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