lsp.rs

   1mod input_handler;
   2
   3pub use lsp_types::request::*;
   4pub use lsp_types::*;
   5
   6use anyhow::{anyhow, Context, Result};
   7use collections::HashMap;
   8use futures::{channel::oneshot, io::BufWriter, select, AsyncRead, AsyncWrite, Future, FutureExt};
   9use gpui::{AppContext, AsyncAppContext, BackgroundExecutor, Task};
  10use parking_lot::{Mutex, RwLock};
  11use postage::{barrier, prelude::Stream};
  12use serde::{de::DeserializeOwned, Deserialize, Serialize};
  13use serde_json::{json, value::RawValue, Value};
  14use smol::{
  15    channel,
  16    io::{AsyncBufReadExt, AsyncWriteExt, BufReader},
  17    process::{self, Child},
  18};
  19
  20#[cfg(target_os = "windows")]
  21use smol::process::windows::CommandExt;
  22
  23use std::{
  24    ffi::OsString,
  25    fmt,
  26    io::Write,
  27    ops::DerefMut,
  28    path::PathBuf,
  29    pin::Pin,
  30    sync::{
  31        atomic::{AtomicI32, Ordering::SeqCst},
  32        Arc, Weak,
  33    },
  34    task::Poll,
  35    time::{Duration, Instant},
  36};
  37use std::{path::Path, process::Stdio};
  38use util::{ResultExt, TryFutureExt};
  39
  40const JSON_RPC_VERSION: &str = "2.0";
  41const CONTENT_LEN_HEADER: &str = "Content-Length: ";
  42
  43const LSP_REQUEST_TIMEOUT: Duration = Duration::from_secs(60 * 2);
  44const SERVER_SHUTDOWN_TIMEOUT: Duration = Duration::from_secs(5);
  45
  46type NotificationHandler = Box<dyn Send + FnMut(Option<RequestId>, Value, AsyncAppContext)>;
  47type ResponseHandler = Box<dyn Send + FnOnce(Result<String, Error>)>;
  48type IoHandler = Box<dyn Send + FnMut(IoKind, &str)>;
  49
  50/// Kind of language server stdio given to an IO handler.
  51#[derive(Debug, Clone, Copy)]
  52pub enum IoKind {
  53    StdOut,
  54    StdIn,
  55    StdErr,
  56}
  57
  58/// Represents a launchable language server. This can either be a standalone binary or the path
  59/// to a runtime with arguments to instruct it to launch the actual language server file.
  60#[derive(Debug, Clone, Deserialize)]
  61pub struct LanguageServerBinary {
  62    pub path: PathBuf,
  63    pub arguments: Vec<OsString>,
  64    pub env: Option<HashMap<String, String>>,
  65}
  66
  67/// Configures the search (and installation) of language servers.
  68#[derive(Debug, Clone, Deserialize)]
  69pub struct LanguageServerBinaryOptions {
  70    /// Whether the adapter should look at the users system
  71    pub allow_path_lookup: bool,
  72    /// Whether the adapter should download its own version
  73    pub allow_binary_download: bool,
  74}
  75
  76/// A running language server process.
  77pub struct LanguageServer {
  78    server_id: LanguageServerId,
  79    next_id: AtomicI32,
  80    outbound_tx: channel::Sender<String>,
  81    name: Arc<str>,
  82    capabilities: RwLock<ServerCapabilities>,
  83    code_action_kinds: Option<Vec<CodeActionKind>>,
  84    notification_handlers: Arc<Mutex<HashMap<&'static str, NotificationHandler>>>,
  85    response_handlers: Arc<Mutex<Option<HashMap<RequestId, ResponseHandler>>>>,
  86    io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
  87    executor: BackgroundExecutor,
  88    #[allow(clippy::type_complexity)]
  89    io_tasks: Mutex<Option<(Task<Option<()>>, Task<Option<()>>)>>,
  90    output_done_rx: Mutex<Option<barrier::Receiver>>,
  91    root_path: PathBuf,
  92    working_dir: PathBuf,
  93    server: Arc<Mutex<Option<Child>>>,
  94}
  95
  96/// Identifies a running language server.
  97#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
  98#[repr(transparent)]
  99pub struct LanguageServerId(pub usize);
 100
 101impl LanguageServerId {
 102    pub fn from_proto(id: u64) -> Self {
 103        Self(id as usize)
 104    }
 105
 106    pub fn to_proto(self) -> u64 {
 107        self.0 as u64
 108    }
 109}
 110
 111/// Handle to a language server RPC activity subscription.
 112pub enum Subscription {
 113    Notification {
 114        method: &'static str,
 115        notification_handlers: Option<Arc<Mutex<HashMap<&'static str, NotificationHandler>>>>,
 116    },
 117    Io {
 118        id: i32,
 119        io_handlers: Option<Weak<Mutex<HashMap<i32, IoHandler>>>>,
 120    },
 121}
 122
 123/// Language server protocol RPC request message ID.
 124///
 125/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
 126#[derive(Debug, Clone, Eq, PartialEq, Hash, Serialize, Deserialize)]
 127#[serde(untagged)]
 128pub enum RequestId {
 129    Int(i32),
 130    Str(String),
 131}
 132
 133/// Language server protocol RPC request message.
 134///
 135/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
 136#[derive(Serialize, Deserialize)]
 137pub struct Request<'a, T> {
 138    jsonrpc: &'static str,
 139    id: RequestId,
 140    method: &'a str,
 141    params: T,
 142}
 143
 144/// Language server protocol RPC request response message before it is deserialized into a concrete type.
 145#[derive(Serialize, Deserialize)]
 146struct AnyResponse<'a> {
 147    jsonrpc: &'a str,
 148    id: RequestId,
 149    #[serde(default)]
 150    error: Option<Error>,
 151    #[serde(borrow)]
 152    result: Option<&'a RawValue>,
 153}
 154
 155/// Language server protocol RPC request response message.
 156///
 157/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#responseMessage)
 158#[derive(Serialize)]
 159struct Response<T> {
 160    jsonrpc: &'static str,
 161    id: RequestId,
 162    #[serde(flatten)]
 163    value: LspResult<T>,
 164}
 165
 166#[derive(Serialize)]
 167#[serde(rename_all = "snake_case")]
 168enum LspResult<T> {
 169    #[serde(rename = "result")]
 170    Ok(Option<T>),
 171    Error(Option<Error>),
 172}
 173
 174/// Language server protocol RPC notification message.
 175///
 176/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
 177#[derive(Serialize, Deserialize)]
 178struct Notification<'a, T> {
 179    jsonrpc: &'static str,
 180    #[serde(borrow)]
 181    method: &'a str,
 182    params: T,
 183}
 184
 185/// Language server RPC notification message before it is deserialized into a concrete type.
 186#[derive(Debug, Clone, Deserialize)]
 187struct AnyNotification {
 188    #[serde(default)]
 189    id: Option<RequestId>,
 190    method: String,
 191    #[serde(default)]
 192    params: Option<Value>,
 193}
 194
 195#[derive(Debug, Serialize, Deserialize)]
 196struct Error {
 197    message: String,
 198}
 199
 200pub trait LspRequestFuture<O>: Future<Output = O> {
 201    fn id(&self) -> i32;
 202}
 203
 204struct LspRequest<F> {
 205    id: i32,
 206    request: F,
 207}
 208
 209impl<F> LspRequest<F> {
 210    pub fn new(id: i32, request: F) -> Self {
 211        Self { id, request }
 212    }
 213}
 214
 215impl<F: Future> Future for LspRequest<F> {
 216    type Output = F::Output;
 217
 218    fn poll(self: Pin<&mut Self>, cx: &mut std::task::Context<'_>) -> Poll<Self::Output> {
 219        // SAFETY: This is standard pin projection, we're pinned so our fields must be pinned.
 220        let inner = unsafe { Pin::new_unchecked(&mut self.get_unchecked_mut().request) };
 221        inner.poll(cx)
 222    }
 223}
 224
 225impl<F: Future> LspRequestFuture<F::Output> for LspRequest<F> {
 226    fn id(&self) -> i32 {
 227        self.id
 228    }
 229}
 230
 231/// Combined capabilities of the server and the adapter.
 232pub struct AdapterServerCapabilities {
 233    // Reported capabilities by the server
 234    pub server_capabilities: ServerCapabilities,
 235    // List of code actions supported by the LspAdapter matching the server
 236    pub code_action_kinds: Option<Vec<CodeActionKind>>,
 237}
 238
 239/// Experimental: Informs the end user about the state of the server
 240///
 241/// [Rust Analyzer Specification](https://github.com/rust-lang/rust-analyzer/blob/master/docs/dev/lsp-extensions.md#server-status)
 242#[derive(Debug)]
 243pub enum ServerStatus {}
 244
 245/// Other(String) variant to handle unknown values due to this still being experimental
 246#[derive(Debug, PartialEq, Deserialize, Serialize, Clone)]
 247#[serde(rename_all = "camelCase")]
 248pub enum ServerHealthStatus {
 249    Ok,
 250    Warning,
 251    Error,
 252    Other(String),
 253}
 254
 255#[derive(Debug, PartialEq, Deserialize, Serialize, Clone)]
 256#[serde(rename_all = "camelCase")]
 257pub struct ServerStatusParams {
 258    pub health: ServerHealthStatus,
 259    pub message: Option<String>,
 260}
 261
 262impl lsp_types::notification::Notification for ServerStatus {
 263    type Params = ServerStatusParams;
 264    const METHOD: &'static str = "experimental/serverStatus";
 265}
 266
 267impl LanguageServer {
 268    /// Starts a language server process.
 269    pub fn new(
 270        stderr_capture: Arc<Mutex<Option<String>>>,
 271        server_id: LanguageServerId,
 272        binary: LanguageServerBinary,
 273        root_path: &Path,
 274        code_action_kinds: Option<Vec<CodeActionKind>>,
 275        cx: AsyncAppContext,
 276    ) -> Result<Self> {
 277        let working_dir = if root_path.is_dir() {
 278            root_path
 279        } else {
 280            root_path.parent().unwrap_or_else(|| Path::new("/"))
 281        };
 282
 283        log::info!(
 284            "starting language server process. binary path: {:?}, working directory: {:?}, args: {:?}",
 285            binary.path,
 286            working_dir,
 287            &binary.arguments
 288        );
 289
 290        let mut command = process::Command::new(&binary.path);
 291        command
 292            .current_dir(working_dir)
 293            .args(&binary.arguments)
 294            .envs(binary.env.unwrap_or_default())
 295            .stdin(Stdio::piped())
 296            .stdout(Stdio::piped())
 297            .stderr(Stdio::piped())
 298            .kill_on_drop(true);
 299        #[cfg(windows)]
 300        command.creation_flags(windows::Win32::System::Threading::CREATE_NO_WINDOW.0);
 301        let mut server = command.spawn().with_context(|| {
 302            format!(
 303                "failed to spawn command. path: {:?}, working directory: {:?}, args: {:?}",
 304                binary.path, working_dir, &binary.arguments
 305            )
 306        })?;
 307
 308        let stdin = server.stdin.take().unwrap();
 309        let stdout = server.stdout.take().unwrap();
 310        let stderr = server.stderr.take().unwrap();
 311        let mut server = Self::new_internal(
 312            server_id,
 313            stdin,
 314            stdout,
 315            Some(stderr),
 316            stderr_capture,
 317            Some(server),
 318            root_path,
 319            working_dir,
 320            code_action_kinds,
 321            cx,
 322            move |notification| {
 323                log::info!(
 324                    "Language server with id {} sent unhandled notification {}:\n{}",
 325                    server_id,
 326                    notification.method,
 327                    serde_json::to_string_pretty(&notification.params).unwrap(),
 328                );
 329            },
 330        );
 331
 332        if let Some(name) = binary.path.file_name() {
 333            server.name = name.to_string_lossy().into();
 334        }
 335
 336        Ok(server)
 337    }
 338
 339    #[allow(clippy::too_many_arguments)]
 340    fn new_internal<Stdin, Stdout, Stderr, F>(
 341        server_id: LanguageServerId,
 342        stdin: Stdin,
 343        stdout: Stdout,
 344        stderr: Option<Stderr>,
 345        stderr_capture: Arc<Mutex<Option<String>>>,
 346        server: Option<Child>,
 347        root_path: &Path,
 348        working_dir: &Path,
 349        code_action_kinds: Option<Vec<CodeActionKind>>,
 350        cx: AsyncAppContext,
 351        on_unhandled_notification: F,
 352    ) -> Self
 353    where
 354        Stdin: AsyncWrite + Unpin + Send + 'static,
 355        Stdout: AsyncRead + Unpin + Send + 'static,
 356        Stderr: AsyncRead + Unpin + Send + 'static,
 357        F: FnMut(AnyNotification) + 'static + Send + Sync + Clone,
 358    {
 359        let (outbound_tx, outbound_rx) = channel::unbounded::<String>();
 360        let (output_done_tx, output_done_rx) = barrier::channel();
 361        let notification_handlers =
 362            Arc::new(Mutex::new(HashMap::<_, NotificationHandler>::default()));
 363        let response_handlers =
 364            Arc::new(Mutex::new(Some(HashMap::<_, ResponseHandler>::default())));
 365        let io_handlers = Arc::new(Mutex::new(HashMap::default()));
 366
 367        let stdout_input_task = cx.spawn({
 368            let on_unhandled_notification = on_unhandled_notification.clone();
 369            let notification_handlers = notification_handlers.clone();
 370            let response_handlers = response_handlers.clone();
 371            let io_handlers = io_handlers.clone();
 372            move |cx| {
 373                Self::handle_input(
 374                    stdout,
 375                    on_unhandled_notification,
 376                    notification_handlers,
 377                    response_handlers,
 378                    io_handlers,
 379                    cx,
 380                )
 381                .log_err()
 382            }
 383        });
 384        let stderr_input_task = stderr
 385            .map(|stderr| {
 386                let io_handlers = io_handlers.clone();
 387                let stderr_captures = stderr_capture.clone();
 388                cx.spawn(|_| Self::handle_stderr(stderr, io_handlers, stderr_captures).log_err())
 389            })
 390            .unwrap_or_else(|| Task::Ready(Some(None)));
 391        let input_task = cx.spawn(|_| async move {
 392            let (stdout, stderr) = futures::join!(stdout_input_task, stderr_input_task);
 393            stdout.or(stderr)
 394        });
 395        let output_task = cx.background_executor().spawn({
 396            Self::handle_output(
 397                stdin,
 398                outbound_rx,
 399                output_done_tx,
 400                response_handlers.clone(),
 401                io_handlers.clone(),
 402            )
 403            .log_err()
 404        });
 405
 406        Self {
 407            server_id,
 408            notification_handlers,
 409            response_handlers,
 410            io_handlers,
 411            name: Arc::default(),
 412            capabilities: Default::default(),
 413            code_action_kinds,
 414            next_id: Default::default(),
 415            outbound_tx,
 416            executor: cx.background_executor().clone(),
 417            io_tasks: Mutex::new(Some((input_task, output_task))),
 418            output_done_rx: Mutex::new(Some(output_done_rx)),
 419            root_path: root_path.to_path_buf(),
 420            working_dir: working_dir.to_path_buf(),
 421            server: Arc::new(Mutex::new(server)),
 422        }
 423    }
 424
 425    /// List of code action kinds this language server reports being able to emit.
 426    pub fn code_action_kinds(&self) -> Option<Vec<CodeActionKind>> {
 427        self.code_action_kinds.clone()
 428    }
 429
 430    async fn handle_input<Stdout, F>(
 431        stdout: Stdout,
 432        mut on_unhandled_notification: F,
 433        notification_handlers: Arc<Mutex<HashMap<&'static str, NotificationHandler>>>,
 434        response_handlers: Arc<Mutex<Option<HashMap<RequestId, ResponseHandler>>>>,
 435        io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
 436        cx: AsyncAppContext,
 437    ) -> anyhow::Result<()>
 438    where
 439        Stdout: AsyncRead + Unpin + Send + 'static,
 440        F: FnMut(AnyNotification) + 'static + Send,
 441    {
 442        use smol::stream::StreamExt;
 443        let stdout = BufReader::new(stdout);
 444        let _clear_response_handlers = util::defer({
 445            let response_handlers = response_handlers.clone();
 446            move || {
 447                response_handlers.lock().take();
 448            }
 449        });
 450        let mut input_handler = input_handler::LspStdoutHandler::new(
 451            stdout,
 452            response_handlers,
 453            io_handlers,
 454            cx.background_executor().clone(),
 455        );
 456
 457        while let Some(msg) = input_handler.notifications_channel.next().await {
 458            {
 459                let mut notification_handlers = notification_handlers.lock();
 460                if let Some(handler) = notification_handlers.get_mut(msg.method.as_str()) {
 461                    handler(msg.id, msg.params.unwrap_or(Value::Null), cx.clone());
 462                } else {
 463                    drop(notification_handlers);
 464                    on_unhandled_notification(msg);
 465                }
 466            }
 467
 468            // Don't starve the main thread when receiving lots of notifications at once.
 469            smol::future::yield_now().await;
 470        }
 471        input_handler.loop_handle.await
 472    }
 473
 474    async fn handle_stderr<Stderr>(
 475        stderr: Stderr,
 476        io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
 477        stderr_capture: Arc<Mutex<Option<String>>>,
 478    ) -> anyhow::Result<()>
 479    where
 480        Stderr: AsyncRead + Unpin + Send + 'static,
 481    {
 482        let mut stderr = BufReader::new(stderr);
 483        let mut buffer = Vec::new();
 484
 485        loop {
 486            buffer.clear();
 487
 488            let bytes_read = stderr.read_until(b'\n', &mut buffer).await?;
 489            if bytes_read == 0 {
 490                return Ok(());
 491            }
 492
 493            if let Ok(message) = std::str::from_utf8(&buffer) {
 494                log::trace!("incoming stderr message:{message}");
 495                for handler in io_handlers.lock().values_mut() {
 496                    handler(IoKind::StdErr, message);
 497                }
 498
 499                if let Some(stderr) = stderr_capture.lock().as_mut() {
 500                    stderr.push_str(message);
 501                }
 502            }
 503
 504            // Don't starve the main thread when receiving lots of messages at once.
 505            smol::future::yield_now().await;
 506        }
 507    }
 508
 509    async fn handle_output<Stdin>(
 510        stdin: Stdin,
 511        outbound_rx: channel::Receiver<String>,
 512        output_done_tx: barrier::Sender,
 513        response_handlers: Arc<Mutex<Option<HashMap<RequestId, ResponseHandler>>>>,
 514        io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
 515    ) -> anyhow::Result<()>
 516    where
 517        Stdin: AsyncWrite + Unpin + Send + 'static,
 518    {
 519        let mut stdin = BufWriter::new(stdin);
 520        let _clear_response_handlers = util::defer({
 521            let response_handlers = response_handlers.clone();
 522            move || {
 523                response_handlers.lock().take();
 524            }
 525        });
 526        let mut content_len_buffer = Vec::new();
 527        while let Ok(message) = outbound_rx.recv().await {
 528            log::trace!("outgoing message:{}", message);
 529            for handler in io_handlers.lock().values_mut() {
 530                handler(IoKind::StdIn, &message);
 531            }
 532
 533            content_len_buffer.clear();
 534            write!(content_len_buffer, "{}", message.len()).unwrap();
 535            stdin.write_all(CONTENT_LEN_HEADER.as_bytes()).await?;
 536            stdin.write_all(&content_len_buffer).await?;
 537            stdin.write_all("\r\n\r\n".as_bytes()).await?;
 538            stdin.write_all(message.as_bytes()).await?;
 539            stdin.flush().await?;
 540        }
 541        drop(output_done_tx);
 542        Ok(())
 543    }
 544
 545    /// Initializes a language server by sending the `Initialize` request.
 546    /// Note that `options` is used directly to construct [`InitializeParams`], which is why it is owned.
 547    ///
 548    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#initialize)
 549    pub fn initialize(
 550        mut self,
 551        options: Option<Value>,
 552        cx: &AppContext,
 553    ) -> Task<Result<Arc<Self>>> {
 554        let root_uri = Url::from_file_path(&self.working_dir).unwrap();
 555        #[allow(deprecated)]
 556        let params = InitializeParams {
 557            process_id: None,
 558            root_path: None,
 559            root_uri: Some(root_uri.clone()),
 560            initialization_options: options,
 561            capabilities: ClientCapabilities {
 562                workspace: Some(WorkspaceClientCapabilities {
 563                    configuration: Some(true),
 564                    did_change_watched_files: Some(DidChangeWatchedFilesClientCapabilities {
 565                        dynamic_registration: Some(true),
 566                        relative_pattern_support: Some(true),
 567                    }),
 568                    did_change_configuration: Some(DynamicRegistrationClientCapabilities {
 569                        dynamic_registration: Some(true),
 570                    }),
 571                    workspace_folders: Some(true),
 572                    symbol: Some(WorkspaceSymbolClientCapabilities {
 573                        resolve_support: None,
 574                        ..WorkspaceSymbolClientCapabilities::default()
 575                    }),
 576                    inlay_hint: Some(InlayHintWorkspaceClientCapabilities {
 577                        refresh_support: Some(true),
 578                    }),
 579                    diagnostic: Some(DiagnosticWorkspaceClientCapabilities {
 580                        refresh_support: None,
 581                    }),
 582                    workspace_edit: Some(WorkspaceEditClientCapabilities {
 583                        resource_operations: Some(vec![
 584                            ResourceOperationKind::Create,
 585                            ResourceOperationKind::Rename,
 586                            ResourceOperationKind::Delete,
 587                        ]),
 588                        document_changes: Some(true),
 589                        snippet_edit_support: Some(true),
 590                        ..WorkspaceEditClientCapabilities::default()
 591                    }),
 592                    ..Default::default()
 593                }),
 594                text_document: Some(TextDocumentClientCapabilities {
 595                    definition: Some(GotoCapability {
 596                        link_support: Some(true),
 597                        dynamic_registration: None,
 598                    }),
 599                    code_action: Some(CodeActionClientCapabilities {
 600                        code_action_literal_support: Some(CodeActionLiteralSupport {
 601                            code_action_kind: CodeActionKindLiteralSupport {
 602                                value_set: vec![
 603                                    CodeActionKind::REFACTOR.as_str().into(),
 604                                    CodeActionKind::QUICKFIX.as_str().into(),
 605                                    CodeActionKind::SOURCE.as_str().into(),
 606                                ],
 607                            },
 608                        }),
 609                        data_support: Some(true),
 610                        resolve_support: Some(CodeActionCapabilityResolveSupport {
 611                            properties: vec![
 612                                "kind".to_string(),
 613                                "diagnostics".to_string(),
 614                                "isPreferred".to_string(),
 615                                "disabled".to_string(),
 616                                "edit".to_string(),
 617                                "command".to_string(),
 618                            ],
 619                        }),
 620                        ..Default::default()
 621                    }),
 622                    completion: Some(CompletionClientCapabilities {
 623                        completion_item: Some(CompletionItemCapability {
 624                            snippet_support: Some(true),
 625                            resolve_support: Some(CompletionItemCapabilityResolveSupport {
 626                                properties: vec![
 627                                    "additionalTextEdits".to_string(),
 628                                    "command".to_string(),
 629                                    "documentation".to_string(),
 630                                    // NB: Do not have this resolved, otherwise Zed becomes slow to complete things
 631                                    // "textEdit".to_string(),
 632                                ],
 633                            }),
 634                            insert_replace_support: Some(true),
 635                            label_details_support: Some(true),
 636                            ..Default::default()
 637                        }),
 638                        completion_list: Some(CompletionListCapability {
 639                            item_defaults: Some(vec![
 640                                "commitCharacters".to_owned(),
 641                                "editRange".to_owned(),
 642                                "insertTextMode".to_owned(),
 643                                "data".to_owned(),
 644                            ]),
 645                        }),
 646                        context_support: Some(true),
 647                        ..Default::default()
 648                    }),
 649                    rename: Some(RenameClientCapabilities {
 650                        prepare_support: Some(true),
 651                        ..Default::default()
 652                    }),
 653                    hover: Some(HoverClientCapabilities {
 654                        content_format: Some(vec![MarkupKind::Markdown]),
 655                        dynamic_registration: None,
 656                    }),
 657                    inlay_hint: Some(InlayHintClientCapabilities {
 658                        resolve_support: Some(InlayHintResolveClientCapabilities {
 659                            properties: vec![
 660                                "textEdits".to_string(),
 661                                "tooltip".to_string(),
 662                                "label.tooltip".to_string(),
 663                                "label.location".to_string(),
 664                                "label.command".to_string(),
 665                            ],
 666                        }),
 667                        dynamic_registration: Some(false),
 668                    }),
 669                    publish_diagnostics: Some(PublishDiagnosticsClientCapabilities {
 670                        related_information: Some(true),
 671                        ..Default::default()
 672                    }),
 673                    formatting: Some(DynamicRegistrationClientCapabilities {
 674                        dynamic_registration: Some(true),
 675                    }),
 676                    range_formatting: Some(DynamicRegistrationClientCapabilities {
 677                        dynamic_registration: Some(true),
 678                    }),
 679                    on_type_formatting: Some(DynamicRegistrationClientCapabilities {
 680                        dynamic_registration: Some(true),
 681                    }),
 682                    signature_help: Some(SignatureHelpClientCapabilities {
 683                        signature_information: Some(SignatureInformationSettings {
 684                            documentation_format: Some(vec![
 685                                MarkupKind::Markdown,
 686                                MarkupKind::PlainText,
 687                            ]),
 688                            parameter_information: Some(ParameterInformationSettings {
 689                                label_offset_support: Some(true),
 690                            }),
 691                            active_parameter_support: Some(true),
 692                        }),
 693                        ..SignatureHelpClientCapabilities::default()
 694                    }),
 695                    synchronization: Some(TextDocumentSyncClientCapabilities {
 696                        did_save: Some(true),
 697                        ..TextDocumentSyncClientCapabilities::default()
 698                    }),
 699                    ..TextDocumentClientCapabilities::default()
 700                }),
 701                experimental: Some(json!({
 702                    "serverStatusNotification": true,
 703                })),
 704                window: Some(WindowClientCapabilities {
 705                    work_done_progress: Some(true),
 706                    ..Default::default()
 707                }),
 708                general: None,
 709            },
 710            trace: None,
 711            workspace_folders: Some(vec![WorkspaceFolder {
 712                uri: root_uri,
 713                name: Default::default(),
 714            }]),
 715            client_info: release_channel::ReleaseChannel::try_global(cx).map(|release_channel| {
 716                ClientInfo {
 717                    name: release_channel.display_name().to_string(),
 718                    version: Some(release_channel::AppVersion::global(cx).to_string()),
 719                }
 720            }),
 721            locale: None,
 722            ..Default::default()
 723        };
 724
 725        cx.spawn(|_| async move {
 726            let response = self.request::<request::Initialize>(params).await?;
 727            if let Some(info) = response.server_info {
 728                self.name = info.name.into();
 729            }
 730            self.capabilities = RwLock::new(response.capabilities);
 731
 732            self.notify::<notification::Initialized>(InitializedParams {})?;
 733            Ok(Arc::new(self))
 734        })
 735    }
 736
 737    /// Sends a shutdown request to the language server process and prepares the [`LanguageServer`] to be dropped.
 738    pub fn shutdown(&self) -> Option<impl 'static + Send + Future<Output = Option<()>>> {
 739        if let Some(tasks) = self.io_tasks.lock().take() {
 740            let response_handlers = self.response_handlers.clone();
 741            let next_id = AtomicI32::new(self.next_id.load(SeqCst));
 742            let outbound_tx = self.outbound_tx.clone();
 743            let executor = self.executor.clone();
 744            let mut output_done = self.output_done_rx.lock().take().unwrap();
 745            let shutdown_request = Self::request_internal::<request::Shutdown>(
 746                &next_id,
 747                &response_handlers,
 748                &outbound_tx,
 749                &executor,
 750                (),
 751            );
 752            let exit = Self::notify_internal::<notification::Exit>(&outbound_tx, ());
 753            outbound_tx.close();
 754
 755            let server = self.server.clone();
 756            let name = self.name.clone();
 757            let mut timer = self.executor.timer(SERVER_SHUTDOWN_TIMEOUT).fuse();
 758            Some(
 759                async move {
 760                    log::debug!("language server shutdown started");
 761
 762                    select! {
 763                        request_result = shutdown_request.fuse() => {
 764                            request_result?;
 765                        }
 766
 767                        _ = timer => {
 768                            log::info!("timeout waiting for language server {name} to shutdown");
 769                        },
 770                    }
 771
 772                    response_handlers.lock().take();
 773                    exit?;
 774                    output_done.recv().await;
 775                    server.lock().take().map(|mut child| child.kill());
 776                    log::debug!("language server shutdown finished");
 777
 778                    drop(tasks);
 779                    anyhow::Ok(())
 780                }
 781                .log_err(),
 782            )
 783        } else {
 784            None
 785        }
 786    }
 787
 788    /// Register a handler to handle incoming LSP notifications.
 789    ///
 790    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
 791    #[must_use]
 792    pub fn on_notification<T, F>(&self, f: F) -> Subscription
 793    where
 794        T: notification::Notification,
 795        F: 'static + Send + FnMut(T::Params, AsyncAppContext),
 796    {
 797        self.on_custom_notification(T::METHOD, f)
 798    }
 799
 800    /// Register a handler to handle incoming LSP requests.
 801    ///
 802    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
 803    #[must_use]
 804    pub fn on_request<T, F, Fut>(&self, f: F) -> Subscription
 805    where
 806        T: request::Request,
 807        T::Params: 'static + Send,
 808        F: 'static + FnMut(T::Params, AsyncAppContext) -> Fut + Send,
 809        Fut: 'static + Future<Output = Result<T::Result>>,
 810    {
 811        self.on_custom_request(T::METHOD, f)
 812    }
 813
 814    /// Registers a handler to inspect all language server process stdio.
 815    #[must_use]
 816    pub fn on_io<F>(&self, f: F) -> Subscription
 817    where
 818        F: 'static + Send + FnMut(IoKind, &str),
 819    {
 820        let id = self.next_id.fetch_add(1, SeqCst);
 821        self.io_handlers.lock().insert(id, Box::new(f));
 822        Subscription::Io {
 823            id,
 824            io_handlers: Some(Arc::downgrade(&self.io_handlers)),
 825        }
 826    }
 827
 828    /// Removes a request handler registers via [`Self::on_request`].
 829    pub fn remove_request_handler<T: request::Request>(&self) {
 830        self.notification_handlers.lock().remove(T::METHOD);
 831    }
 832
 833    /// Removes a notification handler registers via [`Self::on_notification`].
 834    pub fn remove_notification_handler<T: notification::Notification>(&self) {
 835        self.notification_handlers.lock().remove(T::METHOD);
 836    }
 837
 838    /// Checks if a notification handler has been registered via [`Self::on_notification`].
 839    pub fn has_notification_handler<T: notification::Notification>(&self) -> bool {
 840        self.notification_handlers.lock().contains_key(T::METHOD)
 841    }
 842
 843    #[must_use]
 844    fn on_custom_notification<Params, F>(&self, method: &'static str, mut f: F) -> Subscription
 845    where
 846        F: 'static + FnMut(Params, AsyncAppContext) + Send,
 847        Params: DeserializeOwned,
 848    {
 849        let prev_handler = self.notification_handlers.lock().insert(
 850            method,
 851            Box::new(move |_, params, cx| {
 852                if let Some(params) = serde_json::from_value(params).log_err() {
 853                    f(params, cx);
 854                }
 855            }),
 856        );
 857        assert!(
 858            prev_handler.is_none(),
 859            "registered multiple handlers for the same LSP method"
 860        );
 861        Subscription::Notification {
 862            method,
 863            notification_handlers: Some(self.notification_handlers.clone()),
 864        }
 865    }
 866
 867    #[must_use]
 868    fn on_custom_request<Params, Res, Fut, F>(&self, method: &'static str, mut f: F) -> Subscription
 869    where
 870        F: 'static + FnMut(Params, AsyncAppContext) -> Fut + Send,
 871        Fut: 'static + Future<Output = Result<Res>>,
 872        Params: DeserializeOwned + Send + 'static,
 873        Res: Serialize,
 874    {
 875        let outbound_tx = self.outbound_tx.clone();
 876        let prev_handler = self.notification_handlers.lock().insert(
 877            method,
 878            Box::new(move |id, params, cx| {
 879                if let Some(id) = id {
 880                    match serde_json::from_value(params) {
 881                        Ok(params) => {
 882                            let response = f(params, cx.clone());
 883                            cx.foreground_executor()
 884                                .spawn({
 885                                    let outbound_tx = outbound_tx.clone();
 886                                    async move {
 887                                        let response = match response.await {
 888                                            Ok(result) => Response {
 889                                                jsonrpc: JSON_RPC_VERSION,
 890                                                id,
 891                                                value: LspResult::Ok(Some(result)),
 892                                            },
 893                                            Err(error) => Response {
 894                                                jsonrpc: JSON_RPC_VERSION,
 895                                                id,
 896                                                value: LspResult::Error(Some(Error {
 897                                                    message: error.to_string(),
 898                                                })),
 899                                            },
 900                                        };
 901                                        if let Some(response) =
 902                                            serde_json::to_string(&response).log_err()
 903                                        {
 904                                            outbound_tx.try_send(response).ok();
 905                                        }
 906                                    }
 907                                })
 908                                .detach();
 909                        }
 910
 911                        Err(error) => {
 912                            log::error!("error deserializing {} request: {:?}", method, error);
 913                            let response = AnyResponse {
 914                                jsonrpc: JSON_RPC_VERSION,
 915                                id,
 916                                result: None,
 917                                error: Some(Error {
 918                                    message: error.to_string(),
 919                                }),
 920                            };
 921                            if let Some(response) = serde_json::to_string(&response).log_err() {
 922                                outbound_tx.try_send(response).ok();
 923                            }
 924                        }
 925                    }
 926                }
 927            }),
 928        );
 929        assert!(
 930            prev_handler.is_none(),
 931            "registered multiple handlers for the same LSP method"
 932        );
 933        Subscription::Notification {
 934            method,
 935            notification_handlers: Some(self.notification_handlers.clone()),
 936        }
 937    }
 938
 939    /// Get the name of the running language server.
 940    pub fn name(&self) -> &str {
 941        &self.name
 942    }
 943
 944    /// Get the reported capabilities of the running language server.
 945    pub fn capabilities(&self) -> ServerCapabilities {
 946        self.capabilities.read().clone()
 947    }
 948
 949    /// Get the reported capabilities of the running language server and
 950    /// what we know on the client/adapter-side of its capabilities.
 951    pub fn adapter_server_capabilities(&self) -> AdapterServerCapabilities {
 952        AdapterServerCapabilities {
 953            server_capabilities: self.capabilities(),
 954            code_action_kinds: self.code_action_kinds(),
 955        }
 956    }
 957
 958    pub fn update_capabilities(&self, update: impl FnOnce(&mut ServerCapabilities)) {
 959        update(self.capabilities.write().deref_mut());
 960    }
 961
 962    /// Get the id of the running language server.
 963    pub fn server_id(&self) -> LanguageServerId {
 964        self.server_id
 965    }
 966
 967    /// Get the root path of the project the language server is running against.
 968    pub fn root_path(&self) -> &PathBuf {
 969        &self.root_path
 970    }
 971
 972    /// Sends a RPC request to the language server.
 973    ///
 974    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
 975    pub fn request<T: request::Request>(
 976        &self,
 977        params: T::Params,
 978    ) -> impl LspRequestFuture<Result<T::Result>>
 979    where
 980        T::Result: 'static + Send,
 981    {
 982        Self::request_internal::<T>(
 983            &self.next_id,
 984            &self.response_handlers,
 985            &self.outbound_tx,
 986            &self.executor,
 987            params,
 988        )
 989    }
 990
 991    fn request_internal<T: request::Request>(
 992        next_id: &AtomicI32,
 993        response_handlers: &Mutex<Option<HashMap<RequestId, ResponseHandler>>>,
 994        outbound_tx: &channel::Sender<String>,
 995        executor: &BackgroundExecutor,
 996        params: T::Params,
 997    ) -> impl LspRequestFuture<Result<T::Result>>
 998    where
 999        T::Result: 'static + Send,
1000    {
1001        let id = next_id.fetch_add(1, SeqCst);
1002        let message = serde_json::to_string(&Request {
1003            jsonrpc: JSON_RPC_VERSION,
1004            id: RequestId::Int(id),
1005            method: T::METHOD,
1006            params,
1007        })
1008        .unwrap();
1009
1010        let (tx, rx) = oneshot::channel();
1011        let handle_response = response_handlers
1012            .lock()
1013            .as_mut()
1014            .ok_or_else(|| anyhow!("server shut down"))
1015            .map(|handlers| {
1016                let executor = executor.clone();
1017                handlers.insert(
1018                    RequestId::Int(id),
1019                    Box::new(move |result| {
1020                        executor
1021                            .spawn(async move {
1022                                let response = match result {
1023                                    Ok(response) => match serde_json::from_str(&response) {
1024                                        Ok(deserialized) => Ok(deserialized),
1025                                        Err(error) => {
1026                                            log::error!("failed to deserialize response from language server: {}. response from language server: {:?}", error, response);
1027                                            Err(error).context("failed to deserialize response")
1028                                        }
1029                                    }
1030                                    Err(error) => Err(anyhow!("{}", error.message)),
1031                                };
1032                                _ = tx.send(response);
1033                            })
1034                            .detach();
1035                    }),
1036                );
1037            });
1038
1039        let send = outbound_tx
1040            .try_send(message)
1041            .context("failed to write to language server's stdin");
1042
1043        let outbound_tx = outbound_tx.downgrade();
1044        let mut timeout = executor.timer(LSP_REQUEST_TIMEOUT).fuse();
1045        let started = Instant::now();
1046        LspRequest::new(id, async move {
1047            handle_response?;
1048            send?;
1049
1050            let cancel_on_drop = util::defer(move || {
1051                if let Some(outbound_tx) = outbound_tx.upgrade() {
1052                    Self::notify_internal::<notification::Cancel>(
1053                        &outbound_tx,
1054                        CancelParams {
1055                            id: NumberOrString::Number(id),
1056                        },
1057                    )
1058                    .log_err();
1059                }
1060            });
1061
1062            let method = T::METHOD;
1063            select! {
1064                response = rx.fuse() => {
1065                    let elapsed = started.elapsed();
1066                    log::trace!("Took {elapsed:?} to receive response to {method:?} id {id}");
1067                    cancel_on_drop.abort();
1068                    response?
1069                }
1070
1071                _ = timeout => {
1072                    log::error!("Cancelled LSP request task for {method:?} id {id} which took over {LSP_REQUEST_TIMEOUT:?}");
1073                    anyhow::bail!("LSP request timeout");
1074                }
1075            }
1076        })
1077    }
1078
1079    /// Sends a RPC notification to the language server.
1080    ///
1081    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
1082    pub fn notify<T: notification::Notification>(&self, params: T::Params) -> Result<()> {
1083        Self::notify_internal::<T>(&self.outbound_tx, params)
1084    }
1085
1086    fn notify_internal<T: notification::Notification>(
1087        outbound_tx: &channel::Sender<String>,
1088        params: T::Params,
1089    ) -> Result<()> {
1090        let message = serde_json::to_string(&Notification {
1091            jsonrpc: JSON_RPC_VERSION,
1092            method: T::METHOD,
1093            params,
1094        })
1095        .unwrap();
1096        outbound_tx.try_send(message)?;
1097        Ok(())
1098    }
1099}
1100
1101impl Drop for LanguageServer {
1102    fn drop(&mut self) {
1103        if let Some(shutdown) = self.shutdown() {
1104            self.executor.spawn(shutdown).detach();
1105        }
1106    }
1107}
1108
1109impl Subscription {
1110    /// Detaching a subscription handle prevents it from unsubscribing on drop.
1111    pub fn detach(&mut self) {
1112        match self {
1113            Subscription::Notification {
1114                notification_handlers,
1115                ..
1116            } => *notification_handlers = None,
1117            Subscription::Io { io_handlers, .. } => *io_handlers = None,
1118        }
1119    }
1120}
1121
1122impl fmt::Display for LanguageServerId {
1123    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1124        self.0.fmt(f)
1125    }
1126}
1127
1128impl fmt::Debug for LanguageServer {
1129    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1130        f.debug_struct("LanguageServer")
1131            .field("id", &self.server_id.0)
1132            .field("name", &self.name)
1133            .finish_non_exhaustive()
1134    }
1135}
1136
1137impl Drop for Subscription {
1138    fn drop(&mut self) {
1139        match self {
1140            Subscription::Notification {
1141                method,
1142                notification_handlers,
1143            } => {
1144                if let Some(handlers) = notification_handlers {
1145                    handlers.lock().remove(method);
1146                }
1147            }
1148            Subscription::Io { id, io_handlers } => {
1149                if let Some(io_handlers) = io_handlers.as_ref().and_then(|h| h.upgrade()) {
1150                    io_handlers.lock().remove(id);
1151                }
1152            }
1153        }
1154    }
1155}
1156
1157/// Mock language server for use in tests.
1158#[cfg(any(test, feature = "test-support"))]
1159#[derive(Clone)]
1160pub struct FakeLanguageServer {
1161    pub binary: LanguageServerBinary,
1162    pub server: Arc<LanguageServer>,
1163    notifications_rx: channel::Receiver<(String, String)>,
1164}
1165
1166#[cfg(any(test, feature = "test-support"))]
1167impl FakeLanguageServer {
1168    /// Construct a fake language server.
1169    pub fn new(
1170        server_id: LanguageServerId,
1171        binary: LanguageServerBinary,
1172        name: String,
1173        capabilities: ServerCapabilities,
1174        cx: AsyncAppContext,
1175    ) -> (LanguageServer, FakeLanguageServer) {
1176        let (stdin_writer, stdin_reader) = async_pipe::pipe();
1177        let (stdout_writer, stdout_reader) = async_pipe::pipe();
1178        let (notifications_tx, notifications_rx) = channel::unbounded();
1179
1180        let root = Self::root_path();
1181
1182        let mut server = LanguageServer::new_internal(
1183            server_id,
1184            stdin_writer,
1185            stdout_reader,
1186            None::<async_pipe::PipeReader>,
1187            Arc::new(Mutex::new(None)),
1188            None,
1189            root,
1190            root,
1191            None,
1192            cx.clone(),
1193            |_| {},
1194        );
1195        server.name = name.as_str().into();
1196        let fake = FakeLanguageServer {
1197            binary,
1198            server: Arc::new({
1199                let mut server = LanguageServer::new_internal(
1200                    server_id,
1201                    stdout_writer,
1202                    stdin_reader,
1203                    None::<async_pipe::PipeReader>,
1204                    Arc::new(Mutex::new(None)),
1205                    None,
1206                    root,
1207                    root,
1208                    None,
1209                    cx,
1210                    move |msg| {
1211                        notifications_tx
1212                            .try_send((
1213                                msg.method.to_string(),
1214                                msg.params.unwrap_or(Value::Null).to_string(),
1215                            ))
1216                            .ok();
1217                    },
1218                );
1219                server.name = name.as_str().into();
1220                server
1221            }),
1222            notifications_rx,
1223        };
1224        fake.handle_request::<request::Initialize, _, _>({
1225            let capabilities = capabilities;
1226            move |_, _| {
1227                let capabilities = capabilities.clone();
1228                let name = name.clone();
1229                async move {
1230                    Ok(InitializeResult {
1231                        capabilities,
1232                        server_info: Some(ServerInfo {
1233                            name,
1234                            ..Default::default()
1235                        }),
1236                    })
1237                }
1238            }
1239        });
1240
1241        (server, fake)
1242    }
1243
1244    #[cfg(target_os = "windows")]
1245    fn root_path() -> &'static Path {
1246        Path::new("C:\\")
1247    }
1248
1249    #[cfg(not(target_os = "windows"))]
1250    fn root_path() -> &'static Path {
1251        Path::new("/")
1252    }
1253}
1254
1255#[cfg(any(test, feature = "test-support"))]
1256impl LanguageServer {
1257    pub fn full_capabilities() -> ServerCapabilities {
1258        ServerCapabilities {
1259            document_highlight_provider: Some(OneOf::Left(true)),
1260            code_action_provider: Some(CodeActionProviderCapability::Simple(true)),
1261            document_formatting_provider: Some(OneOf::Left(true)),
1262            document_range_formatting_provider: Some(OneOf::Left(true)),
1263            definition_provider: Some(OneOf::Left(true)),
1264            implementation_provider: Some(ImplementationProviderCapability::Simple(true)),
1265            type_definition_provider: Some(TypeDefinitionProviderCapability::Simple(true)),
1266            ..Default::default()
1267        }
1268    }
1269}
1270
1271#[cfg(any(test, feature = "test-support"))]
1272impl FakeLanguageServer {
1273    /// See [`LanguageServer::notify`].
1274    pub fn notify<T: notification::Notification>(&self, params: T::Params) {
1275        self.server.notify::<T>(params).ok();
1276    }
1277
1278    /// See [`LanguageServer::request`].
1279    pub async fn request<T>(&self, params: T::Params) -> Result<T::Result>
1280    where
1281        T: request::Request,
1282        T::Result: 'static + Send,
1283    {
1284        self.server.executor.start_waiting();
1285        self.server.request::<T>(params).await
1286    }
1287
1288    /// Attempts [`Self::try_receive_notification`], unwrapping if it has not received the specified type yet.
1289    pub async fn receive_notification<T: notification::Notification>(&mut self) -> T::Params {
1290        self.server.executor.start_waiting();
1291        self.try_receive_notification::<T>().await.unwrap()
1292    }
1293
1294    /// Consumes the notification channel until it finds a notification for the specified type.
1295    pub async fn try_receive_notification<T: notification::Notification>(
1296        &mut self,
1297    ) -> Option<T::Params> {
1298        use futures::StreamExt as _;
1299
1300        loop {
1301            let (method, params) = self.notifications_rx.next().await?;
1302            if method == T::METHOD {
1303                return Some(serde_json::from_str::<T::Params>(&params).unwrap());
1304            } else {
1305                log::info!("skipping message in fake language server {:?}", params);
1306            }
1307        }
1308    }
1309
1310    /// Registers a handler for a specific kind of request. Removes any existing handler for specified request type.
1311    pub fn handle_request<T, F, Fut>(
1312        &self,
1313        mut handler: F,
1314    ) -> futures::channel::mpsc::UnboundedReceiver<()>
1315    where
1316        T: 'static + request::Request,
1317        T::Params: 'static + Send,
1318        F: 'static + Send + FnMut(T::Params, gpui::AsyncAppContext) -> Fut,
1319        Fut: 'static + Send + Future<Output = Result<T::Result>>,
1320    {
1321        let (responded_tx, responded_rx) = futures::channel::mpsc::unbounded();
1322        self.server.remove_request_handler::<T>();
1323        self.server
1324            .on_request::<T, _, _>(move |params, cx| {
1325                let result = handler(params, cx.clone());
1326                let responded_tx = responded_tx.clone();
1327                let executor = cx.background_executor().clone();
1328                async move {
1329                    executor.simulate_random_delay().await;
1330                    let result = result.await;
1331                    responded_tx.unbounded_send(()).ok();
1332                    result
1333                }
1334            })
1335            .detach();
1336        responded_rx
1337    }
1338
1339    /// Registers a handler for a specific kind of notification. Removes any existing handler for specified notification type.
1340    pub fn handle_notification<T, F>(
1341        &self,
1342        mut handler: F,
1343    ) -> futures::channel::mpsc::UnboundedReceiver<()>
1344    where
1345        T: 'static + notification::Notification,
1346        T::Params: 'static + Send,
1347        F: 'static + Send + FnMut(T::Params, gpui::AsyncAppContext),
1348    {
1349        let (handled_tx, handled_rx) = futures::channel::mpsc::unbounded();
1350        self.server.remove_notification_handler::<T>();
1351        self.server
1352            .on_notification::<T, _>(move |params, cx| {
1353                handler(params, cx.clone());
1354                handled_tx.unbounded_send(()).ok();
1355            })
1356            .detach();
1357        handled_rx
1358    }
1359
1360    /// Removes any existing handler for specified notification type.
1361    pub fn remove_request_handler<T>(&mut self)
1362    where
1363        T: 'static + request::Request,
1364    {
1365        self.server.remove_request_handler::<T>();
1366    }
1367
1368    /// Simulate that the server has started work and notifies about its progress with the specified token.
1369    pub async fn start_progress(&self, token: impl Into<String>) {
1370        self.start_progress_with(token, Default::default()).await
1371    }
1372
1373    pub async fn start_progress_with(
1374        &self,
1375        token: impl Into<String>,
1376        progress: WorkDoneProgressBegin,
1377    ) {
1378        let token = token.into();
1379        self.request::<request::WorkDoneProgressCreate>(WorkDoneProgressCreateParams {
1380            token: NumberOrString::String(token.clone()),
1381        })
1382        .await
1383        .unwrap();
1384        self.notify::<notification::Progress>(ProgressParams {
1385            token: NumberOrString::String(token),
1386            value: ProgressParamsValue::WorkDone(WorkDoneProgress::Begin(progress)),
1387        });
1388    }
1389
1390    /// Simulate that the server has completed work and notifies about that with the specified token.
1391    pub fn end_progress(&self, token: impl Into<String>) {
1392        self.notify::<notification::Progress>(ProgressParams {
1393            token: NumberOrString::String(token.into()),
1394            value: ProgressParamsValue::WorkDone(WorkDoneProgress::End(Default::default())),
1395        });
1396    }
1397}
1398
1399#[cfg(test)]
1400mod tests {
1401    use super::*;
1402    use gpui::{SemanticVersion, TestAppContext};
1403    use std::str::FromStr;
1404
1405    #[ctor::ctor]
1406    fn init_logger() {
1407        if std::env::var("RUST_LOG").is_ok() {
1408            env_logger::init();
1409        }
1410    }
1411
1412    #[gpui::test]
1413    async fn test_fake(cx: &mut TestAppContext) {
1414        cx.update(|cx| {
1415            release_channel::init(SemanticVersion::default(), cx);
1416        });
1417        let (server, mut fake) = FakeLanguageServer::new(
1418            LanguageServerId(0),
1419            LanguageServerBinary {
1420                path: "path/to/language-server".into(),
1421                arguments: vec![],
1422                env: None,
1423            },
1424            "the-lsp".to_string(),
1425            Default::default(),
1426            cx.to_async(),
1427        );
1428
1429        let (message_tx, message_rx) = channel::unbounded();
1430        let (diagnostics_tx, diagnostics_rx) = channel::unbounded();
1431        server
1432            .on_notification::<notification::ShowMessage, _>(move |params, _| {
1433                message_tx.try_send(params).unwrap()
1434            })
1435            .detach();
1436        server
1437            .on_notification::<notification::PublishDiagnostics, _>(move |params, _| {
1438                diagnostics_tx.try_send(params).unwrap()
1439            })
1440            .detach();
1441
1442        let server = cx.update(|cx| server.initialize(None, cx)).await.unwrap();
1443        server
1444            .notify::<notification::DidOpenTextDocument>(DidOpenTextDocumentParams {
1445                text_document: TextDocumentItem::new(
1446                    Url::from_str("file://a/b").unwrap(),
1447                    "rust".to_string(),
1448                    0,
1449                    "".to_string(),
1450                ),
1451            })
1452            .unwrap();
1453        assert_eq!(
1454            fake.receive_notification::<notification::DidOpenTextDocument>()
1455                .await
1456                .text_document
1457                .uri
1458                .as_str(),
1459            "file://a/b"
1460        );
1461
1462        fake.notify::<notification::ShowMessage>(ShowMessageParams {
1463            typ: MessageType::ERROR,
1464            message: "ok".to_string(),
1465        });
1466        fake.notify::<notification::PublishDiagnostics>(PublishDiagnosticsParams {
1467            uri: Url::from_str("file://b/c").unwrap(),
1468            version: Some(5),
1469            diagnostics: vec![],
1470        });
1471        assert_eq!(message_rx.recv().await.unwrap().message, "ok");
1472        assert_eq!(
1473            diagnostics_rx.recv().await.unwrap().uri.as_str(),
1474            "file://b/c"
1475        );
1476
1477        fake.handle_request::<request::Shutdown, _, _>(|_, _| async move { Ok(()) });
1478
1479        drop(server);
1480        fake.receive_notification::<notification::Exit>().await;
1481    }
1482
1483    #[gpui::test]
1484    fn test_deserialize_string_digit_id() {
1485        let json = r#"{"jsonrpc":"2.0","id":"2","method":"workspace/configuration","params":{"items":[{"scopeUri":"file:///Users/mph/Devel/personal/hello-scala/","section":"metals"}]}}"#;
1486        let notification = serde_json::from_str::<AnyNotification>(json)
1487            .expect("message with string id should be parsed");
1488        let expected_id = RequestId::Str("2".to_string());
1489        assert_eq!(notification.id, Some(expected_id));
1490    }
1491
1492    #[gpui::test]
1493    fn test_deserialize_string_id() {
1494        let json = r#"{"jsonrpc":"2.0","id":"anythingAtAll","method":"workspace/configuration","params":{"items":[{"scopeUri":"file:///Users/mph/Devel/personal/hello-scala/","section":"metals"}]}}"#;
1495        let notification = serde_json::from_str::<AnyNotification>(json)
1496            .expect("message with string id should be parsed");
1497        let expected_id = RequestId::Str("anythingAtAll".to_string());
1498        assert_eq!(notification.id, Some(expected_id));
1499    }
1500
1501    #[gpui::test]
1502    fn test_deserialize_int_id() {
1503        let json = r#"{"jsonrpc":"2.0","id":2,"method":"workspace/configuration","params":{"items":[{"scopeUri":"file:///Users/mph/Devel/personal/hello-scala/","section":"metals"}]}}"#;
1504        let notification = serde_json::from_str::<AnyNotification>(json)
1505            .expect("message with string id should be parsed");
1506        let expected_id = RequestId::Int(2);
1507        assert_eq!(notification.id, Some(expected_id));
1508    }
1509
1510    #[test]
1511    fn test_serialize_has_no_nulls() {
1512        // Ensure we're not setting both result and error variants. (ticket #10595)
1513        let no_tag = Response::<u32> {
1514            jsonrpc: "",
1515            id: RequestId::Int(0),
1516            value: LspResult::Ok(None),
1517        };
1518        assert_eq!(
1519            serde_json::to_string(&no_tag).unwrap(),
1520            "{\"jsonrpc\":\"\",\"id\":0,\"result\":null}"
1521        );
1522        let no_tag = Response::<u32> {
1523            jsonrpc: "",
1524            id: RequestId::Int(0),
1525            value: LspResult::Error(None),
1526        };
1527        assert_eq!(
1528            serde_json::to_string(&no_tag).unwrap(),
1529            "{\"jsonrpc\":\"\",\"id\":0,\"error\":null}"
1530        );
1531    }
1532}