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    working_dir: PathBuf,
  83    server: Arc<Mutex<Option<Child>>>,
  84}
  85
  86/// Identifies a running language server.
  87#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
  88#[repr(transparent)]
  89pub struct LanguageServerId(pub usize);
  90
  91/// Handle to a language server RPC activity subscription.
  92pub enum Subscription {
  93    Notification {
  94        method: &'static str,
  95        notification_handlers: Option<Arc<Mutex<HashMap<&'static str, NotificationHandler>>>>,
  96    },
  97    Io {
  98        id: i32,
  99        io_handlers: Option<Weak<Mutex<HashMap<i32, IoHandler>>>>,
 100    },
 101}
 102
 103/// Language server protocol RPC request message ID.
 104///
 105/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
 106#[derive(Debug, Clone, Eq, PartialEq, Hash, Serialize, Deserialize)]
 107#[serde(untagged)]
 108pub enum RequestId {
 109    Int(i32),
 110    Str(String),
 111}
 112
 113/// Language server protocol RPC request message.
 114///
 115/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
 116#[derive(Serialize, Deserialize)]
 117pub struct Request<'a, T> {
 118    jsonrpc: &'static str,
 119    id: RequestId,
 120    method: &'a str,
 121    params: T,
 122}
 123
 124/// Language server protocol RPC request response message before it is deserialized into a concrete type.
 125#[derive(Serialize, Deserialize)]
 126struct AnyResponse<'a> {
 127    jsonrpc: &'a str,
 128    id: RequestId,
 129    #[serde(default)]
 130    error: Option<Error>,
 131    #[serde(borrow)]
 132    result: Option<&'a RawValue>,
 133}
 134
 135/// Language server protocol RPC request response message.
 136///
 137/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#responseMessage)
 138#[derive(Serialize)]
 139struct Response<T> {
 140    jsonrpc: &'static str,
 141    id: RequestId,
 142    #[serde(flatten)]
 143    value: LspResult<T>,
 144}
 145
 146#[derive(Serialize)]
 147#[serde(rename_all = "snake_case")]
 148enum LspResult<T> {
 149    #[serde(rename = "result")]
 150    Ok(Option<T>),
 151    Error(Option<Error>),
 152}
 153
 154/// Language server protocol RPC notification message.
 155///
 156/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
 157#[derive(Serialize, Deserialize)]
 158struct Notification<'a, T> {
 159    jsonrpc: &'static str,
 160    #[serde(borrow)]
 161    method: &'a str,
 162    params: T,
 163}
 164
 165/// Language server RPC notification message before it is deserialized into a concrete type.
 166#[derive(Debug, Clone, Deserialize)]
 167struct AnyNotification<'a> {
 168    #[serde(default)]
 169    id: Option<RequestId>,
 170    #[serde(borrow)]
 171    method: &'a str,
 172    #[serde(borrow, default)]
 173    params: Option<&'a RawValue>,
 174}
 175
 176#[derive(Debug, Serialize, Deserialize)]
 177struct Error {
 178    message: String,
 179}
 180
 181pub trait LspRequestFuture<O>: Future<Output = O> {
 182    fn id(&self) -> i32;
 183}
 184
 185struct LspRequest<F> {
 186    id: i32,
 187    request: F,
 188}
 189
 190impl<F> LspRequest<F> {
 191    pub fn new(id: i32, request: F) -> Self {
 192        Self { id, request }
 193    }
 194}
 195
 196impl<F: Future> Future for LspRequest<F> {
 197    type Output = F::Output;
 198
 199    fn poll(self: Pin<&mut Self>, cx: &mut std::task::Context<'_>) -> Poll<Self::Output> {
 200        // SAFETY: This is standard pin projection, we're pinned so our fields must be pinned.
 201        let inner = unsafe { Pin::new_unchecked(&mut self.get_unchecked_mut().request) };
 202        inner.poll(cx)
 203    }
 204}
 205
 206impl<F: Future> LspRequestFuture<F::Output> for LspRequest<F> {
 207    fn id(&self) -> i32 {
 208        self.id
 209    }
 210}
 211
 212/// Experimental: Informs the end user about the state of the server
 213///
 214/// [Rust Analyzer Specification](https://github.com/rust-lang/rust-analyzer/blob/master/docs/dev/lsp-extensions.md#server-status)
 215#[derive(Debug)]
 216pub enum ServerStatus {}
 217
 218/// Other(String) variant to handle unknown values due to this still being experimental
 219#[derive(Debug, PartialEq, Deserialize, Serialize, Clone)]
 220#[serde(rename_all = "camelCase")]
 221pub enum ServerHealthStatus {
 222    Ok,
 223    Warning,
 224    Error,
 225    Other(String),
 226}
 227
 228#[derive(Debug, PartialEq, Deserialize, Serialize, Clone)]
 229#[serde(rename_all = "camelCase")]
 230pub struct ServerStatusParams {
 231    pub health: ServerHealthStatus,
 232    pub message: Option<String>,
 233}
 234
 235impl lsp_types::notification::Notification for ServerStatus {
 236    type Params = ServerStatusParams;
 237    const METHOD: &'static str = "experimental/serverStatus";
 238}
 239
 240impl LanguageServer {
 241    /// Starts a language server process.
 242    pub fn new(
 243        stderr_capture: Arc<Mutex<Option<String>>>,
 244        server_id: LanguageServerId,
 245        binary: LanguageServerBinary,
 246        root_path: &Path,
 247        code_action_kinds: Option<Vec<CodeActionKind>>,
 248        cx: AsyncAppContext,
 249    ) -> Result<Self> {
 250        let working_dir = if root_path.is_dir() {
 251            root_path
 252        } else {
 253            root_path.parent().unwrap_or_else(|| Path::new("/"))
 254        };
 255
 256        log::info!(
 257            "starting language server. binary path: {:?}, working directory: {:?}, args: {:?}",
 258            binary.path,
 259            working_dir,
 260            &binary.arguments
 261        );
 262
 263        let mut command = process::Command::new(&binary.path);
 264        command
 265            .current_dir(working_dir)
 266            .args(&binary.arguments)
 267            .envs(binary.env.unwrap_or_default())
 268            .stdin(Stdio::piped())
 269            .stdout(Stdio::piped())
 270            .stderr(Stdio::piped())
 271            .kill_on_drop(true);
 272        #[cfg(windows)]
 273        command.creation_flags(windows::Win32::System::Threading::CREATE_NO_WINDOW.0);
 274        let mut server = command.spawn().with_context(|| {
 275            format!(
 276                "failed to spawn command. path: {:?}, working directory: {:?}, args: {:?}",
 277                binary.path, working_dir, &binary.arguments
 278            )
 279        })?;
 280
 281        let stdin = server.stdin.take().unwrap();
 282        let stdout = server.stdout.take().unwrap();
 283        let stderr = server.stderr.take().unwrap();
 284        let mut server = Self::new_internal(
 285            server_id,
 286            stdin,
 287            stdout,
 288            Some(stderr),
 289            stderr_capture,
 290            Some(server),
 291            root_path,
 292            working_dir,
 293            code_action_kinds,
 294            cx,
 295            move |notification| {
 296                log::info!(
 297                    "Language server with id {} sent unhandled notification {}:\n{}",
 298                    server_id,
 299                    notification.method,
 300                    serde_json::to_string_pretty(
 301                        &notification
 302                            .params
 303                            .and_then(|params| Value::from_str(params.get()).ok())
 304                            .unwrap_or(Value::Null)
 305                    )
 306                    .unwrap(),
 307                );
 308            },
 309        );
 310
 311        if let Some(name) = binary.path.file_name() {
 312            server.name = name.to_string_lossy().into();
 313        }
 314
 315        Ok(server)
 316    }
 317
 318    #[allow(clippy::too_many_arguments)]
 319    fn new_internal<Stdin, Stdout, Stderr, F>(
 320        server_id: LanguageServerId,
 321        stdin: Stdin,
 322        stdout: Stdout,
 323        stderr: Option<Stderr>,
 324        stderr_capture: Arc<Mutex<Option<String>>>,
 325        server: Option<Child>,
 326        root_path: &Path,
 327        working_dir: &Path,
 328        code_action_kinds: Option<Vec<CodeActionKind>>,
 329        cx: AsyncAppContext,
 330        on_unhandled_notification: F,
 331    ) -> Self
 332    where
 333        Stdin: AsyncWrite + Unpin + Send + 'static,
 334        Stdout: AsyncRead + Unpin + Send + 'static,
 335        Stderr: AsyncRead + Unpin + Send + 'static,
 336        F: FnMut(AnyNotification) + 'static + Send + Sync + Clone,
 337    {
 338        let (outbound_tx, outbound_rx) = channel::unbounded::<String>();
 339        let (output_done_tx, output_done_rx) = barrier::channel();
 340        let notification_handlers =
 341            Arc::new(Mutex::new(HashMap::<_, NotificationHandler>::default()));
 342        let response_handlers =
 343            Arc::new(Mutex::new(Some(HashMap::<_, ResponseHandler>::default())));
 344        let io_handlers = Arc::new(Mutex::new(HashMap::default()));
 345
 346        let stdout_input_task = cx.spawn({
 347            let on_unhandled_notification = on_unhandled_notification.clone();
 348            let notification_handlers = notification_handlers.clone();
 349            let response_handlers = response_handlers.clone();
 350            let io_handlers = io_handlers.clone();
 351            move |cx| {
 352                Self::handle_input(
 353                    stdout,
 354                    on_unhandled_notification,
 355                    notification_handlers,
 356                    response_handlers,
 357                    io_handlers,
 358                    cx,
 359                )
 360                .log_err()
 361            }
 362        });
 363        let stderr_input_task = stderr
 364            .map(|stderr| {
 365                let io_handlers = io_handlers.clone();
 366                let stderr_captures = stderr_capture.clone();
 367                cx.spawn(|_| Self::handle_stderr(stderr, io_handlers, stderr_captures).log_err())
 368            })
 369            .unwrap_or_else(|| Task::Ready(Some(None)));
 370        let input_task = cx.spawn(|_| async move {
 371            let (stdout, stderr) = futures::join!(stdout_input_task, stderr_input_task);
 372            stdout.or(stderr)
 373        });
 374        let output_task = cx.background_executor().spawn({
 375            Self::handle_output(
 376                stdin,
 377                outbound_rx,
 378                output_done_tx,
 379                response_handlers.clone(),
 380                io_handlers.clone(),
 381            )
 382            .log_err()
 383        });
 384
 385        Self {
 386            server_id,
 387            notification_handlers,
 388            response_handlers,
 389            io_handlers,
 390            name: "".into(),
 391            capabilities: Default::default(),
 392            code_action_kinds,
 393            next_id: Default::default(),
 394            outbound_tx,
 395            executor: cx.background_executor().clone(),
 396            io_tasks: Mutex::new(Some((input_task, output_task))),
 397            output_done_rx: Mutex::new(Some(output_done_rx)),
 398            root_path: root_path.to_path_buf(),
 399            working_dir: working_dir.to_path_buf(),
 400            server: Arc::new(Mutex::new(server)),
 401        }
 402    }
 403
 404    /// List of code action kinds this language server reports being able to emit.
 405    pub fn code_action_kinds(&self) -> Option<Vec<CodeActionKind>> {
 406        self.code_action_kinds.clone()
 407    }
 408
 409    async fn handle_input<Stdout, F>(
 410        stdout: Stdout,
 411        mut on_unhandled_notification: F,
 412        notification_handlers: Arc<Mutex<HashMap<&'static str, NotificationHandler>>>,
 413        response_handlers: Arc<Mutex<Option<HashMap<RequestId, ResponseHandler>>>>,
 414        io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
 415        cx: AsyncAppContext,
 416    ) -> anyhow::Result<()>
 417    where
 418        Stdout: AsyncRead + Unpin + Send + 'static,
 419        F: FnMut(AnyNotification) + 'static + Send,
 420    {
 421        let mut stdout = BufReader::new(stdout);
 422        let _clear_response_handlers = util::defer({
 423            let response_handlers = response_handlers.clone();
 424            move || {
 425                response_handlers.lock().take();
 426            }
 427        });
 428        let mut buffer = Vec::new();
 429        loop {
 430            buffer.clear();
 431
 432            read_headers(&mut stdout, &mut buffer).await?;
 433
 434            let headers = std::str::from_utf8(&buffer)?;
 435
 436            let message_len = headers
 437                .split('\n')
 438                .find(|line| line.starts_with(CONTENT_LEN_HEADER))
 439                .and_then(|line| line.strip_prefix(CONTENT_LEN_HEADER))
 440                .ok_or_else(|| anyhow!("invalid LSP message header {headers:?}"))?
 441                .trim_end()
 442                .parse()?;
 443
 444            buffer.resize(message_len, 0);
 445            stdout.read_exact(&mut buffer).await?;
 446
 447            if let Ok(message) = str::from_utf8(&buffer) {
 448                log::trace!("incoming message: {message}");
 449                for handler in io_handlers.lock().values_mut() {
 450                    handler(IoKind::StdOut, message);
 451                }
 452            }
 453
 454            if let Ok(msg) = serde_json::from_slice::<AnyNotification>(&buffer) {
 455                if let Some(handler) = notification_handlers.lock().get_mut(msg.method) {
 456                    handler(
 457                        msg.id,
 458                        msg.params.map(|params| params.get()).unwrap_or("null"),
 459                        cx.clone(),
 460                    );
 461                } else {
 462                    on_unhandled_notification(msg);
 463                }
 464            } else if let Ok(AnyResponse {
 465                id, error, result, ..
 466            }) = serde_json::from_slice(&buffer)
 467            {
 468                if let Some(handler) = response_handlers
 469                    .lock()
 470                    .as_mut()
 471                    .and_then(|handlers| handlers.remove(&id))
 472                {
 473                    if let Some(error) = error {
 474                        handler(Err(error));
 475                    } else if let Some(result) = result {
 476                        handler(Ok(result.get().into()));
 477                    } else {
 478                        handler(Ok("null".into()));
 479                    }
 480                }
 481            } else {
 482                warn!(
 483                    "failed to deserialize LSP message:\n{}",
 484                    std::str::from_utf8(&buffer)?
 485                );
 486            }
 487
 488            // Don't starve the main thread when receiving lots of messages at once.
 489            smol::future::yield_now().await;
 490        }
 491    }
 492
 493    async fn handle_stderr<Stderr>(
 494        stderr: Stderr,
 495        io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
 496        stderr_capture: Arc<Mutex<Option<String>>>,
 497    ) -> anyhow::Result<()>
 498    where
 499        Stderr: AsyncRead + Unpin + Send + 'static,
 500    {
 501        let mut stderr = BufReader::new(stderr);
 502        let mut buffer = Vec::new();
 503
 504        loop {
 505            buffer.clear();
 506
 507            let bytes_read = stderr.read_until(b'\n', &mut buffer).await?;
 508            if bytes_read == 0 {
 509                return Ok(());
 510            }
 511
 512            if let Ok(message) = str::from_utf8(&buffer) {
 513                log::trace!("incoming stderr message:{message}");
 514                for handler in io_handlers.lock().values_mut() {
 515                    handler(IoKind::StdErr, message);
 516                }
 517
 518                if let Some(stderr) = stderr_capture.lock().as_mut() {
 519                    stderr.push_str(message);
 520                }
 521            }
 522
 523            // Don't starve the main thread when receiving lots of messages at once.
 524            smol::future::yield_now().await;
 525        }
 526    }
 527
 528    async fn handle_output<Stdin>(
 529        stdin: Stdin,
 530        outbound_rx: channel::Receiver<String>,
 531        output_done_tx: barrier::Sender,
 532        response_handlers: Arc<Mutex<Option<HashMap<RequestId, ResponseHandler>>>>,
 533        io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
 534    ) -> anyhow::Result<()>
 535    where
 536        Stdin: AsyncWrite + Unpin + Send + 'static,
 537    {
 538        let mut stdin = BufWriter::new(stdin);
 539        let _clear_response_handlers = util::defer({
 540            let response_handlers = response_handlers.clone();
 541            move || {
 542                response_handlers.lock().take();
 543            }
 544        });
 545        let mut content_len_buffer = Vec::new();
 546        while let Ok(message) = outbound_rx.recv().await {
 547            log::trace!("outgoing message:{}", message);
 548            for handler in io_handlers.lock().values_mut() {
 549                handler(IoKind::StdIn, &message);
 550            }
 551
 552            content_len_buffer.clear();
 553            write!(content_len_buffer, "{}", message.len()).unwrap();
 554            stdin.write_all(CONTENT_LEN_HEADER.as_bytes()).await?;
 555            stdin.write_all(&content_len_buffer).await?;
 556            stdin.write_all("\r\n\r\n".as_bytes()).await?;
 557            stdin.write_all(message.as_bytes()).await?;
 558            stdin.flush().await?;
 559        }
 560        drop(output_done_tx);
 561        Ok(())
 562    }
 563
 564    /// Initializes a language server by sending the `Initialize` request.
 565    /// Note that `options` is used directly to construct [`InitializeParams`], which is why it is owned.
 566    ///
 567    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#initialize)
 568    pub fn initialize(
 569        mut self,
 570        options: Option<Value>,
 571        cx: &AppContext,
 572    ) -> Task<Result<Arc<Self>>> {
 573        let root_uri = Url::from_file_path(&self.working_dir).unwrap();
 574        #[allow(deprecated)]
 575        let params = InitializeParams {
 576            process_id: None,
 577            root_path: None,
 578            root_uri: Some(root_uri.clone()),
 579            initialization_options: options,
 580            capabilities: ClientCapabilities {
 581                workspace: Some(WorkspaceClientCapabilities {
 582                    configuration: Some(true),
 583                    did_change_watched_files: Some(DidChangeWatchedFilesClientCapabilities {
 584                        dynamic_registration: Some(true),
 585                        relative_pattern_support: Some(true),
 586                    }),
 587                    did_change_configuration: Some(DynamicRegistrationClientCapabilities {
 588                        dynamic_registration: Some(true),
 589                    }),
 590                    workspace_folders: Some(true),
 591                    symbol: Some(WorkspaceSymbolClientCapabilities {
 592                        resolve_support: None,
 593                        ..WorkspaceSymbolClientCapabilities::default()
 594                    }),
 595                    inlay_hint: Some(InlayHintWorkspaceClientCapabilities {
 596                        refresh_support: Some(true),
 597                    }),
 598                    diagnostic: Some(DiagnosticWorkspaceClientCapabilities {
 599                        refresh_support: None,
 600                    }),
 601                    workspace_edit: Some(WorkspaceEditClientCapabilities {
 602                        resource_operations: Some(vec![
 603                            ResourceOperationKind::Create,
 604                            ResourceOperationKind::Rename,
 605                            ResourceOperationKind::Delete,
 606                        ]),
 607                        document_changes: Some(true),
 608                        snippet_edit_support: Some(true),
 609                        ..WorkspaceEditClientCapabilities::default()
 610                    }),
 611                    ..Default::default()
 612                }),
 613                text_document: Some(TextDocumentClientCapabilities {
 614                    definition: Some(GotoCapability {
 615                        link_support: Some(true),
 616                        dynamic_registration: None,
 617                    }),
 618                    code_action: Some(CodeActionClientCapabilities {
 619                        code_action_literal_support: Some(CodeActionLiteralSupport {
 620                            code_action_kind: CodeActionKindLiteralSupport {
 621                                value_set: vec![
 622                                    CodeActionKind::REFACTOR.as_str().into(),
 623                                    CodeActionKind::QUICKFIX.as_str().into(),
 624                                    CodeActionKind::SOURCE.as_str().into(),
 625                                ],
 626                            },
 627                        }),
 628                        data_support: Some(true),
 629                        resolve_support: Some(CodeActionCapabilityResolveSupport {
 630                            properties: vec![
 631                                "kind".to_string(),
 632                                "diagnostics".to_string(),
 633                                "isPreferred".to_string(),
 634                                "disabled".to_string(),
 635                                "edit".to_string(),
 636                                "command".to_string(),
 637                            ],
 638                        }),
 639                        ..Default::default()
 640                    }),
 641                    completion: Some(CompletionClientCapabilities {
 642                        completion_item: Some(CompletionItemCapability {
 643                            snippet_support: Some(true),
 644                            resolve_support: Some(CompletionItemCapabilityResolveSupport {
 645                                properties: vec![
 646                                    "documentation".to_string(),
 647                                    "additionalTextEdits".to_string(),
 648                                ],
 649                            }),
 650                            insert_replace_support: Some(true),
 651                            ..Default::default()
 652                        }),
 653                        completion_list: Some(CompletionListCapability {
 654                            item_defaults: Some(vec![
 655                                "commitCharacters".to_owned(),
 656                                "editRange".to_owned(),
 657                                "insertTextMode".to_owned(),
 658                                "data".to_owned(),
 659                            ]),
 660                        }),
 661                        ..Default::default()
 662                    }),
 663                    rename: Some(RenameClientCapabilities {
 664                        prepare_support: Some(true),
 665                        ..Default::default()
 666                    }),
 667                    hover: Some(HoverClientCapabilities {
 668                        content_format: Some(vec![MarkupKind::Markdown]),
 669                        dynamic_registration: None,
 670                    }),
 671                    inlay_hint: Some(InlayHintClientCapabilities {
 672                        resolve_support: Some(InlayHintResolveClientCapabilities {
 673                            properties: vec![
 674                                "textEdits".to_string(),
 675                                "tooltip".to_string(),
 676                                "label.tooltip".to_string(),
 677                                "label.location".to_string(),
 678                                "label.command".to_string(),
 679                            ],
 680                        }),
 681                        dynamic_registration: Some(false),
 682                    }),
 683                    publish_diagnostics: Some(PublishDiagnosticsClientCapabilities {
 684                        related_information: Some(true),
 685                        ..Default::default()
 686                    }),
 687                    formatting: Some(DynamicRegistrationClientCapabilities {
 688                        dynamic_registration: None,
 689                    }),
 690                    on_type_formatting: Some(DynamicRegistrationClientCapabilities {
 691                        dynamic_registration: None,
 692                    }),
 693                    diagnostic: Some(DiagnosticClientCapabilities {
 694                        related_document_support: Some(true),
 695                        dynamic_registration: None,
 696                    }),
 697                    ..Default::default()
 698                }),
 699                experimental: Some(json!({
 700                    "serverStatusNotification": true,
 701                })),
 702                window: Some(WindowClientCapabilities {
 703                    work_done_progress: Some(true),
 704                    ..Default::default()
 705                }),
 706                general: None,
 707            },
 708            trace: None,
 709            workspace_folders: Some(vec![WorkspaceFolder {
 710                uri: root_uri,
 711                name: Default::default(),
 712            }]),
 713            client_info: release_channel::ReleaseChannel::try_global(cx).map(|release_channel| {
 714                ClientInfo {
 715                    name: release_channel.display_name().to_string(),
 716                    version: Some(release_channel::AppVersion::global(cx).to_string()),
 717                }
 718            }),
 719            locale: None,
 720            ..Default::default()
 721        };
 722
 723        cx.spawn(|_| async move {
 724            let response = self.request::<request::Initialize>(params).await?;
 725            if let Some(info) = response.server_info {
 726                self.name = info.name.into();
 727            }
 728            self.capabilities = response.capabilities;
 729
 730            self.notify::<notification::Initialized>(InitializedParams {})?;
 731            Ok(Arc::new(self))
 732        })
 733    }
 734
 735    /// Sends a shutdown request to the language server process and prepares the [`LanguageServer`] to be dropped.
 736    pub fn shutdown(&self) -> Option<impl 'static + Send + Future<Output = Option<()>>> {
 737        if let Some(tasks) = self.io_tasks.lock().take() {
 738            let response_handlers = self.response_handlers.clone();
 739            let next_id = AtomicI32::new(self.next_id.load(SeqCst));
 740            let outbound_tx = self.outbound_tx.clone();
 741            let executor = self.executor.clone();
 742            let mut output_done = self.output_done_rx.lock().take().unwrap();
 743            let shutdown_request = Self::request_internal::<request::Shutdown>(
 744                &next_id,
 745                &response_handlers,
 746                &outbound_tx,
 747                &executor,
 748                (),
 749            );
 750            let exit = Self::notify_internal::<notification::Exit>(&outbound_tx, ());
 751            outbound_tx.close();
 752
 753            let server = self.server.clone();
 754            let name = self.name.clone();
 755            let mut timer = self.executor.timer(SERVER_SHUTDOWN_TIMEOUT).fuse();
 756            Some(
 757                async move {
 758                    log::debug!("language server shutdown started");
 759
 760                    select! {
 761                        request_result = shutdown_request.fuse() => {
 762                            request_result?;
 763                        }
 764
 765                        _ = timer => {
 766                            log::info!("timeout waiting for language server {name} to shutdown");
 767                        },
 768                    }
 769
 770                    response_handlers.lock().take();
 771                    exit?;
 772                    output_done.recv().await;
 773                    server.lock().take().map(|mut child| child.kill());
 774                    log::debug!("language server shutdown finished");
 775
 776                    drop(tasks);
 777                    anyhow::Ok(())
 778                }
 779                .log_err(),
 780            )
 781        } else {
 782            None
 783        }
 784    }
 785
 786    /// Register a handler to handle incoming LSP notifications.
 787    ///
 788    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
 789    #[must_use]
 790    pub fn on_notification<T, F>(&self, f: F) -> Subscription
 791    where
 792        T: notification::Notification,
 793        F: 'static + Send + FnMut(T::Params, AsyncAppContext),
 794    {
 795        self.on_custom_notification(T::METHOD, f)
 796    }
 797
 798    /// Register a handler to handle incoming LSP requests.
 799    ///
 800    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
 801    #[must_use]
 802    pub fn on_request<T, F, Fut>(&self, f: F) -> Subscription
 803    where
 804        T: request::Request,
 805        T::Params: 'static + Send,
 806        F: 'static + FnMut(T::Params, AsyncAppContext) -> Fut + Send,
 807        Fut: 'static + Future<Output = Result<T::Result>>,
 808    {
 809        self.on_custom_request(T::METHOD, f)
 810    }
 811
 812    /// Registers a handler to inspect all language server process stdio.
 813    #[must_use]
 814    pub fn on_io<F>(&self, f: F) -> Subscription
 815    where
 816        F: 'static + Send + FnMut(IoKind, &str),
 817    {
 818        let id = self.next_id.fetch_add(1, SeqCst);
 819        self.io_handlers.lock().insert(id, Box::new(f));
 820        Subscription::Io {
 821            id,
 822            io_handlers: Some(Arc::downgrade(&self.io_handlers)),
 823        }
 824    }
 825
 826    /// Removes a request handler registers via [`Self::on_request`].
 827    pub fn remove_request_handler<T: request::Request>(&self) {
 828        self.notification_handlers.lock().remove(T::METHOD);
 829    }
 830
 831    /// Removes a notification handler registers via [`Self::on_notification`].
 832    pub fn remove_notification_handler<T: notification::Notification>(&self) {
 833        self.notification_handlers.lock().remove(T::METHOD);
 834    }
 835
 836    /// Checks if a notification handler has been registered via [`Self::on_notification`].
 837    pub fn has_notification_handler<T: notification::Notification>(&self) -> bool {
 838        self.notification_handlers.lock().contains_key(T::METHOD)
 839    }
 840
 841    #[must_use]
 842    fn on_custom_notification<Params, F>(&self, method: &'static str, mut f: F) -> Subscription
 843    where
 844        F: 'static + FnMut(Params, AsyncAppContext) + Send,
 845        Params: DeserializeOwned,
 846    {
 847        let prev_handler = self.notification_handlers.lock().insert(
 848            method,
 849            Box::new(move |_, params, cx| {
 850                if let Some(params) = serde_json::from_str(params).log_err() {
 851                    f(params, cx);
 852                }
 853            }),
 854        );
 855        assert!(
 856            prev_handler.is_none(),
 857            "registered multiple handlers for the same LSP method"
 858        );
 859        Subscription::Notification {
 860            method,
 861            notification_handlers: Some(self.notification_handlers.clone()),
 862        }
 863    }
 864
 865    #[must_use]
 866    fn on_custom_request<Params, Res, Fut, F>(&self, method: &'static str, mut f: F) -> Subscription
 867    where
 868        F: 'static + FnMut(Params, AsyncAppContext) -> Fut + Send,
 869        Fut: 'static + Future<Output = Result<Res>>,
 870        Params: DeserializeOwned + Send + 'static,
 871        Res: Serialize,
 872    {
 873        let outbound_tx = self.outbound_tx.clone();
 874        let prev_handler = self.notification_handlers.lock().insert(
 875            method,
 876            Box::new(move |id, params, cx| {
 877                if let Some(id) = id {
 878                    match serde_json::from_str(params) {
 879                        Ok(params) => {
 880                            let response = f(params, cx.clone());
 881                            cx.foreground_executor()
 882                                .spawn({
 883                                    let outbound_tx = outbound_tx.clone();
 884                                    async move {
 885                                        let response = match response.await {
 886                                            Ok(result) => Response {
 887                                                jsonrpc: JSON_RPC_VERSION,
 888                                                id,
 889                                                value: LspResult::Ok(Some(result)),
 890                                            },
 891                                            Err(error) => Response {
 892                                                jsonrpc: JSON_RPC_VERSION,
 893                                                id,
 894                                                value: LspResult::Error(Some(Error {
 895                                                    message: error.to_string(),
 896                                                })),
 897                                            },
 898                                        };
 899                                        if let Some(response) =
 900                                            serde_json::to_string(&response).log_err()
 901                                        {
 902                                            outbound_tx.try_send(response).ok();
 903                                        }
 904                                    }
 905                                })
 906                                .detach();
 907                        }
 908
 909                        Err(error) => {
 910                            log::error!(
 911                                "error deserializing {} request: {:?}, message: {:?}",
 912                                method,
 913                                error,
 914                                params
 915                            );
 916                            let response = AnyResponse {
 917                                jsonrpc: JSON_RPC_VERSION,
 918                                id,
 919                                result: None,
 920                                error: Some(Error {
 921                                    message: error.to_string(),
 922                                }),
 923                            };
 924                            if let Some(response) = serde_json::to_string(&response).log_err() {
 925                                outbound_tx.try_send(response).ok();
 926                            }
 927                        }
 928                    }
 929                }
 930            }),
 931        );
 932        assert!(
 933            prev_handler.is_none(),
 934            "registered multiple handlers for the same LSP method"
 935        );
 936        Subscription::Notification {
 937            method,
 938            notification_handlers: Some(self.notification_handlers.clone()),
 939        }
 940    }
 941
 942    /// Get the name of the running language server.
 943    pub fn name(&self) -> &str {
 944        &self.name
 945    }
 946
 947    /// Get the reported capabilities of the running language server.
 948    pub fn capabilities(&self) -> &ServerCapabilities {
 949        &self.capabilities
 950    }
 951
 952    /// Get the id of the running language server.
 953    pub fn server_id(&self) -> LanguageServerId {
 954        self.server_id
 955    }
 956
 957    /// Get the root path of the project the language server is running against.
 958    pub fn root_path(&self) -> &PathBuf {
 959        &self.root_path
 960    }
 961
 962    /// Sends a RPC request to the language server.
 963    ///
 964    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
 965    pub fn request<T: request::Request>(
 966        &self,
 967        params: T::Params,
 968    ) -> impl LspRequestFuture<Result<T::Result>>
 969    where
 970        T::Result: 'static + Send,
 971    {
 972        Self::request_internal::<T>(
 973            &self.next_id,
 974            &self.response_handlers,
 975            &self.outbound_tx,
 976            &self.executor,
 977            params,
 978        )
 979    }
 980
 981    fn request_internal<T: request::Request>(
 982        next_id: &AtomicI32,
 983        response_handlers: &Mutex<Option<HashMap<RequestId, ResponseHandler>>>,
 984        outbound_tx: &channel::Sender<String>,
 985        executor: &BackgroundExecutor,
 986        params: T::Params,
 987    ) -> impl LspRequestFuture<Result<T::Result>>
 988    where
 989        T::Result: 'static + Send,
 990    {
 991        let id = next_id.fetch_add(1, SeqCst);
 992        let message = serde_json::to_string(&Request {
 993            jsonrpc: JSON_RPC_VERSION,
 994            id: RequestId::Int(id),
 995            method: T::METHOD,
 996            params,
 997        })
 998        .unwrap();
 999
1000        let (tx, rx) = oneshot::channel();
1001        let handle_response = response_handlers
1002            .lock()
1003            .as_mut()
1004            .ok_or_else(|| anyhow!("server shut down"))
1005            .map(|handlers| {
1006                let executor = executor.clone();
1007                handlers.insert(
1008                    RequestId::Int(id),
1009                    Box::new(move |result| {
1010                        executor
1011                            .spawn(async move {
1012                                let response = match result {
1013                                    Ok(response) => match serde_json::from_str(&response) {
1014                                        Ok(deserialized) => Ok(deserialized),
1015                                        Err(error) => {
1016                                            log::error!("failed to deserialize response from language server: {}. response from language server: {:?}", error, response);
1017                                            Err(error).context("failed to deserialize response")
1018                                        }
1019                                    }
1020                                    Err(error) => Err(anyhow!("{}", error.message)),
1021                                };
1022                                _ = tx.send(response);
1023                            })
1024                            .detach();
1025                    }),
1026                );
1027            });
1028
1029        let send = outbound_tx
1030            .try_send(message)
1031            .context("failed to write to language server's stdin");
1032
1033        let outbound_tx = outbound_tx.downgrade();
1034        let mut timeout = executor.timer(LSP_REQUEST_TIMEOUT).fuse();
1035        let started = Instant::now();
1036        LspRequest::new(id, async move {
1037            handle_response?;
1038            send?;
1039
1040            let cancel_on_drop = util::defer(move || {
1041                if let Some(outbound_tx) = outbound_tx.upgrade() {
1042                    Self::notify_internal::<notification::Cancel>(
1043                        &outbound_tx,
1044                        CancelParams {
1045                            id: NumberOrString::Number(id),
1046                        },
1047                    )
1048                    .log_err();
1049                }
1050            });
1051
1052            let method = T::METHOD;
1053            select! {
1054                response = rx.fuse() => {
1055                    let elapsed = started.elapsed();
1056                    log::trace!("Took {elapsed:?} to receive response to {method:?} id {id}");
1057                    cancel_on_drop.abort();
1058                    response?
1059                }
1060
1061                _ = timeout => {
1062                    log::error!("Cancelled LSP request task for {method:?} id {id} which took over {LSP_REQUEST_TIMEOUT:?}");
1063                    anyhow::bail!("LSP request timeout");
1064                }
1065            }
1066        })
1067    }
1068
1069    /// Sends a RPC notification to the language server.
1070    ///
1071    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
1072    pub fn notify<T: notification::Notification>(&self, params: T::Params) -> Result<()> {
1073        Self::notify_internal::<T>(&self.outbound_tx, params)
1074    }
1075
1076    fn notify_internal<T: notification::Notification>(
1077        outbound_tx: &channel::Sender<String>,
1078        params: T::Params,
1079    ) -> Result<()> {
1080        let message = serde_json::to_string(&Notification {
1081            jsonrpc: JSON_RPC_VERSION,
1082            method: T::METHOD,
1083            params,
1084        })
1085        .unwrap();
1086        outbound_tx.try_send(message)?;
1087        Ok(())
1088    }
1089}
1090
1091impl Drop for LanguageServer {
1092    fn drop(&mut self) {
1093        if let Some(shutdown) = self.shutdown() {
1094            self.executor.spawn(shutdown).detach();
1095        }
1096    }
1097}
1098
1099impl Subscription {
1100    /// Detaching a subscription handle prevents it from unsubscribing on drop.
1101    pub fn detach(&mut self) {
1102        match self {
1103            Subscription::Notification {
1104                notification_handlers,
1105                ..
1106            } => *notification_handlers = None,
1107            Subscription::Io { io_handlers, .. } => *io_handlers = None,
1108        }
1109    }
1110}
1111
1112impl fmt::Display for LanguageServerId {
1113    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1114        self.0.fmt(f)
1115    }
1116}
1117
1118impl fmt::Debug for LanguageServer {
1119    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1120        f.debug_struct("LanguageServer")
1121            .field("id", &self.server_id.0)
1122            .field("name", &self.name)
1123            .finish_non_exhaustive()
1124    }
1125}
1126
1127impl Drop for Subscription {
1128    fn drop(&mut self) {
1129        match self {
1130            Subscription::Notification {
1131                method,
1132                notification_handlers,
1133            } => {
1134                if let Some(handlers) = notification_handlers {
1135                    handlers.lock().remove(method);
1136                }
1137            }
1138            Subscription::Io { id, io_handlers } => {
1139                if let Some(io_handlers) = io_handlers.as_ref().and_then(|h| h.upgrade()) {
1140                    io_handlers.lock().remove(id);
1141                }
1142            }
1143        }
1144    }
1145}
1146
1147/// Mock language server for use in tests.
1148#[cfg(any(test, feature = "test-support"))]
1149#[derive(Clone)]
1150pub struct FakeLanguageServer {
1151    pub binary: LanguageServerBinary,
1152    pub server: Arc<LanguageServer>,
1153    notifications_rx: channel::Receiver<(String, String)>,
1154}
1155
1156#[cfg(any(test, feature = "test-support"))]
1157impl FakeLanguageServer {
1158    /// Construct a fake language server.
1159    pub fn new(
1160        server_id: LanguageServerId,
1161        binary: LanguageServerBinary,
1162        name: String,
1163        capabilities: ServerCapabilities,
1164        cx: AsyncAppContext,
1165    ) -> (LanguageServer, FakeLanguageServer) {
1166        let (stdin_writer, stdin_reader) = async_pipe::pipe();
1167        let (stdout_writer, stdout_reader) = async_pipe::pipe();
1168        let (notifications_tx, notifications_rx) = channel::unbounded();
1169
1170        let mut server = LanguageServer::new_internal(
1171            server_id,
1172            stdin_writer,
1173            stdout_reader,
1174            None::<async_pipe::PipeReader>,
1175            Arc::new(Mutex::new(None)),
1176            None,
1177            Path::new("/"),
1178            Path::new("/"),
1179            None,
1180            cx.clone(),
1181            |_| {},
1182        );
1183        server.name = name.as_str().into();
1184        let fake = FakeLanguageServer {
1185            binary,
1186            server: Arc::new({
1187                let mut server = LanguageServer::new_internal(
1188                    server_id,
1189                    stdout_writer,
1190                    stdin_reader,
1191                    None::<async_pipe::PipeReader>,
1192                    Arc::new(Mutex::new(None)),
1193                    None,
1194                    Path::new("/"),
1195                    Path::new("/"),
1196                    None,
1197                    cx,
1198                    move |msg| {
1199                        notifications_tx
1200                            .try_send((
1201                                msg.method.to_string(),
1202                                msg.params
1203                                    .map(|raw_value| raw_value.get())
1204                                    .unwrap_or("null")
1205                                    .to_string(),
1206                            ))
1207                            .ok();
1208                    },
1209                );
1210                server.name = name.as_str().into();
1211                server
1212            }),
1213            notifications_rx,
1214        };
1215        fake.handle_request::<request::Initialize, _, _>({
1216            let capabilities = capabilities;
1217            move |_, _| {
1218                let capabilities = capabilities.clone();
1219                let name = name.clone();
1220                async move {
1221                    Ok(InitializeResult {
1222                        capabilities,
1223                        server_info: Some(ServerInfo {
1224                            name,
1225                            ..Default::default()
1226                        }),
1227                    })
1228                }
1229            }
1230        });
1231
1232        (server, fake)
1233    }
1234}
1235
1236#[cfg(any(test, feature = "test-support"))]
1237impl LanguageServer {
1238    pub fn full_capabilities() -> ServerCapabilities {
1239        ServerCapabilities {
1240            document_highlight_provider: Some(OneOf::Left(true)),
1241            code_action_provider: Some(CodeActionProviderCapability::Simple(true)),
1242            document_formatting_provider: Some(OneOf::Left(true)),
1243            document_range_formatting_provider: Some(OneOf::Left(true)),
1244            definition_provider: Some(OneOf::Left(true)),
1245            implementation_provider: Some(ImplementationProviderCapability::Simple(true)),
1246            type_definition_provider: Some(TypeDefinitionProviderCapability::Simple(true)),
1247            ..Default::default()
1248        }
1249    }
1250}
1251
1252#[cfg(any(test, feature = "test-support"))]
1253impl FakeLanguageServer {
1254    /// See [`LanguageServer::notify`].
1255    pub fn notify<T: notification::Notification>(&self, params: T::Params) {
1256        self.server.notify::<T>(params).ok();
1257    }
1258
1259    /// See [`LanguageServer::request`].
1260    pub async fn request<T>(&self, params: T::Params) -> Result<T::Result>
1261    where
1262        T: request::Request,
1263        T::Result: 'static + Send,
1264    {
1265        self.server.executor.start_waiting();
1266        self.server.request::<T>(params).await
1267    }
1268
1269    /// Attempts [`Self::try_receive_notification`], unwrapping if it has not received the specified type yet.
1270    pub async fn receive_notification<T: notification::Notification>(&mut self) -> T::Params {
1271        self.server.executor.start_waiting();
1272        self.try_receive_notification::<T>().await.unwrap()
1273    }
1274
1275    /// Consumes the notification channel until it finds a notification for the specified type.
1276    pub async fn try_receive_notification<T: notification::Notification>(
1277        &mut self,
1278    ) -> Option<T::Params> {
1279        use futures::StreamExt as _;
1280
1281        loop {
1282            let (method, params) = self.notifications_rx.next().await?;
1283            if method == T::METHOD {
1284                return Some(serde_json::from_str::<T::Params>(&params).unwrap());
1285            } else {
1286                log::info!("skipping message in fake language server {:?}", params);
1287            }
1288        }
1289    }
1290
1291    /// Registers a handler for a specific kind of request. Removes any existing handler for specified request type.
1292    pub fn handle_request<T, F, Fut>(
1293        &self,
1294        mut handler: F,
1295    ) -> futures::channel::mpsc::UnboundedReceiver<()>
1296    where
1297        T: 'static + request::Request,
1298        T::Params: 'static + Send,
1299        F: 'static + Send + FnMut(T::Params, gpui::AsyncAppContext) -> Fut,
1300        Fut: 'static + Send + Future<Output = Result<T::Result>>,
1301    {
1302        let (responded_tx, responded_rx) = futures::channel::mpsc::unbounded();
1303        self.server.remove_request_handler::<T>();
1304        self.server
1305            .on_request::<T, _, _>(move |params, cx| {
1306                let result = handler(params, cx.clone());
1307                let responded_tx = responded_tx.clone();
1308                let executor = cx.background_executor().clone();
1309                async move {
1310                    executor.simulate_random_delay().await;
1311                    let result = result.await;
1312                    responded_tx.unbounded_send(()).ok();
1313                    result
1314                }
1315            })
1316            .detach();
1317        responded_rx
1318    }
1319
1320    /// Registers a handler for a specific kind of notification. Removes any existing handler for specified notification type.
1321    pub fn handle_notification<T, F>(
1322        &self,
1323        mut handler: F,
1324    ) -> futures::channel::mpsc::UnboundedReceiver<()>
1325    where
1326        T: 'static + notification::Notification,
1327        T::Params: 'static + Send,
1328        F: 'static + Send + FnMut(T::Params, gpui::AsyncAppContext),
1329    {
1330        let (handled_tx, handled_rx) = futures::channel::mpsc::unbounded();
1331        self.server.remove_notification_handler::<T>();
1332        self.server
1333            .on_notification::<T, _>(move |params, cx| {
1334                handler(params, cx.clone());
1335                handled_tx.unbounded_send(()).ok();
1336            })
1337            .detach();
1338        handled_rx
1339    }
1340
1341    /// Removes any existing handler for specified notification type.
1342    pub fn remove_request_handler<T>(&mut self)
1343    where
1344        T: 'static + request::Request,
1345    {
1346        self.server.remove_request_handler::<T>();
1347    }
1348
1349    /// Simulate that the server has started work and notifies about its progress with the specified token.
1350    pub async fn start_progress(&self, token: impl Into<String>) {
1351        let token = token.into();
1352        self.request::<request::WorkDoneProgressCreate>(WorkDoneProgressCreateParams {
1353            token: NumberOrString::String(token.clone()),
1354        })
1355        .await
1356        .unwrap();
1357        self.notify::<notification::Progress>(ProgressParams {
1358            token: NumberOrString::String(token),
1359            value: ProgressParamsValue::WorkDone(WorkDoneProgress::Begin(Default::default())),
1360        });
1361    }
1362
1363    /// Simulate that the server has completed work and notifies about that with the specified token.
1364    pub fn end_progress(&self, token: impl Into<String>) {
1365        self.notify::<notification::Progress>(ProgressParams {
1366            token: NumberOrString::String(token.into()),
1367            value: ProgressParamsValue::WorkDone(WorkDoneProgress::End(Default::default())),
1368        });
1369    }
1370}
1371
1372pub(self) async fn read_headers<Stdout>(
1373    reader: &mut BufReader<Stdout>,
1374    buffer: &mut Vec<u8>,
1375) -> Result<()>
1376where
1377    Stdout: AsyncRead + Unpin + Send + 'static,
1378{
1379    loop {
1380        if buffer.len() >= HEADER_DELIMITER.len()
1381            && buffer[(buffer.len() - HEADER_DELIMITER.len())..] == HEADER_DELIMITER[..]
1382        {
1383            return Ok(());
1384        }
1385
1386        if reader.read_until(b'\n', buffer).await? == 0 {
1387            return Err(anyhow!("cannot read LSP message headers"));
1388        }
1389    }
1390}
1391
1392#[cfg(test)]
1393mod tests {
1394    use super::*;
1395    use gpui::TestAppContext;
1396
1397    #[ctor::ctor]
1398    fn init_logger() {
1399        if std::env::var("RUST_LOG").is_ok() {
1400            env_logger::init();
1401        }
1402    }
1403
1404    #[gpui::test]
1405    async fn test_fake(cx: &mut TestAppContext) {
1406        cx.update(|cx| {
1407            release_channel::init("0.0.0", cx);
1408        });
1409        let (server, mut fake) = FakeLanguageServer::new(
1410            LanguageServerId(0),
1411            LanguageServerBinary {
1412                path: "path/to/language-server".into(),
1413                arguments: vec![],
1414                env: None,
1415            },
1416            "the-lsp".to_string(),
1417            Default::default(),
1418            cx.to_async(),
1419        );
1420
1421        let (message_tx, message_rx) = channel::unbounded();
1422        let (diagnostics_tx, diagnostics_rx) = channel::unbounded();
1423        server
1424            .on_notification::<notification::ShowMessage, _>(move |params, _| {
1425                message_tx.try_send(params).unwrap()
1426            })
1427            .detach();
1428        server
1429            .on_notification::<notification::PublishDiagnostics, _>(move |params, _| {
1430                diagnostics_tx.try_send(params).unwrap()
1431            })
1432            .detach();
1433
1434        let server = cx.update(|cx| server.initialize(None, cx)).await.unwrap();
1435        server
1436            .notify::<notification::DidOpenTextDocument>(DidOpenTextDocumentParams {
1437                text_document: TextDocumentItem::new(
1438                    Url::from_str("file://a/b").unwrap(),
1439                    "rust".to_string(),
1440                    0,
1441                    "".to_string(),
1442                ),
1443            })
1444            .unwrap();
1445        assert_eq!(
1446            fake.receive_notification::<notification::DidOpenTextDocument>()
1447                .await
1448                .text_document
1449                .uri
1450                .as_str(),
1451            "file://a/b"
1452        );
1453
1454        fake.notify::<notification::ShowMessage>(ShowMessageParams {
1455            typ: MessageType::ERROR,
1456            message: "ok".to_string(),
1457        });
1458        fake.notify::<notification::PublishDiagnostics>(PublishDiagnosticsParams {
1459            uri: Url::from_str("file://b/c").unwrap(),
1460            version: Some(5),
1461            diagnostics: vec![],
1462        });
1463        assert_eq!(message_rx.recv().await.unwrap().message, "ok");
1464        assert_eq!(
1465            diagnostics_rx.recv().await.unwrap().uri.as_str(),
1466            "file://b/c"
1467        );
1468
1469        fake.handle_request::<request::Shutdown, _, _>(|_, _| async move { Ok(()) });
1470
1471        drop(server);
1472        fake.receive_notification::<notification::Exit>().await;
1473    }
1474
1475    #[gpui::test]
1476    async fn test_read_headers() {
1477        let mut buf = Vec::new();
1478        let mut reader = smol::io::BufReader::new(b"Content-Length: 123\r\n\r\n" as &[u8]);
1479        read_headers(&mut reader, &mut buf).await.unwrap();
1480        assert_eq!(buf, b"Content-Length: 123\r\n\r\n");
1481
1482        let mut buf = Vec::new();
1483        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]);
1484        read_headers(&mut reader, &mut buf).await.unwrap();
1485        assert_eq!(
1486            buf,
1487            b"Content-Type: application/vscode-jsonrpc\r\nContent-Length: 1235\r\n\r\n"
1488        );
1489
1490        let mut buf = Vec::new();
1491        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]);
1492        read_headers(&mut reader, &mut buf).await.unwrap();
1493        assert_eq!(
1494            buf,
1495            b"Content-Length: 1235\r\nContent-Type: application/vscode-jsonrpc\r\n\r\n"
1496        );
1497    }
1498
1499    #[gpui::test]
1500    fn test_deserialize_string_digit_id() {
1501        let json = r#"{"jsonrpc":"2.0","id":"2","method":"workspace/configuration","params":{"items":[{"scopeUri":"file:///Users/mph/Devel/personal/hello-scala/","section":"metals"}]}}"#;
1502        let notification = serde_json::from_str::<AnyNotification>(json)
1503            .expect("message with string id should be parsed");
1504        let expected_id = RequestId::Str("2".to_string());
1505        assert_eq!(notification.id, Some(expected_id));
1506    }
1507
1508    #[gpui::test]
1509    fn test_deserialize_string_id() {
1510        let json = r#"{"jsonrpc":"2.0","id":"anythingAtAll","method":"workspace/configuration","params":{"items":[{"scopeUri":"file:///Users/mph/Devel/personal/hello-scala/","section":"metals"}]}}"#;
1511        let notification = serde_json::from_str::<AnyNotification>(json)
1512            .expect("message with string id should be parsed");
1513        let expected_id = RequestId::Str("anythingAtAll".to_string());
1514        assert_eq!(notification.id, Some(expected_id));
1515    }
1516
1517    #[gpui::test]
1518    fn test_deserialize_int_id() {
1519        let json = r#"{"jsonrpc":"2.0","id":2,"method":"workspace/configuration","params":{"items":[{"scopeUri":"file:///Users/mph/Devel/personal/hello-scala/","section":"metals"}]}}"#;
1520        let notification = serde_json::from_str::<AnyNotification>(json)
1521            .expect("message with string id should be parsed");
1522        let expected_id = RequestId::Int(2);
1523        assert_eq!(notification.id, Some(expected_id));
1524    }
1525
1526    #[test]
1527    fn test_serialize_has_no_nulls() {
1528        // Ensure we're not setting both result and error variants. (ticket #10595)
1529        let no_tag = Response::<u32> {
1530            jsonrpc: "",
1531            id: RequestId::Int(0),
1532            value: LspResult::Ok(None),
1533        };
1534        assert_eq!(
1535            serde_json::to_string(&no_tag).unwrap(),
1536            "{\"jsonrpc\":\"\",\"id\":0,\"result\":null}"
1537        );
1538        let no_tag = Response::<u32> {
1539            jsonrpc: "",
1540            id: RequestId::Int(0),
1541            value: LspResult::Error(None),
1542        };
1543        assert_eq!(
1544            serde_json::to_string(&no_tag).unwrap(),
1545            "{\"jsonrpc\":\"\",\"id\":0,\"error\":null}"
1546        );
1547    }
1548}