client.rs

   1#[cfg(any(test, feature = "test-support"))]
   2pub mod test;
   3
   4pub mod channel;
   5pub mod http;
   6pub mod telemetry;
   7pub mod user;
   8
   9use anyhow::{anyhow, Context, Result};
  10use async_recursion::async_recursion;
  11use async_tungstenite::tungstenite::{
  12    error::Error as WebsocketError,
  13    http::{Request, StatusCode},
  14};
  15use db::Db;
  16use futures::{future::LocalBoxFuture, FutureExt, SinkExt, StreamExt, TryStreamExt};
  17use gpui::{
  18    actions, serde_json::Value, AnyModelHandle, AnyViewHandle, AnyWeakModelHandle,
  19    AnyWeakViewHandle, AppContext, AsyncAppContext, Entity, ModelContext, ModelHandle,
  20    MutableAppContext, Task, View, ViewContext, ViewHandle,
  21};
  22use http::HttpClient;
  23use lazy_static::lazy_static;
  24use parking_lot::RwLock;
  25use postage::watch;
  26use rand::prelude::*;
  27use rpc::proto::{AnyTypedEnvelope, EntityMessage, EnvelopedMessage, RequestMessage};
  28use std::{
  29    any::TypeId,
  30    collections::HashMap,
  31    convert::TryFrom,
  32    fmt::Write as _,
  33    future::Future,
  34    path::PathBuf,
  35    sync::{Arc, Weak},
  36    time::{Duration, Instant},
  37};
  38use telemetry::Telemetry;
  39use thiserror::Error;
  40use url::Url;
  41use util::{ResultExt, TryFutureExt};
  42
  43pub use channel::*;
  44pub use rpc::*;
  45pub use user::*;
  46
  47lazy_static! {
  48    pub static ref ZED_SERVER_URL: String =
  49        std::env::var("ZED_SERVER_URL").unwrap_or_else(|_| "https://zed.dev".to_string());
  50    pub static ref IMPERSONATE_LOGIN: Option<String> = std::env::var("ZED_IMPERSONATE")
  51        .ok()
  52        .and_then(|s| if s.is_empty() { None } else { Some(s) });
  53}
  54
  55pub const ZED_SECRET_CLIENT_TOKEN: &str = "618033988749894";
  56pub const INITIAL_RECONNECTION_DELAY: Duration = Duration::from_millis(100);
  57pub const CONNECTION_TIMEOUT: Duration = Duration::from_secs(5);
  58
  59actions!(client, [Authenticate]);
  60
  61pub fn init(client: Arc<Client>, cx: &mut MutableAppContext) {
  62    cx.add_global_action({
  63        let client = client.clone();
  64        move |_: &Authenticate, cx| {
  65            let client = client.clone();
  66            cx.spawn(
  67                |cx| async move { client.authenticate_and_connect(true, &cx).log_err().await },
  68            )
  69            .detach();
  70        }
  71    });
  72}
  73
  74pub struct Client {
  75    id: usize,
  76    peer: Arc<Peer>,
  77    http: Arc<dyn HttpClient>,
  78    telemetry: Arc<Telemetry>,
  79    state: RwLock<ClientState>,
  80
  81    #[allow(clippy::type_complexity)]
  82    #[cfg(any(test, feature = "test-support"))]
  83    authenticate: RwLock<
  84        Option<Box<dyn 'static + Send + Sync + Fn(&AsyncAppContext) -> Task<Result<Credentials>>>>,
  85    >,
  86
  87    #[allow(clippy::type_complexity)]
  88    #[cfg(any(test, feature = "test-support"))]
  89    establish_connection: RwLock<
  90        Option<
  91            Box<
  92                dyn 'static
  93                    + Send
  94                    + Sync
  95                    + Fn(
  96                        &Credentials,
  97                        &AsyncAppContext,
  98                    ) -> Task<Result<Connection, EstablishConnectionError>>,
  99            >,
 100        >,
 101    >,
 102}
 103
 104#[derive(Error, Debug)]
 105pub enum EstablishConnectionError {
 106    #[error("upgrade required")]
 107    UpgradeRequired,
 108    #[error("unauthorized")]
 109    Unauthorized,
 110    #[error("{0}")]
 111    Other(#[from] anyhow::Error),
 112    #[error("{0}")]
 113    Http(#[from] http::Error),
 114    #[error("{0}")]
 115    Io(#[from] std::io::Error),
 116    #[error("{0}")]
 117    Websocket(#[from] async_tungstenite::tungstenite::http::Error),
 118}
 119
 120impl From<WebsocketError> for EstablishConnectionError {
 121    fn from(error: WebsocketError) -> Self {
 122        if let WebsocketError::Http(response) = &error {
 123            match response.status() {
 124                StatusCode::UNAUTHORIZED => return EstablishConnectionError::Unauthorized,
 125                StatusCode::UPGRADE_REQUIRED => return EstablishConnectionError::UpgradeRequired,
 126                _ => {}
 127            }
 128        }
 129        EstablishConnectionError::Other(error.into())
 130    }
 131}
 132
 133impl EstablishConnectionError {
 134    pub fn other(error: impl Into<anyhow::Error> + Send + Sync) -> Self {
 135        Self::Other(error.into())
 136    }
 137}
 138
 139#[derive(Copy, Clone, Debug, Eq, PartialEq)]
 140pub enum Status {
 141    SignedOut,
 142    UpgradeRequired,
 143    Authenticating,
 144    Connecting,
 145    ConnectionError,
 146    Connected { connection_id: ConnectionId },
 147    ConnectionLost,
 148    Reauthenticating,
 149    Reconnecting,
 150    ReconnectionError { next_reconnection: Instant },
 151}
 152
 153impl Status {
 154    pub fn is_connected(&self) -> bool {
 155        matches!(self, Self::Connected { .. })
 156    }
 157}
 158
 159struct ClientState {
 160    credentials: Option<Credentials>,
 161    status: (watch::Sender<Status>, watch::Receiver<Status>),
 162    entity_id_extractors: HashMap<TypeId, fn(&dyn AnyTypedEnvelope) -> u64>,
 163    _reconnect_task: Option<Task<()>>,
 164    reconnect_interval: Duration,
 165    entities_by_type_and_remote_id: HashMap<(TypeId, u64), AnyWeakEntityHandle>,
 166    models_by_message_type: HashMap<TypeId, AnyWeakModelHandle>,
 167    entity_types_by_message_type: HashMap<TypeId, TypeId>,
 168    #[allow(clippy::type_complexity)]
 169    message_handlers: HashMap<
 170        TypeId,
 171        Arc<
 172            dyn Send
 173                + Sync
 174                + Fn(
 175                    AnyEntityHandle,
 176                    Box<dyn AnyTypedEnvelope>,
 177                    &Arc<Client>,
 178                    AsyncAppContext,
 179                ) -> LocalBoxFuture<'static, Result<()>>,
 180        >,
 181    >,
 182}
 183
 184enum AnyWeakEntityHandle {
 185    Model(AnyWeakModelHandle),
 186    View(AnyWeakViewHandle),
 187}
 188
 189enum AnyEntityHandle {
 190    Model(AnyModelHandle),
 191    View(AnyViewHandle),
 192}
 193
 194#[derive(Clone, Debug)]
 195pub struct Credentials {
 196    pub user_id: u64,
 197    pub access_token: String,
 198}
 199
 200impl Default for ClientState {
 201    fn default() -> Self {
 202        Self {
 203            credentials: None,
 204            status: watch::channel_with(Status::SignedOut),
 205            entity_id_extractors: Default::default(),
 206            _reconnect_task: None,
 207            reconnect_interval: Duration::from_secs(5),
 208            models_by_message_type: Default::default(),
 209            entities_by_type_and_remote_id: Default::default(),
 210            entity_types_by_message_type: Default::default(),
 211            message_handlers: Default::default(),
 212        }
 213    }
 214}
 215
 216pub enum Subscription {
 217    Entity {
 218        client: Weak<Client>,
 219        id: (TypeId, u64),
 220    },
 221    Message {
 222        client: Weak<Client>,
 223        id: TypeId,
 224    },
 225}
 226
 227impl Drop for Subscription {
 228    fn drop(&mut self) {
 229        match self {
 230            Subscription::Entity { client, id } => {
 231                if let Some(client) = client.upgrade() {
 232                    let mut state = client.state.write();
 233                    let _ = state.entities_by_type_and_remote_id.remove(id);
 234                }
 235            }
 236            Subscription::Message { client, id } => {
 237                if let Some(client) = client.upgrade() {
 238                    let mut state = client.state.write();
 239                    let _ = state.entity_types_by_message_type.remove(id);
 240                    let _ = state.message_handlers.remove(id);
 241                }
 242            }
 243        }
 244    }
 245}
 246
 247impl Client {
 248    pub fn new(http: Arc<dyn HttpClient>, cx: &AppContext) -> Arc<Self> {
 249        Arc::new(Self {
 250            id: 0,
 251            peer: Peer::new(),
 252            telemetry: Telemetry::new(http.clone(), cx),
 253            http,
 254            state: Default::default(),
 255
 256            #[cfg(any(test, feature = "test-support"))]
 257            authenticate: Default::default(),
 258            #[cfg(any(test, feature = "test-support"))]
 259            establish_connection: Default::default(),
 260        })
 261    }
 262
 263    pub fn id(&self) -> usize {
 264        self.id
 265    }
 266
 267    pub fn http_client(&self) -> Arc<dyn HttpClient> {
 268        self.http.clone()
 269    }
 270
 271    #[cfg(any(test, feature = "test-support"))]
 272    pub fn set_id(&mut self, id: usize) -> &Self {
 273        self.id = id;
 274        self
 275    }
 276
 277    #[cfg(any(test, feature = "test-support"))]
 278    pub fn tear_down(&self) {
 279        let mut state = self.state.write();
 280        state._reconnect_task.take();
 281        state.message_handlers.clear();
 282        state.models_by_message_type.clear();
 283        state.entities_by_type_and_remote_id.clear();
 284        state.entity_id_extractors.clear();
 285        self.peer.reset();
 286    }
 287
 288    #[cfg(any(test, feature = "test-support"))]
 289    pub fn override_authenticate<F>(&self, authenticate: F) -> &Self
 290    where
 291        F: 'static + Send + Sync + Fn(&AsyncAppContext) -> Task<Result<Credentials>>,
 292    {
 293        *self.authenticate.write() = Some(Box::new(authenticate));
 294        self
 295    }
 296
 297    #[cfg(any(test, feature = "test-support"))]
 298    pub fn override_establish_connection<F>(&self, connect: F) -> &Self
 299    where
 300        F: 'static
 301            + Send
 302            + Sync
 303            + Fn(&Credentials, &AsyncAppContext) -> Task<Result<Connection, EstablishConnectionError>>,
 304    {
 305        *self.establish_connection.write() = Some(Box::new(connect));
 306        self
 307    }
 308
 309    pub fn user_id(&self) -> Option<u64> {
 310        self.state
 311            .read()
 312            .credentials
 313            .as_ref()
 314            .map(|credentials| credentials.user_id)
 315    }
 316
 317    pub fn status(&self) -> watch::Receiver<Status> {
 318        self.state.read().status.1.clone()
 319    }
 320
 321    fn set_status(self: &Arc<Self>, status: Status, cx: &AsyncAppContext) {
 322        log::info!("set status on client {}: {:?}", self.id, status);
 323        let mut state = self.state.write();
 324        *state.status.0.borrow_mut() = status;
 325
 326        match status {
 327            Status::Connected { .. } => {
 328                state._reconnect_task = None;
 329            }
 330            Status::ConnectionLost => {
 331                let this = self.clone();
 332                let reconnect_interval = state.reconnect_interval;
 333                state._reconnect_task = Some(cx.spawn(|cx| async move {
 334                    let mut rng = StdRng::from_entropy();
 335                    let mut delay = INITIAL_RECONNECTION_DELAY;
 336                    while let Err(error) = this.authenticate_and_connect(true, &cx).await {
 337                        log::error!("failed to connect {}", error);
 338                        if matches!(*this.status().borrow(), Status::ConnectionError) {
 339                            this.set_status(
 340                                Status::ReconnectionError {
 341                                    next_reconnection: Instant::now() + delay,
 342                                },
 343                                &cx,
 344                            );
 345                            cx.background().timer(delay).await;
 346                            delay = delay
 347                                .mul_f32(rng.gen_range(1.0..=2.0))
 348                                .min(reconnect_interval);
 349                        } else {
 350                            break;
 351                        }
 352                    }
 353                }));
 354            }
 355            Status::SignedOut | Status::UpgradeRequired => {
 356                self.telemetry.set_authenticated_user_info(None, false);
 357                state._reconnect_task.take();
 358            }
 359            _ => {}
 360        }
 361    }
 362
 363    pub fn add_view_for_remote_entity<T: View>(
 364        self: &Arc<Self>,
 365        remote_id: u64,
 366        cx: &mut ViewContext<T>,
 367    ) -> Subscription {
 368        let id = (TypeId::of::<T>(), remote_id);
 369        self.state
 370            .write()
 371            .entities_by_type_and_remote_id
 372            .insert(id, AnyWeakEntityHandle::View(cx.weak_handle().into()));
 373        Subscription::Entity {
 374            client: Arc::downgrade(self),
 375            id,
 376        }
 377    }
 378
 379    pub fn add_model_for_remote_entity<T: Entity>(
 380        self: &Arc<Self>,
 381        remote_id: u64,
 382        cx: &mut ModelContext<T>,
 383    ) -> Subscription {
 384        let id = (TypeId::of::<T>(), remote_id);
 385        self.state
 386            .write()
 387            .entities_by_type_and_remote_id
 388            .insert(id, AnyWeakEntityHandle::Model(cx.weak_handle().into()));
 389        Subscription::Entity {
 390            client: Arc::downgrade(self),
 391            id,
 392        }
 393    }
 394
 395    pub fn add_message_handler<M, E, H, F>(
 396        self: &Arc<Self>,
 397        model: ModelHandle<E>,
 398        handler: H,
 399    ) -> Subscription
 400    where
 401        M: EnvelopedMessage,
 402        E: Entity,
 403        H: 'static
 404            + Send
 405            + Sync
 406            + Fn(ModelHandle<E>, TypedEnvelope<M>, Arc<Self>, AsyncAppContext) -> F,
 407        F: 'static + Future<Output = Result<()>>,
 408    {
 409        let message_type_id = TypeId::of::<M>();
 410
 411        let mut state = self.state.write();
 412        state
 413            .models_by_message_type
 414            .insert(message_type_id, model.downgrade().into());
 415
 416        let prev_handler = state.message_handlers.insert(
 417            message_type_id,
 418            Arc::new(move |handle, envelope, client, cx| {
 419                let handle = if let AnyEntityHandle::Model(handle) = handle {
 420                    handle
 421                } else {
 422                    unreachable!();
 423                };
 424                let model = handle.downcast::<E>().unwrap();
 425                let envelope = envelope.into_any().downcast::<TypedEnvelope<M>>().unwrap();
 426                handler(model, *envelope, client.clone(), cx).boxed_local()
 427            }),
 428        );
 429        if prev_handler.is_some() {
 430            panic!("registered handler for the same message twice");
 431        }
 432
 433        Subscription::Message {
 434            client: Arc::downgrade(self),
 435            id: message_type_id,
 436        }
 437    }
 438
 439    pub fn add_request_handler<M, E, H, F>(
 440        self: &Arc<Self>,
 441        model: ModelHandle<E>,
 442        handler: H,
 443    ) -> Subscription
 444    where
 445        M: RequestMessage,
 446        E: Entity,
 447        H: 'static
 448            + Send
 449            + Sync
 450            + Fn(ModelHandle<E>, TypedEnvelope<M>, Arc<Self>, AsyncAppContext) -> F,
 451        F: 'static + Future<Output = Result<M::Response>>,
 452    {
 453        self.add_message_handler(model, move |handle, envelope, this, cx| {
 454            Self::respond_to_request(
 455                envelope.receipt(),
 456                handler(handle, envelope, this.clone(), cx),
 457                this,
 458            )
 459        })
 460    }
 461
 462    pub fn add_view_message_handler<M, E, H, F>(self: &Arc<Self>, handler: H)
 463    where
 464        M: EntityMessage,
 465        E: View,
 466        H: 'static
 467            + Send
 468            + Sync
 469            + Fn(ViewHandle<E>, TypedEnvelope<M>, Arc<Self>, AsyncAppContext) -> F,
 470        F: 'static + Future<Output = Result<()>>,
 471    {
 472        self.add_entity_message_handler::<M, E, _, _>(move |handle, message, client, cx| {
 473            if let AnyEntityHandle::View(handle) = handle {
 474                handler(handle.downcast::<E>().unwrap(), message, client, cx)
 475            } else {
 476                unreachable!();
 477            }
 478        })
 479    }
 480
 481    pub fn add_model_message_handler<M, E, H, F>(self: &Arc<Self>, handler: H)
 482    where
 483        M: EntityMessage,
 484        E: Entity,
 485        H: 'static
 486            + Send
 487            + Sync
 488            + Fn(ModelHandle<E>, TypedEnvelope<M>, Arc<Self>, AsyncAppContext) -> F,
 489        F: 'static + Future<Output = Result<()>>,
 490    {
 491        self.add_entity_message_handler::<M, E, _, _>(move |handle, message, client, cx| {
 492            if let AnyEntityHandle::Model(handle) = handle {
 493                handler(handle.downcast::<E>().unwrap(), message, client, cx)
 494            } else {
 495                unreachable!();
 496            }
 497        })
 498    }
 499
 500    fn add_entity_message_handler<M, E, H, F>(self: &Arc<Self>, handler: H)
 501    where
 502        M: EntityMessage,
 503        E: Entity,
 504        H: 'static
 505            + Send
 506            + Sync
 507            + Fn(AnyEntityHandle, TypedEnvelope<M>, Arc<Self>, AsyncAppContext) -> F,
 508        F: 'static + Future<Output = Result<()>>,
 509    {
 510        let model_type_id = TypeId::of::<E>();
 511        let message_type_id = TypeId::of::<M>();
 512
 513        let mut state = self.state.write();
 514        state
 515            .entity_types_by_message_type
 516            .insert(message_type_id, model_type_id);
 517        state
 518            .entity_id_extractors
 519            .entry(message_type_id)
 520            .or_insert_with(|| {
 521                |envelope| {
 522                    envelope
 523                        .as_any()
 524                        .downcast_ref::<TypedEnvelope<M>>()
 525                        .unwrap()
 526                        .payload
 527                        .remote_entity_id()
 528                }
 529            });
 530        let prev_handler = state.message_handlers.insert(
 531            message_type_id,
 532            Arc::new(move |handle, envelope, client, cx| {
 533                let envelope = envelope.into_any().downcast::<TypedEnvelope<M>>().unwrap();
 534                handler(handle, *envelope, client.clone(), cx).boxed_local()
 535            }),
 536        );
 537        if prev_handler.is_some() {
 538            panic!("registered handler for the same message twice");
 539        }
 540    }
 541
 542    pub fn add_model_request_handler<M, E, H, F>(self: &Arc<Self>, handler: H)
 543    where
 544        M: EntityMessage + RequestMessage,
 545        E: Entity,
 546        H: 'static
 547            + Send
 548            + Sync
 549            + Fn(ModelHandle<E>, TypedEnvelope<M>, Arc<Self>, AsyncAppContext) -> F,
 550        F: 'static + Future<Output = Result<M::Response>>,
 551    {
 552        self.add_model_message_handler(move |entity, envelope, client, cx| {
 553            Self::respond_to_request::<M, _>(
 554                envelope.receipt(),
 555                handler(entity, envelope, client.clone(), cx),
 556                client,
 557            )
 558        })
 559    }
 560
 561    pub fn add_view_request_handler<M, E, H, F>(self: &Arc<Self>, handler: H)
 562    where
 563        M: EntityMessage + RequestMessage,
 564        E: View,
 565        H: 'static
 566            + Send
 567            + Sync
 568            + Fn(ViewHandle<E>, TypedEnvelope<M>, Arc<Self>, AsyncAppContext) -> F,
 569        F: 'static + Future<Output = Result<M::Response>>,
 570    {
 571        self.add_view_message_handler(move |entity, envelope, client, cx| {
 572            Self::respond_to_request::<M, _>(
 573                envelope.receipt(),
 574                handler(entity, envelope, client.clone(), cx),
 575                client,
 576            )
 577        })
 578    }
 579
 580    async fn respond_to_request<T: RequestMessage, F: Future<Output = Result<T::Response>>>(
 581        receipt: Receipt<T>,
 582        response: F,
 583        client: Arc<Self>,
 584    ) -> Result<()> {
 585        match response.await {
 586            Ok(response) => {
 587                client.respond(receipt, response)?;
 588                Ok(())
 589            }
 590            Err(error) => {
 591                client.respond_with_error(
 592                    receipt,
 593                    proto::Error {
 594                        message: format!("{:?}", error),
 595                    },
 596                )?;
 597                Err(error)
 598            }
 599        }
 600    }
 601
 602    pub fn has_keychain_credentials(&self, cx: &AsyncAppContext) -> bool {
 603        read_credentials_from_keychain(cx).is_some()
 604    }
 605
 606    #[async_recursion(?Send)]
 607    pub async fn authenticate_and_connect(
 608        self: &Arc<Self>,
 609        try_keychain: bool,
 610        cx: &AsyncAppContext,
 611    ) -> anyhow::Result<()> {
 612        let was_disconnected = match *self.status().borrow() {
 613            Status::SignedOut => true,
 614            Status::ConnectionError
 615            | Status::ConnectionLost
 616            | Status::Authenticating { .. }
 617            | Status::Reauthenticating { .. }
 618            | Status::ReconnectionError { .. } => false,
 619            Status::Connected { .. } | Status::Connecting { .. } | Status::Reconnecting { .. } => {
 620                return Ok(())
 621            }
 622            Status::UpgradeRequired => return Err(EstablishConnectionError::UpgradeRequired)?,
 623        };
 624
 625        if was_disconnected {
 626            self.set_status(Status::Authenticating, cx);
 627        } else {
 628            self.set_status(Status::Reauthenticating, cx)
 629        }
 630
 631        let mut read_from_keychain = false;
 632        let mut credentials = self.state.read().credentials.clone();
 633        if credentials.is_none() && try_keychain {
 634            credentials = read_credentials_from_keychain(cx);
 635            read_from_keychain = credentials.is_some();
 636            if read_from_keychain {
 637                self.report_event("read credentials from keychain", Default::default());
 638            }
 639        }
 640        if credentials.is_none() {
 641            let mut status_rx = self.status();
 642            let _ = status_rx.next().await;
 643            futures::select_biased! {
 644                authenticate = self.authenticate(cx).fuse() => {
 645                    match authenticate {
 646                        Ok(creds) => credentials = Some(creds),
 647                        Err(err) => {
 648                            self.set_status(Status::ConnectionError, cx);
 649                            return Err(err);
 650                        }
 651                    }
 652                }
 653                _ = status_rx.next().fuse() => {
 654                    return Err(anyhow!("authentication canceled"));
 655                }
 656            }
 657        }
 658        let credentials = credentials.unwrap();
 659
 660        if was_disconnected {
 661            self.set_status(Status::Connecting, cx);
 662        } else {
 663            self.set_status(Status::Reconnecting, cx);
 664        }
 665
 666        let mut timeout = cx.background().timer(CONNECTION_TIMEOUT).fuse();
 667        futures::select_biased! {
 668            connection = self.establish_connection(&credentials, cx).fuse() => {
 669                match connection {
 670                    Ok(conn) => {
 671                        self.state.write().credentials = Some(credentials.clone());
 672                        if !read_from_keychain && IMPERSONATE_LOGIN.is_none() {
 673                            write_credentials_to_keychain(&credentials, cx).log_err();
 674                        }
 675                        self.set_connection(conn, cx).await;
 676                        Ok(())
 677                    }
 678                    Err(EstablishConnectionError::Unauthorized) => {
 679                        self.state.write().credentials.take();
 680                        if read_from_keychain {
 681                            cx.platform().delete_credentials(&ZED_SERVER_URL).log_err();
 682                            self.set_status(Status::SignedOut, cx);
 683                            self.authenticate_and_connect(false, cx).await
 684                        } else {
 685                            self.set_status(Status::ConnectionError, cx);
 686                            Err(EstablishConnectionError::Unauthorized)?
 687                        }
 688                    }
 689                    Err(EstablishConnectionError::UpgradeRequired) => {
 690                        self.set_status(Status::UpgradeRequired, cx);
 691                        Err(EstablishConnectionError::UpgradeRequired)?
 692                    }
 693                    Err(error) => {
 694                        self.set_status(Status::ConnectionError, cx);
 695                        Err(error)?
 696                    }
 697                }
 698            }
 699            _ = timeout => {
 700                self.set_status(Status::ConnectionError, cx);
 701                Err(anyhow!("timed out trying to establish connection"))
 702            }
 703        }
 704    }
 705
 706    async fn set_connection(self: &Arc<Self>, conn: Connection, cx: &AsyncAppContext) {
 707        let executor = cx.background();
 708        log::info!("add connection to peer");
 709        let (connection_id, handle_io, mut incoming) = self
 710            .peer
 711            .add_connection(conn, move |duration| executor.timer(duration))
 712            .await;
 713        log::info!("set status to connected {}", connection_id);
 714        self.set_status(Status::Connected { connection_id }, cx);
 715        cx.foreground()
 716            .spawn({
 717                let cx = cx.clone();
 718                let this = self.clone();
 719                async move {
 720                    let mut message_id = 0_usize;
 721                    while let Some(message) = incoming.next().await {
 722                        let mut state = this.state.write();
 723                        message_id += 1;
 724                        let type_name = message.payload_type_name();
 725                        let payload_type_id = message.payload_type_id();
 726                        let sender_id = message.original_sender_id().map(|id| id.0);
 727
 728                        let model = state
 729                            .models_by_message_type
 730                            .get(&payload_type_id)
 731                            .and_then(|model| model.upgrade(&cx))
 732                            .map(AnyEntityHandle::Model)
 733                            .or_else(|| {
 734                                let entity_type_id =
 735                                    *state.entity_types_by_message_type.get(&payload_type_id)?;
 736                                let entity_id = state
 737                                    .entity_id_extractors
 738                                    .get(&message.payload_type_id())
 739                                    .map(|extract_entity_id| {
 740                                        (extract_entity_id)(message.as_ref())
 741                                    })?;
 742
 743                                let entity = state
 744                                    .entities_by_type_and_remote_id
 745                                    .get(&(entity_type_id, entity_id))?;
 746                                if let Some(entity) = entity.upgrade(&cx) {
 747                                    Some(entity)
 748                                } else {
 749                                    state
 750                                        .entities_by_type_and_remote_id
 751                                        .remove(&(entity_type_id, entity_id));
 752                                    None
 753                                }
 754                            });
 755
 756                        let model = if let Some(model) = model {
 757                            model
 758                        } else {
 759                            log::info!("unhandled message {}", type_name);
 760                            continue;
 761                        };
 762
 763                        if let Some(handler) = state.message_handlers.get(&payload_type_id).cloned()
 764                        {
 765                            drop(state); // Avoid deadlocks if the handler interacts with rpc::Client
 766                            let future = handler(model, message, &this, cx.clone());
 767
 768                            let client_id = this.id;
 769                            log::debug!(
 770                                "rpc message received. client_id:{}, message_id:{}, sender_id:{:?}, type:{}",
 771                                client_id,
 772                                message_id,
 773                                sender_id,
 774                                type_name
 775                            );
 776                            cx.foreground()
 777                                .spawn(async move {
 778                                    match future.await {
 779                                        Ok(()) => {
 780                                            log::debug!(
 781                                                "rpc message handled. client_id:{}, message_id:{}, sender_id:{:?}, type:{}",
 782                                                client_id,
 783                                                message_id,
 784                                                sender_id,
 785                                                type_name
 786                                            );
 787                                        }
 788                                        Err(error) => {
 789                                            log::error!(
 790                                                "error handling message. client_id:{}, message_id:{}, sender_id:{:?}, type:{}, error:{:?}",
 791                                                client_id,
 792                                                message_id,
 793                                                sender_id,
 794                                                type_name,
 795                                                error
 796                                            );
 797                                        }
 798                                    }
 799                                })
 800                                .detach();
 801                        } else {
 802                            log::info!("unhandled message {}", type_name);
 803                        }
 804
 805                        // Don't starve the main thread when receiving lots of messages at once.
 806                        smol::future::yield_now().await;
 807                    }
 808                }
 809            })
 810            .detach();
 811
 812        let handle_io = cx.background().spawn(handle_io);
 813        let this = self.clone();
 814        let cx = cx.clone();
 815        cx.foreground()
 816            .spawn(async move {
 817                match handle_io.await {
 818                    Ok(()) => {
 819                        if *this.status().borrow() == (Status::Connected { connection_id }) {
 820                            this.set_status(Status::SignedOut, &cx);
 821                        }
 822                    }
 823                    Err(err) => {
 824                        log::error!("connection error: {:?}", err);
 825                        this.set_status(Status::ConnectionLost, &cx);
 826                    }
 827                }
 828            })
 829            .detach();
 830    }
 831
 832    fn authenticate(self: &Arc<Self>, cx: &AsyncAppContext) -> Task<Result<Credentials>> {
 833        #[cfg(any(test, feature = "test-support"))]
 834        if let Some(callback) = self.authenticate.read().as_ref() {
 835            return callback(cx);
 836        }
 837
 838        self.authenticate_with_browser(cx)
 839    }
 840
 841    fn establish_connection(
 842        self: &Arc<Self>,
 843        credentials: &Credentials,
 844        cx: &AsyncAppContext,
 845    ) -> Task<Result<Connection, EstablishConnectionError>> {
 846        #[cfg(any(test, feature = "test-support"))]
 847        if let Some(callback) = self.establish_connection.read().as_ref() {
 848            return callback(credentials, cx);
 849        }
 850
 851        self.establish_websocket_connection(credentials, cx)
 852    }
 853
 854    fn establish_websocket_connection(
 855        self: &Arc<Self>,
 856        credentials: &Credentials,
 857        cx: &AsyncAppContext,
 858    ) -> Task<Result<Connection, EstablishConnectionError>> {
 859        let request = Request::builder()
 860            .header(
 861                "Authorization",
 862                format!("{} {}", credentials.user_id, credentials.access_token),
 863            )
 864            .header("x-zed-protocol-version", rpc::PROTOCOL_VERSION);
 865
 866        let http = self.http.clone();
 867        cx.background().spawn(async move {
 868            let mut rpc_url = format!("{}/rpc", *ZED_SERVER_URL);
 869            let rpc_response = http.get(&rpc_url, Default::default(), false).await?;
 870            if rpc_response.status().is_redirection() {
 871                rpc_url = rpc_response
 872                    .headers()
 873                    .get("Location")
 874                    .ok_or_else(|| anyhow!("missing location header in /rpc response"))?
 875                    .to_str()
 876                    .map_err(EstablishConnectionError::other)?
 877                    .to_string();
 878            }
 879            // Until we switch the zed.dev domain to point to the new Next.js app, there
 880            // will be no redirect required, and the app will connect directly to
 881            // wss://zed.dev/rpc.
 882            else if rpc_response.status() != StatusCode::UPGRADE_REQUIRED {
 883                Err(anyhow!(
 884                    "unexpected /rpc response status {}",
 885                    rpc_response.status()
 886                ))?
 887            }
 888
 889            let mut rpc_url = Url::parse(&rpc_url).context("invalid rpc url")?;
 890            let rpc_host = rpc_url
 891                .host_str()
 892                .zip(rpc_url.port_or_known_default())
 893                .ok_or_else(|| anyhow!("missing host in rpc url"))?;
 894            let stream = smol::net::TcpStream::connect(rpc_host).await?;
 895
 896            log::info!("connected to rpc endpoint {}", rpc_url);
 897
 898            match rpc_url.scheme() {
 899                "https" => {
 900                    rpc_url.set_scheme("wss").unwrap();
 901                    let request = request.uri(rpc_url.as_str()).body(())?;
 902                    let (stream, _) =
 903                        async_tungstenite::async_tls::client_async_tls(request, stream).await?;
 904                    Ok(Connection::new(
 905                        stream
 906                            .map_err(|error| anyhow!(error))
 907                            .sink_map_err(|error| anyhow!(error)),
 908                    ))
 909                }
 910                "http" => {
 911                    rpc_url.set_scheme("ws").unwrap();
 912                    let request = request.uri(rpc_url.as_str()).body(())?;
 913                    let (stream, _) = async_tungstenite::client_async(request, stream).await?;
 914                    Ok(Connection::new(
 915                        stream
 916                            .map_err(|error| anyhow!(error))
 917                            .sink_map_err(|error| anyhow!(error)),
 918                    ))
 919                }
 920                _ => Err(anyhow!("invalid rpc url: {}", rpc_url))?,
 921            }
 922        })
 923    }
 924
 925    pub fn authenticate_with_browser(
 926        self: &Arc<Self>,
 927        cx: &AsyncAppContext,
 928    ) -> Task<Result<Credentials>> {
 929        let platform = cx.platform();
 930        let executor = cx.background();
 931        let telemetry = self.telemetry.clone();
 932        executor.clone().spawn(async move {
 933            // Generate a pair of asymmetric encryption keys. The public key will be used by the
 934            // zed server to encrypt the user's access token, so that it can'be intercepted by
 935            // any other app running on the user's device.
 936            let (public_key, private_key) =
 937                rpc::auth::keypair().expect("failed to generate keypair for auth");
 938            let public_key_string =
 939                String::try_from(public_key).expect("failed to serialize public key for auth");
 940
 941            // Start an HTTP server to receive the redirect from Zed's sign-in page.
 942            let server = tiny_http::Server::http("127.0.0.1:0").expect("failed to find open port");
 943            let port = server.server_addr().port();
 944
 945            // Open the Zed sign-in page in the user's browser, with query parameters that indicate
 946            // that the user is signing in from a Zed app running on the same device.
 947            let mut url = format!(
 948                "{}/native_app_signin?native_app_port={}&native_app_public_key={}",
 949                *ZED_SERVER_URL, port, public_key_string
 950            );
 951
 952            if let Some(impersonate_login) = IMPERSONATE_LOGIN.as_ref() {
 953                log::info!("impersonating user @{}", impersonate_login);
 954                write!(&mut url, "&impersonate={}", impersonate_login).unwrap();
 955            }
 956
 957            platform.open_url(&url);
 958
 959            // Receive the HTTP request from the user's browser. Retrieve the user id and encrypted
 960            // access token from the query params.
 961            //
 962            // TODO - Avoid ever starting more than one HTTP server. Maybe switch to using a
 963            // custom URL scheme instead of this local HTTP server.
 964            let (user_id, access_token) = executor
 965                .spawn(async move {
 966                    for _ in 0..100 {
 967                        if let Some(req) = server.recv_timeout(Duration::from_secs(1))? {
 968                            let path = req.url();
 969                            let mut user_id = None;
 970                            let mut access_token = None;
 971                            let url = Url::parse(&format!("http://example.com{}", path))
 972                                .context("failed to parse login notification url")?;
 973                            for (key, value) in url.query_pairs() {
 974                                if key == "access_token" {
 975                                    access_token = Some(value.to_string());
 976                                } else if key == "user_id" {
 977                                    user_id = Some(value.to_string());
 978                                }
 979                            }
 980
 981                            let post_auth_url =
 982                                format!("{}/native_app_signin_succeeded", *ZED_SERVER_URL);
 983                            req.respond(
 984                                tiny_http::Response::empty(302).with_header(
 985                                    tiny_http::Header::from_bytes(
 986                                        &b"Location"[..],
 987                                        post_auth_url.as_bytes(),
 988                                    )
 989                                    .unwrap(),
 990                                ),
 991                            )
 992                            .context("failed to respond to login http request")?;
 993                            return Ok((
 994                                user_id.ok_or_else(|| anyhow!("missing user_id parameter"))?,
 995                                access_token
 996                                    .ok_or_else(|| anyhow!("missing access_token parameter"))?,
 997                            ));
 998                        }
 999                    }
1000
1001                    Err(anyhow!("didn't receive login redirect"))
1002                })
1003                .await?;
1004
1005            let access_token = private_key
1006                .decrypt_string(&access_token)
1007                .context("failed to decrypt access token")?;
1008            platform.activate(true);
1009
1010            telemetry.report_event("authenticate with browser", Default::default());
1011
1012            Ok(Credentials {
1013                user_id: user_id.parse()?,
1014                access_token,
1015            })
1016        })
1017    }
1018
1019    pub fn disconnect(self: &Arc<Self>, cx: &AsyncAppContext) -> Result<()> {
1020        let conn_id = self.connection_id()?;
1021        self.peer.disconnect(conn_id);
1022        self.set_status(Status::SignedOut, cx);
1023        Ok(())
1024    }
1025
1026    fn connection_id(&self) -> Result<ConnectionId> {
1027        if let Status::Connected { connection_id, .. } = *self.status().borrow() {
1028            Ok(connection_id)
1029        } else {
1030            Err(anyhow!("not connected"))
1031        }
1032    }
1033
1034    pub fn send<T: EnvelopedMessage>(&self, message: T) -> Result<()> {
1035        log::debug!("rpc send. client_id:{}, name:{}", self.id, T::NAME);
1036        self.peer.send(self.connection_id()?, message)
1037    }
1038
1039    pub fn request<T: RequestMessage>(
1040        &self,
1041        request: T,
1042    ) -> impl Future<Output = Result<T::Response>> {
1043        let client_id = self.id;
1044        log::debug!(
1045            "rpc request start. client_id:{}. name:{}",
1046            client_id,
1047            T::NAME
1048        );
1049        let response = self
1050            .connection_id()
1051            .map(|conn_id| self.peer.request(conn_id, request));
1052        async move {
1053            let response = response?.await;
1054            log::debug!(
1055                "rpc request finish. client_id:{}. name:{}",
1056                client_id,
1057                T::NAME
1058            );
1059            response
1060        }
1061    }
1062
1063    fn respond<T: RequestMessage>(&self, receipt: Receipt<T>, response: T::Response) -> Result<()> {
1064        log::debug!("rpc respond. client_id:{}. name:{}", self.id, T::NAME);
1065        self.peer.respond(receipt, response)
1066    }
1067
1068    fn respond_with_error<T: RequestMessage>(
1069        &self,
1070        receipt: Receipt<T>,
1071        error: proto::Error,
1072    ) -> Result<()> {
1073        log::debug!("rpc respond. client_id:{}. name:{}", self.id, T::NAME);
1074        self.peer.respond_with_error(receipt, error)
1075    }
1076
1077    pub fn start_telemetry(&self, db: Arc<Db>) {
1078        self.telemetry.start(db);
1079    }
1080
1081    pub fn report_event(&self, kind: &str, properties: Value) {
1082        self.telemetry.report_event(kind, properties)
1083    }
1084
1085    pub fn telemetry_log_file_path(&self) -> Option<PathBuf> {
1086        self.telemetry.log_file_path()
1087    }
1088}
1089
1090impl AnyWeakEntityHandle {
1091    fn upgrade(&self, cx: &AsyncAppContext) -> Option<AnyEntityHandle> {
1092        match self {
1093            AnyWeakEntityHandle::Model(handle) => handle.upgrade(cx).map(AnyEntityHandle::Model),
1094            AnyWeakEntityHandle::View(handle) => handle.upgrade(cx).map(AnyEntityHandle::View),
1095        }
1096    }
1097}
1098
1099fn read_credentials_from_keychain(cx: &AsyncAppContext) -> Option<Credentials> {
1100    if IMPERSONATE_LOGIN.is_some() {
1101        return None;
1102    }
1103
1104    let (user_id, access_token) = cx
1105        .platform()
1106        .read_credentials(&ZED_SERVER_URL)
1107        .log_err()
1108        .flatten()?;
1109    Some(Credentials {
1110        user_id: user_id.parse().ok()?,
1111        access_token: String::from_utf8(access_token).ok()?,
1112    })
1113}
1114
1115fn write_credentials_to_keychain(credentials: &Credentials, cx: &AsyncAppContext) -> Result<()> {
1116    cx.platform().write_credentials(
1117        &ZED_SERVER_URL,
1118        &credentials.user_id.to_string(),
1119        credentials.access_token.as_bytes(),
1120    )
1121}
1122
1123const WORKTREE_URL_PREFIX: &str = "zed://worktrees/";
1124
1125pub fn encode_worktree_url(id: u64, access_token: &str) -> String {
1126    format!("{}{}/{}", WORKTREE_URL_PREFIX, id, access_token)
1127}
1128
1129pub fn decode_worktree_url(url: &str) -> Option<(u64, String)> {
1130    let path = url.trim().strip_prefix(WORKTREE_URL_PREFIX)?;
1131    let mut parts = path.split('/');
1132    let id = parts.next()?.parse::<u64>().ok()?;
1133    let access_token = parts.next()?;
1134    if access_token.is_empty() {
1135        return None;
1136    }
1137    Some((id, access_token.to_string()))
1138}
1139
1140#[cfg(test)]
1141mod tests {
1142    use super::*;
1143    use crate::test::{FakeHttpClient, FakeServer};
1144    use gpui::{executor::Deterministic, TestAppContext};
1145    use parking_lot::Mutex;
1146    use std::future;
1147
1148    #[gpui::test(iterations = 10)]
1149    async fn test_reconnection(cx: &mut TestAppContext) {
1150        cx.foreground().forbid_parking();
1151
1152        let user_id = 5;
1153        let client = cx.update(|cx| Client::new(FakeHttpClient::with_404_response(), cx));
1154        let server = FakeServer::for_client(user_id, &client, cx).await;
1155        let mut status = client.status();
1156        assert!(matches!(
1157            status.next().await,
1158            Some(Status::Connected { .. })
1159        ));
1160        assert_eq!(server.auth_count(), 1);
1161
1162        server.forbid_connections();
1163        server.disconnect();
1164        while !matches!(status.next().await, Some(Status::ReconnectionError { .. })) {}
1165
1166        server.allow_connections();
1167        cx.foreground().advance_clock(Duration::from_secs(10));
1168        while !matches!(status.next().await, Some(Status::Connected { .. })) {}
1169        assert_eq!(server.auth_count(), 1); // Client reused the cached credentials when reconnecting
1170
1171        server.forbid_connections();
1172        server.disconnect();
1173        while !matches!(status.next().await, Some(Status::ReconnectionError { .. })) {}
1174
1175        // Clear cached credentials after authentication fails
1176        server.roll_access_token();
1177        server.allow_connections();
1178        cx.foreground().advance_clock(Duration::from_secs(10));
1179        while !matches!(status.next().await, Some(Status::Connected { .. })) {}
1180        assert_eq!(server.auth_count(), 2); // Client re-authenticated due to an invalid token
1181    }
1182
1183    #[gpui::test(iterations = 10)]
1184    async fn test_connection_timeout(deterministic: Arc<Deterministic>, cx: &mut TestAppContext) {
1185        deterministic.forbid_parking();
1186
1187        let user_id = 5;
1188        let client = cx.update(|cx| Client::new(FakeHttpClient::with_404_response(), cx));
1189        let mut status = client.status();
1190
1191        // Time out when client tries to connect.
1192        client.override_authenticate(move |cx| {
1193            cx.foreground().spawn(async move {
1194                Ok(Credentials {
1195                    user_id,
1196                    access_token: "token".into(),
1197                })
1198            })
1199        });
1200        client.override_establish_connection(|_, cx| {
1201            cx.foreground().spawn(async move {
1202                future::pending::<()>().await;
1203                unreachable!()
1204            })
1205        });
1206        let auth_and_connect = cx.spawn({
1207            let client = client.clone();
1208            |cx| async move { client.authenticate_and_connect(false, &cx).await }
1209        });
1210        deterministic.run_until_parked();
1211        assert!(matches!(status.next().await, Some(Status::Connecting)));
1212
1213        deterministic.advance_clock(CONNECTION_TIMEOUT);
1214        assert!(matches!(
1215            status.next().await,
1216            Some(Status::ConnectionError { .. })
1217        ));
1218        auth_and_connect.await.unwrap_err();
1219
1220        // Allow the connection to be established.
1221        let server = FakeServer::for_client(user_id, &client, cx).await;
1222        assert!(matches!(
1223            status.next().await,
1224            Some(Status::Connected { .. })
1225        ));
1226
1227        // Disconnect client.
1228        server.forbid_connections();
1229        server.disconnect();
1230        while !matches!(status.next().await, Some(Status::ReconnectionError { .. })) {}
1231
1232        // Time out when re-establishing the connection.
1233        server.allow_connections();
1234        client.override_establish_connection(|_, cx| {
1235            cx.foreground().spawn(async move {
1236                future::pending::<()>().await;
1237                unreachable!()
1238            })
1239        });
1240        deterministic.advance_clock(2 * INITIAL_RECONNECTION_DELAY);
1241        assert!(matches!(
1242            status.next().await,
1243            Some(Status::Reconnecting { .. })
1244        ));
1245
1246        deterministic.advance_clock(CONNECTION_TIMEOUT);
1247        assert!(matches!(
1248            status.next().await,
1249            Some(Status::ReconnectionError { .. })
1250        ));
1251    }
1252
1253    #[gpui::test(iterations = 10)]
1254    async fn test_authenticating_more_than_once(
1255        cx: &mut TestAppContext,
1256        deterministic: Arc<Deterministic>,
1257    ) {
1258        cx.foreground().forbid_parking();
1259
1260        let auth_count = Arc::new(Mutex::new(0));
1261        let dropped_auth_count = Arc::new(Mutex::new(0));
1262        let client = cx.update(|cx| Client::new(FakeHttpClient::with_404_response(), cx));
1263        client.override_authenticate({
1264            let auth_count = auth_count.clone();
1265            let dropped_auth_count = dropped_auth_count.clone();
1266            move |cx| {
1267                let auth_count = auth_count.clone();
1268                let dropped_auth_count = dropped_auth_count.clone();
1269                cx.foreground().spawn(async move {
1270                    *auth_count.lock() += 1;
1271                    let _drop = util::defer(move || *dropped_auth_count.lock() += 1);
1272                    future::pending::<()>().await;
1273                    unreachable!()
1274                })
1275            }
1276        });
1277
1278        let _authenticate = cx.spawn(|cx| {
1279            let client = client.clone();
1280            async move { client.authenticate_and_connect(false, &cx).await }
1281        });
1282        deterministic.run_until_parked();
1283        assert_eq!(*auth_count.lock(), 1);
1284        assert_eq!(*dropped_auth_count.lock(), 0);
1285
1286        let _authenticate = cx.spawn(|cx| {
1287            let client = client.clone();
1288            async move { client.authenticate_and_connect(false, &cx).await }
1289        });
1290        deterministic.run_until_parked();
1291        assert_eq!(*auth_count.lock(), 2);
1292        assert_eq!(*dropped_auth_count.lock(), 1);
1293    }
1294
1295    #[test]
1296    fn test_encode_and_decode_worktree_url() {
1297        let url = encode_worktree_url(5, "deadbeef");
1298        assert_eq!(decode_worktree_url(&url), Some((5, "deadbeef".to_string())));
1299        assert_eq!(
1300            decode_worktree_url(&format!("\n {}\t", url)),
1301            Some((5, "deadbeef".to_string()))
1302        );
1303        assert_eq!(decode_worktree_url("not://the-right-format"), None);
1304    }
1305
1306    #[gpui::test]
1307    async fn test_subscribing_to_entity(cx: &mut TestAppContext) {
1308        cx.foreground().forbid_parking();
1309
1310        let user_id = 5;
1311        let client = cx.update(|cx| Client::new(FakeHttpClient::with_404_response(), cx));
1312        let server = FakeServer::for_client(user_id, &client, cx).await;
1313
1314        let (done_tx1, mut done_rx1) = smol::channel::unbounded();
1315        let (done_tx2, mut done_rx2) = smol::channel::unbounded();
1316        client.add_model_message_handler(
1317            move |model: ModelHandle<Model>, _: TypedEnvelope<proto::JoinProject>, _, cx| {
1318                match model.read_with(&cx, |model, _| model.id) {
1319                    1 => done_tx1.try_send(()).unwrap(),
1320                    2 => done_tx2.try_send(()).unwrap(),
1321                    _ => unreachable!(),
1322                }
1323                async { Ok(()) }
1324            },
1325        );
1326        let model1 = cx.add_model(|_| Model {
1327            id: 1,
1328            subscription: None,
1329        });
1330        let model2 = cx.add_model(|_| Model {
1331            id: 2,
1332            subscription: None,
1333        });
1334        let model3 = cx.add_model(|_| Model {
1335            id: 3,
1336            subscription: None,
1337        });
1338
1339        let _subscription1 = model1.update(cx, |_, cx| client.add_model_for_remote_entity(1, cx));
1340        let _subscription2 = model2.update(cx, |_, cx| client.add_model_for_remote_entity(2, cx));
1341        // Ensure dropping a subscription for the same entity type still allows receiving of
1342        // messages for other entity IDs of the same type.
1343        let subscription3 = model3.update(cx, |_, cx| client.add_model_for_remote_entity(3, cx));
1344        drop(subscription3);
1345
1346        server.send(proto::JoinProject { project_id: 1 });
1347        server.send(proto::JoinProject { project_id: 2 });
1348        done_rx1.next().await.unwrap();
1349        done_rx2.next().await.unwrap();
1350    }
1351
1352    #[gpui::test]
1353    async fn test_subscribing_after_dropping_subscription(cx: &mut TestAppContext) {
1354        cx.foreground().forbid_parking();
1355
1356        let user_id = 5;
1357        let client = cx.update(|cx| Client::new(FakeHttpClient::with_404_response(), cx));
1358        let server = FakeServer::for_client(user_id, &client, cx).await;
1359
1360        let model = cx.add_model(|_| Model::default());
1361        let (done_tx1, _done_rx1) = smol::channel::unbounded();
1362        let (done_tx2, mut done_rx2) = smol::channel::unbounded();
1363        let subscription1 = client.add_message_handler(
1364            model.clone(),
1365            move |_, _: TypedEnvelope<proto::Ping>, _, _| {
1366                done_tx1.try_send(()).unwrap();
1367                async { Ok(()) }
1368            },
1369        );
1370        drop(subscription1);
1371        let _subscription2 =
1372            client.add_message_handler(model, move |_, _: TypedEnvelope<proto::Ping>, _, _| {
1373                done_tx2.try_send(()).unwrap();
1374                async { Ok(()) }
1375            });
1376        server.send(proto::Ping {});
1377        done_rx2.next().await.unwrap();
1378    }
1379
1380    #[gpui::test]
1381    async fn test_dropping_subscription_in_handler(cx: &mut TestAppContext) {
1382        cx.foreground().forbid_parking();
1383
1384        let user_id = 5;
1385        let client = cx.update(|cx| Client::new(FakeHttpClient::with_404_response(), cx));
1386        let server = FakeServer::for_client(user_id, &client, cx).await;
1387
1388        let model = cx.add_model(|_| Model::default());
1389        let (done_tx, mut done_rx) = smol::channel::unbounded();
1390        let subscription = client.add_message_handler(
1391            model.clone(),
1392            move |model, _: TypedEnvelope<proto::Ping>, _, mut cx| {
1393                model.update(&mut cx, |model, _| model.subscription.take());
1394                done_tx.try_send(()).unwrap();
1395                async { Ok(()) }
1396            },
1397        );
1398        model.update(cx, |model, _| {
1399            model.subscription = Some(subscription);
1400        });
1401        server.send(proto::Ping {});
1402        done_rx.next().await.unwrap();
1403    }
1404
1405    #[derive(Default)]
1406    struct Model {
1407        id: usize,
1408        subscription: Option<Subscription>,
1409    }
1410
1411    impl Entity for Model {
1412        type Event = ();
1413    }
1414}