lsp.rs

   1mod input_handler;
   2
   3pub use lsp_types::request::*;
   4pub use lsp_types::*;
   5
   6use anyhow::{Context as _, Result, anyhow};
   7use collections::HashMap;
   8use futures::{
   9    AsyncRead, AsyncWrite, Future, FutureExt,
  10    channel::oneshot::{self, Canceled},
  11    io::BufWriter,
  12    select,
  13};
  14use gpui::{App, AppContext as _, AsyncApp, BackgroundExecutor, SharedString, Task};
  15use notification::DidChangeWorkspaceFolders;
  16use parking_lot::{Mutex, RwLock};
  17use postage::{barrier, prelude::Stream};
  18use schemars::{
  19    JsonSchema,
  20    r#gen::SchemaGenerator,
  21    schema::{InstanceType, Schema, SchemaObject},
  22};
  23use serde::{Deserialize, Serialize, de::DeserializeOwned};
  24use serde_json::{Value, json, value::RawValue};
  25use smol::{
  26    channel,
  27    io::{AsyncBufReadExt, AsyncWriteExt, BufReader},
  28    process::Child,
  29};
  30
  31use std::{
  32    collections::BTreeSet,
  33    ffi::{OsStr, OsString},
  34    fmt,
  35    io::Write,
  36    ops::{Deref, DerefMut},
  37    path::PathBuf,
  38    pin::Pin,
  39    sync::{
  40        Arc, Weak,
  41        atomic::{AtomicI32, Ordering::SeqCst},
  42    },
  43    task::Poll,
  44    time::{Duration, Instant},
  45};
  46use std::{path::Path, process::Stdio};
  47use util::{ConnectionResult, ResultExt, TryFutureExt};
  48
  49const JSON_RPC_VERSION: &str = "2.0";
  50const CONTENT_LEN_HEADER: &str = "Content-Length: ";
  51
  52const LSP_REQUEST_TIMEOUT: Duration = Duration::from_secs(60 * 2);
  53const SERVER_SHUTDOWN_TIMEOUT: Duration = Duration::from_secs(5);
  54
  55type NotificationHandler = Box<dyn Send + FnMut(Option<RequestId>, Value, &mut AsyncApp)>;
  56type ResponseHandler = Box<dyn Send + FnOnce(Result<String, Error>)>;
  57type IoHandler = Box<dyn Send + FnMut(IoKind, &str)>;
  58
  59/// Kind of language server stdio given to an IO handler.
  60#[derive(Debug, Clone, Copy)]
  61pub enum IoKind {
  62    StdOut,
  63    StdIn,
  64    StdErr,
  65}
  66
  67/// Represents a launchable language server. This can either be a standalone binary or the path
  68/// to a runtime with arguments to instruct it to launch the actual language server file.
  69#[derive(Debug, Clone, Deserialize)]
  70pub struct LanguageServerBinary {
  71    pub path: PathBuf,
  72    pub arguments: Vec<OsString>,
  73    pub env: Option<HashMap<String, String>>,
  74}
  75
  76/// Configures the search (and installation) of language servers.
  77#[derive(Debug, Clone, Deserialize)]
  78pub struct LanguageServerBinaryOptions {
  79    /// Whether the adapter should look at the users system
  80    pub allow_path_lookup: bool,
  81    /// Whether the adapter should download its own version
  82    pub allow_binary_download: bool,
  83}
  84
  85/// A running language server process.
  86pub struct LanguageServer {
  87    server_id: LanguageServerId,
  88    next_id: AtomicI32,
  89    outbound_tx: channel::Sender<String>,
  90    name: LanguageServerName,
  91    process_name: Arc<str>,
  92    binary: LanguageServerBinary,
  93    capabilities: RwLock<ServerCapabilities>,
  94    /// Configuration sent to the server, stored for display in the language server logs
  95    /// buffer. This is represented as the message sent to the LSP in order to avoid cloning it (can
  96    /// be large in cases like sending schemas to the json server).
  97    configuration: Arc<DidChangeConfigurationParams>,
  98    code_action_kinds: Option<Vec<CodeActionKind>>,
  99    notification_handlers: Arc<Mutex<HashMap<&'static str, NotificationHandler>>>,
 100    response_handlers: Arc<Mutex<Option<HashMap<RequestId, ResponseHandler>>>>,
 101    io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
 102    executor: BackgroundExecutor,
 103    #[allow(clippy::type_complexity)]
 104    io_tasks: Mutex<Option<(Task<Option<()>>, Task<Option<()>>)>>,
 105    output_done_rx: Mutex<Option<barrier::Receiver>>,
 106    server: Arc<Mutex<Option<Child>>>,
 107    workspace_folders: Arc<Mutex<BTreeSet<Url>>>,
 108    root_uri: Url,
 109}
 110
 111/// Identifies a running language server.
 112#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
 113#[repr(transparent)]
 114pub struct LanguageServerId(pub usize);
 115
 116impl LanguageServerId {
 117    pub fn from_proto(id: u64) -> Self {
 118        Self(id as usize)
 119    }
 120
 121    pub fn to_proto(self) -> u64 {
 122        self.0 as u64
 123    }
 124}
 125
 126/// A name of a language server.
 127#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Deserialize, Serialize)]
 128pub struct LanguageServerName(pub SharedString);
 129
 130impl std::fmt::Display for LanguageServerName {
 131    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 132        std::fmt::Display::fmt(&self.0, f)
 133    }
 134}
 135
 136impl AsRef<str> for LanguageServerName {
 137    fn as_ref(&self) -> &str {
 138        self.0.as_ref()
 139    }
 140}
 141
 142impl AsRef<OsStr> for LanguageServerName {
 143    fn as_ref(&self) -> &OsStr {
 144        self.0.as_ref().as_ref()
 145    }
 146}
 147
 148impl JsonSchema for LanguageServerName {
 149    fn schema_name() -> String {
 150        "LanguageServerName".into()
 151    }
 152
 153    fn json_schema(_: &mut SchemaGenerator) -> Schema {
 154        SchemaObject {
 155            instance_type: Some(InstanceType::String.into()),
 156            ..Default::default()
 157        }
 158        .into()
 159    }
 160}
 161
 162impl LanguageServerName {
 163    pub const fn new_static(s: &'static str) -> Self {
 164        Self(SharedString::new_static(s))
 165    }
 166
 167    pub fn from_proto(s: String) -> Self {
 168        Self(s.into())
 169    }
 170}
 171
 172impl<'a> From<&'a str> for LanguageServerName {
 173    fn from(str: &'a str) -> LanguageServerName {
 174        LanguageServerName(str.to_string().into())
 175    }
 176}
 177
 178/// Handle to a language server RPC activity subscription.
 179pub enum Subscription {
 180    Notification {
 181        method: &'static str,
 182        notification_handlers: Option<Arc<Mutex<HashMap<&'static str, NotificationHandler>>>>,
 183    },
 184    Io {
 185        id: i32,
 186        io_handlers: Option<Weak<Mutex<HashMap<i32, IoHandler>>>>,
 187    },
 188}
 189
 190/// Language server protocol RPC request message ID.
 191///
 192/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
 193#[derive(Debug, Clone, Eq, PartialEq, Hash, Serialize, Deserialize)]
 194#[serde(untagged)]
 195pub enum RequestId {
 196    Int(i32),
 197    Str(String),
 198}
 199
 200/// Language server protocol RPC request message.
 201///
 202/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
 203#[derive(Serialize, Deserialize)]
 204pub struct Request<'a, T> {
 205    jsonrpc: &'static str,
 206    id: RequestId,
 207    method: &'a str,
 208    params: T,
 209}
 210
 211/// Language server protocol RPC request response message before it is deserialized into a concrete type.
 212#[derive(Serialize, Deserialize)]
 213struct AnyResponse<'a> {
 214    jsonrpc: &'a str,
 215    id: RequestId,
 216    #[serde(default)]
 217    error: Option<Error>,
 218    #[serde(borrow)]
 219    result: Option<&'a RawValue>,
 220}
 221
 222/// Language server protocol RPC request response message.
 223///
 224/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#responseMessage)
 225#[derive(Serialize)]
 226struct Response<T> {
 227    jsonrpc: &'static str,
 228    id: RequestId,
 229    #[serde(flatten)]
 230    value: LspResult<T>,
 231}
 232
 233#[derive(Serialize)]
 234#[serde(rename_all = "snake_case")]
 235enum LspResult<T> {
 236    #[serde(rename = "result")]
 237    Ok(Option<T>),
 238    Error(Option<Error>),
 239}
 240
 241/// Language server protocol RPC notification message.
 242///
 243/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
 244#[derive(Serialize, Deserialize)]
 245struct Notification<'a, T> {
 246    jsonrpc: &'static str,
 247    #[serde(borrow)]
 248    method: &'a str,
 249    params: T,
 250}
 251
 252/// Language server RPC notification message before it is deserialized into a concrete type.
 253#[derive(Debug, Clone, Deserialize)]
 254struct AnyNotification {
 255    #[serde(default)]
 256    id: Option<RequestId>,
 257    method: String,
 258    #[serde(default)]
 259    params: Option<Value>,
 260}
 261
 262#[derive(Debug, Serialize, Deserialize)]
 263struct Error {
 264    message: String,
 265}
 266
 267pub trait LspRequestFuture<O>: Future<Output = ConnectionResult<O>> {
 268    fn id(&self) -> i32;
 269}
 270
 271struct LspRequest<F> {
 272    id: i32,
 273    request: F,
 274}
 275
 276impl<F> LspRequest<F> {
 277    pub fn new(id: i32, request: F) -> Self {
 278        Self { id, request }
 279    }
 280}
 281
 282impl<F: Future> Future for LspRequest<F> {
 283    type Output = F::Output;
 284
 285    fn poll(self: Pin<&mut Self>, cx: &mut std::task::Context<'_>) -> Poll<Self::Output> {
 286        // SAFETY: This is standard pin projection, we're pinned so our fields must be pinned.
 287        let inner = unsafe { Pin::new_unchecked(&mut self.get_unchecked_mut().request) };
 288        inner.poll(cx)
 289    }
 290}
 291
 292impl<F, O> LspRequestFuture<O> for LspRequest<F>
 293where
 294    F: Future<Output = ConnectionResult<O>>,
 295{
 296    fn id(&self) -> i32 {
 297        self.id
 298    }
 299}
 300
 301/// Combined capabilities of the server and the adapter.
 302#[derive(Debug)]
 303pub struct AdapterServerCapabilities {
 304    // Reported capabilities by the server
 305    pub server_capabilities: ServerCapabilities,
 306    // List of code actions supported by the LspAdapter matching the server
 307    pub code_action_kinds: Option<Vec<CodeActionKind>>,
 308}
 309
 310impl LanguageServer {
 311    /// Starts a language server process.
 312    pub fn new(
 313        stderr_capture: Arc<Mutex<Option<String>>>,
 314        server_id: LanguageServerId,
 315        server_name: LanguageServerName,
 316        binary: LanguageServerBinary,
 317        root_path: &Path,
 318        code_action_kinds: Option<Vec<CodeActionKind>>,
 319        workspace_folders: Arc<Mutex<BTreeSet<Url>>>,
 320        cx: &mut AsyncApp,
 321    ) -> Result<Self> {
 322        let working_dir = if root_path.is_dir() {
 323            root_path
 324        } else {
 325            root_path.parent().unwrap_or_else(|| Path::new("/"))
 326        };
 327
 328        log::info!(
 329            "starting language server process. binary path: {:?}, working directory: {:?}, args: {:?}",
 330            binary.path,
 331            working_dir,
 332            &binary.arguments
 333        );
 334
 335        let mut server = util::command::new_smol_command(&binary.path)
 336            .current_dir(working_dir)
 337            .args(&binary.arguments)
 338            .envs(binary.env.clone().unwrap_or_default())
 339            .stdin(Stdio::piped())
 340            .stdout(Stdio::piped())
 341            .stderr(Stdio::piped())
 342            .kill_on_drop(true)
 343            .spawn()
 344            .with_context(|| {
 345                format!(
 346                    "failed to spawn command. path: {:?}, working directory: {:?}, args: {:?}",
 347                    binary.path, working_dir, &binary.arguments
 348                )
 349            })?;
 350
 351        let stdin = server.stdin.take().unwrap();
 352        let stdout = server.stdout.take().unwrap();
 353        let stderr = server.stderr.take().unwrap();
 354        let root_uri = Url::from_file_path(&working_dir)
 355            .map_err(|()| anyhow!("{working_dir:?} is not a valid URI"))?;
 356        let server = Self::new_internal(
 357            server_id,
 358            server_name,
 359            stdin,
 360            stdout,
 361            Some(stderr),
 362            stderr_capture,
 363            Some(server),
 364            code_action_kinds,
 365            binary,
 366            root_uri,
 367            workspace_folders,
 368            cx,
 369            move |notification| {
 370                log::info!(
 371                    "Language server with id {} sent unhandled notification {}:\n{}",
 372                    server_id,
 373                    notification.method,
 374                    serde_json::to_string_pretty(&notification.params).unwrap(),
 375                );
 376            },
 377        );
 378
 379        Ok(server)
 380    }
 381
 382    fn new_internal<Stdin, Stdout, Stderr, F>(
 383        server_id: LanguageServerId,
 384        server_name: LanguageServerName,
 385        stdin: Stdin,
 386        stdout: Stdout,
 387        stderr: Option<Stderr>,
 388        stderr_capture: Arc<Mutex<Option<String>>>,
 389        server: Option<Child>,
 390        code_action_kinds: Option<Vec<CodeActionKind>>,
 391        binary: LanguageServerBinary,
 392        root_uri: Url,
 393        workspace_folders: Arc<Mutex<BTreeSet<Url>>>,
 394        cx: &mut AsyncApp,
 395        on_unhandled_notification: F,
 396    ) -> Self
 397    where
 398        Stdin: AsyncWrite + Unpin + Send + 'static,
 399        Stdout: AsyncRead + Unpin + Send + 'static,
 400        Stderr: AsyncRead + Unpin + Send + 'static,
 401        F: FnMut(AnyNotification) + 'static + Send + Sync + Clone,
 402    {
 403        let (outbound_tx, outbound_rx) = channel::unbounded::<String>();
 404        let (output_done_tx, output_done_rx) = barrier::channel();
 405        let notification_handlers =
 406            Arc::new(Mutex::new(HashMap::<_, NotificationHandler>::default()));
 407        let response_handlers =
 408            Arc::new(Mutex::new(Some(HashMap::<_, ResponseHandler>::default())));
 409        let io_handlers = Arc::new(Mutex::new(HashMap::default()));
 410
 411        let stdout_input_task = cx.spawn({
 412            let on_unhandled_notification = on_unhandled_notification.clone();
 413            let notification_handlers = notification_handlers.clone();
 414            let response_handlers = response_handlers.clone();
 415            let io_handlers = io_handlers.clone();
 416            async move |cx| {
 417                Self::handle_input(
 418                    stdout,
 419                    on_unhandled_notification,
 420                    notification_handlers,
 421                    response_handlers,
 422                    io_handlers,
 423                    cx,
 424                )
 425                .log_err()
 426                .await
 427            }
 428        });
 429        let stderr_input_task = stderr
 430            .map(|stderr| {
 431                let io_handlers = io_handlers.clone();
 432                let stderr_captures = stderr_capture.clone();
 433                cx.spawn(async move |_| {
 434                    Self::handle_stderr(stderr, io_handlers, stderr_captures)
 435                        .log_err()
 436                        .await
 437                })
 438            })
 439            .unwrap_or_else(|| Task::ready(None));
 440        let input_task = cx.spawn(async move |_| {
 441            let (stdout, stderr) = futures::join!(stdout_input_task, stderr_input_task);
 442            stdout.or(stderr)
 443        });
 444        let output_task = cx.background_spawn({
 445            Self::handle_output(
 446                stdin,
 447                outbound_rx,
 448                output_done_tx,
 449                response_handlers.clone(),
 450                io_handlers.clone(),
 451            )
 452            .log_err()
 453        });
 454
 455        let configuration = DidChangeConfigurationParams {
 456            settings: Value::Null,
 457        }
 458        .into();
 459
 460        Self {
 461            server_id,
 462            notification_handlers,
 463            response_handlers,
 464            io_handlers,
 465            name: server_name,
 466            process_name: binary
 467                .path
 468                .file_name()
 469                .map(|name| Arc::from(name.to_string_lossy()))
 470                .unwrap_or_default(),
 471            binary,
 472            capabilities: Default::default(),
 473            configuration,
 474            code_action_kinds,
 475            next_id: Default::default(),
 476            outbound_tx,
 477            executor: cx.background_executor().clone(),
 478            io_tasks: Mutex::new(Some((input_task, output_task))),
 479            output_done_rx: Mutex::new(Some(output_done_rx)),
 480            server: Arc::new(Mutex::new(server)),
 481            workspace_folders,
 482            root_uri,
 483        }
 484    }
 485
 486    /// List of code action kinds this language server reports being able to emit.
 487    pub fn code_action_kinds(&self) -> Option<Vec<CodeActionKind>> {
 488        self.code_action_kinds.clone()
 489    }
 490
 491    async fn handle_input<Stdout, F>(
 492        stdout: Stdout,
 493        mut on_unhandled_notification: F,
 494        notification_handlers: Arc<Mutex<HashMap<&'static str, NotificationHandler>>>,
 495        response_handlers: Arc<Mutex<Option<HashMap<RequestId, ResponseHandler>>>>,
 496        io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
 497        cx: &mut AsyncApp,
 498    ) -> anyhow::Result<()>
 499    where
 500        Stdout: AsyncRead + Unpin + Send + 'static,
 501        F: FnMut(AnyNotification) + 'static + Send,
 502    {
 503        use smol::stream::StreamExt;
 504        let stdout = BufReader::new(stdout);
 505        let _clear_response_handlers = util::defer({
 506            let response_handlers = response_handlers.clone();
 507            move || {
 508                response_handlers.lock().take();
 509            }
 510        });
 511        let mut input_handler = input_handler::LspStdoutHandler::new(
 512            stdout,
 513            response_handlers,
 514            io_handlers,
 515            cx.background_executor().clone(),
 516        );
 517
 518        while let Some(msg) = input_handler.notifications_channel.next().await {
 519            {
 520                let mut notification_handlers = notification_handlers.lock();
 521                if let Some(handler) = notification_handlers.get_mut(msg.method.as_str()) {
 522                    handler(msg.id, msg.params.unwrap_or(Value::Null), cx);
 523                } else {
 524                    drop(notification_handlers);
 525                    on_unhandled_notification(msg);
 526                }
 527            }
 528
 529            // Don't starve the main thread when receiving lots of notifications at once.
 530            smol::future::yield_now().await;
 531        }
 532        input_handler.loop_handle.await
 533    }
 534
 535    async fn handle_stderr<Stderr>(
 536        stderr: Stderr,
 537        io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
 538        stderr_capture: Arc<Mutex<Option<String>>>,
 539    ) -> anyhow::Result<()>
 540    where
 541        Stderr: AsyncRead + Unpin + Send + 'static,
 542    {
 543        let mut stderr = BufReader::new(stderr);
 544        let mut buffer = Vec::new();
 545
 546        loop {
 547            buffer.clear();
 548
 549            let bytes_read = stderr.read_until(b'\n', &mut buffer).await?;
 550            if bytes_read == 0 {
 551                return Ok(());
 552            }
 553
 554            if let Ok(message) = std::str::from_utf8(&buffer) {
 555                log::trace!("incoming stderr message:{message}");
 556                for handler in io_handlers.lock().values_mut() {
 557                    handler(IoKind::StdErr, message);
 558                }
 559
 560                if let Some(stderr) = stderr_capture.lock().as_mut() {
 561                    stderr.push_str(message);
 562                }
 563            }
 564
 565            // Don't starve the main thread when receiving lots of messages at once.
 566            smol::future::yield_now().await;
 567        }
 568    }
 569
 570    async fn handle_output<Stdin>(
 571        stdin: Stdin,
 572        outbound_rx: channel::Receiver<String>,
 573        output_done_tx: barrier::Sender,
 574        response_handlers: Arc<Mutex<Option<HashMap<RequestId, ResponseHandler>>>>,
 575        io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
 576    ) -> anyhow::Result<()>
 577    where
 578        Stdin: AsyncWrite + Unpin + Send + 'static,
 579    {
 580        let mut stdin = BufWriter::new(stdin);
 581        let _clear_response_handlers = util::defer({
 582            let response_handlers = response_handlers.clone();
 583            move || {
 584                response_handlers.lock().take();
 585            }
 586        });
 587        let mut content_len_buffer = Vec::new();
 588        while let Ok(message) = outbound_rx.recv().await {
 589            log::trace!("outgoing message:{}", message);
 590            for handler in io_handlers.lock().values_mut() {
 591                handler(IoKind::StdIn, &message);
 592            }
 593
 594            content_len_buffer.clear();
 595            write!(content_len_buffer, "{}", message.len()).unwrap();
 596            stdin.write_all(CONTENT_LEN_HEADER.as_bytes()).await?;
 597            stdin.write_all(&content_len_buffer).await?;
 598            stdin.write_all("\r\n\r\n".as_bytes()).await?;
 599            stdin.write_all(message.as_bytes()).await?;
 600            stdin.flush().await?;
 601        }
 602        drop(output_done_tx);
 603        Ok(())
 604    }
 605
 606    pub fn default_initialize_params(&self, pull_diagnostics: bool, cx: &App) -> InitializeParams {
 607        let workspace_folders = self
 608            .workspace_folders
 609            .lock()
 610            .iter()
 611            .cloned()
 612            .map(|uri| WorkspaceFolder {
 613                name: Default::default(),
 614                uri,
 615            })
 616            .collect::<Vec<_>>();
 617        #[allow(deprecated)]
 618        InitializeParams {
 619            process_id: None,
 620            root_path: None,
 621            root_uri: Some(self.root_uri.clone()),
 622            initialization_options: None,
 623            capabilities: ClientCapabilities {
 624                general: Some(GeneralClientCapabilities {
 625                    position_encodings: Some(vec![PositionEncodingKind::UTF16]),
 626                    ..Default::default()
 627                }),
 628                workspace: Some(WorkspaceClientCapabilities {
 629                    configuration: Some(true),
 630                    did_change_watched_files: Some(DidChangeWatchedFilesClientCapabilities {
 631                        dynamic_registration: Some(true),
 632                        relative_pattern_support: Some(true),
 633                    }),
 634                    did_change_configuration: Some(DynamicRegistrationClientCapabilities {
 635                        dynamic_registration: Some(true),
 636                    }),
 637                    workspace_folders: Some(true),
 638                    symbol: Some(WorkspaceSymbolClientCapabilities {
 639                        resolve_support: None,
 640                        ..WorkspaceSymbolClientCapabilities::default()
 641                    }),
 642                    inlay_hint: Some(InlayHintWorkspaceClientCapabilities {
 643                        refresh_support: Some(true),
 644                    }),
 645                    diagnostic: Some(DiagnosticWorkspaceClientCapabilities {
 646                        refresh_support: Some(true),
 647                    })
 648                    .filter(|_| pull_diagnostics),
 649                    code_lens: Some(CodeLensWorkspaceClientCapabilities {
 650                        refresh_support: Some(true),
 651                    }),
 652                    workspace_edit: Some(WorkspaceEditClientCapabilities {
 653                        resource_operations: Some(vec![
 654                            ResourceOperationKind::Create,
 655                            ResourceOperationKind::Rename,
 656                            ResourceOperationKind::Delete,
 657                        ]),
 658                        document_changes: Some(true),
 659                        snippet_edit_support: Some(true),
 660                        ..WorkspaceEditClientCapabilities::default()
 661                    }),
 662                    file_operations: Some(WorkspaceFileOperationsClientCapabilities {
 663                        dynamic_registration: Some(false),
 664                        did_rename: Some(true),
 665                        will_rename: Some(true),
 666                        ..Default::default()
 667                    }),
 668                    apply_edit: Some(true),
 669                    execute_command: Some(ExecuteCommandClientCapabilities {
 670                        dynamic_registration: Some(false),
 671                    }),
 672                    ..Default::default()
 673                }),
 674                text_document: Some(TextDocumentClientCapabilities {
 675                    definition: Some(GotoCapability {
 676                        link_support: Some(true),
 677                        dynamic_registration: None,
 678                    }),
 679                    code_action: Some(CodeActionClientCapabilities {
 680                        code_action_literal_support: Some(CodeActionLiteralSupport {
 681                            code_action_kind: CodeActionKindLiteralSupport {
 682                                value_set: vec![
 683                                    CodeActionKind::REFACTOR.as_str().into(),
 684                                    CodeActionKind::QUICKFIX.as_str().into(),
 685                                    CodeActionKind::SOURCE.as_str().into(),
 686                                ],
 687                            },
 688                        }),
 689                        data_support: Some(true),
 690                        resolve_support: Some(CodeActionCapabilityResolveSupport {
 691                            properties: vec![
 692                                "kind".to_string(),
 693                                "diagnostics".to_string(),
 694                                "isPreferred".to_string(),
 695                                "disabled".to_string(),
 696                                "edit".to_string(),
 697                                "command".to_string(),
 698                            ],
 699                        }),
 700                        ..Default::default()
 701                    }),
 702                    completion: Some(CompletionClientCapabilities {
 703                        completion_item: Some(CompletionItemCapability {
 704                            snippet_support: Some(true),
 705                            resolve_support: Some(CompletionItemCapabilityResolveSupport {
 706                                properties: vec![
 707                                    "additionalTextEdits".to_string(),
 708                                    "command".to_string(),
 709                                    "documentation".to_string(),
 710                                    // NB: Do not have this resolved, otherwise Zed becomes slow to complete things
 711                                    // "textEdit".to_string(),
 712                                ],
 713                            }),
 714                            insert_replace_support: Some(true),
 715                            label_details_support: Some(true),
 716                            insert_text_mode_support: Some(InsertTextModeSupport {
 717                                value_set: vec![
 718                                    InsertTextMode::AS_IS,
 719                                    InsertTextMode::ADJUST_INDENTATION,
 720                                ],
 721                            }),
 722                            ..Default::default()
 723                        }),
 724                        insert_text_mode: Some(InsertTextMode::ADJUST_INDENTATION),
 725                        completion_list: Some(CompletionListCapability {
 726                            item_defaults: Some(vec![
 727                                "commitCharacters".to_owned(),
 728                                "editRange".to_owned(),
 729                                "insertTextMode".to_owned(),
 730                                "insertTextFormat".to_owned(),
 731                                "data".to_owned(),
 732                            ]),
 733                        }),
 734                        context_support: Some(true),
 735                        ..Default::default()
 736                    }),
 737                    rename: Some(RenameClientCapabilities {
 738                        prepare_support: Some(true),
 739                        prepare_support_default_behavior: Some(
 740                            PrepareSupportDefaultBehavior::IDENTIFIER,
 741                        ),
 742                        ..Default::default()
 743                    }),
 744                    hover: Some(HoverClientCapabilities {
 745                        content_format: Some(vec![MarkupKind::Markdown]),
 746                        dynamic_registration: None,
 747                    }),
 748                    inlay_hint: Some(InlayHintClientCapabilities {
 749                        resolve_support: Some(InlayHintResolveClientCapabilities {
 750                            properties: vec![
 751                                "textEdits".to_string(),
 752                                "tooltip".to_string(),
 753                                "label.tooltip".to_string(),
 754                                "label.location".to_string(),
 755                                "label.command".to_string(),
 756                            ],
 757                        }),
 758                        dynamic_registration: Some(false),
 759                    }),
 760                    publish_diagnostics: Some(PublishDiagnosticsClientCapabilities {
 761                        related_information: Some(true),
 762                        version_support: Some(true),
 763                        data_support: Some(true),
 764                        tag_support: Some(TagSupport {
 765                            value_set: vec![DiagnosticTag::UNNECESSARY, DiagnosticTag::DEPRECATED],
 766                        }),
 767                        code_description_support: Some(true),
 768                    }),
 769                    formatting: Some(DynamicRegistrationClientCapabilities {
 770                        dynamic_registration: Some(true),
 771                    }),
 772                    range_formatting: Some(DynamicRegistrationClientCapabilities {
 773                        dynamic_registration: Some(true),
 774                    }),
 775                    on_type_formatting: Some(DynamicRegistrationClientCapabilities {
 776                        dynamic_registration: Some(true),
 777                    }),
 778                    signature_help: Some(SignatureHelpClientCapabilities {
 779                        signature_information: Some(SignatureInformationSettings {
 780                            documentation_format: Some(vec![
 781                                MarkupKind::Markdown,
 782                                MarkupKind::PlainText,
 783                            ]),
 784                            parameter_information: Some(ParameterInformationSettings {
 785                                label_offset_support: Some(true),
 786                            }),
 787                            active_parameter_support: Some(true),
 788                        }),
 789                        ..SignatureHelpClientCapabilities::default()
 790                    }),
 791                    synchronization: Some(TextDocumentSyncClientCapabilities {
 792                        did_save: Some(true),
 793                        ..TextDocumentSyncClientCapabilities::default()
 794                    }),
 795                    code_lens: Some(CodeLensClientCapabilities {
 796                        dynamic_registration: Some(false),
 797                    }),
 798                    document_symbol: Some(DocumentSymbolClientCapabilities {
 799                        hierarchical_document_symbol_support: Some(true),
 800                        ..DocumentSymbolClientCapabilities::default()
 801                    }),
 802                    diagnostic: Some(DiagnosticClientCapabilities {
 803                        dynamic_registration: Some(false),
 804                        related_document_support: Some(true),
 805                    })
 806                    .filter(|_| pull_diagnostics),
 807                    color_provider: Some(DocumentColorClientCapabilities {
 808                        dynamic_registration: Some(false),
 809                    }),
 810                    ..TextDocumentClientCapabilities::default()
 811                }),
 812                experimental: Some(json!({
 813                    "serverStatusNotification": true,
 814                    "localDocs": true,
 815                })),
 816                window: Some(WindowClientCapabilities {
 817                    work_done_progress: Some(true),
 818                    show_message: Some(ShowMessageRequestClientCapabilities {
 819                        message_action_item: None,
 820                    }),
 821                    ..Default::default()
 822                }),
 823            },
 824            trace: None,
 825            workspace_folders: Some(workspace_folders),
 826            client_info: release_channel::ReleaseChannel::try_global(cx).map(|release_channel| {
 827                ClientInfo {
 828                    name: release_channel.display_name().to_string(),
 829                    version: Some(release_channel::AppVersion::global(cx).to_string()),
 830                }
 831            }),
 832            locale: None,
 833
 834            ..Default::default()
 835        }
 836    }
 837
 838    /// Initializes a language server by sending the `Initialize` request.
 839    /// Note that `options` is used directly to construct [`InitializeParams`], which is why it is owned.
 840    ///
 841    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#initialize)
 842    pub fn initialize(
 843        mut self,
 844        params: InitializeParams,
 845        configuration: Arc<DidChangeConfigurationParams>,
 846        cx: &App,
 847    ) -> Task<Result<Arc<Self>>> {
 848        cx.spawn(async move |_| {
 849            let response = self
 850                .request::<request::Initialize>(params)
 851                .await
 852                .into_response()
 853                .with_context(|| {
 854                    format!(
 855                        "initializing server {}, id {}",
 856                        self.name(),
 857                        self.server_id()
 858                    )
 859                })?;
 860            if let Some(info) = response.server_info {
 861                self.process_name = info.name.into();
 862            }
 863            self.capabilities = RwLock::new(response.capabilities);
 864            self.configuration = configuration;
 865
 866            self.notify::<notification::Initialized>(&InitializedParams {})?;
 867            Ok(Arc::new(self))
 868        })
 869    }
 870
 871    /// Sends a shutdown request to the language server process and prepares the [`LanguageServer`] to be dropped.
 872    pub fn shutdown(&self) -> Option<impl 'static + Send + Future<Output = Option<()>> + use<>> {
 873        if let Some(tasks) = self.io_tasks.lock().take() {
 874            let response_handlers = self.response_handlers.clone();
 875            let next_id = AtomicI32::new(self.next_id.load(SeqCst));
 876            let outbound_tx = self.outbound_tx.clone();
 877            let executor = self.executor.clone();
 878            let mut output_done = self.output_done_rx.lock().take().unwrap();
 879            let shutdown_request = Self::request_internal::<request::Shutdown>(
 880                &next_id,
 881                &response_handlers,
 882                &outbound_tx,
 883                &executor,
 884                (),
 885            );
 886            let exit = Self::notify_internal::<notification::Exit>(&outbound_tx, &());
 887            outbound_tx.close();
 888
 889            let server = self.server.clone();
 890            let name = self.name.clone();
 891            let mut timer = self.executor.timer(SERVER_SHUTDOWN_TIMEOUT).fuse();
 892            Some(
 893                async move {
 894                    log::debug!("language server shutdown started");
 895
 896                    select! {
 897                        request_result = shutdown_request.fuse() => {
 898                            match request_result {
 899                                ConnectionResult::Timeout => {
 900                                    log::warn!("timeout waiting for language server {name} to shutdown");
 901                                },
 902                                ConnectionResult::ConnectionReset => {},
 903                                ConnectionResult::Result(r) => r?,
 904                            }
 905                        }
 906
 907                        _ = timer => {
 908                            log::info!("timeout waiting for language server {name} to shutdown");
 909                        },
 910                    }
 911
 912                    response_handlers.lock().take();
 913                    exit?;
 914                    output_done.recv().await;
 915                    server.lock().take().map(|mut child| child.kill());
 916                    log::debug!("language server shutdown finished");
 917
 918                    drop(tasks);
 919                    anyhow::Ok(())
 920                }
 921                .log_err(),
 922            )
 923        } else {
 924            None
 925        }
 926    }
 927
 928    /// Register a handler to handle incoming LSP notifications.
 929    ///
 930    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
 931    #[must_use]
 932    pub fn on_notification<T, F>(&self, f: F) -> Subscription
 933    where
 934        T: notification::Notification,
 935        F: 'static + Send + FnMut(T::Params, &mut AsyncApp),
 936    {
 937        self.on_custom_notification(T::METHOD, f)
 938    }
 939
 940    /// Register a handler to handle incoming LSP requests.
 941    ///
 942    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
 943    #[must_use]
 944    pub fn on_request<T, F, Fut>(&self, f: F) -> Subscription
 945    where
 946        T: request::Request,
 947        T::Params: 'static + Send,
 948        F: 'static + FnMut(T::Params, &mut AsyncApp) -> Fut + Send,
 949        Fut: 'static + Future<Output = Result<T::Result>>,
 950    {
 951        self.on_custom_request(T::METHOD, f)
 952    }
 953
 954    /// Registers a handler to inspect all language server process stdio.
 955    #[must_use]
 956    pub fn on_io<F>(&self, f: F) -> Subscription
 957    where
 958        F: 'static + Send + FnMut(IoKind, &str),
 959    {
 960        let id = self.next_id.fetch_add(1, SeqCst);
 961        self.io_handlers.lock().insert(id, Box::new(f));
 962        Subscription::Io {
 963            id,
 964            io_handlers: Some(Arc::downgrade(&self.io_handlers)),
 965        }
 966    }
 967
 968    /// Removes a request handler registers via [`Self::on_request`].
 969    pub fn remove_request_handler<T: request::Request>(&self) {
 970        self.notification_handlers.lock().remove(T::METHOD);
 971    }
 972
 973    /// Removes a notification handler registers via [`Self::on_notification`].
 974    pub fn remove_notification_handler<T: notification::Notification>(&self) {
 975        self.notification_handlers.lock().remove(T::METHOD);
 976    }
 977
 978    /// Checks if a notification handler has been registered via [`Self::on_notification`].
 979    pub fn has_notification_handler<T: notification::Notification>(&self) -> bool {
 980        self.notification_handlers.lock().contains_key(T::METHOD)
 981    }
 982
 983    #[must_use]
 984    fn on_custom_notification<Params, F>(&self, method: &'static str, mut f: F) -> Subscription
 985    where
 986        F: 'static + FnMut(Params, &mut AsyncApp) + Send,
 987        Params: DeserializeOwned,
 988    {
 989        let prev_handler = self.notification_handlers.lock().insert(
 990            method,
 991            Box::new(move |_, params, cx| {
 992                if let Some(params) = serde_json::from_value(params).log_err() {
 993                    f(params, cx);
 994                }
 995            }),
 996        );
 997        assert!(
 998            prev_handler.is_none(),
 999            "registered multiple handlers for the same LSP method"
1000        );
1001        Subscription::Notification {
1002            method,
1003            notification_handlers: Some(self.notification_handlers.clone()),
1004        }
1005    }
1006
1007    #[must_use]
1008    fn on_custom_request<Params, Res, Fut, F>(&self, method: &'static str, mut f: F) -> Subscription
1009    where
1010        F: 'static + FnMut(Params, &mut AsyncApp) -> Fut + Send,
1011        Fut: 'static + Future<Output = Result<Res>>,
1012        Params: DeserializeOwned + Send + 'static,
1013        Res: Serialize,
1014    {
1015        let outbound_tx = self.outbound_tx.clone();
1016        let prev_handler = self.notification_handlers.lock().insert(
1017            method,
1018            Box::new(move |id, params, cx| {
1019                if let Some(id) = id {
1020                    match serde_json::from_value(params) {
1021                        Ok(params) => {
1022                            let response = f(params, cx);
1023                            cx.foreground_executor()
1024                                .spawn({
1025                                    let outbound_tx = outbound_tx.clone();
1026                                    async move {
1027                                        let response = match response.await {
1028                                            Ok(result) => Response {
1029                                                jsonrpc: JSON_RPC_VERSION,
1030                                                id,
1031                                                value: LspResult::Ok(Some(result)),
1032                                            },
1033                                            Err(error) => Response {
1034                                                jsonrpc: JSON_RPC_VERSION,
1035                                                id,
1036                                                value: LspResult::Error(Some(Error {
1037                                                    message: error.to_string(),
1038                                                })),
1039                                            },
1040                                        };
1041                                        if let Some(response) =
1042                                            serde_json::to_string(&response).log_err()
1043                                        {
1044                                            outbound_tx.try_send(response).ok();
1045                                        }
1046                                    }
1047                                })
1048                                .detach();
1049                        }
1050
1051                        Err(error) => {
1052                            log::error!("error deserializing {} request: {:?}", method, error);
1053                            let response = AnyResponse {
1054                                jsonrpc: JSON_RPC_VERSION,
1055                                id,
1056                                result: None,
1057                                error: Some(Error {
1058                                    message: error.to_string(),
1059                                }),
1060                            };
1061                            if let Some(response) = serde_json::to_string(&response).log_err() {
1062                                outbound_tx.try_send(response).ok();
1063                            }
1064                        }
1065                    }
1066                }
1067            }),
1068        );
1069        assert!(
1070            prev_handler.is_none(),
1071            "registered multiple handlers for the same LSP method"
1072        );
1073        Subscription::Notification {
1074            method,
1075            notification_handlers: Some(self.notification_handlers.clone()),
1076        }
1077    }
1078
1079    /// Get the name of the running language server.
1080    pub fn name(&self) -> LanguageServerName {
1081        self.name.clone()
1082    }
1083
1084    pub fn process_name(&self) -> &str {
1085        &self.process_name
1086    }
1087
1088    /// Get the reported capabilities of the running language server.
1089    pub fn capabilities(&self) -> ServerCapabilities {
1090        self.capabilities.read().clone()
1091    }
1092
1093    /// Get the reported capabilities of the running language server and
1094    /// what we know on the client/adapter-side of its capabilities.
1095    pub fn adapter_server_capabilities(&self) -> AdapterServerCapabilities {
1096        AdapterServerCapabilities {
1097            server_capabilities: self.capabilities(),
1098            code_action_kinds: self.code_action_kinds(),
1099        }
1100    }
1101
1102    pub fn update_capabilities(&self, update: impl FnOnce(&mut ServerCapabilities)) {
1103        update(self.capabilities.write().deref_mut());
1104    }
1105
1106    pub fn configuration(&self) -> &Value {
1107        &self.configuration.settings
1108    }
1109
1110    /// Get the id of the running language server.
1111    pub fn server_id(&self) -> LanguageServerId {
1112        self.server_id
1113    }
1114
1115    /// Language server's binary information.
1116    pub fn binary(&self) -> &LanguageServerBinary {
1117        &self.binary
1118    }
1119    /// Sends a RPC request to the language server.
1120    ///
1121    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
1122    pub fn request<T: request::Request>(
1123        &self,
1124        params: T::Params,
1125    ) -> impl LspRequestFuture<T::Result> + use<T>
1126    where
1127        T::Result: 'static + Send,
1128    {
1129        Self::request_internal::<T>(
1130            &self.next_id,
1131            &self.response_handlers,
1132            &self.outbound_tx,
1133            &self.executor,
1134            params,
1135        )
1136    }
1137
1138    fn request_internal<T>(
1139        next_id: &AtomicI32,
1140        response_handlers: &Mutex<Option<HashMap<RequestId, ResponseHandler>>>,
1141        outbound_tx: &channel::Sender<String>,
1142        executor: &BackgroundExecutor,
1143        params: T::Params,
1144    ) -> impl LspRequestFuture<T::Result> + use<T>
1145    where
1146        T::Result: 'static + Send,
1147        T: request::Request,
1148    {
1149        let id = next_id.fetch_add(1, SeqCst);
1150        let message = serde_json::to_string(&Request {
1151            jsonrpc: JSON_RPC_VERSION,
1152            id: RequestId::Int(id),
1153            method: T::METHOD,
1154            params,
1155        })
1156        .unwrap();
1157
1158        let (tx, rx) = oneshot::channel();
1159        let handle_response = response_handlers
1160            .lock()
1161            .as_mut()
1162            .context("server shut down")
1163            .map(|handlers| {
1164                let executor = executor.clone();
1165                handlers.insert(
1166                    RequestId::Int(id),
1167                    Box::new(move |result| {
1168                        executor
1169                            .spawn(async move {
1170                                let response = match result {
1171                                    Ok(response) => match serde_json::from_str(&response) {
1172                                        Ok(deserialized) => Ok(deserialized),
1173                                        Err(error) => {
1174                                            log::error!("failed to deserialize response from language server: {}. response from language server: {:?}", error, response);
1175                                            Err(error).context("failed to deserialize response")
1176                                        }
1177                                    }
1178                                    Err(error) => Err(anyhow!("{}", error.message)),
1179                                };
1180                                _ = tx.send(response);
1181                            })
1182                            .detach();
1183                    }),
1184                );
1185            });
1186
1187        let send = outbound_tx
1188            .try_send(message)
1189            .context("failed to write to language server's stdin");
1190
1191        let outbound_tx = outbound_tx.downgrade();
1192        let mut timeout = executor.timer(LSP_REQUEST_TIMEOUT).fuse();
1193        let started = Instant::now();
1194        LspRequest::new(id, async move {
1195            if let Err(e) = handle_response {
1196                return ConnectionResult::Result(Err(e));
1197            }
1198            if let Err(e) = send {
1199                return ConnectionResult::Result(Err(e));
1200            }
1201
1202            let cancel_on_drop = util::defer(move || {
1203                if let Some(outbound_tx) = outbound_tx.upgrade() {
1204                    Self::notify_internal::<notification::Cancel>(
1205                        &outbound_tx,
1206                        &CancelParams {
1207                            id: NumberOrString::Number(id),
1208                        },
1209                    )
1210                    .ok();
1211                }
1212            });
1213
1214            let method = T::METHOD;
1215            select! {
1216                response = rx.fuse() => {
1217                    let elapsed = started.elapsed();
1218                    log::trace!("Took {elapsed:?} to receive response to {method:?} id {id}");
1219                    cancel_on_drop.abort();
1220                    match response {
1221                        Ok(response_result) => ConnectionResult::Result(response_result),
1222                        Err(Canceled) => {
1223                            log::error!("Server reset connection for a request {method:?} id {id}");
1224                            ConnectionResult::ConnectionReset
1225                        },
1226                    }
1227                }
1228
1229                _ = timeout => {
1230                    log::error!("Cancelled LSP request task for {method:?} id {id} which took over {LSP_REQUEST_TIMEOUT:?}");
1231                    ConnectionResult::Timeout
1232                }
1233            }
1234        })
1235    }
1236
1237    /// Sends a RPC notification to the language server.
1238    ///
1239    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
1240    pub fn notify<T: notification::Notification>(&self, params: &T::Params) -> Result<()> {
1241        Self::notify_internal::<T>(&self.outbound_tx, params)
1242    }
1243
1244    fn notify_internal<T: notification::Notification>(
1245        outbound_tx: &channel::Sender<String>,
1246        params: &T::Params,
1247    ) -> Result<()> {
1248        let message = serde_json::to_string(&Notification {
1249            jsonrpc: JSON_RPC_VERSION,
1250            method: T::METHOD,
1251            params,
1252        })
1253        .unwrap();
1254        outbound_tx.try_send(message)?;
1255        Ok(())
1256    }
1257
1258    /// Add new workspace folder to the list.
1259    pub fn add_workspace_folder(&self, uri: Url) {
1260        if self
1261            .capabilities()
1262            .workspace
1263            .and_then(|ws| {
1264                ws.workspace_folders.and_then(|folders| {
1265                    folders
1266                        .change_notifications
1267                        .map(|caps| matches!(caps, OneOf::Left(false)))
1268                })
1269            })
1270            .unwrap_or(true)
1271        {
1272            return;
1273        }
1274
1275        let is_new_folder = self.workspace_folders.lock().insert(uri.clone());
1276        if is_new_folder {
1277            let params = DidChangeWorkspaceFoldersParams {
1278                event: WorkspaceFoldersChangeEvent {
1279                    added: vec![WorkspaceFolder {
1280                        uri,
1281                        name: String::default(),
1282                    }],
1283                    removed: vec![],
1284                },
1285            };
1286            self.notify::<DidChangeWorkspaceFolders>(&params).ok();
1287        }
1288    }
1289    /// Add new workspace folder to the list.
1290    pub fn remove_workspace_folder(&self, uri: Url) {
1291        if self
1292            .capabilities()
1293            .workspace
1294            .and_then(|ws| {
1295                ws.workspace_folders.and_then(|folders| {
1296                    folders
1297                        .change_notifications
1298                        .map(|caps| !matches!(caps, OneOf::Left(false)))
1299                })
1300            })
1301            .unwrap_or(true)
1302        {
1303            return;
1304        }
1305        let was_removed = self.workspace_folders.lock().remove(&uri);
1306        if was_removed {
1307            let params = DidChangeWorkspaceFoldersParams {
1308                event: WorkspaceFoldersChangeEvent {
1309                    added: vec![],
1310                    removed: vec![WorkspaceFolder {
1311                        uri,
1312                        name: String::default(),
1313                    }],
1314                },
1315            };
1316            self.notify::<DidChangeWorkspaceFolders>(&params).ok();
1317        }
1318    }
1319    pub fn set_workspace_folders(&self, folders: BTreeSet<Url>) {
1320        let mut workspace_folders = self.workspace_folders.lock();
1321
1322        let old_workspace_folders = std::mem::take(&mut *workspace_folders);
1323        let added: Vec<_> = folders
1324            .difference(&old_workspace_folders)
1325            .map(|uri| WorkspaceFolder {
1326                uri: uri.clone(),
1327                name: String::default(),
1328            })
1329            .collect();
1330
1331        let removed: Vec<_> = old_workspace_folders
1332            .difference(&folders)
1333            .map(|uri| WorkspaceFolder {
1334                uri: uri.clone(),
1335                name: String::default(),
1336            })
1337            .collect();
1338        *workspace_folders = folders;
1339        let should_notify = !added.is_empty() || !removed.is_empty();
1340        if should_notify {
1341            drop(workspace_folders);
1342            let params = DidChangeWorkspaceFoldersParams {
1343                event: WorkspaceFoldersChangeEvent { added, removed },
1344            };
1345            self.notify::<DidChangeWorkspaceFolders>(&params).ok();
1346        }
1347    }
1348
1349    pub fn workspace_folders(&self) -> impl Deref<Target = BTreeSet<Url>> + '_ {
1350        self.workspace_folders.lock()
1351    }
1352
1353    pub fn register_buffer(
1354        &self,
1355        uri: Url,
1356        language_id: String,
1357        version: i32,
1358        initial_text: String,
1359    ) {
1360        self.notify::<notification::DidOpenTextDocument>(&DidOpenTextDocumentParams {
1361            text_document: TextDocumentItem::new(uri, language_id, version, initial_text),
1362        })
1363        .ok();
1364    }
1365
1366    pub fn unregister_buffer(&self, uri: Url) {
1367        self.notify::<notification::DidCloseTextDocument>(&DidCloseTextDocumentParams {
1368            text_document: TextDocumentIdentifier::new(uri),
1369        })
1370        .ok();
1371    }
1372}
1373
1374impl Drop for LanguageServer {
1375    fn drop(&mut self) {
1376        if let Some(shutdown) = self.shutdown() {
1377            self.executor.spawn(shutdown).detach();
1378        }
1379    }
1380}
1381
1382impl Subscription {
1383    /// Detaching a subscription handle prevents it from unsubscribing on drop.
1384    pub fn detach(&mut self) {
1385        match self {
1386            Subscription::Notification {
1387                notification_handlers,
1388                ..
1389            } => *notification_handlers = None,
1390            Subscription::Io { io_handlers, .. } => *io_handlers = None,
1391        }
1392    }
1393}
1394
1395impl fmt::Display for LanguageServerId {
1396    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1397        self.0.fmt(f)
1398    }
1399}
1400
1401impl fmt::Debug for LanguageServer {
1402    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1403        f.debug_struct("LanguageServer")
1404            .field("id", &self.server_id.0)
1405            .field("name", &self.name)
1406            .finish_non_exhaustive()
1407    }
1408}
1409
1410impl Drop for Subscription {
1411    fn drop(&mut self) {
1412        match self {
1413            Subscription::Notification {
1414                method,
1415                notification_handlers,
1416            } => {
1417                if let Some(handlers) = notification_handlers {
1418                    handlers.lock().remove(method);
1419                }
1420            }
1421            Subscription::Io { id, io_handlers } => {
1422                if let Some(io_handlers) = io_handlers.as_ref().and_then(|h| h.upgrade()) {
1423                    io_handlers.lock().remove(id);
1424                }
1425            }
1426        }
1427    }
1428}
1429
1430/// Mock language server for use in tests.
1431#[cfg(any(test, feature = "test-support"))]
1432#[derive(Clone)]
1433pub struct FakeLanguageServer {
1434    pub binary: LanguageServerBinary,
1435    pub server: Arc<LanguageServer>,
1436    notifications_rx: channel::Receiver<(String, String)>,
1437}
1438
1439#[cfg(any(test, feature = "test-support"))]
1440impl FakeLanguageServer {
1441    /// Construct a fake language server.
1442    pub fn new(
1443        server_id: LanguageServerId,
1444        binary: LanguageServerBinary,
1445        name: String,
1446        capabilities: ServerCapabilities,
1447        cx: &mut AsyncApp,
1448    ) -> (LanguageServer, FakeLanguageServer) {
1449        let (stdin_writer, stdin_reader) = async_pipe::pipe();
1450        let (stdout_writer, stdout_reader) = async_pipe::pipe();
1451        let (notifications_tx, notifications_rx) = channel::unbounded();
1452
1453        let server_name = LanguageServerName(name.clone().into());
1454        let process_name = Arc::from(name.as_str());
1455        let root = Self::root_path();
1456        let workspace_folders: Arc<Mutex<BTreeSet<Url>>> = Default::default();
1457        let mut server = LanguageServer::new_internal(
1458            server_id,
1459            server_name.clone(),
1460            stdin_writer,
1461            stdout_reader,
1462            None::<async_pipe::PipeReader>,
1463            Arc::new(Mutex::new(None)),
1464            None,
1465            None,
1466            binary.clone(),
1467            root,
1468            workspace_folders.clone(),
1469            cx,
1470            |_| {},
1471        );
1472        server.process_name = process_name;
1473        let fake = FakeLanguageServer {
1474            binary: binary.clone(),
1475            server: Arc::new({
1476                let mut server = LanguageServer::new_internal(
1477                    server_id,
1478                    server_name,
1479                    stdout_writer,
1480                    stdin_reader,
1481                    None::<async_pipe::PipeReader>,
1482                    Arc::new(Mutex::new(None)),
1483                    None,
1484                    None,
1485                    binary,
1486                    Self::root_path(),
1487                    workspace_folders,
1488                    cx,
1489                    move |msg| {
1490                        notifications_tx
1491                            .try_send((
1492                                msg.method.to_string(),
1493                                msg.params.unwrap_or(Value::Null).to_string(),
1494                            ))
1495                            .ok();
1496                    },
1497                );
1498                server.process_name = name.as_str().into();
1499                server
1500            }),
1501            notifications_rx,
1502        };
1503        fake.set_request_handler::<request::Initialize, _, _>({
1504            let capabilities = capabilities;
1505            move |_, _| {
1506                let capabilities = capabilities.clone();
1507                let name = name.clone();
1508                async move {
1509                    Ok(InitializeResult {
1510                        capabilities,
1511                        server_info: Some(ServerInfo {
1512                            name,
1513                            ..Default::default()
1514                        }),
1515                    })
1516                }
1517            }
1518        });
1519
1520        (server, fake)
1521    }
1522    #[cfg(target_os = "windows")]
1523    fn root_path() -> Url {
1524        Url::from_file_path("C:/").unwrap()
1525    }
1526
1527    #[cfg(not(target_os = "windows"))]
1528    fn root_path() -> Url {
1529        Url::from_file_path("/").unwrap()
1530    }
1531}
1532
1533#[cfg(any(test, feature = "test-support"))]
1534impl LanguageServer {
1535    pub fn full_capabilities() -> ServerCapabilities {
1536        ServerCapabilities {
1537            document_highlight_provider: Some(OneOf::Left(true)),
1538            code_action_provider: Some(CodeActionProviderCapability::Simple(true)),
1539            document_formatting_provider: Some(OneOf::Left(true)),
1540            document_range_formatting_provider: Some(OneOf::Left(true)),
1541            definition_provider: Some(OneOf::Left(true)),
1542            workspace_symbol_provider: Some(OneOf::Left(true)),
1543            implementation_provider: Some(ImplementationProviderCapability::Simple(true)),
1544            type_definition_provider: Some(TypeDefinitionProviderCapability::Simple(true)),
1545            ..Default::default()
1546        }
1547    }
1548}
1549
1550#[cfg(any(test, feature = "test-support"))]
1551impl FakeLanguageServer {
1552    /// See [`LanguageServer::notify`].
1553    pub fn notify<T: notification::Notification>(&self, params: &T::Params) {
1554        self.server.notify::<T>(params).ok();
1555    }
1556
1557    /// See [`LanguageServer::request`].
1558    pub async fn request<T>(&self, params: T::Params) -> ConnectionResult<T::Result>
1559    where
1560        T: request::Request,
1561        T::Result: 'static + Send,
1562    {
1563        self.server.executor.start_waiting();
1564        self.server.request::<T>(params).await
1565    }
1566
1567    /// Attempts [`Self::try_receive_notification`], unwrapping if it has not received the specified type yet.
1568    pub async fn receive_notification<T: notification::Notification>(&mut self) -> T::Params {
1569        self.server.executor.start_waiting();
1570        self.try_receive_notification::<T>().await.unwrap()
1571    }
1572
1573    /// Consumes the notification channel until it finds a notification for the specified type.
1574    pub async fn try_receive_notification<T: notification::Notification>(
1575        &mut self,
1576    ) -> Option<T::Params> {
1577        loop {
1578            let (method, params) = self.notifications_rx.recv().await.ok()?;
1579            if method == T::METHOD {
1580                return Some(serde_json::from_str::<T::Params>(&params).unwrap());
1581            } else {
1582                log::info!("skipping message in fake language server {:?}", params);
1583            }
1584        }
1585    }
1586
1587    /// Registers a handler for a specific kind of request. Removes any existing handler for specified request type.
1588    pub fn set_request_handler<T, F, Fut>(
1589        &self,
1590        mut handler: F,
1591    ) -> futures::channel::mpsc::UnboundedReceiver<()>
1592    where
1593        T: 'static + request::Request,
1594        T::Params: 'static + Send,
1595        F: 'static + Send + FnMut(T::Params, gpui::AsyncApp) -> Fut,
1596        Fut: 'static + Future<Output = Result<T::Result>>,
1597    {
1598        let (responded_tx, responded_rx) = futures::channel::mpsc::unbounded();
1599        self.server.remove_request_handler::<T>();
1600        self.server
1601            .on_request::<T, _, _>(move |params, cx| {
1602                let result = handler(params, cx.clone());
1603                let responded_tx = responded_tx.clone();
1604                let executor = cx.background_executor().clone();
1605                async move {
1606                    executor.simulate_random_delay().await;
1607                    let result = result.await;
1608                    responded_tx.unbounded_send(()).ok();
1609                    result
1610                }
1611            })
1612            .detach();
1613        responded_rx
1614    }
1615
1616    /// Registers a handler for a specific kind of notification. Removes any existing handler for specified notification type.
1617    pub fn handle_notification<T, F>(
1618        &self,
1619        mut handler: F,
1620    ) -> futures::channel::mpsc::UnboundedReceiver<()>
1621    where
1622        T: 'static + notification::Notification,
1623        T::Params: 'static + Send,
1624        F: 'static + Send + FnMut(T::Params, gpui::AsyncApp),
1625    {
1626        let (handled_tx, handled_rx) = futures::channel::mpsc::unbounded();
1627        self.server.remove_notification_handler::<T>();
1628        self.server
1629            .on_notification::<T, _>(move |params, cx| {
1630                handler(params, cx.clone());
1631                handled_tx.unbounded_send(()).ok();
1632            })
1633            .detach();
1634        handled_rx
1635    }
1636
1637    /// Removes any existing handler for specified notification type.
1638    pub fn remove_request_handler<T>(&mut self)
1639    where
1640        T: 'static + request::Request,
1641    {
1642        self.server.remove_request_handler::<T>();
1643    }
1644
1645    /// Simulate that the server has started work and notifies about its progress with the specified token.
1646    pub async fn start_progress(&self, token: impl Into<String>) {
1647        self.start_progress_with(token, Default::default()).await
1648    }
1649
1650    pub async fn start_progress_with(
1651        &self,
1652        token: impl Into<String>,
1653        progress: WorkDoneProgressBegin,
1654    ) {
1655        let token = token.into();
1656        self.request::<request::WorkDoneProgressCreate>(WorkDoneProgressCreateParams {
1657            token: NumberOrString::String(token.clone()),
1658        })
1659        .await
1660        .into_response()
1661        .unwrap();
1662        self.notify::<notification::Progress>(&ProgressParams {
1663            token: NumberOrString::String(token),
1664            value: ProgressParamsValue::WorkDone(WorkDoneProgress::Begin(progress)),
1665        });
1666    }
1667
1668    /// Simulate that the server has completed work and notifies about that with the specified token.
1669    pub fn end_progress(&self, token: impl Into<String>) {
1670        self.notify::<notification::Progress>(&ProgressParams {
1671            token: NumberOrString::String(token.into()),
1672            value: ProgressParamsValue::WorkDone(WorkDoneProgress::End(Default::default())),
1673        });
1674    }
1675}
1676
1677#[cfg(test)]
1678mod tests {
1679    use super::*;
1680    use gpui::{SemanticVersion, TestAppContext};
1681    use std::str::FromStr;
1682
1683    #[ctor::ctor]
1684    fn init_logger() {
1685        zlog::init_test();
1686    }
1687
1688    #[gpui::test]
1689    async fn test_fake(cx: &mut TestAppContext) {
1690        cx.update(|cx| {
1691            release_channel::init(SemanticVersion::default(), cx);
1692        });
1693        let (server, mut fake) = FakeLanguageServer::new(
1694            LanguageServerId(0),
1695            LanguageServerBinary {
1696                path: "path/to/language-server".into(),
1697                arguments: vec![],
1698                env: None,
1699            },
1700            "the-lsp".to_string(),
1701            Default::default(),
1702            &mut cx.to_async(),
1703        );
1704
1705        let (message_tx, message_rx) = channel::unbounded();
1706        let (diagnostics_tx, diagnostics_rx) = channel::unbounded();
1707        server
1708            .on_notification::<notification::ShowMessage, _>(move |params, _| {
1709                message_tx.try_send(params).unwrap()
1710            })
1711            .detach();
1712        server
1713            .on_notification::<notification::PublishDiagnostics, _>(move |params, _| {
1714                diagnostics_tx.try_send(params).unwrap()
1715            })
1716            .detach();
1717
1718        let server = cx
1719            .update(|cx| {
1720                let params = server.default_initialize_params(false, cx);
1721                let configuration = DidChangeConfigurationParams {
1722                    settings: Default::default(),
1723                };
1724                server.initialize(params, configuration.into(), cx)
1725            })
1726            .await
1727            .unwrap();
1728        server
1729            .notify::<notification::DidOpenTextDocument>(&DidOpenTextDocumentParams {
1730                text_document: TextDocumentItem::new(
1731                    Url::from_str("file://a/b").unwrap(),
1732                    "rust".to_string(),
1733                    0,
1734                    "".to_string(),
1735                ),
1736            })
1737            .unwrap();
1738        assert_eq!(
1739            fake.receive_notification::<notification::DidOpenTextDocument>()
1740                .await
1741                .text_document
1742                .uri
1743                .as_str(),
1744            "file://a/b"
1745        );
1746
1747        fake.notify::<notification::ShowMessage>(&ShowMessageParams {
1748            typ: MessageType::ERROR,
1749            message: "ok".to_string(),
1750        });
1751        fake.notify::<notification::PublishDiagnostics>(&PublishDiagnosticsParams {
1752            uri: Url::from_str("file://b/c").unwrap(),
1753            version: Some(5),
1754            diagnostics: vec![],
1755        });
1756        assert_eq!(message_rx.recv().await.unwrap().message, "ok");
1757        assert_eq!(
1758            diagnostics_rx.recv().await.unwrap().uri.as_str(),
1759            "file://b/c"
1760        );
1761
1762        fake.set_request_handler::<request::Shutdown, _, _>(|_, _| async move { Ok(()) });
1763
1764        drop(server);
1765        fake.receive_notification::<notification::Exit>().await;
1766    }
1767
1768    #[gpui::test]
1769    fn test_deserialize_string_digit_id() {
1770        let json = r#"{"jsonrpc":"2.0","id":"2","method":"workspace/configuration","params":{"items":[{"scopeUri":"file:///Users/mph/Devel/personal/hello-scala/","section":"metals"}]}}"#;
1771        let notification = serde_json::from_str::<AnyNotification>(json)
1772            .expect("message with string id should be parsed");
1773        let expected_id = RequestId::Str("2".to_string());
1774        assert_eq!(notification.id, Some(expected_id));
1775    }
1776
1777    #[gpui::test]
1778    fn test_deserialize_string_id() {
1779        let json = r#"{"jsonrpc":"2.0","id":"anythingAtAll","method":"workspace/configuration","params":{"items":[{"scopeUri":"file:///Users/mph/Devel/personal/hello-scala/","section":"metals"}]}}"#;
1780        let notification = serde_json::from_str::<AnyNotification>(json)
1781            .expect("message with string id should be parsed");
1782        let expected_id = RequestId::Str("anythingAtAll".to_string());
1783        assert_eq!(notification.id, Some(expected_id));
1784    }
1785
1786    #[gpui::test]
1787    fn test_deserialize_int_id() {
1788        let json = r#"{"jsonrpc":"2.0","id":2,"method":"workspace/configuration","params":{"items":[{"scopeUri":"file:///Users/mph/Devel/personal/hello-scala/","section":"metals"}]}}"#;
1789        let notification = serde_json::from_str::<AnyNotification>(json)
1790            .expect("message with string id should be parsed");
1791        let expected_id = RequestId::Int(2);
1792        assert_eq!(notification.id, Some(expected_id));
1793    }
1794
1795    #[test]
1796    fn test_serialize_has_no_nulls() {
1797        // Ensure we're not setting both result and error variants. (ticket #10595)
1798        let no_tag = Response::<u32> {
1799            jsonrpc: "",
1800            id: RequestId::Int(0),
1801            value: LspResult::Ok(None),
1802        };
1803        assert_eq!(
1804            serde_json::to_string(&no_tag).unwrap(),
1805            "{\"jsonrpc\":\"\",\"id\":0,\"result\":null}"
1806        );
1807        let no_tag = Response::<u32> {
1808            jsonrpc: "",
1809            id: RequestId::Int(0),
1810            value: LspResult::Error(None),
1811        };
1812        assert_eq!(
1813            serde_json::to_string(&no_tag).unwrap(),
1814            "{\"jsonrpc\":\"\",\"id\":0,\"error\":null}"
1815        );
1816    }
1817}