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