
1004                                        Err(error) => {
1005                                            log::error!("failed to deserialize response from language server: {}. response from language server: {:?}", error, response);
1006                                            Err(error).context("failed to deserialize response")
1007                                        }
1008                                    }
1009                                    Err(error) => Err(anyhow!("{}", error.message)),
1010                                };
1011                                _ = tx.send(response);
1012                            })
1013                            .detach();
1014                    }),
1015                );
1016            });
1017
1018        let send = outbound_tx
1019            .try_send(message)
1020            .context("failed to write to language server's stdin");
1021
1022        let outbound_tx = outbound_tx.downgrade();
1023        let mut timeout = executor.timer(LSP_REQUEST_TIMEOUT).fuse();
1024        let started = Instant::now();
1025        LspRequest::new(id, async move {
1026            handle_response?;
1027            send?;
1028
1029            let cancel_on_drop = util::defer(move || {
1030                if let Some(outbound_tx) = outbound_tx.upgrade() {
1031                    Self::notify_internal::<notification::Cancel>(
1032                        &outbound_tx,
1033                        CancelParams {
1034                            id: NumberOrString::Number(id),
1035                        },
1036                    )
1037                    .log_err();
1038                }
1039            });
1040
1041            let method = T::METHOD;
1042            select! {
1043                response = rx.fuse() => {
1044                    let elapsed = started.elapsed();
1045                    log::trace!("Took {elapsed:?} to receive response to {method:?} id {id}");
1046                    cancel_on_drop.abort();
1047                    response?
1048                }
1049
1050                _ = timeout => {
1051                    log::error!("Cancelled LSP request task for {method:?} id {id} which took over {LSP_REQUEST_TIMEOUT:?}");
1052                    anyhow::bail!("LSP request timeout");
1053                }
1054            }
1055        })
1056    }
1057
1058    /// Sends a RPC notification to the language server.
1059    ///
1060    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
1061    pub fn notify<T: notification::Notification>(&self, params: T::Params) -> Result<()> {
1062        Self::notify_internal::<T>(&self.outbound_tx, params)
1063    }
1064
1065    fn notify_internal<T: notification::Notification>(
1066        outbound_tx: &channel::Sender<String>,
1067        params: T::Params,
1068    ) -> Result<()> {
1069        let message = serde_json::to_string(&Notification {
1070            jsonrpc: JSON_RPC_VERSION,
1071            method: T::METHOD,
1072            params,
1073        })
1074        .unwrap();
1075        outbound_tx.try_send(message)?;
1076        Ok(())
1077    }
1078}
1079
1080impl Drop for LanguageServer {
1081    fn drop(&mut self) {
1082        if let Some(shutdown) = self.shutdown() {
1083            self.executor.spawn(shutdown).detach();
1084        }
1085    }
1086}
1087
1088impl Subscription {
1089    /// Detaching a subscription handle prevents it from unsubscribing on drop.
1090    pub fn detach(&mut self) {
1091        match self {
1092            Subscription::Notification {
1093                notification_handlers,
1094                ..
1095            } => *notification_handlers = None,
1096            Subscription::Io { io_handlers, .. } => *io_handlers = None,
1097        }
1098    }
1099}
1100
1101impl fmt::Display for LanguageServerId {
1102    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1103        self.0.fmt(f)
1104    }
1105}
1106
1107impl fmt::Debug for LanguageServer {
1108    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1109        f.debug_struct("LanguageServer")
1110            .field("id", &self.server_id.0)
1111            .field("name", &self.name)
1112            .finish_non_exhaustive()
1113    }
1114}
1115
1116impl Drop for Subscription {
1117    fn drop(&mut self) {
1118        match self {
1119            Subscription::Notification {
1120                method,
1121                notification_handlers,
1122            } => {
1123                if let Some(handlers) = notification_handlers {
1124                    handlers.lock().remove(method);
1125                }
1126            }
1127            Subscription::Io { id, io_handlers } => {
1128                if let Some(io_handlers) = io_handlers.as_ref().and_then(|h| h.upgrade()) {
1129                    io_handlers.lock().remove(id);
1130                }
1131            }
1132        }
1133    }
1134}
1135
1136/// Mock language server for use in tests.
1137#[cfg(any(test, feature = "test-support"))]
1138#[derive(Clone)]
1139pub struct FakeLanguageServer {
1140    pub binary: LanguageServerBinary,
1141    pub server: Arc<LanguageServer>,
1142    notifications_rx: channel::Receiver<(String, String)>,
1143}
1144
1145#[cfg(any(test, feature = "test-support"))]
1146impl FakeLanguageServer {
1147    /// Construct a fake language server.
1148    pub fn new(
1149        server_id: LanguageServerId,
1150        binary: LanguageServerBinary,
1151        name: String,
1152        capabilities: ServerCapabilities,
1153        cx: AsyncAppContext,
1154    ) -> (LanguageServer, FakeLanguageServer) {
1155        let (stdin_writer, stdin_reader) = async_pipe::pipe();
1156        let (stdout_writer, stdout_reader) = async_pipe::pipe();
1157        let (notifications_tx, notifications_rx) = channel::unbounded();
1158
1159        let mut server = LanguageServer::new_internal(
1160            server_id,
1161            stdin_writer,
1162            stdout_reader,
1163            None::<async_pipe::PipeReader>,
1164            Arc::new(Mutex::new(None)),
1165            None,
1166            Path::new("/"),
1167            None,
1168            cx.clone(),
1169            |_| {},
1170        );
1171        server.name = name.as_str().into();
1172        let fake = FakeLanguageServer {
1173            binary,
1174            server: Arc::new({
1175                let mut server = LanguageServer::new_internal(
1176                    server_id,
1177                    stdout_writer,
1178                    stdin_reader,
1179                    None::<async_pipe::PipeReader>,
1180                    Arc::new(Mutex::new(None)),
1181                    None,
1182                    Path::new("/"),
1183                    None,
1184                    cx,
1185                    move |msg| {
1186                        notifications_tx
1187                            .try_send((
1188                                msg.method.to_string(),
1189                                msg.params
1190                                    .map(|raw_value| raw_value.get())
1191                                    .unwrap_or("null")
1192                                    .to_string(),
1193                            ))
1194                            .ok();
1195                    },
1196                );
1197                server.name = name.as_str().into();
1198                server
1199            }),
1200            notifications_rx,
1201        };
1202        fake.handle_request::<request::Initialize, _, _>({
1203            let capabilities = capabilities;
1204            move |_, _| {
1205                let capabilities = capabilities.clone();
1206                let name = name.clone();
1207                async move {
1208                    Ok(InitializeResult {
1209                        capabilities,
1210                        server_info: Some(ServerInfo {
1211                            name,
1212                            ..Default::default()
1213                        }),
1214                    })
1215                }
1216            }
1217        });
1218
1219        (server, fake)
1220    }
1221}
1222
1223#[cfg(any(test, feature = "test-support"))]
1224impl LanguageServer {
1225    pub fn full_capabilities() -> ServerCapabilities {
1226        ServerCapabilities {
1227            document_highlight_provider: Some(OneOf::Left(true)),
1228            code_action_provider: Some(CodeActionProviderCapability::Simple(true)),
1229            document_formatting_provider: Some(OneOf::Left(true)),
1230            document_range_formatting_provider: Some(OneOf::Left(true)),
1231            definition_provider: Some(OneOf::Left(true)),
1232            implementation_provider: Some(ImplementationProviderCapability::Simple(true)),
1233            type_definition_provider: Some(TypeDefinitionProviderCapability::Simple(true)),
1234            ..Default::default()
1235        }
1236    }
1237}
1238
1239#[cfg(any(test, feature = "test-support"))]
1240impl FakeLanguageServer {
1241    /// See [`LanguageServer::notify`].
1242    pub fn notify<T: notification::Notification>(&self, params: T::Params) {
1243        self.server.notify::<T>(params).ok();
1244    }
1245
1246    /// See [`LanguageServer::request`].
1247    pub async fn request<T>(&self, params: T::Params) -> Result<T::Result>
1248    where
1249        T: request::Request,
1250        T::Result: 'static + Send,
1251    {
1252        self.server.executor.start_waiting();
1253        self.server.request::<T>(params).await
1254    }
1255
1256    /// Attempts [`Self::try_receive_notification`], unwrapping if it has not received the specified type yet.
1257    pub async fn receive_notification<T: notification::Notification>(&mut self) -> T::Params {
1258        self.server.executor.start_waiting();
1259        self.try_receive_notification::<T>().await.unwrap()
1260    }
1261
1262    /// Consumes the notification channel until it finds a notification for the specified type.
1263    pub async fn try_receive_notification<T: notification::Notification>(
1264        &mut self,
1265    ) -> Option<T::Params> {
1266        use futures::StreamExt as _;
1267
1268        loop {
1269            let (method, params) = self.notifications_rx.next().await?;
1270            if method == T::METHOD {
1271                return Some(serde_json::from_str::<T::Params>(&params).unwrap());
1272            } else {
1273                log::info!("skipping message in fake language server {:?}", params);
1274            }
1275        }
1276    }
1277
1278    /// Registers a handler for a specific kind of request. Removes any existing handler for specified request type.
1279    pub fn handle_request<T, F, Fut>(
1280        &self,
1281        mut handler: F,
1282    ) -> futures::channel::mpsc::UnboundedReceiver<()>
1283    where
1284        T: 'static + request::Request,
1285        T::Params: 'static + Send,
1286        F: 'static + Send + FnMut(T::Params, gpui::AsyncAppContext) -> Fut,
1287        Fut: 'static + Send + Future<Output = Result<T::Result>>,
1288    {
1289        let (responded_tx, responded_rx) = futures::channel::mpsc::unbounded();
1290        self.server.remove_request_handler::<T>();
1291        self.server
1292            .on_request::<T, _, _>(move |params, cx| {
1293                let result = handler(params, cx.clone());
1294                let responded_tx = responded_tx.clone();
1295                let executor = cx.background_executor().clone();
1296                async move {
1297                    executor.simulate_random_delay().await;
1298                    let result = result.await;
1299                    responded_tx.unbounded_send(()).ok();
1300                    result
1301                }
1302            })
1303            .detach();
1304        responded_rx
1305    }
1306
1307    /// Registers a handler for a specific kind of notification. Removes any existing handler for specified notification type.
1308    pub fn handle_notification<T, F>(
1309        &self,
1310        mut handler: F,
1311    ) -> futures::channel::mpsc::UnboundedReceiver<()>
1312    where
1313        T: 'static + notification::Notification,
1314        T::Params: 'static + Send,
1315        F: 'static + Send + FnMut(T::Params, gpui::AsyncAppContext),
1316    {
1317        let (handled_tx, handled_rx) = futures::channel::mpsc::unbounded();
1318        self.server.remove_notification_handler::<T>();
1319        self.server
1320            .on_notification::<T, _>(move |params, cx| {
1321                handler(params, cx.clone());
1322                handled_tx.unbounded_send(()).ok();
1323            })
1324            .detach();
1325        handled_rx
1326    }
1327
1328    /// Removes any existing handler for specified notification type.
1329    pub fn remove_request_handler<T>(&mut self)
1330    where
1331        T: 'static + request::Request,
1332    {
1333        self.server.remove_request_handler::<T>();
1334    }
1335
1336    /// Simulate that the server has started work and notifies about its progress with the specified token.
1337    pub async fn start_progress(&self, token: impl Into<String>) {
1338        let token = token.into();
1339        self.request::<request::WorkDoneProgressCreate>(WorkDoneProgressCreateParams {
1340            token: NumberOrString::String(token.clone()),
1341        })
1342        .await
1343        .unwrap();
1344        self.notify::<notification::Progress>(ProgressParams {
1345            token: NumberOrString::String(token),
1346            value: ProgressParamsValue::WorkDone(WorkDoneProgress::Begin(Default::default())),
1347        });
1348    }
1349
1350    /// Simulate that the server has completed work and notifies about that with the specified token.
1351    pub fn end_progress(&self, token: impl Into<String>) {
1352        self.notify::<notification::Progress>(ProgressParams {
1353            token: NumberOrString::String(token.into()),
1354            value: ProgressParamsValue::WorkDone(WorkDoneProgress::End(Default::default())),
1355        });
1356    }
1357}
1358
1359pub(self) async fn read_headers<Stdout>(
1360    reader: &mut BufReader<Stdout>,
1361    buffer: &mut Vec<u8>,
1362) -> Result<()>
1363where
1364    Stdout: AsyncRead + Unpin + Send + 'static,
1365{
1366    loop {
1367        if buffer.len() >= HEADER_DELIMITER.len()
1368            && buffer[(buffer.len() - HEADER_DELIMITER.len())..] == HEADER_DELIMITER[..]
1369        {
1370            return Ok(());
1371        }
1372
1373        if reader.read_until(b'\n', buffer).await? == 0 {
1374            return Err(anyhow!("cannot read LSP message headers"));
1375        }
1376    }
1377}
1378
1379#[cfg(test)]
1380mod tests {
1381    use super::*;
1382    use gpui::TestAppContext;
1383
1384    #[ctor::ctor]
1385    fn init_logger() {
1386        if std::env::var("RUST_LOG").is_ok() {
1387            env_logger::init();
1388        }
1389    }
1390
1391    #[gpui::test]
1392    async fn test_fake(cx: &mut TestAppContext) {
1393        cx.update(|cx| {
1394            release_channel::init("0.0.0", cx);
1395        });
1396        let (server, mut fake) = FakeLanguageServer::new(
1397            LanguageServerId(0),
1398            LanguageServerBinary {
1399                path: "path/to/language-server".into(),
1400                arguments: vec![],
1401                env: None,
1402            },
1403            "the-lsp".to_string(),
1404            Default::default(),
1405            cx.to_async(),
1406        );
1407
1408        let (message_tx, message_rx) = channel::unbounded();
1409        let (diagnostics_tx, diagnostics_rx) = channel::unbounded();
1410        server
1411            .on_notification::<notification::ShowMessage, _>(move |params, _| {
1412                message_tx.try_send(params).unwrap()
1413            })
1414            .detach();
1415        server
1416            .on_notification::<notification::PublishDiagnostics, _>(move |params, _| {
1417                diagnostics_tx.try_send(params).unwrap()
1418            })
1419            .detach();
1420
1421        let server = cx.update(|cx| server.initialize(None, cx)).await.unwrap();
1422        server
1423            .notify::<notification::DidOpenTextDocument>(DidOpenTextDocumentParams {
1424                text_document: TextDocumentItem::new(
1425                    Url::from_str("file://a/b").unwrap(),
1426                    "rust".to_string(),
1427                    0,
1428                    "".to_string(),
1429                ),
1430            })
1431            .unwrap();
1432        assert_eq!(
1433            fake.receive_notification::<notification::DidOpenTextDocument>()
1434                .await
1435                .text_document
1436                .uri
1437                .as_str(),
1438            "file://a/b"
1439        );
1440
1441        fake.notify::<notification::ShowMessage>(ShowMessageParams {
1442            typ: MessageType::ERROR,
1443            message: "ok".to_string(),
1444        });
1445        fake.notify::<notification::PublishDiagnostics>(PublishDiagnosticsParams {
1446            uri: Url::from_str("file://b/c").unwrap(),
1447            version: Some(5),
1448            diagnostics: vec![],
1449        });
1450        assert_eq!(message_rx.recv().await.unwrap().message, "ok");
1451        assert_eq!(
1452            diagnostics_rx.recv().await.unwrap().uri.as_str(),
1453            "file://b/c"
1454        );
1455
1456        fake.handle_request::<request::Shutdown, _, _>(|_, _| async move { Ok(()) });
1457
1458        drop(server);
1459        fake.receive_notification::<notification::Exit>().await;
1460    }
1461
1462    #[gpui::test]
1463    async fn test_read_headers() {
1464        let mut buf = Vec::new();
1465        let mut reader = smol::io::BufReader::new(b"Content-Length: 123\r\n\r\n" as &[u8]);
1466        read_headers(&mut reader, &mut buf).await.unwrap();
1467        assert_eq!(buf, b"Content-Length: 123\r\n\r\n");
1468
1469        let mut buf = Vec::new();
1470        let mut reader = smol::io::BufReader::new(b"Content-Type: application/vscode-jsonrpc\r\nContent-Length: 1235\r\n\r\n{\"somecontent\":123}" as &[u8]);
1471        read_headers(&mut reader, &mut buf).await.unwrap();
1472        assert_eq!(
1473            buf,
1474            b"Content-Type: application/vscode-jsonrpc\r\nContent-Length: 1235\r\n\r\n"
1475        );
1476
1477        let mut buf = Vec::new();
1478        let mut reader = smol::io::BufReader::new(b"Content-Length: 1235\r\nContent-Type: application/vscode-jsonrpc\r\n\r\n{\"somecontent\":true}" as &[u8]);
1479        read_headers(&mut reader, &mut buf).await.unwrap();
1480        assert_eq!(
1481            buf,
1482            b"Content-Length: 1235\r\nContent-Type: application/vscode-jsonrpc\r\n\r\n"
1483        );
1484    }
1485
1486    #[gpui::test]
1487    fn test_deserialize_string_digit_id() {
1488        let json = r#"{"jsonrpc":"2.0","id":"2","method":"workspace/configuration","params":{"items":[{"scopeUri":"file:///Users/mph/Devel/personal/hello-scala/","section":"metals"}]}}"#;
1489        let notification = serde_json::from_str::<AnyNotification>(json)
1490            .expect("message with string id should be parsed");
1491        let expected_id = RequestId::Str("2".to_string());
1492        assert_eq!(notification.id, Some(expected_id));
1493    }
1494
1495    #[gpui::test]
1496    fn test_deserialize_string_id() {
1497        let json = r#"{"jsonrpc":"2.0","id":"anythingAtAll","method":"workspace/configuration","params":{"items":[{"scopeUri":"file:///Users/mph/Devel/personal/hello-scala/","section":"metals"}]}}"#;
1498        let notification = serde_json::from_str::<AnyNotification>(json)
1499            .expect("message with string id should be parsed");
1500        let expected_id = RequestId::Str("anythingAtAll".to_string());
1501        assert_eq!(notification.id, Some(expected_id));
1502    }
1503
1504    #[gpui::test]
1505    fn test_deserialize_int_id() {
1506        let json = r#"{"jsonrpc":"2.0","id":2,"method":"workspace/configuration","params":{"items":[{"scopeUri":"file:///Users/mph/Devel/personal/hello-scala/","section":"metals"}]}}"#;
1507        let notification = serde_json::from_str::<AnyNotification>(json)
1508            .expect("message with string id should be parsed");
1509        let expected_id = RequestId::Int(2);
1510        assert_eq!(notification.id, Some(expected_id));
1511    }
1512
1513    #[test]
1514    fn test_serialize_has_no_nulls() {
1515        // Ensure we're not setting both result and error variants. (ticket #10595)
1516        let no_tag = Response::<u32> {
1517            jsonrpc: "",
1518            id: RequestId::Int(0),
1519            value: LspResult::Ok(None),
1520        };
1521        assert_eq!(
1522            serde_json::to_string(&no_tag).unwrap(),
1523            "{\"jsonrpc\":\"\",\"id\":0,\"result\":null}"
1524        );
1525        let no_tag = Response::<u32> {
1526            jsonrpc: "",
1527            id: RequestId::Int(0),
1528            value: LspResult::Error(None),
1529        };
1530        assert_eq!(
1531            serde_json::to_string(&no_tag).unwrap(),
1532            "{\"jsonrpc\":\"\",\"id\":0,\"error\":null}"
1533        );
1534    }
1535}