lsp.rs

   1mod input_handler;
   2
   3pub use lsp_types::request::*;
   4pub use lsp_types::*;
   5
   6use anyhow::{Context as _, Result, anyhow};
   7use collections::{BTreeMap, 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::JsonSchema;
  19use serde::{Deserialize, Serialize, de::DeserializeOwned};
  20use serde_json::{Value, json, value::RawValue};
  21use smol::{
  22    channel,
  23    io::{AsyncBufReadExt, AsyncWriteExt, BufReader},
  24    process::Child,
  25};
  26
  27use std::{
  28    collections::BTreeSet,
  29    ffi::{OsStr, OsString},
  30    fmt,
  31    io::Write,
  32    ops::DerefMut,
  33    path::PathBuf,
  34    pin::Pin,
  35    sync::{
  36        Arc, Weak,
  37        atomic::{AtomicI32, Ordering::SeqCst},
  38    },
  39    task::Poll,
  40    time::{Duration, Instant},
  41};
  42use std::{path::Path, process::Stdio};
  43use util::{ConnectionResult, ResultExt, TryFutureExt, redact};
  44
  45const JSON_RPC_VERSION: &str = "2.0";
  46const CONTENT_LEN_HEADER: &str = "Content-Length: ";
  47
  48const LSP_REQUEST_TIMEOUT: Duration = Duration::from_secs(60 * 2);
  49const SERVER_SHUTDOWN_TIMEOUT: Duration = Duration::from_secs(5);
  50
  51type NotificationHandler = Box<dyn Send + FnMut(Option<RequestId>, Value, &mut AsyncApp)>;
  52type ResponseHandler = Box<dyn Send + FnOnce(Result<String, Error>)>;
  53type IoHandler = Box<dyn Send + FnMut(IoKind, &str)>;
  54
  55/// Kind of language server stdio given to an IO handler.
  56#[derive(Debug, Clone, Copy)]
  57pub enum IoKind {
  58    StdOut,
  59    StdIn,
  60    StdErr,
  61}
  62
  63/// Represents a launchable language server. This can either be a standalone binary or the path
  64/// to a runtime with arguments to instruct it to launch the actual language server file.
  65#[derive(Clone, Deserialize)]
  66pub struct LanguageServerBinary {
  67    pub path: PathBuf,
  68    pub arguments: Vec<OsString>,
  69    pub env: Option<HashMap<String, String>>,
  70}
  71
  72/// Configures the search (and installation) of language servers.
  73#[derive(Debug, Clone, Deserialize)]
  74pub struct LanguageServerBinaryOptions {
  75    /// Whether the adapter should look at the users system
  76    pub allow_path_lookup: bool,
  77    /// Whether the adapter should download its own version
  78    pub allow_binary_download: bool,
  79}
  80
  81/// A running language server process.
  82pub struct LanguageServer {
  83    server_id: LanguageServerId,
  84    next_id: AtomicI32,
  85    outbound_tx: channel::Sender<String>,
  86    name: LanguageServerName,
  87    process_name: Arc<str>,
  88    binary: LanguageServerBinary,
  89    capabilities: RwLock<ServerCapabilities>,
  90    /// Configuration sent to the server, stored for display in the language server logs
  91    /// buffer. This is represented as the message sent to the LSP in order to avoid cloning it (can
  92    /// be large in cases like sending schemas to the json server).
  93    configuration: Arc<DidChangeConfigurationParams>,
  94    code_action_kinds: Option<Vec<CodeActionKind>>,
  95    notification_handlers: Arc<Mutex<HashMap<&'static str, NotificationHandler>>>,
  96    response_handlers: Arc<Mutex<Option<HashMap<RequestId, ResponseHandler>>>>,
  97    io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
  98    executor: BackgroundExecutor,
  99    #[allow(clippy::type_complexity)]
 100    io_tasks: Mutex<Option<(Task<Option<()>>, Task<Option<()>>)>>,
 101    output_done_rx: Mutex<Option<barrier::Receiver>>,
 102    server: Arc<Mutex<Option<Child>>>,
 103    workspace_folders: Option<Arc<Mutex<BTreeSet<Url>>>>,
 104    root_uri: Url,
 105}
 106
 107#[derive(Clone, Debug, PartialEq, Eq, Hash)]
 108pub enum LanguageServerSelector {
 109    Id(LanguageServerId),
 110    Name(LanguageServerName),
 111}
 112
 113/// Identifies a running language server.
 114#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
 115#[repr(transparent)]
 116pub struct LanguageServerId(pub usize);
 117
 118impl LanguageServerId {
 119    pub fn from_proto(id: u64) -> Self {
 120        Self(id as usize)
 121    }
 122
 123    pub fn to_proto(self) -> u64 {
 124        self.0 as u64
 125    }
 126}
 127
 128/// A name of a language server.
 129#[derive(
 130    Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Deserialize, Serialize, JsonSchema,
 131)]
 132#[serde(transparent)]
 133pub struct LanguageServerName(pub SharedString);
 134
 135impl std::fmt::Display for LanguageServerName {
 136    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 137        std::fmt::Display::fmt(&self.0, f)
 138    }
 139}
 140
 141impl AsRef<str> for LanguageServerName {
 142    fn as_ref(&self) -> &str {
 143        self.0.as_ref()
 144    }
 145}
 146
 147impl AsRef<OsStr> for LanguageServerName {
 148    fn as_ref(&self) -> &OsStr {
 149        self.0.as_ref().as_ref()
 150    }
 151}
 152
 153impl LanguageServerName {
 154    pub const fn new_static(s: &'static str) -> Self {
 155        Self(SharedString::new_static(s))
 156    }
 157
 158    pub fn from_proto(s: String) -> Self {
 159        Self(s.into())
 160    }
 161}
 162
 163impl<'a> From<&'a str> for LanguageServerName {
 164    fn from(str: &'a str) -> LanguageServerName {
 165        LanguageServerName(str.to_string().into())
 166    }
 167}
 168
 169/// Handle to a language server RPC activity subscription.
 170pub enum Subscription {
 171    Notification {
 172        method: &'static str,
 173        notification_handlers: Option<Arc<Mutex<HashMap<&'static str, NotificationHandler>>>>,
 174    },
 175    Io {
 176        id: i32,
 177        io_handlers: Option<Weak<Mutex<HashMap<i32, IoHandler>>>>,
 178    },
 179}
 180
 181/// Language server protocol RPC request message ID.
 182///
 183/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
 184#[derive(Debug, Clone, Eq, PartialEq, Hash, Serialize, Deserialize)]
 185#[serde(untagged)]
 186pub enum RequestId {
 187    Int(i32),
 188    Str(String),
 189}
 190
 191/// Language server protocol RPC request message.
 192///
 193/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
 194#[derive(Serialize, Deserialize)]
 195pub struct Request<'a, T> {
 196    jsonrpc: &'static str,
 197    id: RequestId,
 198    method: &'a str,
 199    params: T,
 200}
 201
 202/// Language server protocol RPC request response message before it is deserialized into a concrete type.
 203#[derive(Serialize, Deserialize)]
 204struct AnyResponse<'a> {
 205    jsonrpc: &'a str,
 206    id: RequestId,
 207    #[serde(default)]
 208    error: Option<Error>,
 209    #[serde(borrow)]
 210    result: Option<&'a RawValue>,
 211}
 212
 213/// Language server protocol RPC request response message.
 214///
 215/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#responseMessage)
 216#[derive(Serialize)]
 217struct Response<T> {
 218    jsonrpc: &'static str,
 219    id: RequestId,
 220    #[serde(flatten)]
 221    value: LspResult<T>,
 222}
 223
 224#[derive(Serialize)]
 225#[serde(rename_all = "snake_case")]
 226enum LspResult<T> {
 227    #[serde(rename = "result")]
 228    Ok(Option<T>),
 229    Error(Option<Error>),
 230}
 231
 232/// Language server protocol RPC notification message.
 233///
 234/// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
 235#[derive(Serialize, Deserialize)]
 236struct Notification<'a, T> {
 237    jsonrpc: &'static str,
 238    #[serde(borrow)]
 239    method: &'a str,
 240    params: T,
 241}
 242
 243/// Language server RPC notification message before it is deserialized into a concrete type.
 244#[derive(Debug, Clone, Deserialize)]
 245struct NotificationOrRequest {
 246    #[serde(default)]
 247    id: Option<RequestId>,
 248    method: String,
 249    #[serde(default)]
 250    params: Option<Value>,
 251}
 252
 253#[derive(Debug, Serialize, Deserialize)]
 254struct Error {
 255    code: i64,
 256    message: String,
 257    #[serde(default)]
 258    data: Option<serde_json::Value>,
 259}
 260
 261pub trait LspRequestFuture<O>: Future<Output = ConnectionResult<O>> {
 262    fn id(&self) -> i32;
 263}
 264
 265struct LspRequest<F> {
 266    id: i32,
 267    request: F,
 268}
 269
 270impl<F> LspRequest<F> {
 271    pub fn new(id: i32, request: F) -> Self {
 272        Self { id, request }
 273    }
 274}
 275
 276impl<F: Future> Future for LspRequest<F> {
 277    type Output = F::Output;
 278
 279    fn poll(self: Pin<&mut Self>, cx: &mut std::task::Context<'_>) -> Poll<Self::Output> {
 280        // SAFETY: This is standard pin projection, we're pinned so our fields must be pinned.
 281        let inner = unsafe { Pin::new_unchecked(&mut self.get_unchecked_mut().request) };
 282        inner.poll(cx)
 283    }
 284}
 285
 286impl<F, O> LspRequestFuture<O> for LspRequest<F>
 287where
 288    F: Future<Output = ConnectionResult<O>>,
 289{
 290    fn id(&self) -> i32 {
 291        self.id
 292    }
 293}
 294
 295/// Combined capabilities of the server and the adapter.
 296#[derive(Debug)]
 297pub struct AdapterServerCapabilities {
 298    // Reported capabilities by the server
 299    pub server_capabilities: ServerCapabilities,
 300    // List of code actions supported by the LspAdapter matching the server
 301    pub code_action_kinds: Option<Vec<CodeActionKind>>,
 302}
 303
 304impl LanguageServer {
 305    /// Starts a language server process.
 306    pub fn new(
 307        stderr_capture: Arc<Mutex<Option<String>>>,
 308        server_id: LanguageServerId,
 309        server_name: LanguageServerName,
 310        binary: LanguageServerBinary,
 311        root_path: &Path,
 312        code_action_kinds: Option<Vec<CodeActionKind>>,
 313        workspace_folders: Option<Arc<Mutex<BTreeSet<Url>>>>,
 314        cx: &mut AsyncApp,
 315    ) -> Result<Self> {
 316        let working_dir = if root_path.is_dir() {
 317            root_path
 318        } else {
 319            root_path.parent().unwrap_or_else(|| Path::new("/"))
 320        };
 321
 322        log::info!(
 323            "starting language server process. binary path: {:?}, working directory: {:?}, args: {:?}",
 324            binary.path,
 325            working_dir,
 326            &binary.arguments
 327        );
 328
 329        let mut server = util::command::new_smol_command(&binary.path)
 330            .current_dir(working_dir)
 331            .args(&binary.arguments)
 332            .envs(binary.env.clone().unwrap_or_default())
 333            .stdin(Stdio::piped())
 334            .stdout(Stdio::piped())
 335            .stderr(Stdio::piped())
 336            .kill_on_drop(true)
 337            .spawn()
 338            .with_context(|| {
 339                format!(
 340                    "failed to spawn command. path: {:?}, working directory: {:?}, args: {:?}",
 341                    binary.path, working_dir, &binary.arguments
 342                )
 343            })?;
 344
 345        let stdin = server.stdin.take().unwrap();
 346        let stdout = server.stdout.take().unwrap();
 347        let stderr = server.stderr.take().unwrap();
 348        let root_uri = Url::from_file_path(&working_dir)
 349            .map_err(|()| anyhow!("{working_dir:?} is not a valid URI"))?;
 350        let server = Self::new_internal(
 351            server_id,
 352            server_name,
 353            stdin,
 354            stdout,
 355            Some(stderr),
 356            stderr_capture,
 357            Some(server),
 358            code_action_kinds,
 359            binary,
 360            root_uri,
 361            workspace_folders,
 362            cx,
 363            move |notification| {
 364                log::info!(
 365                    "Language server with id {} sent unhandled notification {}:\n{}",
 366                    server_id,
 367                    notification.method,
 368                    serde_json::to_string_pretty(&notification.params).unwrap(),
 369                );
 370                false
 371            },
 372        );
 373
 374        Ok(server)
 375    }
 376
 377    fn new_internal<Stdin, Stdout, Stderr, F>(
 378        server_id: LanguageServerId,
 379        server_name: LanguageServerName,
 380        stdin: Stdin,
 381        stdout: Stdout,
 382        stderr: Option<Stderr>,
 383        stderr_capture: Arc<Mutex<Option<String>>>,
 384        server: Option<Child>,
 385        code_action_kinds: Option<Vec<CodeActionKind>>,
 386        binary: LanguageServerBinary,
 387        root_uri: Url,
 388        workspace_folders: Option<Arc<Mutex<BTreeSet<Url>>>>,
 389        cx: &mut AsyncApp,
 390        on_unhandled_notification: F,
 391    ) -> Self
 392    where
 393        Stdin: AsyncWrite + Unpin + Send + 'static,
 394        Stdout: AsyncRead + Unpin + Send + 'static,
 395        Stderr: AsyncRead + Unpin + Send + 'static,
 396        F: Fn(&NotificationOrRequest) -> bool + 'static + Send + Sync + Clone,
 397    {
 398        let (outbound_tx, outbound_rx) = channel::unbounded::<String>();
 399        let (output_done_tx, output_done_rx) = barrier::channel();
 400        let notification_handlers =
 401            Arc::new(Mutex::new(HashMap::<_, NotificationHandler>::default()));
 402        let response_handlers =
 403            Arc::new(Mutex::new(Some(HashMap::<_, ResponseHandler>::default())));
 404        let io_handlers = Arc::new(Mutex::new(HashMap::default()));
 405
 406        let stdout_input_task = cx.spawn({
 407            let unhandled_notification_wrapper = {
 408                let response_channel = outbound_tx.clone();
 409                async move |msg: NotificationOrRequest| {
 410                    let did_handle = on_unhandled_notification(&msg);
 411                    if !did_handle && let Some(message_id) = msg.id {
 412                        let response = AnyResponse {
 413                            jsonrpc: JSON_RPC_VERSION,
 414                            id: message_id,
 415                            error: Some(Error {
 416                                code: -32601,
 417                                message: format!("Unrecognized method `{}`", msg.method),
 418                                data: None,
 419                            }),
 420                            result: None,
 421                        };
 422                        if let Ok(response) = serde_json::to_string(&response) {
 423                            response_channel.send(response).await.ok();
 424                        }
 425                    }
 426                }
 427            };
 428            let notification_handlers = notification_handlers.clone();
 429            let response_handlers = response_handlers.clone();
 430            let io_handlers = io_handlers.clone();
 431            async move |cx| {
 432                Self::handle_incoming_messages(
 433                    stdout,
 434                    unhandled_notification_wrapper,
 435                    notification_handlers,
 436                    response_handlers,
 437                    io_handlers,
 438                    cx,
 439                )
 440                .log_err()
 441                .await
 442            }
 443        });
 444        let stderr_input_task = stderr
 445            .map(|stderr| {
 446                let io_handlers = io_handlers.clone();
 447                let stderr_captures = stderr_capture.clone();
 448                cx.background_spawn(async move {
 449                    Self::handle_stderr(stderr, io_handlers, stderr_captures)
 450                        .log_err()
 451                        .await
 452                })
 453            })
 454            .unwrap_or_else(|| Task::ready(None));
 455        let input_task = cx.background_spawn(async move {
 456            let (stdout, stderr) = futures::join!(stdout_input_task, stderr_input_task);
 457            stdout.or(stderr)
 458        });
 459        let output_task = cx.background_spawn({
 460            Self::handle_outgoing_messages(
 461                stdin,
 462                outbound_rx,
 463                output_done_tx,
 464                response_handlers.clone(),
 465                io_handlers.clone(),
 466            )
 467            .log_err()
 468        });
 469
 470        let configuration = DidChangeConfigurationParams {
 471            settings: Value::Null,
 472        }
 473        .into();
 474
 475        Self {
 476            server_id,
 477            notification_handlers,
 478            response_handlers,
 479            io_handlers,
 480            name: server_name,
 481            process_name: binary
 482                .path
 483                .file_name()
 484                .map(|name| Arc::from(name.to_string_lossy()))
 485                .unwrap_or_default(),
 486            binary,
 487            capabilities: Default::default(),
 488            configuration,
 489            code_action_kinds,
 490            next_id: Default::default(),
 491            outbound_tx,
 492            executor: cx.background_executor().clone(),
 493            io_tasks: Mutex::new(Some((input_task, output_task))),
 494            output_done_rx: Mutex::new(Some(output_done_rx)),
 495            server: Arc::new(Mutex::new(server)),
 496            workspace_folders,
 497            root_uri,
 498        }
 499    }
 500
 501    /// List of code action kinds this language server reports being able to emit.
 502    pub fn code_action_kinds(&self) -> Option<Vec<CodeActionKind>> {
 503        self.code_action_kinds.clone()
 504    }
 505
 506    async fn handle_incoming_messages<Stdout>(
 507        stdout: Stdout,
 508        on_unhandled_notification: impl AsyncFn(NotificationOrRequest) + 'static + Send,
 509        notification_handlers: Arc<Mutex<HashMap<&'static str, NotificationHandler>>>,
 510        response_handlers: Arc<Mutex<Option<HashMap<RequestId, ResponseHandler>>>>,
 511        io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
 512        cx: &mut AsyncApp,
 513    ) -> anyhow::Result<()>
 514    where
 515        Stdout: AsyncRead + Unpin + Send + 'static,
 516    {
 517        use smol::stream::StreamExt;
 518        let stdout = BufReader::new(stdout);
 519        let _clear_response_handlers = util::defer({
 520            let response_handlers = response_handlers.clone();
 521            move || {
 522                response_handlers.lock().take();
 523            }
 524        });
 525        let mut input_handler = input_handler::LspStdoutHandler::new(
 526            stdout,
 527            response_handlers,
 528            io_handlers,
 529            cx.background_executor().clone(),
 530        );
 531
 532        while let Some(msg) = input_handler.incoming_messages.next().await {
 533            let unhandled_message = {
 534                let mut notification_handlers = notification_handlers.lock();
 535                if let Some(handler) = notification_handlers.get_mut(msg.method.as_str()) {
 536                    handler(msg.id, msg.params.unwrap_or(Value::Null), cx);
 537                    None
 538                } else {
 539                    Some(msg)
 540                }
 541            };
 542
 543            if let Some(msg) = unhandled_message {
 544                on_unhandled_notification(msg).await;
 545            }
 546
 547            // Don't starve the main thread when receiving lots of notifications at once.
 548            smol::future::yield_now().await;
 549        }
 550        input_handler.loop_handle.await
 551    }
 552
 553    async fn handle_stderr<Stderr>(
 554        stderr: Stderr,
 555        io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
 556        stderr_capture: Arc<Mutex<Option<String>>>,
 557    ) -> anyhow::Result<()>
 558    where
 559        Stderr: AsyncRead + Unpin + Send + 'static,
 560    {
 561        let mut stderr = BufReader::new(stderr);
 562        let mut buffer = Vec::new();
 563
 564        loop {
 565            buffer.clear();
 566
 567            let bytes_read = stderr.read_until(b'\n', &mut buffer).await?;
 568            if bytes_read == 0 {
 569                return Ok(());
 570            }
 571
 572            if let Ok(message) = std::str::from_utf8(&buffer) {
 573                log::trace!("incoming stderr message:{message}");
 574                for handler in io_handlers.lock().values_mut() {
 575                    handler(IoKind::StdErr, message);
 576                }
 577
 578                if let Some(stderr) = stderr_capture.lock().as_mut() {
 579                    stderr.push_str(message);
 580                }
 581            }
 582
 583            // Don't starve the main thread when receiving lots of messages at once.
 584            smol::future::yield_now().await;
 585        }
 586    }
 587
 588    async fn handle_outgoing_messages<Stdin>(
 589        stdin: Stdin,
 590        outbound_rx: channel::Receiver<String>,
 591        output_done_tx: barrier::Sender,
 592        response_handlers: Arc<Mutex<Option<HashMap<RequestId, ResponseHandler>>>>,
 593        io_handlers: Arc<Mutex<HashMap<i32, IoHandler>>>,
 594    ) -> anyhow::Result<()>
 595    where
 596        Stdin: AsyncWrite + Unpin + Send + 'static,
 597    {
 598        let mut stdin = BufWriter::new(stdin);
 599        let _clear_response_handlers = util::defer({
 600            let response_handlers = response_handlers.clone();
 601            move || {
 602                response_handlers.lock().take();
 603            }
 604        });
 605        let mut content_len_buffer = Vec::new();
 606        while let Ok(message) = outbound_rx.recv().await {
 607            log::trace!("outgoing message:{}", message);
 608            for handler in io_handlers.lock().values_mut() {
 609                handler(IoKind::StdIn, &message);
 610            }
 611
 612            content_len_buffer.clear();
 613            write!(content_len_buffer, "{}", message.len()).unwrap();
 614            stdin.write_all(CONTENT_LEN_HEADER.as_bytes()).await?;
 615            stdin.write_all(&content_len_buffer).await?;
 616            stdin.write_all("\r\n\r\n".as_bytes()).await?;
 617            stdin.write_all(message.as_bytes()).await?;
 618            stdin.flush().await?;
 619        }
 620        drop(output_done_tx);
 621        Ok(())
 622    }
 623
 624    pub fn default_initialize_params(&self, pull_diagnostics: bool, cx: &App) -> InitializeParams {
 625        let workspace_folders = self.workspace_folders.as_ref().map_or_else(
 626            || {
 627                vec![WorkspaceFolder {
 628                    name: Default::default(),
 629                    uri: self.root_uri.clone(),
 630                }]
 631            },
 632            |folders| {
 633                folders
 634                    .lock()
 635                    .iter()
 636                    .cloned()
 637                    .map(|uri| WorkspaceFolder {
 638                        name: Default::default(),
 639                        uri,
 640                    })
 641                    .collect()
 642            },
 643        );
 644
 645        #[allow(deprecated)]
 646        InitializeParams {
 647            process_id: None,
 648            root_path: None,
 649            root_uri: Some(self.root_uri.clone()),
 650            initialization_options: None,
 651            capabilities: ClientCapabilities {
 652                general: Some(GeneralClientCapabilities {
 653                    position_encodings: Some(vec![PositionEncodingKind::UTF16]),
 654                    ..Default::default()
 655                }),
 656                workspace: Some(WorkspaceClientCapabilities {
 657                    configuration: Some(true),
 658                    did_change_watched_files: Some(DidChangeWatchedFilesClientCapabilities {
 659                        dynamic_registration: Some(true),
 660                        relative_pattern_support: Some(true),
 661                    }),
 662                    did_change_configuration: Some(DynamicRegistrationClientCapabilities {
 663                        dynamic_registration: Some(true),
 664                    }),
 665                    workspace_folders: Some(true),
 666                    symbol: Some(WorkspaceSymbolClientCapabilities {
 667                        resolve_support: None,
 668                        ..WorkspaceSymbolClientCapabilities::default()
 669                    }),
 670                    inlay_hint: Some(InlayHintWorkspaceClientCapabilities {
 671                        refresh_support: Some(true),
 672                    }),
 673                    diagnostics: Some(DiagnosticWorkspaceClientCapabilities {
 674                        refresh_support: Some(true),
 675                    })
 676                    .filter(|_| pull_diagnostics),
 677                    code_lens: Some(CodeLensWorkspaceClientCapabilities {
 678                        refresh_support: Some(true),
 679                    }),
 680                    workspace_edit: Some(WorkspaceEditClientCapabilities {
 681                        resource_operations: Some(vec![
 682                            ResourceOperationKind::Create,
 683                            ResourceOperationKind::Rename,
 684                            ResourceOperationKind::Delete,
 685                        ]),
 686                        document_changes: Some(true),
 687                        snippet_edit_support: Some(true),
 688                        ..WorkspaceEditClientCapabilities::default()
 689                    }),
 690                    file_operations: Some(WorkspaceFileOperationsClientCapabilities {
 691                        dynamic_registration: Some(false),
 692                        did_rename: Some(true),
 693                        will_rename: Some(true),
 694                        ..Default::default()
 695                    }),
 696                    apply_edit: Some(true),
 697                    execute_command: Some(ExecuteCommandClientCapabilities {
 698                        dynamic_registration: Some(false),
 699                    }),
 700                    ..Default::default()
 701                }),
 702                text_document: Some(TextDocumentClientCapabilities {
 703                    definition: Some(GotoCapability {
 704                        link_support: Some(true),
 705                        dynamic_registration: None,
 706                    }),
 707                    code_action: Some(CodeActionClientCapabilities {
 708                        code_action_literal_support: Some(CodeActionLiteralSupport {
 709                            code_action_kind: CodeActionKindLiteralSupport {
 710                                value_set: vec![
 711                                    CodeActionKind::REFACTOR.as_str().into(),
 712                                    CodeActionKind::QUICKFIX.as_str().into(),
 713                                    CodeActionKind::SOURCE.as_str().into(),
 714                                ],
 715                            },
 716                        }),
 717                        data_support: Some(true),
 718                        resolve_support: Some(CodeActionCapabilityResolveSupport {
 719                            properties: vec![
 720                                "kind".to_string(),
 721                                "diagnostics".to_string(),
 722                                "isPreferred".to_string(),
 723                                "disabled".to_string(),
 724                                "edit".to_string(),
 725                                "command".to_string(),
 726                            ],
 727                        }),
 728                        ..Default::default()
 729                    }),
 730                    completion: Some(CompletionClientCapabilities {
 731                        completion_item: Some(CompletionItemCapability {
 732                            snippet_support: Some(true),
 733                            resolve_support: Some(CompletionItemCapabilityResolveSupport {
 734                                properties: vec![
 735                                    "additionalTextEdits".to_string(),
 736                                    "command".to_string(),
 737                                    "documentation".to_string(),
 738                                    // NB: Do not have this resolved, otherwise Zed becomes slow to complete things
 739                                    // "textEdit".to_string(),
 740                                ],
 741                            }),
 742                            insert_replace_support: Some(true),
 743                            label_details_support: Some(true),
 744                            insert_text_mode_support: Some(InsertTextModeSupport {
 745                                value_set: vec![
 746                                    InsertTextMode::AS_IS,
 747                                    InsertTextMode::ADJUST_INDENTATION,
 748                                ],
 749                            }),
 750                            ..Default::default()
 751                        }),
 752                        insert_text_mode: Some(InsertTextMode::ADJUST_INDENTATION),
 753                        completion_list: Some(CompletionListCapability {
 754                            item_defaults: Some(vec![
 755                                "commitCharacters".to_owned(),
 756                                "editRange".to_owned(),
 757                                "insertTextMode".to_owned(),
 758                                "insertTextFormat".to_owned(),
 759                                "data".to_owned(),
 760                            ]),
 761                        }),
 762                        context_support: Some(true),
 763                        ..Default::default()
 764                    }),
 765                    rename: Some(RenameClientCapabilities {
 766                        prepare_support: Some(true),
 767                        prepare_support_default_behavior: Some(
 768                            PrepareSupportDefaultBehavior::IDENTIFIER,
 769                        ),
 770                        ..Default::default()
 771                    }),
 772                    hover: Some(HoverClientCapabilities {
 773                        content_format: Some(vec![MarkupKind::Markdown]),
 774                        dynamic_registration: None,
 775                    }),
 776                    inlay_hint: Some(InlayHintClientCapabilities {
 777                        resolve_support: Some(InlayHintResolveClientCapabilities {
 778                            properties: vec![
 779                                "textEdits".to_string(),
 780                                "tooltip".to_string(),
 781                                "label.tooltip".to_string(),
 782                                "label.location".to_string(),
 783                                "label.command".to_string(),
 784                            ],
 785                        }),
 786                        dynamic_registration: Some(false),
 787                    }),
 788                    publish_diagnostics: Some(PublishDiagnosticsClientCapabilities {
 789                        related_information: Some(true),
 790                        version_support: Some(true),
 791                        data_support: Some(true),
 792                        tag_support: Some(TagSupport {
 793                            value_set: vec![DiagnosticTag::UNNECESSARY, DiagnosticTag::DEPRECATED],
 794                        }),
 795                        code_description_support: Some(true),
 796                    }),
 797                    formatting: Some(DynamicRegistrationClientCapabilities {
 798                        dynamic_registration: Some(true),
 799                    }),
 800                    range_formatting: Some(DynamicRegistrationClientCapabilities {
 801                        dynamic_registration: Some(true),
 802                    }),
 803                    on_type_formatting: Some(DynamicRegistrationClientCapabilities {
 804                        dynamic_registration: Some(true),
 805                    }),
 806                    signature_help: Some(SignatureHelpClientCapabilities {
 807                        signature_information: Some(SignatureInformationSettings {
 808                            documentation_format: Some(vec![
 809                                MarkupKind::Markdown,
 810                                MarkupKind::PlainText,
 811                            ]),
 812                            parameter_information: Some(ParameterInformationSettings {
 813                                label_offset_support: Some(true),
 814                            }),
 815                            active_parameter_support: Some(true),
 816                        }),
 817                        ..SignatureHelpClientCapabilities::default()
 818                    }),
 819                    synchronization: Some(TextDocumentSyncClientCapabilities {
 820                        did_save: Some(true),
 821                        ..TextDocumentSyncClientCapabilities::default()
 822                    }),
 823                    code_lens: Some(CodeLensClientCapabilities {
 824                        dynamic_registration: Some(false),
 825                    }),
 826                    document_symbol: Some(DocumentSymbolClientCapabilities {
 827                        hierarchical_document_symbol_support: Some(true),
 828                        ..DocumentSymbolClientCapabilities::default()
 829                    }),
 830                    diagnostic: Some(DiagnosticClientCapabilities {
 831                        dynamic_registration: Some(false),
 832                        related_document_support: Some(true),
 833                    })
 834                    .filter(|_| pull_diagnostics),
 835                    color_provider: Some(DocumentColorClientCapabilities {
 836                        dynamic_registration: Some(false),
 837                    }),
 838                    ..TextDocumentClientCapabilities::default()
 839                }),
 840                experimental: Some(json!({
 841                    "serverStatusNotification": true,
 842                    "localDocs": true,
 843                })),
 844                window: Some(WindowClientCapabilities {
 845                    work_done_progress: Some(true),
 846                    show_message: Some(ShowMessageRequestClientCapabilities {
 847                        message_action_item: None,
 848                    }),
 849                    ..Default::default()
 850                }),
 851            },
 852            trace: None,
 853            workspace_folders: Some(workspace_folders),
 854            client_info: release_channel::ReleaseChannel::try_global(cx).map(|release_channel| {
 855                ClientInfo {
 856                    name: release_channel.display_name().to_string(),
 857                    version: Some(release_channel::AppVersion::global(cx).to_string()),
 858                }
 859            }),
 860            locale: None,
 861
 862            ..Default::default()
 863        }
 864    }
 865
 866    /// Initializes a language server by sending the `Initialize` request.
 867    /// Note that `options` is used directly to construct [`InitializeParams`], which is why it is owned.
 868    ///
 869    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#initialize)
 870    pub fn initialize(
 871        mut self,
 872        params: InitializeParams,
 873        configuration: Arc<DidChangeConfigurationParams>,
 874        cx: &App,
 875    ) -> Task<Result<Arc<Self>>> {
 876        cx.background_spawn(async move {
 877            let response = self
 878                .request::<request::Initialize>(params)
 879                .await
 880                .into_response()
 881                .with_context(|| {
 882                    format!(
 883                        "initializing server {}, id {}",
 884                        self.name(),
 885                        self.server_id()
 886                    )
 887                })?;
 888            if let Some(info) = response.server_info {
 889                self.process_name = info.name.into();
 890            }
 891            self.capabilities = RwLock::new(response.capabilities);
 892            self.configuration = configuration;
 893
 894            self.notify::<notification::Initialized>(&InitializedParams {})?;
 895            Ok(Arc::new(self))
 896        })
 897    }
 898
 899    /// Sends a shutdown request to the language server process and prepares the [`LanguageServer`] to be dropped.
 900    pub fn shutdown(&self) -> Option<impl 'static + Send + Future<Output = Option<()>> + use<>> {
 901        if let Some(tasks) = self.io_tasks.lock().take() {
 902            let response_handlers = self.response_handlers.clone();
 903            let next_id = AtomicI32::new(self.next_id.load(SeqCst));
 904            let outbound_tx = self.outbound_tx.clone();
 905            let executor = self.executor.clone();
 906            let mut output_done = self.output_done_rx.lock().take().unwrap();
 907            let shutdown_request = Self::request_internal::<request::Shutdown>(
 908                &next_id,
 909                &response_handlers,
 910                &outbound_tx,
 911                &executor,
 912                (),
 913            );
 914
 915            let server = self.server.clone();
 916            let name = self.name.clone();
 917            let server_id = self.server_id;
 918            let mut timer = self.executor.timer(SERVER_SHUTDOWN_TIMEOUT).fuse();
 919            Some(async move {
 920                log::debug!("language server shutdown started");
 921
 922                select! {
 923                    request_result = shutdown_request.fuse() => {
 924                        match request_result {
 925                            ConnectionResult::Timeout => {
 926                                log::warn!("timeout waiting for language server {name} (id {server_id}) to shutdown");
 927                            },
 928                            ConnectionResult::ConnectionReset => {
 929                                log::warn!("language server {name} (id {server_id}) closed the shutdown request connection");
 930                            },
 931                            ConnectionResult::Result(Err(e)) => {
 932                                log::error!("Shutdown request failure, server {name} (id {server_id}): {e:#}");
 933                            },
 934                            ConnectionResult::Result(Ok(())) => {}
 935                        }
 936                    }
 937
 938                    _ = timer => {
 939                        log::info!("timeout waiting for language server {name} (id {server_id}) to shutdown");
 940                    },
 941                }
 942
 943                response_handlers.lock().take();
 944                Self::notify_internal::<notification::Exit>(&outbound_tx, &()).ok();
 945                outbound_tx.close();
 946                output_done.recv().await;
 947                server.lock().take().map(|mut child| child.kill());
 948                drop(tasks);
 949                log::debug!("language server shutdown finished");
 950                Some(())
 951            })
 952        } else {
 953            None
 954        }
 955    }
 956
 957    /// Register a handler to handle incoming LSP notifications.
 958    ///
 959    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
 960    #[must_use]
 961    pub fn on_notification<T, F>(&self, f: F) -> Subscription
 962    where
 963        T: notification::Notification,
 964        F: 'static + Send + FnMut(T::Params, &mut AsyncApp),
 965    {
 966        self.on_custom_notification(T::METHOD, f)
 967    }
 968
 969    /// Register a handler to handle incoming LSP requests.
 970    ///
 971    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
 972    #[must_use]
 973    pub fn on_request<T, F, Fut>(&self, f: F) -> Subscription
 974    where
 975        T: request::Request,
 976        T::Params: 'static + Send,
 977        F: 'static + FnMut(T::Params, &mut AsyncApp) -> Fut + Send,
 978        Fut: 'static + Future<Output = Result<T::Result>>,
 979    {
 980        self.on_custom_request(T::METHOD, f)
 981    }
 982
 983    /// Registers a handler to inspect all language server process stdio.
 984    #[must_use]
 985    pub fn on_io<F>(&self, f: F) -> Subscription
 986    where
 987        F: 'static + Send + FnMut(IoKind, &str),
 988    {
 989        let id = self.next_id.fetch_add(1, SeqCst);
 990        self.io_handlers.lock().insert(id, Box::new(f));
 991        Subscription::Io {
 992            id,
 993            io_handlers: Some(Arc::downgrade(&self.io_handlers)),
 994        }
 995    }
 996
 997    /// Removes a request handler registers via [`Self::on_request`].
 998    pub fn remove_request_handler<T: request::Request>(&self) {
 999        self.notification_handlers.lock().remove(T::METHOD);
1000    }
1001
1002    /// Removes a notification handler registers via [`Self::on_notification`].
1003    pub fn remove_notification_handler<T: notification::Notification>(&self) {
1004        self.notification_handlers.lock().remove(T::METHOD);
1005    }
1006
1007    /// Checks if a notification handler has been registered via [`Self::on_notification`].
1008    pub fn has_notification_handler<T: notification::Notification>(&self) -> bool {
1009        self.notification_handlers.lock().contains_key(T::METHOD)
1010    }
1011
1012    #[must_use]
1013    fn on_custom_notification<Params, F>(&self, method: &'static str, mut f: F) -> Subscription
1014    where
1015        F: 'static + FnMut(Params, &mut AsyncApp) + Send,
1016        Params: DeserializeOwned,
1017    {
1018        let prev_handler = self.notification_handlers.lock().insert(
1019            method,
1020            Box::new(move |_, params, cx| {
1021                if let Some(params) = serde_json::from_value(params).log_err() {
1022                    f(params, cx);
1023                }
1024            }),
1025        );
1026        assert!(
1027            prev_handler.is_none(),
1028            "registered multiple handlers for the same LSP method"
1029        );
1030        Subscription::Notification {
1031            method,
1032            notification_handlers: Some(self.notification_handlers.clone()),
1033        }
1034    }
1035
1036    #[must_use]
1037    fn on_custom_request<Params, Res, Fut, F>(&self, method: &'static str, mut f: F) -> Subscription
1038    where
1039        F: 'static + FnMut(Params, &mut AsyncApp) -> Fut + Send,
1040        Fut: 'static + Future<Output = Result<Res>>,
1041        Params: DeserializeOwned + Send + 'static,
1042        Res: Serialize,
1043    {
1044        let outbound_tx = self.outbound_tx.clone();
1045        let prev_handler = self.notification_handlers.lock().insert(
1046            method,
1047            Box::new(move |id, params, cx| {
1048                if let Some(id) = id {
1049                    match serde_json::from_value(params) {
1050                        Ok(params) => {
1051                            let response = f(params, cx);
1052                            cx.foreground_executor()
1053                                .spawn({
1054                                    let outbound_tx = outbound_tx.clone();
1055                                    async move {
1056                                        let response = match response.await {
1057                                            Ok(result) => Response {
1058                                                jsonrpc: JSON_RPC_VERSION,
1059                                                id,
1060                                                value: LspResult::Ok(Some(result)),
1061                                            },
1062                                            Err(error) => Response {
1063                                                jsonrpc: JSON_RPC_VERSION,
1064                                                id,
1065                                                value: LspResult::Error(Some(Error {
1066                                                    code: lsp_types::error_codes::REQUEST_FAILED,
1067                                                    message: error.to_string(),
1068                                                    data: None,
1069                                                })),
1070                                            },
1071                                        };
1072                                        if let Some(response) =
1073                                            serde_json::to_string(&response).log_err()
1074                                        {
1075                                            outbound_tx.try_send(response).ok();
1076                                        }
1077                                    }
1078                                })
1079                                .detach();
1080                        }
1081
1082                        Err(error) => {
1083                            log::error!("error deserializing {} request: {:?}", method, error);
1084                            let response = AnyResponse {
1085                                jsonrpc: JSON_RPC_VERSION,
1086                                id,
1087                                result: None,
1088                                error: Some(Error {
1089                                    code: -32700, // Parse error
1090                                    message: error.to_string(),
1091                                    data: None,
1092                                }),
1093                            };
1094                            if let Some(response) = serde_json::to_string(&response).log_err() {
1095                                outbound_tx.try_send(response).ok();
1096                            }
1097                        }
1098                    }
1099                }
1100            }),
1101        );
1102        assert!(
1103            prev_handler.is_none(),
1104            "registered multiple handlers for the same LSP method"
1105        );
1106        Subscription::Notification {
1107            method,
1108            notification_handlers: Some(self.notification_handlers.clone()),
1109        }
1110    }
1111
1112    /// Get the name of the running language server.
1113    pub fn name(&self) -> LanguageServerName {
1114        self.name.clone()
1115    }
1116
1117    pub fn process_name(&self) -> &str {
1118        &self.process_name
1119    }
1120
1121    /// Get the reported capabilities of the running language server.
1122    pub fn capabilities(&self) -> ServerCapabilities {
1123        self.capabilities.read().clone()
1124    }
1125
1126    /// Get the reported capabilities of the running language server and
1127    /// what we know on the client/adapter-side of its capabilities.
1128    pub fn adapter_server_capabilities(&self) -> AdapterServerCapabilities {
1129        AdapterServerCapabilities {
1130            server_capabilities: self.capabilities(),
1131            code_action_kinds: self.code_action_kinds(),
1132        }
1133    }
1134
1135    pub fn update_capabilities(&self, update: impl FnOnce(&mut ServerCapabilities)) {
1136        update(self.capabilities.write().deref_mut());
1137    }
1138
1139    pub fn configuration(&self) -> &Value {
1140        &self.configuration.settings
1141    }
1142
1143    /// Get the id of the running language server.
1144    pub fn server_id(&self) -> LanguageServerId {
1145        self.server_id
1146    }
1147
1148    /// Language server's binary information.
1149    pub fn binary(&self) -> &LanguageServerBinary {
1150        &self.binary
1151    }
1152
1153    /// Sends a RPC request to the language server.
1154    ///
1155    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
1156    pub fn request<T: request::Request>(
1157        &self,
1158        params: T::Params,
1159    ) -> impl LspRequestFuture<T::Result> + use<T>
1160    where
1161        T::Result: 'static + Send,
1162    {
1163        Self::request_internal::<T>(
1164            &self.next_id,
1165            &self.response_handlers,
1166            &self.outbound_tx,
1167            &self.executor,
1168            params,
1169        )
1170    }
1171
1172    /// Sends a RPC request to the language server, with a custom timer, a future which when becoming
1173    /// ready causes the request to be timed out with the future's output message.
1174    ///
1175    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#requestMessage)
1176    pub fn request_with_timer<T: request::Request, U: Future<Output = String>>(
1177        &self,
1178        params: T::Params,
1179        timer: U,
1180    ) -> impl LspRequestFuture<T::Result> + use<T, U>
1181    where
1182        T::Result: 'static + Send,
1183    {
1184        Self::request_internal_with_timer::<T, U>(
1185            &self.next_id,
1186            &self.response_handlers,
1187            &self.outbound_tx,
1188            &self.executor,
1189            timer,
1190            params,
1191        )
1192    }
1193
1194    fn request_internal_with_timer<T, U>(
1195        next_id: &AtomicI32,
1196        response_handlers: &Mutex<Option<HashMap<RequestId, ResponseHandler>>>,
1197        outbound_tx: &channel::Sender<String>,
1198        executor: &BackgroundExecutor,
1199        timer: U,
1200        params: T::Params,
1201    ) -> impl LspRequestFuture<T::Result> + use<T, U>
1202    where
1203        T::Result: 'static + Send,
1204        T: request::Request,
1205        U: Future<Output = String>,
1206    {
1207        let id = next_id.fetch_add(1, SeqCst);
1208        let message = serde_json::to_string(&Request {
1209            jsonrpc: JSON_RPC_VERSION,
1210            id: RequestId::Int(id),
1211            method: T::METHOD,
1212            params,
1213        })
1214        .unwrap();
1215
1216        let (tx, rx) = oneshot::channel();
1217        let handle_response = response_handlers
1218            .lock()
1219            .as_mut()
1220            .context("server shut down")
1221            .map(|handlers| {
1222                let executor = executor.clone();
1223                handlers.insert(
1224                    RequestId::Int(id),
1225                    Box::new(move |result| {
1226                        executor
1227                            .spawn(async move {
1228                                let response = match result {
1229                                    Ok(response) => match serde_json::from_str(&response) {
1230                                        Ok(deserialized) => Ok(deserialized),
1231                                        Err(error) => {
1232                                            log::error!("failed to deserialize response from language server: {}. response from language server: {:?}", error, response);
1233                                            Err(error).context("failed to deserialize response")
1234                                        }
1235                                    }
1236                                    Err(error) => Err(anyhow!("{}", error.message)),
1237                                };
1238                                _ = tx.send(response);
1239                            })
1240                            .detach();
1241                    }),
1242                );
1243            });
1244
1245        let send = outbound_tx
1246            .try_send(message)
1247            .context("failed to write to language server's stdin");
1248
1249        let outbound_tx = outbound_tx.downgrade();
1250        let started = Instant::now();
1251        LspRequest::new(id, async move {
1252            if let Err(e) = handle_response {
1253                return ConnectionResult::Result(Err(e));
1254            }
1255            if let Err(e) = send {
1256                return ConnectionResult::Result(Err(e));
1257            }
1258
1259            let cancel_on_drop = util::defer(move || {
1260                if let Some(outbound_tx) = outbound_tx.upgrade() {
1261                    Self::notify_internal::<notification::Cancel>(
1262                        &outbound_tx,
1263                        &CancelParams {
1264                            id: NumberOrString::Number(id),
1265                        },
1266                    )
1267                    .ok();
1268                }
1269            });
1270
1271            let method = T::METHOD;
1272            select! {
1273                response = rx.fuse() => {
1274                    let elapsed = started.elapsed();
1275                    log::trace!("Took {elapsed:?} to receive response to {method:?} id {id}");
1276                    cancel_on_drop.abort();
1277                    match response {
1278                        Ok(response_result) => ConnectionResult::Result(response_result),
1279                        Err(Canceled) => {
1280                            log::error!("Server reset connection for a request {method:?} id {id}");
1281                            ConnectionResult::ConnectionReset
1282                        },
1283                    }
1284                }
1285
1286                message = timer.fuse() => {
1287                    log::error!("Cancelled LSP request task for {method:?} id {id} {message}");
1288                    ConnectionResult::Timeout
1289                }
1290            }
1291        })
1292    }
1293
1294    fn request_internal<T>(
1295        next_id: &AtomicI32,
1296        response_handlers: &Mutex<Option<HashMap<RequestId, ResponseHandler>>>,
1297        outbound_tx: &channel::Sender<String>,
1298        executor: &BackgroundExecutor,
1299        params: T::Params,
1300    ) -> impl LspRequestFuture<T::Result> + use<T>
1301    where
1302        T::Result: 'static + Send,
1303        T: request::Request,
1304    {
1305        Self::request_internal_with_timer::<T, _>(
1306            next_id,
1307            response_handlers,
1308            outbound_tx,
1309            executor,
1310            Self::default_request_timer(executor.clone()),
1311            params,
1312        )
1313    }
1314
1315    pub fn default_request_timer(executor: BackgroundExecutor) -> impl Future<Output = String> {
1316        executor
1317            .timer(LSP_REQUEST_TIMEOUT)
1318            .map(|_| format!("which took over {LSP_REQUEST_TIMEOUT:?}"))
1319    }
1320
1321    /// Sends a RPC notification to the language server.
1322    ///
1323    /// [LSP Specification](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#notificationMessage)
1324    pub fn notify<T: notification::Notification>(&self, params: &T::Params) -> Result<()> {
1325        Self::notify_internal::<T>(&self.outbound_tx, params)
1326    }
1327
1328    fn notify_internal<T: notification::Notification>(
1329        outbound_tx: &channel::Sender<String>,
1330        params: &T::Params,
1331    ) -> Result<()> {
1332        let message = serde_json::to_string(&Notification {
1333            jsonrpc: JSON_RPC_VERSION,
1334            method: T::METHOD,
1335            params,
1336        })
1337        .unwrap();
1338        outbound_tx.try_send(message)?;
1339        Ok(())
1340    }
1341
1342    /// Add new workspace folder to the list.
1343    pub fn add_workspace_folder(&self, uri: Url) {
1344        if self
1345            .capabilities()
1346            .workspace
1347            .and_then(|ws| {
1348                ws.workspace_folders.and_then(|folders| {
1349                    folders
1350                        .change_notifications
1351                        .map(|caps| matches!(caps, OneOf::Left(false)))
1352                })
1353            })
1354            .unwrap_or(true)
1355        {
1356            return;
1357        }
1358
1359        let Some(workspace_folders) = self.workspace_folders.as_ref() else {
1360            return;
1361        };
1362        let is_new_folder = workspace_folders.lock().insert(uri.clone());
1363        if is_new_folder {
1364            let params = DidChangeWorkspaceFoldersParams {
1365                event: WorkspaceFoldersChangeEvent {
1366                    added: vec![WorkspaceFolder {
1367                        uri,
1368                        name: String::default(),
1369                    }],
1370                    removed: vec![],
1371                },
1372            };
1373            self.notify::<DidChangeWorkspaceFolders>(&params).ok();
1374        }
1375    }
1376    /// Add new workspace folder to the list.
1377    pub fn remove_workspace_folder(&self, uri: Url) {
1378        if self
1379            .capabilities()
1380            .workspace
1381            .and_then(|ws| {
1382                ws.workspace_folders.and_then(|folders| {
1383                    folders
1384                        .change_notifications
1385                        .map(|caps| !matches!(caps, OneOf::Left(false)))
1386                })
1387            })
1388            .unwrap_or(true)
1389        {
1390            return;
1391        }
1392        let Some(workspace_folders) = self.workspace_folders.as_ref() else {
1393            return;
1394        };
1395        let was_removed = workspace_folders.lock().remove(&uri);
1396        if was_removed {
1397            let params = DidChangeWorkspaceFoldersParams {
1398                event: WorkspaceFoldersChangeEvent {
1399                    added: vec![],
1400                    removed: vec![WorkspaceFolder {
1401                        uri,
1402                        name: String::default(),
1403                    }],
1404                },
1405            };
1406            self.notify::<DidChangeWorkspaceFolders>(&params).ok();
1407        }
1408    }
1409    pub fn set_workspace_folders(&self, folders: BTreeSet<Url>) {
1410        let Some(workspace_folders) = self.workspace_folders.as_ref() else {
1411            return;
1412        };
1413        let mut workspace_folders = workspace_folders.lock();
1414
1415        let old_workspace_folders = std::mem::take(&mut *workspace_folders);
1416        let added: Vec<_> = folders
1417            .difference(&old_workspace_folders)
1418            .map(|uri| WorkspaceFolder {
1419                uri: uri.clone(),
1420                name: String::default(),
1421            })
1422            .collect();
1423
1424        let removed: Vec<_> = old_workspace_folders
1425            .difference(&folders)
1426            .map(|uri| WorkspaceFolder {
1427                uri: uri.clone(),
1428                name: String::default(),
1429            })
1430            .collect();
1431        *workspace_folders = folders;
1432        let should_notify = !added.is_empty() || !removed.is_empty();
1433        if should_notify {
1434            drop(workspace_folders);
1435            let params = DidChangeWorkspaceFoldersParams {
1436                event: WorkspaceFoldersChangeEvent { added, removed },
1437            };
1438            self.notify::<DidChangeWorkspaceFolders>(&params).ok();
1439        }
1440    }
1441
1442    pub fn workspace_folders(&self) -> BTreeSet<Url> {
1443        self.workspace_folders.as_ref().map_or_else(
1444            || BTreeSet::from_iter([self.root_uri.clone()]),
1445            |folders| folders.lock().clone(),
1446        )
1447    }
1448
1449    pub fn register_buffer(
1450        &self,
1451        uri: Url,
1452        language_id: String,
1453        version: i32,
1454        initial_text: String,
1455    ) {
1456        self.notify::<notification::DidOpenTextDocument>(&DidOpenTextDocumentParams {
1457            text_document: TextDocumentItem::new(uri, language_id, version, initial_text),
1458        })
1459        .ok();
1460    }
1461
1462    pub fn unregister_buffer(&self, uri: Url) {
1463        self.notify::<notification::DidCloseTextDocument>(&DidCloseTextDocumentParams {
1464            text_document: TextDocumentIdentifier::new(uri),
1465        })
1466        .ok();
1467    }
1468}
1469
1470impl Drop for LanguageServer {
1471    fn drop(&mut self) {
1472        if let Some(shutdown) = self.shutdown() {
1473            self.executor.spawn(shutdown).detach();
1474        }
1475    }
1476}
1477
1478impl Subscription {
1479    /// Detaching a subscription handle prevents it from unsubscribing on drop.
1480    pub fn detach(&mut self) {
1481        match self {
1482            Subscription::Notification {
1483                notification_handlers,
1484                ..
1485            } => *notification_handlers = None,
1486            Subscription::Io { io_handlers, .. } => *io_handlers = None,
1487        }
1488    }
1489}
1490
1491impl fmt::Display for LanguageServerId {
1492    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1493        self.0.fmt(f)
1494    }
1495}
1496
1497impl fmt::Debug for LanguageServer {
1498    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1499        f.debug_struct("LanguageServer")
1500            .field("id", &self.server_id.0)
1501            .field("name", &self.name)
1502            .finish_non_exhaustive()
1503    }
1504}
1505
1506impl fmt::Debug for LanguageServerBinary {
1507    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1508        let mut debug = f.debug_struct("LanguageServerBinary");
1509        debug.field("path", &self.path);
1510        debug.field("arguments", &self.arguments);
1511
1512        if let Some(env) = &self.env {
1513            let redacted_env: BTreeMap<String, String> = env
1514                .iter()
1515                .map(|(key, value)| {
1516                    let redacted_value = if redact::should_redact(key) {
1517                        "REDACTED".to_string()
1518                    } else {
1519                        value.clone()
1520                    };
1521                    (key.clone(), redacted_value)
1522                })
1523                .collect();
1524            debug.field("env", &Some(redacted_env));
1525        } else {
1526            debug.field("env", &self.env);
1527        }
1528
1529        debug.finish()
1530    }
1531}
1532
1533impl Drop for Subscription {
1534    fn drop(&mut self) {
1535        match self {
1536            Subscription::Notification {
1537                method,
1538                notification_handlers,
1539            } => {
1540                if let Some(handlers) = notification_handlers {
1541                    handlers.lock().remove(method);
1542                }
1543            }
1544            Subscription::Io { id, io_handlers } => {
1545                if let Some(io_handlers) = io_handlers.as_ref().and_then(|h| h.upgrade()) {
1546                    io_handlers.lock().remove(id);
1547                }
1548            }
1549        }
1550    }
1551}
1552
1553/// Mock language server for use in tests.
1554#[cfg(any(test, feature = "test-support"))]
1555#[derive(Clone)]
1556pub struct FakeLanguageServer {
1557    pub binary: LanguageServerBinary,
1558    pub server: Arc<LanguageServer>,
1559    notifications_rx: channel::Receiver<(String, String)>,
1560}
1561
1562#[cfg(any(test, feature = "test-support"))]
1563impl FakeLanguageServer {
1564    /// Construct a fake language server.
1565    pub fn new(
1566        server_id: LanguageServerId,
1567        binary: LanguageServerBinary,
1568        name: String,
1569        capabilities: ServerCapabilities,
1570        cx: &mut AsyncApp,
1571    ) -> (LanguageServer, FakeLanguageServer) {
1572        let (stdin_writer, stdin_reader) = async_pipe::pipe();
1573        let (stdout_writer, stdout_reader) = async_pipe::pipe();
1574        let (notifications_tx, notifications_rx) = channel::unbounded();
1575
1576        let server_name = LanguageServerName(name.clone().into());
1577        let process_name = Arc::from(name.as_str());
1578        let root = Self::root_path();
1579        let workspace_folders: Arc<Mutex<BTreeSet<Url>>> = Default::default();
1580        let mut server = LanguageServer::new_internal(
1581            server_id,
1582            server_name.clone(),
1583            stdin_writer,
1584            stdout_reader,
1585            None::<async_pipe::PipeReader>,
1586            Arc::new(Mutex::new(None)),
1587            None,
1588            None,
1589            binary.clone(),
1590            root,
1591            Some(workspace_folders.clone()),
1592            cx,
1593            |_| false,
1594        );
1595        server.process_name = process_name;
1596        let fake = FakeLanguageServer {
1597            binary: binary.clone(),
1598            server: Arc::new({
1599                let mut server = LanguageServer::new_internal(
1600                    server_id,
1601                    server_name,
1602                    stdout_writer,
1603                    stdin_reader,
1604                    None::<async_pipe::PipeReader>,
1605                    Arc::new(Mutex::new(None)),
1606                    None,
1607                    None,
1608                    binary,
1609                    Self::root_path(),
1610                    Some(workspace_folders),
1611                    cx,
1612                    move |msg| {
1613                        notifications_tx
1614                            .try_send((
1615                                msg.method.to_string(),
1616                                msg.params.as_ref().unwrap_or(&Value::Null).to_string(),
1617                            ))
1618                            .ok();
1619                        true
1620                    },
1621                );
1622                server.process_name = name.as_str().into();
1623                server
1624            }),
1625            notifications_rx,
1626        };
1627        fake.set_request_handler::<request::Initialize, _, _>({
1628            let capabilities = capabilities;
1629            move |_, _| {
1630                let capabilities = capabilities.clone();
1631                let name = name.clone();
1632                async move {
1633                    Ok(InitializeResult {
1634                        capabilities,
1635                        server_info: Some(ServerInfo {
1636                            name,
1637                            ..Default::default()
1638                        }),
1639                    })
1640                }
1641            }
1642        });
1643
1644        fake.set_request_handler::<request::Shutdown, _, _>(|_, _| async move { Ok(()) });
1645
1646        (server, fake)
1647    }
1648    #[cfg(target_os = "windows")]
1649    fn root_path() -> Url {
1650        Url::from_file_path("C:/").unwrap()
1651    }
1652
1653    #[cfg(not(target_os = "windows"))]
1654    fn root_path() -> Url {
1655        Url::from_file_path("/").unwrap()
1656    }
1657}
1658
1659#[cfg(any(test, feature = "test-support"))]
1660impl LanguageServer {
1661    pub fn full_capabilities() -> ServerCapabilities {
1662        ServerCapabilities {
1663            document_highlight_provider: Some(OneOf::Left(true)),
1664            code_action_provider: Some(CodeActionProviderCapability::Simple(true)),
1665            document_formatting_provider: Some(OneOf::Left(true)),
1666            document_range_formatting_provider: Some(OneOf::Left(true)),
1667            definition_provider: Some(OneOf::Left(true)),
1668            workspace_symbol_provider: Some(OneOf::Left(true)),
1669            implementation_provider: Some(ImplementationProviderCapability::Simple(true)),
1670            type_definition_provider: Some(TypeDefinitionProviderCapability::Simple(true)),
1671            ..Default::default()
1672        }
1673    }
1674}
1675
1676#[cfg(any(test, feature = "test-support"))]
1677impl FakeLanguageServer {
1678    /// See [`LanguageServer::notify`].
1679    pub fn notify<T: notification::Notification>(&self, params: &T::Params) {
1680        self.server.notify::<T>(params).ok();
1681    }
1682
1683    /// See [`LanguageServer::request`].
1684    pub async fn request<T>(&self, params: T::Params) -> ConnectionResult<T::Result>
1685    where
1686        T: request::Request,
1687        T::Result: 'static + Send,
1688    {
1689        self.server.executor.start_waiting();
1690        self.server.request::<T>(params).await
1691    }
1692
1693    /// Attempts [`Self::try_receive_notification`], unwrapping if it has not received the specified type yet.
1694    pub async fn receive_notification<T: notification::Notification>(&mut self) -> T::Params {
1695        self.server.executor.start_waiting();
1696        self.try_receive_notification::<T>().await.unwrap()
1697    }
1698
1699    /// Consumes the notification channel until it finds a notification for the specified type.
1700    pub async fn try_receive_notification<T: notification::Notification>(
1701        &mut self,
1702    ) -> Option<T::Params> {
1703        loop {
1704            let (method, params) = self.notifications_rx.recv().await.ok()?;
1705            if method == T::METHOD {
1706                return Some(serde_json::from_str::<T::Params>(&params).unwrap());
1707            } else {
1708                log::info!("skipping message in fake language server {:?}", params);
1709            }
1710        }
1711    }
1712
1713    /// Registers a handler for a specific kind of request. Removes any existing handler for specified request type.
1714    pub fn set_request_handler<T, F, Fut>(
1715        &self,
1716        mut handler: F,
1717    ) -> futures::channel::mpsc::UnboundedReceiver<()>
1718    where
1719        T: 'static + request::Request,
1720        T::Params: 'static + Send,
1721        F: 'static + Send + FnMut(T::Params, gpui::AsyncApp) -> Fut,
1722        Fut: 'static + Future<Output = Result<T::Result>>,
1723    {
1724        let (responded_tx, responded_rx) = futures::channel::mpsc::unbounded();
1725        self.server.remove_request_handler::<T>();
1726        self.server
1727            .on_request::<T, _, _>(move |params, cx| {
1728                let result = handler(params, cx.clone());
1729                let responded_tx = responded_tx.clone();
1730                let executor = cx.background_executor().clone();
1731                async move {
1732                    executor.simulate_random_delay().await;
1733                    let result = result.await;
1734                    responded_tx.unbounded_send(()).ok();
1735                    result
1736                }
1737            })
1738            .detach();
1739        responded_rx
1740    }
1741
1742    /// Registers a handler for a specific kind of notification. Removes any existing handler for specified notification type.
1743    pub fn handle_notification<T, F>(
1744        &self,
1745        mut handler: F,
1746    ) -> futures::channel::mpsc::UnboundedReceiver<()>
1747    where
1748        T: 'static + notification::Notification,
1749        T::Params: 'static + Send,
1750        F: 'static + Send + FnMut(T::Params, gpui::AsyncApp),
1751    {
1752        let (handled_tx, handled_rx) = futures::channel::mpsc::unbounded();
1753        self.server.remove_notification_handler::<T>();
1754        self.server
1755            .on_notification::<T, _>(move |params, cx| {
1756                handler(params, cx.clone());
1757                handled_tx.unbounded_send(()).ok();
1758            })
1759            .detach();
1760        handled_rx
1761    }
1762
1763    /// Removes any existing handler for specified notification type.
1764    pub fn remove_request_handler<T>(&mut self)
1765    where
1766        T: 'static + request::Request,
1767    {
1768        self.server.remove_request_handler::<T>();
1769    }
1770
1771    /// Simulate that the server has started work and notifies about its progress with the specified token.
1772    pub async fn start_progress(&self, token: impl Into<String>) {
1773        self.start_progress_with(token, Default::default()).await
1774    }
1775
1776    pub async fn start_progress_with(
1777        &self,
1778        token: impl Into<String>,
1779        progress: WorkDoneProgressBegin,
1780    ) {
1781        let token = token.into();
1782        self.request::<request::WorkDoneProgressCreate>(WorkDoneProgressCreateParams {
1783            token: NumberOrString::String(token.clone()),
1784        })
1785        .await
1786        .into_response()
1787        .unwrap();
1788        self.notify::<notification::Progress>(&ProgressParams {
1789            token: NumberOrString::String(token),
1790            value: ProgressParamsValue::WorkDone(WorkDoneProgress::Begin(progress)),
1791        });
1792    }
1793
1794    /// Simulate that the server has completed work and notifies about that with the specified token.
1795    pub fn end_progress(&self, token: impl Into<String>) {
1796        self.notify::<notification::Progress>(&ProgressParams {
1797            token: NumberOrString::String(token.into()),
1798            value: ProgressParamsValue::WorkDone(WorkDoneProgress::End(Default::default())),
1799        });
1800    }
1801}
1802
1803#[cfg(test)]
1804mod tests {
1805    use super::*;
1806    use gpui::{SemanticVersion, TestAppContext};
1807    use std::str::FromStr;
1808
1809    #[ctor::ctor]
1810    fn init_logger() {
1811        zlog::init_test();
1812    }
1813
1814    #[gpui::test]
1815    async fn test_fake(cx: &mut TestAppContext) {
1816        cx.update(|cx| {
1817            release_channel::init(SemanticVersion::default(), cx);
1818        });
1819        let (server, mut fake) = FakeLanguageServer::new(
1820            LanguageServerId(0),
1821            LanguageServerBinary {
1822                path: "path/to/language-server".into(),
1823                arguments: vec![],
1824                env: None,
1825            },
1826            "the-lsp".to_string(),
1827            Default::default(),
1828            &mut cx.to_async(),
1829        );
1830
1831        let (message_tx, message_rx) = channel::unbounded();
1832        let (diagnostics_tx, diagnostics_rx) = channel::unbounded();
1833        server
1834            .on_notification::<notification::ShowMessage, _>(move |params, _| {
1835                message_tx.try_send(params).unwrap()
1836            })
1837            .detach();
1838        server
1839            .on_notification::<notification::PublishDiagnostics, _>(move |params, _| {
1840                diagnostics_tx.try_send(params).unwrap()
1841            })
1842            .detach();
1843
1844        let server = cx
1845            .update(|cx| {
1846                let params = server.default_initialize_params(false, cx);
1847                let configuration = DidChangeConfigurationParams {
1848                    settings: Default::default(),
1849                };
1850                server.initialize(params, configuration.into(), cx)
1851            })
1852            .await
1853            .unwrap();
1854        server
1855            .notify::<notification::DidOpenTextDocument>(&DidOpenTextDocumentParams {
1856                text_document: TextDocumentItem::new(
1857                    Url::from_str("file://a/b").unwrap(),
1858                    "rust".to_string(),
1859                    0,
1860                    "".to_string(),
1861                ),
1862            })
1863            .unwrap();
1864        assert_eq!(
1865            fake.receive_notification::<notification::DidOpenTextDocument>()
1866                .await
1867                .text_document
1868                .uri
1869                .as_str(),
1870            "file://a/b"
1871        );
1872
1873        fake.notify::<notification::ShowMessage>(&ShowMessageParams {
1874            typ: MessageType::ERROR,
1875            message: "ok".to_string(),
1876        });
1877        fake.notify::<notification::PublishDiagnostics>(&PublishDiagnosticsParams {
1878            uri: Url::from_str("file://b/c").unwrap(),
1879            version: Some(5),
1880            diagnostics: vec![],
1881        });
1882        assert_eq!(message_rx.recv().await.unwrap().message, "ok");
1883        assert_eq!(
1884            diagnostics_rx.recv().await.unwrap().uri.as_str(),
1885            "file://b/c"
1886        );
1887
1888        fake.set_request_handler::<request::Shutdown, _, _>(|_, _| async move { Ok(()) });
1889
1890        drop(server);
1891        fake.receive_notification::<notification::Exit>().await;
1892    }
1893
1894    #[gpui::test]
1895    fn test_deserialize_string_digit_id() {
1896        let json = r#"{"jsonrpc":"2.0","id":"2","method":"workspace/configuration","params":{"items":[{"scopeUri":"file:///Users/mph/Devel/personal/hello-scala/","section":"metals"}]}}"#;
1897        let notification = serde_json::from_str::<NotificationOrRequest>(json)
1898            .expect("message with string id should be parsed");
1899        let expected_id = RequestId::Str("2".to_string());
1900        assert_eq!(notification.id, Some(expected_id));
1901    }
1902
1903    #[gpui::test]
1904    fn test_deserialize_string_id() {
1905        let json = r#"{"jsonrpc":"2.0","id":"anythingAtAll","method":"workspace/configuration","params":{"items":[{"scopeUri":"file:///Users/mph/Devel/personal/hello-scala/","section":"metals"}]}}"#;
1906        let notification = serde_json::from_str::<NotificationOrRequest>(json)
1907            .expect("message with string id should be parsed");
1908        let expected_id = RequestId::Str("anythingAtAll".to_string());
1909        assert_eq!(notification.id, Some(expected_id));
1910    }
1911
1912    #[gpui::test]
1913    fn test_deserialize_int_id() {
1914        let json = r#"{"jsonrpc":"2.0","id":2,"method":"workspace/configuration","params":{"items":[{"scopeUri":"file:///Users/mph/Devel/personal/hello-scala/","section":"metals"}]}}"#;
1915        let notification = serde_json::from_str::<NotificationOrRequest>(json)
1916            .expect("message with string id should be parsed");
1917        let expected_id = RequestId::Int(2);
1918        assert_eq!(notification.id, Some(expected_id));
1919    }
1920
1921    #[test]
1922    fn test_serialize_has_no_nulls() {
1923        // Ensure we're not setting both result and error variants. (ticket #10595)
1924        let no_tag = Response::<u32> {
1925            jsonrpc: "",
1926            id: RequestId::Int(0),
1927            value: LspResult::Ok(None),
1928        };
1929        assert_eq!(
1930            serde_json::to_string(&no_tag).unwrap(),
1931            "{\"jsonrpc\":\"\",\"id\":0,\"result\":null}"
1932        );
1933        let no_tag = Response::<u32> {
1934            jsonrpc: "",
1935            id: RequestId::Int(0),
1936            value: LspResult::Error(None),
1937        };
1938        assert_eq!(
1939            serde_json::to_string(&no_tag).unwrap(),
1940            "{\"jsonrpc\":\"\",\"id\":0,\"error\":null}"
1941        );
1942    }
1943}