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().with_context(|| {
 274            format!(
 275                "failed to spawn command. path: {:?}, working directory: {:?}, args: {:?}",
 276                binary.path, working_dir, &binary.arguments
 277            )
 278        })?;
 279
 280        let stdin = server.stdin.take().unwrap();
 281        let stdout = server.stdout.take().unwrap();
 282        let stderr = server.stderr.take().unwrap();
 283        let mut server = Self::new_internal(
 284            server_id,
 285            stdin,
 286            stdout,
 287            Some(stderr),
 288            stderr_capture,
 289            Some(server),
 290            root_path,
 291            code_action_kinds,
 292            cx,
 293            move |notification| {
 294                log::info!(
 295                    "Language server with id {} sent unhandled notification {}:\n{}",
 296                    server_id,
 297                    notification.method,
 298                    serde_json::to_string_pretty(
 299                        &notification
 300                            .params
 301                            .and_then(|params| Value::from_str(params.get()).ok())
 302                            .unwrap_or(Value::Null)
 303                    )
 304                    .unwrap(),
 305                );
 306            },
 307        );
 308
 309        if let Some(name) = binary.path.file_name() {
 310            server.name = name.to_string_lossy().into();
 311        }
 312
 313        Ok(server)
 314    }
 315
 316    #[allow(clippy::too_many_arguments)]
 317    fn new_internal<Stdin, Stdout, Stderr, F>(
 318        server_id: LanguageServerId,
 319        stdin: Stdin,
 320        stdout: Stdout,
 321        stderr: Option<Stderr>,
 322        stderr_capture: Arc<Mutex<Option<String>>>,
 323        server: Option<Child>,
 324        root_path: &Path,
 325        code_action_kinds: Option<Vec<CodeActionKind>>,
 326        cx: AsyncAppContext,
 327        on_unhandled_notification: F,
 328    ) -> Self
 329    where
 330        Stdin: AsyncWrite + Unpin + Send + 'static,
 331        Stdout: AsyncRead + Unpin + Send + 'static,
 332        Stderr: AsyncRead + Unpin + Send + 'static,
 333        F: FnMut(AnyNotification) + 'static + Send + Sync + Clone,
 334    {
 335        let (outbound_tx, outbound_rx) = channel::unbounded::<String>();
 336        let (output_done_tx, output_done_rx) = barrier::channel();
 337        let notification_handlers =
 338            Arc::new(Mutex::new(HashMap::<_, NotificationHandler>::default()));
 339        let response_handlers =
 340            Arc::new(Mutex::new(Some(HashMap::<_, ResponseHandler>::default())));
 341        let io_handlers = Arc::new(Mutex::new(HashMap::default()));
 342
 343        let stdout_input_task = cx.spawn({
 344            let on_unhandled_notification = on_unhandled_notification.clone();
 345            let notification_handlers = notification_handlers.clone();
 346            let response_handlers = response_handlers.clone();
 347            let io_handlers = io_handlers.clone();
 348            move |cx| {
 349                Self::handle_input(
 350                    stdout,
 351                    on_unhandled_notification,
 352                    notification_handlers,
 353                    response_handlers,
 354                    io_handlers,
 355                    cx,
 356                )
 357                .log_err()
 358            }
 359        });
 360        let stderr_input_task = stderr
 361            .map(|stderr| {
 362                let io_handlers = io_handlers.clone();
 363                let stderr_captures = stderr_capture.clone();
 364                cx.spawn(|_| Self::handle_stderr(stderr, io_handlers, stderr_captures).log_err())
 365            })
 366            .unwrap_or_else(|| Task::Ready(Some(None)));
 367        let input_task = cx.spawn(|_| async move {
 368            let (stdout, stderr) = futures::join!(stdout_input_task, stderr_input_task);
 369            stdout.or(stderr)
 370        });
 371        let output_task = cx.background_executor().spawn({
 372            Self::handle_output(
 373                stdin,
 374                outbound_rx,
 375                output_done_tx,
 376                response_handlers.clone(),
 377                io_handlers.clone(),
 378            )
 379            .log_err()
 380        });
 381
 382        Self {
 383            server_id,
 384            notification_handlers,
 385            response_handlers,
 386            io_handlers,
 387            name: "".into(),
 388            capabilities: Default::default(),
 389            code_action_kinds,
 390            next_id: Default::default(),
 391            outbound_tx,
 392            executor: cx.background_executor().clone(),
 393            io_tasks: Mutex::new(Some((input_task, output_task))),
 394            output_done_rx: Mutex::new(Some(output_done_rx)),
 395            root_path: root_path.to_path_buf(),
 396            server: Arc::new(Mutex::new(server)),
 397        }
 398    }
 399
 400    /// List of code action kinds this language server reports being able to emit.
 401    pub fn code_action_kinds(&self) -> Option<Vec<CodeActionKind>> {
 402        self.code_action_kinds.clone()
 403    }
 404
 405    async fn handle_input<Stdout, F>(
 406        stdout: Stdout,
 407        mut on_unhandled_notification: F,
 408        notification_handlers: Arc<Mutex<HashMap<&'static str, NotificationHandler>>>,
 409        response_handlers: Arc<Mutex<Option<HashMap<RequestId, ResponseHandler>>>>,
 410        io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
 411        cx: AsyncAppContext,
 412    ) -> anyhow::Result<()>
 413    where
 414        Stdout: AsyncRead + Unpin + Send + 'static,
 415        F: FnMut(AnyNotification) + 'static + Send,
 416    {
 417        let mut stdout = BufReader::new(stdout);
 418        let _clear_response_handlers = util::defer({
 419            let response_handlers = response_handlers.clone();
 420            move || {
 421                response_handlers.lock().take();
 422            }
 423        });
 424        let mut buffer = Vec::new();
 425        loop {
 426            buffer.clear();
 427
 428            read_headers(&mut stdout, &mut buffer).await?;
 429
 430            let headers = std::str::from_utf8(&buffer)?;
 431
 432            let message_len = headers
 433                .split('\n')
 434                .find(|line| line.starts_with(CONTENT_LEN_HEADER))
 435                .and_then(|line| line.strip_prefix(CONTENT_LEN_HEADER))
 436                .ok_or_else(|| anyhow!("invalid LSP message header {headers:?}"))?
 437                .trim_end()
 438                .parse()?;
 439
 440            buffer.resize(message_len, 0);
 441            stdout.read_exact(&mut buffer).await?;
 442
 443            if let Ok(message) = str::from_utf8(&buffer) {
 444                log::trace!("incoming message: {message}");
 445                for handler in io_handlers.lock().values_mut() {
 446                    handler(IoKind::StdOut, message);
 447                }
 448            }
 449
 450            if let Ok(msg) = serde_json::from_slice::<AnyNotification>(&buffer) {
 451                if let Some(handler) = notification_handlers.lock().get_mut(msg.method) {
 452                    handler(
 453                        msg.id,
 454                        msg.params.map(|params| params.get()).unwrap_or("null"),
 455                        cx.clone(),
 456                    );
 457                } else {
 458                    on_unhandled_notification(msg);
 459                }
 460            } else if let Ok(AnyResponse {
 461                id, error, result, ..
 462            }) = serde_json::from_slice(&buffer)
 463            {
 464                if let Some(handler) = response_handlers
 465                    .lock()
 466                    .as_mut()
 467                    .and_then(|handlers| handlers.remove(&id))
 468                {
 469                    if let Some(error) = error {
 470                        handler(Err(error));
 471                    } else if let Some(result) = result {
 472                        handler(Ok(result.get().into()));
 473                    } else {
 474                        handler(Ok("null".into()));
 475                    }
 476                }
 477            } else {
 478                warn!(
 479                    "failed to deserialize LSP message:\n{}",
 480                    std::str::from_utf8(&buffer)?
 481                );
 482            }
 483
 484            // Don't starve the main thread when receiving lots of messages at once.
 485            smol::future::yield_now().await;
 486        }
 487    }
 488
 489    async fn handle_stderr<Stderr>(
 490        stderr: Stderr,
 491        io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
 492        stderr_capture: Arc<Mutex<Option<String>>>,
 493    ) -> anyhow::Result<()>
 494    where
 495        Stderr: AsyncRead + Unpin + Send + 'static,
 496    {
 497        let mut stderr = BufReader::new(stderr);
 498        let mut buffer = Vec::new();
 499
 500        loop {
 501            buffer.clear();
 502
 503            let bytes_read = stderr.read_until(b'\n', &mut buffer).await?;
 504            if bytes_read == 0 {
 505                return Ok(());
 506            }
 507
 508            if let Ok(message) = str::from_utf8(&buffer) {
 509                log::trace!("incoming stderr message:{message}");
 510                for handler in io_handlers.lock().values_mut() {
 511                    handler(IoKind::StdErr, message);
 512                }
 513
 514                if let Some(stderr) = stderr_capture.lock().as_mut() {
 515                    stderr.push_str(message);
 516                }
 517            }
 518
 519            // Don't starve the main thread when receiving lots of messages at once.
 520            smol::future::yield_now().await;
 521        }
 522    }
 523
 524    async fn handle_output<Stdin>(
 525        stdin: Stdin,
 526        outbound_rx: channel::Receiver<String>,
 527        output_done_tx: barrier::Sender,
 528        response_handlers: Arc<Mutex<Option<HashMap<RequestId, ResponseHandler>>>>,
 529        io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
 530    ) -> anyhow::Result<()>
 531    where
 532        Stdin: AsyncWrite + Unpin + Send + 'static,
 533    {
 534        let mut stdin = BufWriter::new(stdin);
 535        let _clear_response_handlers = util::defer({
 536            let response_handlers = response_handlers.clone();
 537            move || {
 538                response_handlers.lock().take();
 539            }
 540        });
 541        let mut content_len_buffer = Vec::new();
 542        while let Ok(message) = outbound_rx.recv().await {
 543            log::trace!("outgoing message:{}", message);
 544            for handler in io_handlers.lock().values_mut() {
 545                handler(IoKind::StdIn, &message);
 546            }
 547
 548            content_len_buffer.clear();
 549            write!(content_len_buffer, "{}", message.len()).unwrap();
 550            stdin.write_all(CONTENT_LEN_HEADER.as_bytes()).await?;
 551            stdin.write_all(&content_len_buffer).await?;
 552            stdin.write_all("\r\n\r\n".as_bytes()).await?;
 553            stdin.write_all(message.as_bytes()).await?;
 554            stdin.flush().await?;
 555        }
 556        drop(output_done_tx);
 557        Ok(())
 558    }
 559
 560    /// Initializes a language server by sending the `Initialize` request.
 561    /// Note that `options` is used directly to construct [`InitializeParams`], which is why it is owned.
 562    ///
 563    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#initialize)
 564    pub fn initialize(
 565        mut self,
 566        options: Option<Value>,
 567        cx: &AppContext,
 568    ) -> Task<Result<Arc<Self>>> {
 569        let root_uri = Url::from_file_path(&self.root_path).unwrap();
 570        #[allow(deprecated)]
 571        let params = InitializeParams {
 572            process_id: None,
 573            root_path: None,
 574            root_uri: Some(root_uri.clone()),
 575            initialization_options: options,
 576            capabilities: ClientCapabilities {
 577                workspace: Some(WorkspaceClientCapabilities {
 578                    configuration: Some(true),
 579                    did_change_watched_files: Some(DidChangeWatchedFilesClientCapabilities {
 580                        dynamic_registration: Some(true),
 581                        relative_pattern_support: Some(true),
 582                    }),
 583                    did_change_configuration: Some(DynamicRegistrationClientCapabilities {
 584                        dynamic_registration: Some(true),
 585                    }),
 586                    workspace_folders: Some(true),
 587                    symbol: Some(WorkspaceSymbolClientCapabilities {
 588                        resolve_support: None,
 589                        ..WorkspaceSymbolClientCapabilities::default()
 590                    }),
 591                    inlay_hint: Some(InlayHintWorkspaceClientCapabilities {
 592                        refresh_support: Some(true),
 593                    }),
 594                    diagnostic: Some(DiagnosticWorkspaceClientCapabilities {
 595                        refresh_support: None,
 596                    }),
 597                    workspace_edit: Some(WorkspaceEditClientCapabilities {
 598                        resource_operations: Some(vec![
 599                            ResourceOperationKind::Create,
 600                            ResourceOperationKind::Rename,
 601                            ResourceOperationKind::Delete,
 602                        ]),
 603                        document_changes: Some(true),
 604                        snippet_edit_support: Some(true),
 605                        ..WorkspaceEditClientCapabilities::default()
 606                    }),
 607                    ..Default::default()
 608                }),
 609                text_document: Some(TextDocumentClientCapabilities {
 610                    definition: Some(GotoCapability {
 611                        link_support: Some(true),
 612                        dynamic_registration: None,
 613                    }),
 614                    code_action: Some(CodeActionClientCapabilities {
 615                        code_action_literal_support: Some(CodeActionLiteralSupport {
 616                            code_action_kind: CodeActionKindLiteralSupport {
 617                                value_set: vec![
 618                                    CodeActionKind::REFACTOR.as_str().into(),
 619                                    CodeActionKind::QUICKFIX.as_str().into(),
 620                                    CodeActionKind::SOURCE.as_str().into(),
 621                                ],
 622                            },
 623                        }),
 624                        data_support: Some(true),
 625                        resolve_support: Some(CodeActionCapabilityResolveSupport {
 626                            properties: vec![
 627                                "kind".to_string(),
 628                                "diagnostics".to_string(),
 629                                "isPreferred".to_string(),
 630                                "disabled".to_string(),
 631                                "edit".to_string(),
 632                                "command".to_string(),
 633                            ],
 634                        }),
 635                        ..Default::default()
 636                    }),
 637                    completion: Some(CompletionClientCapabilities {
 638                        completion_item: Some(CompletionItemCapability {
 639                            snippet_support: Some(true),
 640                            resolve_support: Some(CompletionItemCapabilityResolveSupport {
 641                                properties: vec![
 642                                    "documentation".to_string(),
 643                                    "additionalTextEdits".to_string(),
 644                                ],
 645                            }),
 646                            insert_replace_support: Some(true),
 647                            ..Default::default()
 648                        }),
 649                        completion_list: Some(CompletionListCapability {
 650                            item_defaults: Some(vec![
 651                                "commitCharacters".to_owned(),
 652                                "editRange".to_owned(),
 653                                "insertTextMode".to_owned(),
 654                                "data".to_owned(),
 655                            ]),
 656                        }),
 657                        ..Default::default()
 658                    }),
 659                    rename: Some(RenameClientCapabilities {
 660                        prepare_support: Some(true),
 661                        ..Default::default()
 662                    }),
 663                    hover: Some(HoverClientCapabilities {
 664                        content_format: Some(vec![MarkupKind::Markdown]),
 665                        dynamic_registration: None,
 666                    }),
 667                    inlay_hint: Some(InlayHintClientCapabilities {
 668                        resolve_support: Some(InlayHintResolveClientCapabilities {
 669                            properties: vec![
 670                                "textEdits".to_string(),
 671                                "tooltip".to_string(),
 672                                "label.tooltip".to_string(),
 673                                "label.location".to_string(),
 674                                "label.command".to_string(),
 675                            ],
 676                        }),
 677                        dynamic_registration: Some(false),
 678                    }),
 679                    publish_diagnostics: Some(PublishDiagnosticsClientCapabilities {
 680                        related_information: Some(true),
 681                        ..Default::default()
 682                    }),
 683                    formatting: Some(DynamicRegistrationClientCapabilities {
 684                        dynamic_registration: None,
 685                    }),
 686                    on_type_formatting: Some(DynamicRegistrationClientCapabilities {
 687                        dynamic_registration: None,
 688                    }),
 689                    diagnostic: Some(DiagnosticClientCapabilities {
 690                        related_document_support: Some(true),
 691                        dynamic_registration: None,
 692                    }),
 693                    ..Default::default()
 694                }),
 695                experimental: Some(json!({
 696                    "serverStatusNotification": true,
 697                })),
 698                window: Some(WindowClientCapabilities {
 699                    work_done_progress: Some(true),
 700                    ..Default::default()
 701                }),
 702                general: None,
 703            },
 704            trace: None,
 705            workspace_folders: Some(vec![WorkspaceFolder {
 706                uri: root_uri,
 707                name: Default::default(),
 708            }]),
 709            client_info: release_channel::ReleaseChannel::try_global(cx).map(|release_channel| {
 710                ClientInfo {
 711                    name: release_channel.display_name().to_string(),
 712                    version: Some(release_channel::AppVersion::global(cx).to_string()),
 713                }
 714            }),
 715            locale: None,
 716            ..Default::default()
 717        };
 718
 719        cx.spawn(|_| async move {
 720            let response = self.request::<request::Initialize>(params).await?;
 721            if let Some(info) = response.server_info {
 722                self.name = info.name.into();
 723            }
 724            self.capabilities = response.capabilities;
 725
 726            self.notify::<notification::Initialized>(InitializedParams {})?;
 727            Ok(Arc::new(self))
 728        })
 729    }
 730
 731    /// Sends a shutdown request to the language server process and prepares the [`LanguageServer`] to be dropped.
 732    pub fn shutdown(&self) -> Option<impl 'static + Send + Future<Output = Option<()>>> {
 733        if let Some(tasks) = self.io_tasks.lock().take() {
 734            let response_handlers = self.response_handlers.clone();
 735            let next_id = AtomicI32::new(self.next_id.load(SeqCst));
 736            let outbound_tx = self.outbound_tx.clone();
 737            let executor = self.executor.clone();
 738            let mut output_done = self.output_done_rx.lock().take().unwrap();
 739            let shutdown_request = Self::request_internal::<request::Shutdown>(
 740                &next_id,
 741                &response_handlers,
 742                &outbound_tx,
 743                &executor,
 744                (),
 745            );
 746            let exit = Self::notify_internal::<notification::Exit>(&outbound_tx, ());
 747            outbound_tx.close();
 748
 749            let server = self.server.clone();
 750            let name = self.name.clone();
 751            let mut timer = self.executor.timer(SERVER_SHUTDOWN_TIMEOUT).fuse();
 752            Some(
 753                async move {
 754                    log::debug!("language server shutdown started");
 755
 756                    select! {
 757                        request_result = shutdown_request.fuse() => {
 758                            request_result?;
 759                        }
 760
 761                        _ = timer => {
 762                            log::info!("timeout waiting for language server {name} to shutdown");
 763                        },
 764                    }
 765
 766                    response_handlers.lock().take();
 767                    exit?;
 768                    output_done.recv().await;
 769                    server.lock().take().map(|mut child| child.kill());
 770                    log::debug!("language server shutdown finished");
 771
 772                    drop(tasks);
 773                    anyhow::Ok(())
 774                }
 775                .log_err(),
 776            )
 777        } else {
 778            None
 779        }
 780    }
 781
 782    /// Register a handler to handle incoming LSP notifications.
 783    ///
 784    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
 785    #[must_use]
 786    pub fn on_notification<T, F>(&self, f: F) -> Subscription
 787    where
 788        T: notification::Notification,
 789        F: 'static + Send + FnMut(T::Params, AsyncAppContext),
 790    {
 791        self.on_custom_notification(T::METHOD, f)
 792    }
 793
 794    /// Register a handler to handle incoming LSP requests.
 795    ///
 796    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
 797    #[must_use]
 798    pub fn on_request<T, F, Fut>(&self, f: F) -> Subscription
 799    where
 800        T: request::Request,
 801        T::Params: 'static + Send,
 802        F: 'static + FnMut(T::Params, AsyncAppContext) -> Fut + Send,
 803        Fut: 'static + Future<Output = Result<T::Result>>,
 804    {
 805        self.on_custom_request(T::METHOD, f)
 806    }
 807
 808    /// Registers a handler to inspect all language server process stdio.
 809    #[must_use]
 810    pub fn on_io<F>(&self, f: F) -> Subscription
 811    where
 812        F: 'static + Send + FnMut(IoKind, &str),
 813    {
 814        let id = self.next_id.fetch_add(1, SeqCst);
 815        self.io_handlers.lock().insert(id, Box::new(f));
 816        Subscription::Io {
 817            id,
 818            io_handlers: Some(Arc::downgrade(&self.io_handlers)),
 819        }
 820    }
 821
 822    /// Removes a request handler registers via [`Self::on_request`].
 823    pub fn remove_request_handler<T: request::Request>(&self) {
 824        self.notification_handlers.lock().remove(T::METHOD);
 825    }
 826
 827    /// Removes a notification handler registers via [`Self::on_notification`].
 828    pub fn remove_notification_handler<T: notification::Notification>(&self) {
 829        self.notification_handlers.lock().remove(T::METHOD);
 830    }
 831
 832    /// Checks if a notification handler has been registered via [`Self::on_notification`].
 833    pub fn has_notification_handler<T: notification::Notification>(&self) -> bool {
 834        self.notification_handlers.lock().contains_key(T::METHOD)
 835    }
 836
 837    #[must_use]
 838    fn on_custom_notification<Params, F>(&self, method: &'static str, mut f: F) -> Subscription
 839    where
 840        F: 'static + FnMut(Params, AsyncAppContext) + Send,
 841        Params: DeserializeOwned,
 842    {
 843        let prev_handler = self.notification_handlers.lock().insert(
 844            method,
 845            Box::new(move |_, params, cx| {
 846                if let Some(params) = serde_json::from_str(params).log_err() {
 847                    f(params, cx);
 848                }
 849            }),
 850        );
 851        assert!(
 852            prev_handler.is_none(),
 853            "registered multiple handlers for the same LSP method"
 854        );
 855        Subscription::Notification {
 856            method,
 857            notification_handlers: Some(self.notification_handlers.clone()),
 858        }
 859    }
 860
 861    #[must_use]
 862    fn on_custom_request<Params, Res, Fut, F>(&self, method: &'static str, mut f: F) -> Subscription
 863    where
 864        F: 'static + FnMut(Params, AsyncAppContext) -> Fut + Send,
 865        Fut: 'static + Future<Output = Result<Res>>,
 866        Params: DeserializeOwned + Send + 'static,
 867        Res: Serialize,
 868    {
 869        let outbound_tx = self.outbound_tx.clone();
 870        let prev_handler = self.notification_handlers.lock().insert(
 871            method,
 872            Box::new(move |id, params, cx| {
 873                if let Some(id) = id {
 874                    match serde_json::from_str(params) {
 875                        Ok(params) => {
 876                            let response = f(params, cx.clone());
 877                            cx.foreground_executor()
 878                                .spawn({
 879                                    let outbound_tx = outbound_tx.clone();
 880                                    async move {
 881                                        let response = match response.await {
 882                                            Ok(result) => Response {
 883                                                jsonrpc: JSON_RPC_VERSION,
 884                                                id,
 885                                                value: LspResult::Ok(Some(result)),
 886                                            },
 887                                            Err(error) => Response {
 888                                                jsonrpc: JSON_RPC_VERSION,
 889                                                id,
 890                                                value: LspResult::Error(Some(Error {
 891                                                    message: error.to_string(),
 892                                                })),
 893                                            },
 894                                        };
 895                                        if let Some(response) =
 896                                            serde_json::to_string(&response).log_err()
 897                                        {
 898                                            outbound_tx.try_send(response).ok();
 899                                        }
 900                                    }
 901                                })
 902                                .detach();
 903                        }
 904
 905                        Err(error) => {
 906                            log::error!(
 907                                "error deserializing {} request: {:?}, message: {:?}",
 908                                method,
 909                                error,
 910                                params
 911                            );
 912                            let response = AnyResponse {
 913                                jsonrpc: JSON_RPC_VERSION,
 914                                id,
 915                                result: None,
 916                                error: Some(Error {
 917                                    message: error.to_string(),
 918                                }),
 919                            };
 920                            if let Some(response) = serde_json::to_string(&response).log_err() {
 921                                outbound_tx.try_send(response).ok();
 922                            }
 923                        }
 924                    }
 925                }
 926            }),
 927        );
 928        assert!(
 929            prev_handler.is_none(),
 930            "registered multiple handlers for the same LSP method"
 931        );
 932        Subscription::Notification {
 933            method,
 934            notification_handlers: Some(self.notification_handlers.clone()),
 935        }
 936    }
 937
 938    /// Get the name of the running language server.
 939    pub fn name(&self) -> &str {
 940        &self.name
 941    }
 942
 943    /// Get the reported capabilities of the running language server.
 944    pub fn capabilities(&self) -> &ServerCapabilities {
 945        &self.capabilities
 946    }
 947
 948    /// Get the id of the running language server.
 949    pub fn server_id(&self) -> LanguageServerId {
 950        self.server_id
 951    }
 952
 953    /// Get the root path of the project the language server is running against.
 954    pub fn root_path(&self) -> &PathBuf {
 955        &self.root_path
 956    }
 957
 958    /// Sends a RPC request to the language server.
 959    ///
 960    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
 961    pub fn request<T: request::Request>(
 962        &self,
 963        params: T::Params,
 964    ) -> impl LspRequestFuture<Result<T::Result>>
 965    where
 966        T::Result: 'static + Send,
 967    {
 968        Self::request_internal::<T>(
 969            &self.next_id,
 970            &self.response_handlers,
 971            &self.outbound_tx,
 972            &self.executor,
 973            params,
 974        )
 975    }
 976
 977    fn request_internal<T: request::Request>(
 978        next_id: &AtomicI32,
 979        response_handlers: &Mutex<Option<HashMap<RequestId, ResponseHandler>>>,
 980        outbound_tx: &channel::Sender<String>,
 981        executor: &BackgroundExecutor,
 982        params: T::Params,
 983    ) -> impl LspRequestFuture<Result<T::Result>>
 984    where
 985        T::Result: 'static + Send,
 986    {
 987        let id = next_id.fetch_add(1, SeqCst);
 988        let message = serde_json::to_string(&Request {
 989            jsonrpc: JSON_RPC_VERSION,
 990            id: RequestId::Int(id),
 991            method: T::METHOD,
 992            params,
 993        })
 994        .unwrap();
 995
 996        let (tx, rx) = oneshot::channel();
 997        let handle_response = response_handlers
 998            .lock()
 999            .as_mut()
1000            .ok_or_else(|| anyhow!("server shut down"))
1001            .map(|handlers| {
1002                let executor = executor.clone();
1003                handlers.insert(
1004                    RequestId::Int(id),
1005                    Box::new(move |result| {
1006                        executor
1007                            .spawn(async move {
1008                                let response = match result {
1009                                    Ok(response) => match serde_json::from_str(&response) {
1010                                        Ok(deserialized) => Ok(deserialized),
1011                                        Err(error) => {
1012                                            log::error!("failed to deserialize response from language server: {}. response from language server: {:?}", error, response);
1013                                            Err(error).context("failed to deserialize response")
1014                                        }
1015                                    }
1016                                    Err(error) => Err(anyhow!("{}", error.message)),
1017                                };
1018                                _ = tx.send(response);
1019                            })
1020                            .detach();
1021                    }),
1022                );
1023            });
1024
1025        let send = outbound_tx
1026            .try_send(message)
1027            .context("failed to write to language server's stdin");
1028
1029        let outbound_tx = outbound_tx.downgrade();
1030        let mut timeout = executor.timer(LSP_REQUEST_TIMEOUT).fuse();
1031        let started = Instant::now();
1032        LspRequest::new(id, async move {
1033            handle_response?;
1034            send?;
1035
1036            let cancel_on_drop = util::defer(move || {
1037                if let Some(outbound_tx) = outbound_tx.upgrade() {
1038                    Self::notify_internal::<notification::Cancel>(
1039                        &outbound_tx,
1040                        CancelParams {
1041                            id: NumberOrString::Number(id),
1042                        },
1043                    )
1044                    .log_err();
1045                }
1046            });
1047
1048            let method = T::METHOD;
1049            select! {
1050                response = rx.fuse() => {
1051                    let elapsed = started.elapsed();
1052                    log::trace!("Took {elapsed:?} to receive response to {method:?} id {id}");
1053                    cancel_on_drop.abort();
1054                    response?
1055                }
1056
1057                _ = timeout => {
1058                    log::error!("Cancelled LSP request task for {method:?} id {id} which took over {LSP_REQUEST_TIMEOUT:?}");
1059                    anyhow::bail!("LSP request timeout");
1060                }
1061            }
1062        })
1063    }
1064
1065    /// Sends a RPC notification to the language server.
1066    ///
1067    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
1068    pub fn notify<T: notification::Notification>(&self, params: T::Params) -> Result<()> {
1069        Self::notify_internal::<T>(&self.outbound_tx, params)
1070    }
1071
1072    fn notify_internal<T: notification::Notification>(
1073        outbound_tx: &channel::Sender<String>,
1074        params: T::Params,
1075    ) -> Result<()> {
1076        let message = serde_json::to_string(&Notification {
1077            jsonrpc: JSON_RPC_VERSION,
1078            method: T::METHOD,
1079            params,
1080        })
1081        .unwrap();
1082        outbound_tx.try_send(message)?;
1083        Ok(())
1084    }
1085}
1086
1087impl Drop for LanguageServer {
1088    fn drop(&mut self) {
1089        if let Some(shutdown) = self.shutdown() {
1090            self.executor.spawn(shutdown).detach();
1091        }
1092    }
1093}
1094
1095impl Subscription {
1096    /// Detaching a subscription handle prevents it from unsubscribing on drop.
1097    pub fn detach(&mut self) {
1098        match self {
1099            Subscription::Notification {
1100                notification_handlers,
1101                ..
1102            } => *notification_handlers = None,
1103            Subscription::Io { io_handlers, .. } => *io_handlers = None,
1104        }
1105    }
1106}
1107
1108impl fmt::Display for LanguageServerId {
1109    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1110        self.0.fmt(f)
1111    }
1112}
1113
1114impl fmt::Debug for LanguageServer {
1115    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1116        f.debug_struct("LanguageServer")
1117            .field("id", &self.server_id.0)
1118            .field("name", &self.name)
1119            .finish_non_exhaustive()
1120    }
1121}
1122
1123impl Drop for Subscription {
1124    fn drop(&mut self) {
1125        match self {
1126            Subscription::Notification {
1127                method,
1128                notification_handlers,
1129            } => {
1130                if let Some(handlers) = notification_handlers {
1131                    handlers.lock().remove(method);
1132                }
1133            }
1134            Subscription::Io { id, io_handlers } => {
1135                if let Some(io_handlers) = io_handlers.as_ref().and_then(|h| h.upgrade()) {
1136                    io_handlers.lock().remove(id);
1137                }
1138            }
1139        }
1140    }
1141}
1142
1143/// Mock language server for use in tests.
1144#[cfg(any(test, feature = "test-support"))]
1145#[derive(Clone)]
1146pub struct FakeLanguageServer {
1147    pub binary: LanguageServerBinary,
1148    pub server: Arc<LanguageServer>,
1149    notifications_rx: channel::Receiver<(String, String)>,
1150}
1151
1152#[cfg(any(test, feature = "test-support"))]
1153impl FakeLanguageServer {
1154    /// Construct a fake language server.
1155    pub fn new(
1156        server_id: LanguageServerId,
1157        binary: LanguageServerBinary,
1158        name: String,
1159        capabilities: ServerCapabilities,
1160        cx: AsyncAppContext,
1161    ) -> (LanguageServer, FakeLanguageServer) {
1162        let (stdin_writer, stdin_reader) = async_pipe::pipe();
1163        let (stdout_writer, stdout_reader) = async_pipe::pipe();
1164        let (notifications_tx, notifications_rx) = channel::unbounded();
1165
1166        let mut server = LanguageServer::new_internal(
1167            server_id,
1168            stdin_writer,
1169            stdout_reader,
1170            None::<async_pipe::PipeReader>,
1171            Arc::new(Mutex::new(None)),
1172            None,
1173            Path::new("/"),
1174            None,
1175            cx.clone(),
1176            |_| {},
1177        );
1178        server.name = name.as_str().into();
1179        let fake = FakeLanguageServer {
1180            binary,
1181            server: Arc::new({
1182                let mut server = LanguageServer::new_internal(
1183                    server_id,
1184                    stdout_writer,
1185                    stdin_reader,
1186                    None::<async_pipe::PipeReader>,
1187                    Arc::new(Mutex::new(None)),
1188                    None,
1189                    Path::new("/"),
1190                    None,
1191                    cx,
1192                    move |msg| {
1193                        notifications_tx
1194                            .try_send((
1195                                msg.method.to_string(),
1196                                msg.params
1197                                    .map(|raw_value| raw_value.get())
1198                                    .unwrap_or("null")
1199                                    .to_string(),
1200                            ))
1201                            .ok();
1202                    },
1203                );
1204                server.name = name.as_str().into();
1205                server
1206            }),
1207            notifications_rx,
1208        };
1209        fake.handle_request::<request::Initialize, _, _>({
1210            let capabilities = capabilities;
1211            move |_, _| {
1212                let capabilities = capabilities.clone();
1213                let name = name.clone();
1214                async move {
1215                    Ok(InitializeResult {
1216                        capabilities,
1217                        server_info: Some(ServerInfo {
1218                            name,
1219                            ..Default::default()
1220                        }),
1221                    })
1222                }
1223            }
1224        });
1225
1226        (server, fake)
1227    }
1228}
1229
1230#[cfg(any(test, feature = "test-support"))]
1231impl LanguageServer {
1232    pub fn full_capabilities() -> ServerCapabilities {
1233        ServerCapabilities {
1234            document_highlight_provider: Some(OneOf::Left(true)),
1235            code_action_provider: Some(CodeActionProviderCapability::Simple(true)),
1236            document_formatting_provider: Some(OneOf::Left(true)),
1237            document_range_formatting_provider: Some(OneOf::Left(true)),
1238            definition_provider: Some(OneOf::Left(true)),
1239            implementation_provider: Some(ImplementationProviderCapability::Simple(true)),
1240            type_definition_provider: Some(TypeDefinitionProviderCapability::Simple(true)),
1241            ..Default::default()
1242        }
1243    }
1244}
1245
1246#[cfg(any(test, feature = "test-support"))]
1247impl FakeLanguageServer {
1248    /// See [`LanguageServer::notify`].
1249    pub fn notify<T: notification::Notification>(&self, params: T::Params) {
1250        self.server.notify::<T>(params).ok();
1251    }
1252
1253    /// See [`LanguageServer::request`].
1254    pub async fn request<T>(&self, params: T::Params) -> Result<T::Result>
1255    where
1256        T: request::Request,
1257        T::Result: 'static + Send,
1258    {
1259        self.server.executor.start_waiting();
1260        self.server.request::<T>(params).await
1261    }
1262
1263    /// Attempts [`Self::try_receive_notification`], unwrapping if it has not received the specified type yet.
1264    pub async fn receive_notification<T: notification::Notification>(&mut self) -> T::Params {
1265        self.server.executor.start_waiting();
1266        self.try_receive_notification::<T>().await.unwrap()
1267    }
1268
1269    /// Consumes the notification channel until it finds a notification for the specified type.
1270    pub async fn try_receive_notification<T: notification::Notification>(
1271        &mut self,
1272    ) -> Option<T::Params> {
1273        use futures::StreamExt as _;
1274
1275        loop {
1276            let (method, params) = self.notifications_rx.next().await?;
1277            if method == T::METHOD {
1278                return Some(serde_json::from_str::<T::Params>(&params).unwrap());
1279            } else {
1280                log::info!("skipping message in fake language server {:?}", params);
1281            }
1282        }
1283    }
1284
1285    /// Registers a handler for a specific kind of request. Removes any existing handler for specified request type.
1286    pub fn handle_request<T, F, Fut>(
1287        &self,
1288        mut handler: F,
1289    ) -> futures::channel::mpsc::UnboundedReceiver<()>
1290    where
1291        T: 'static + request::Request,
1292        T::Params: 'static + Send,
1293        F: 'static + Send + FnMut(T::Params, gpui::AsyncAppContext) -> Fut,
1294        Fut: 'static + Send + Future<Output = Result<T::Result>>,
1295    {
1296        let (responded_tx, responded_rx) = futures::channel::mpsc::unbounded();
1297        self.server.remove_request_handler::<T>();
1298        self.server
1299            .on_request::<T, _, _>(move |params, cx| {
1300                let result = handler(params, cx.clone());
1301                let responded_tx = responded_tx.clone();
1302                let executor = cx.background_executor().clone();
1303                async move {
1304                    executor.simulate_random_delay().await;
1305                    let result = result.await;
1306                    responded_tx.unbounded_send(()).ok();
1307                    result
1308                }
1309            })
1310            .detach();
1311        responded_rx
1312    }
1313
1314    /// Registers a handler for a specific kind of notification. Removes any existing handler for specified notification type.
1315    pub fn handle_notification<T, F>(
1316        &self,
1317        mut handler: F,
1318    ) -> futures::channel::mpsc::UnboundedReceiver<()>
1319    where
1320        T: 'static + notification::Notification,
1321        T::Params: 'static + Send,
1322        F: 'static + Send + FnMut(T::Params, gpui::AsyncAppContext),
1323    {
1324        let (handled_tx, handled_rx) = futures::channel::mpsc::unbounded();
1325        self.server.remove_notification_handler::<T>();
1326        self.server
1327            .on_notification::<T, _>(move |params, cx| {
1328                handler(params, cx.clone());
1329                handled_tx.unbounded_send(()).ok();
1330            })
1331            .detach();
1332        handled_rx
1333    }
1334
1335    /// Removes any existing handler for specified notification type.
1336    pub fn remove_request_handler<T>(&mut self)
1337    where
1338        T: 'static + request::Request,
1339    {
1340        self.server.remove_request_handler::<T>();
1341    }
1342
1343    /// Simulate that the server has started work and notifies about its progress with the specified token.
1344    pub async fn start_progress(&self, token: impl Into<String>) {
1345        let token = token.into();
1346        self.request::<request::WorkDoneProgressCreate>(WorkDoneProgressCreateParams {
1347            token: NumberOrString::String(token.clone()),
1348        })
1349        .await
1350        .unwrap();
1351        self.notify::<notification::Progress>(ProgressParams {
1352            token: NumberOrString::String(token),
1353            value: ProgressParamsValue::WorkDone(WorkDoneProgress::Begin(Default::default())),
1354        });
1355    }
1356
1357    /// Simulate that the server has completed work and notifies about that with the specified token.
1358    pub fn end_progress(&self, token: impl Into<String>) {
1359        self.notify::<notification::Progress>(ProgressParams {
1360            token: NumberOrString::String(token.into()),
1361            value: ProgressParamsValue::WorkDone(WorkDoneProgress::End(Default::default())),
1362        });
1363    }
1364}
1365
1366pub(self) async fn read_headers<Stdout>(
1367    reader: &mut BufReader<Stdout>,
1368    buffer: &mut Vec<u8>,
1369) -> Result<()>
1370where
1371    Stdout: AsyncRead + Unpin + Send + 'static,
1372{
1373    loop {
1374        if buffer.len() >= HEADER_DELIMITER.len()
1375            && buffer[(buffer.len() - HEADER_DELIMITER.len())..] == HEADER_DELIMITER[..]
1376        {
1377            return Ok(());
1378        }
1379
1380        if reader.read_until(b'\n', buffer).await? == 0 {
1381            return Err(anyhow!("cannot read LSP message headers"));
1382        }
1383    }
1384}
1385
1386#[cfg(test)]
1387mod tests {
1388    use super::*;
1389    use gpui::TestAppContext;
1390
1391    #[ctor::ctor]
1392    fn init_logger() {
1393        if std::env::var("RUST_LOG").is_ok() {
1394            env_logger::init();
1395        }
1396    }
1397
1398    #[gpui::test]
1399    async fn test_fake(cx: &mut TestAppContext) {
1400        cx.update(|cx| {
1401            release_channel::init("0.0.0", cx);
1402        });
1403        let (server, mut fake) = FakeLanguageServer::new(
1404            LanguageServerId(0),
1405            LanguageServerBinary {
1406                path: "path/to/language-server".into(),
1407                arguments: vec![],
1408                env: None,
1409            },
1410            "the-lsp".to_string(),
1411            Default::default(),
1412            cx.to_async(),
1413        );
1414
1415        let (message_tx, message_rx) = channel::unbounded();
1416        let (diagnostics_tx, diagnostics_rx) = channel::unbounded();
1417        server
1418            .on_notification::<notification::ShowMessage, _>(move |params, _| {
1419                message_tx.try_send(params).unwrap()
1420            })
1421            .detach();
1422        server
1423            .on_notification::<notification::PublishDiagnostics, _>(move |params, _| {
1424                diagnostics_tx.try_send(params).unwrap()
1425            })
1426            .detach();
1427
1428        let server = cx.update(|cx| server.initialize(None, cx)).await.unwrap();
1429        server
1430            .notify::<notification::DidOpenTextDocument>(DidOpenTextDocumentParams {
1431                text_document: TextDocumentItem::new(
1432                    Url::from_str("file://a/b").unwrap(),
1433                    "rust".to_string(),
1434                    0,
1435                    "".to_string(),
1436                ),
1437            })
1438            .unwrap();
1439        assert_eq!(
1440            fake.receive_notification::<notification::DidOpenTextDocument>()
1441                .await
1442                .text_document
1443                .uri
1444                .as_str(),
1445            "file://a/b"
1446        );
1447
1448        fake.notify::<notification::ShowMessage>(ShowMessageParams {
1449            typ: MessageType::ERROR,
1450            message: "ok".to_string(),
1451        });
1452        fake.notify::<notification::PublishDiagnostics>(PublishDiagnosticsParams {
1453            uri: Url::from_str("file://b/c").unwrap(),
1454            version: Some(5),
1455            diagnostics: vec![],
1456        });
1457        assert_eq!(message_rx.recv().await.unwrap().message, "ok");
1458        assert_eq!(
1459            diagnostics_rx.recv().await.unwrap().uri.as_str(),
1460            "file://b/c"
1461        );
1462
1463        fake.handle_request::<request::Shutdown, _, _>(|_, _| async move { Ok(()) });
1464
1465        drop(server);
1466        fake.receive_notification::<notification::Exit>().await;
1467    }
1468
1469    #[gpui::test]
1470    async fn test_read_headers() {
1471        let mut buf = Vec::new();
1472        let mut reader = smol::io::BufReader::new(b"Content-Length: 123\r\n\r\n" as &[u8]);
1473        read_headers(&mut reader, &mut buf).await.unwrap();
1474        assert_eq!(buf, b"Content-Length: 123\r\n\r\n");
1475
1476        let mut buf = Vec::new();
1477        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]);
1478        read_headers(&mut reader, &mut buf).await.unwrap();
1479        assert_eq!(
1480            buf,
1481            b"Content-Type: application/vscode-jsonrpc\r\nContent-Length: 1235\r\n\r\n"
1482        );
1483
1484        let mut buf = Vec::new();
1485        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]);
1486        read_headers(&mut reader, &mut buf).await.unwrap();
1487        assert_eq!(
1488            buf,
1489            b"Content-Length: 1235\r\nContent-Type: application/vscode-jsonrpc\r\n\r\n"
1490        );
1491    }
1492
1493    #[gpui::test]
1494    fn test_deserialize_string_digit_id() {
1495        let json = r#"{"jsonrpc":"2.0","id":"2","method":"workspace/configuration","params":{"items":[{"scopeUri":"file:///Users/mph/Devel/personal/hello-scala/","section":"metals"}]}}"#;
1496        let notification = serde_json::from_str::<AnyNotification>(json)
1497            .expect("message with string id should be parsed");
1498        let expected_id = RequestId::Str("2".to_string());
1499        assert_eq!(notification.id, Some(expected_id));
1500    }
1501
1502    #[gpui::test]
1503    fn test_deserialize_string_id() {
1504        let json = r#"{"jsonrpc":"2.0","id":"anythingAtAll","method":"workspace/configuration","params":{"items":[{"scopeUri":"file:///Users/mph/Devel/personal/hello-scala/","section":"metals"}]}}"#;
1505        let notification = serde_json::from_str::<AnyNotification>(json)
1506            .expect("message with string id should be parsed");
1507        let expected_id = RequestId::Str("anythingAtAll".to_string());
1508        assert_eq!(notification.id, Some(expected_id));
1509    }
1510
1511    #[gpui::test]
1512    fn test_deserialize_int_id() {
1513        let json = r#"{"jsonrpc":"2.0","id":2,"method":"workspace/configuration","params":{"items":[{"scopeUri":"file:///Users/mph/Devel/personal/hello-scala/","section":"metals"}]}}"#;
1514        let notification = serde_json::from_str::<AnyNotification>(json)
1515            .expect("message with string id should be parsed");
1516        let expected_id = RequestId::Int(2);
1517        assert_eq!(notification.id, Some(expected_id));
1518    }
1519
1520    #[test]
1521    fn test_serialize_has_no_nulls() {
1522        // Ensure we're not setting both result and error variants. (ticket #10595)
1523        let no_tag = Response::<u32> {
1524            jsonrpc: "",
1525            id: RequestId::Int(0),
1526            value: LspResult::Ok(None),
1527        };
1528        assert_eq!(
1529            serde_json::to_string(&no_tag).unwrap(),
1530            "{\"jsonrpc\":\"\",\"id\":0,\"result\":null}"
1531        );
1532        let no_tag = Response::<u32> {
1533            jsonrpc: "",
1534            id: RequestId::Int(0),
1535            value: LspResult::Error(None),
1536        };
1537        assert_eq!(
1538            serde_json::to_string(&no_tag).unwrap(),
1539            "{\"jsonrpc\":\"\",\"id\":0,\"error\":null}"
1540        );
1541    }
1542}