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