lsp.rs

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