test_context.rs

   1use crate::{
   2    Action, AnyView, AnyWindowHandle, App, AppCell, AppContext, AsyncApp, AvailableSpace,
   3    BackgroundExecutor, BorrowAppContext, Bounds, ClipboardItem, DrawPhase, Drawable, Element,
   4    Empty, EventEmitter, ForegroundExecutor, Global, InputEvent, Keystroke, Modifiers,
   5    ModifiersChangedEvent, MouseButton, MouseDownEvent, MouseMoveEvent, MouseUpEvent, Pixels,
   6    Platform, Point, Render, Result, Size, Task, TestDispatcher, TestPlatform,
   7    TestScreenCaptureSource, TestWindow, TextSystem, VisualContext, Window, WindowBounds,
   8    WindowHandle, WindowOptions,
   9};
  10use anyhow::{anyhow, bail};
  11use futures::{Stream, StreamExt, channel::oneshot};
  12use std::{cell::RefCell, future::Future, ops::Deref, rc::Rc, sync::Arc, time::Duration};
  13
  14/// A TestAppContext is provided to tests created with `#[gpui::test]`, it provides
  15/// an implementation of `Context` with additional methods that are useful in tests.
  16#[derive(Clone)]
  17pub struct TestAppContext {
  18    #[doc(hidden)]
  19    pub app: Rc<AppCell>,
  20    #[doc(hidden)]
  21    pub background_executor: BackgroundExecutor,
  22    #[doc(hidden)]
  23    pub foreground_executor: ForegroundExecutor,
  24    #[doc(hidden)]
  25    pub dispatcher: TestDispatcher,
  26    test_platform: Rc<TestPlatform>,
  27    text_system: Arc<TextSystem>,
  28    fn_name: Option<&'static str>,
  29    on_quit: Rc<RefCell<Vec<Box<dyn FnOnce() + 'static>>>>,
  30}
  31
  32impl AppContext for TestAppContext {
  33    type Result<T> = T;
  34
  35    fn new<T: 'static>(
  36        &mut self,
  37        build_entity: impl FnOnce(&mut Context<T>) -> T,
  38    ) -> Self::Result<Entity<T>> {
  39        let mut app = self.app.borrow_mut();
  40        app.new(build_entity)
  41    }
  42
  43    fn reserve_entity<T: 'static>(&mut self) -> Self::Result<crate::Reservation<T>> {
  44        let mut app = self.app.borrow_mut();
  45        app.reserve_entity()
  46    }
  47
  48    fn insert_entity<T: 'static>(
  49        &mut self,
  50        reservation: crate::Reservation<T>,
  51        build_entity: impl FnOnce(&mut Context<T>) -> T,
  52    ) -> Self::Result<Entity<T>> {
  53        let mut app = self.app.borrow_mut();
  54        app.insert_entity(reservation, build_entity)
  55    }
  56
  57    fn update_entity<T: 'static, R>(
  58        &mut self,
  59        handle: &Entity<T>,
  60        update: impl FnOnce(&mut T, &mut Context<T>) -> R,
  61    ) -> Self::Result<R> {
  62        let mut app = self.app.borrow_mut();
  63        app.update_entity(handle, update)
  64    }
  65
  66    fn read_entity<T, R>(
  67        &self,
  68        handle: &Entity<T>,
  69        read: impl FnOnce(&T, &App) -> R,
  70    ) -> Self::Result<R>
  71    where
  72        T: 'static,
  73    {
  74        let app = self.app.borrow();
  75        app.read_entity(handle, read)
  76    }
  77
  78    fn update_window<T, F>(&mut self, window: AnyWindowHandle, f: F) -> Result<T>
  79    where
  80        F: FnOnce(AnyView, &mut Window, &mut App) -> T,
  81    {
  82        let mut lock = self.app.borrow_mut();
  83        lock.update_window(window, f)
  84    }
  85
  86    fn read_window<T, R>(
  87        &self,
  88        window: &WindowHandle<T>,
  89        read: impl FnOnce(Entity<T>, &App) -> R,
  90    ) -> Result<R>
  91    where
  92        T: 'static,
  93    {
  94        let app = self.app.borrow();
  95        app.read_window(window, read)
  96    }
  97
  98    fn background_spawn<R>(&self, future: impl Future<Output = R> + Send + 'static) -> Task<R>
  99    where
 100        R: Send + 'static,
 101    {
 102        self.background_executor.spawn(future)
 103    }
 104
 105    fn read_global<G, R>(&self, callback: impl FnOnce(&G, &App) -> R) -> Self::Result<R>
 106    where
 107        G: Global,
 108    {
 109        let app = self.app.borrow();
 110        app.read_global(callback)
 111    }
 112}
 113
 114impl TestAppContext {
 115    /// Creates a new `TestAppContext`. Usually you can rely on `#[gpui::test]` to do this for you.
 116    pub fn build(dispatcher: TestDispatcher, fn_name: Option<&'static str>) -> Self {
 117        let arc_dispatcher = Arc::new(dispatcher.clone());
 118        let background_executor = BackgroundExecutor::new(arc_dispatcher.clone());
 119        let foreground_executor = ForegroundExecutor::new(arc_dispatcher);
 120        let platform = TestPlatform::new(background_executor.clone(), foreground_executor.clone());
 121        let asset_source = Arc::new(());
 122        let http_client = http_client::FakeHttpClient::with_404_response();
 123        let text_system = Arc::new(TextSystem::new(platform.text_system()));
 124
 125        Self {
 126            app: App::new_app(platform.clone(), asset_source, http_client),
 127            background_executor,
 128            foreground_executor,
 129            dispatcher: dispatcher.clone(),
 130            test_platform: platform,
 131            text_system,
 132            fn_name,
 133            on_quit: Rc::new(RefCell::new(Vec::default())),
 134        }
 135    }
 136
 137    /// The name of the test function that created this `TestAppContext`
 138    pub fn test_function_name(&self) -> Option<&'static str> {
 139        self.fn_name
 140    }
 141
 142    /// Checks whether there have been any new path prompts received by the platform.
 143    pub fn did_prompt_for_new_path(&self) -> bool {
 144        self.test_platform.did_prompt_for_new_path()
 145    }
 146
 147    /// returns a new `TestAppContext` re-using the same executors to interleave tasks.
 148    pub fn new_app(&self) -> TestAppContext {
 149        Self::build(self.dispatcher.clone(), self.fn_name)
 150    }
 151
 152    /// Called by the test helper to end the test.
 153    /// public so the macro can call it.
 154    pub fn quit(&self) {
 155        self.on_quit.borrow_mut().drain(..).for_each(|f| f());
 156        self.app.borrow_mut().shutdown();
 157    }
 158
 159    /// Register cleanup to run when the test ends.
 160    pub fn on_quit(&mut self, f: impl FnOnce() + 'static) {
 161        self.on_quit.borrow_mut().push(Box::new(f));
 162    }
 163
 164    /// Schedules all windows to be redrawn on the next effect cycle.
 165    pub fn refresh(&mut self) -> Result<()> {
 166        let mut app = self.app.borrow_mut();
 167        app.refresh_windows();
 168        Ok(())
 169    }
 170
 171    /// Returns an executor (for running tasks in the background)
 172    pub fn executor(&self) -> BackgroundExecutor {
 173        self.background_executor.clone()
 174    }
 175
 176    /// Returns an executor (for running tasks on the main thread)
 177    pub fn foreground_executor(&self) -> &ForegroundExecutor {
 178        &self.foreground_executor
 179    }
 180
 181    fn new<T: 'static>(&mut self, build_entity: impl FnOnce(&mut Context<T>) -> T) -> Entity<T> {
 182        let mut cx = self.app.borrow_mut();
 183        cx.new(build_entity)
 184    }
 185
 186    /// Gives you an `&mut App` for the duration of the closure
 187    pub fn update<R>(&self, f: impl FnOnce(&mut App) -> R) -> R {
 188        let mut cx = self.app.borrow_mut();
 189        cx.update(f)
 190    }
 191
 192    /// Gives you an `&App` for the duration of the closure
 193    pub fn read<R>(&self, f: impl FnOnce(&App) -> R) -> R {
 194        let cx = self.app.borrow();
 195        f(&cx)
 196    }
 197
 198    /// Adds a new window. The Window will always be backed by a `TestWindow` which
 199    /// can be retrieved with `self.test_window(handle)`
 200    pub fn add_window<F, V>(&mut self, build_window: F) -> WindowHandle<V>
 201    where
 202        F: FnOnce(&mut Window, &mut Context<V>) -> V,
 203        V: 'static + Render,
 204    {
 205        let mut cx = self.app.borrow_mut();
 206
 207        // Some tests rely on the window size matching the bounds of the test display
 208        let bounds = Bounds::maximized(None, &mut cx);
 209        cx.open_window(
 210            WindowOptions {
 211                window_bounds: Some(WindowBounds::Windowed(bounds)),
 212                ..Default::default()
 213            },
 214            |window, cx| cx.new(|cx| build_window(window, cx)),
 215        )
 216        .unwrap()
 217    }
 218
 219    /// Adds a new window with no content.
 220    pub fn add_empty_window(&mut self) -> &mut VisualTestContext {
 221        let mut cx = self.app.borrow_mut();
 222        let bounds = Bounds::maximized(None, &mut cx);
 223        let window = cx
 224            .open_window(
 225                WindowOptions {
 226                    window_bounds: Some(WindowBounds::Windowed(bounds)),
 227                    ..Default::default()
 228                },
 229                |_, cx| cx.new(|_| Empty),
 230            )
 231            .unwrap();
 232        drop(cx);
 233        let cx = VisualTestContext::from_window(*window.deref(), self).as_mut();
 234        cx.run_until_parked();
 235        cx
 236    }
 237
 238    /// Adds a new window, and returns its root view and a `VisualTestContext` which can be used
 239    /// as a `Window` and `App` for the rest of the test. Typically you would shadow this context with
 240    /// the returned one. `let (view, cx) = cx.add_window_view(...);`
 241    pub fn add_window_view<F, V>(
 242        &mut self,
 243        build_root_view: F,
 244    ) -> (Entity<V>, &mut VisualTestContext)
 245    where
 246        F: FnOnce(&mut Window, &mut Context<V>) -> V,
 247        V: 'static + Render,
 248    {
 249        let mut cx = self.app.borrow_mut();
 250        let bounds = Bounds::maximized(None, &mut cx);
 251        let window = cx
 252            .open_window(
 253                WindowOptions {
 254                    window_bounds: Some(WindowBounds::Windowed(bounds)),
 255                    ..Default::default()
 256                },
 257                |window, cx| cx.new(|cx| build_root_view(window, cx)),
 258            )
 259            .unwrap();
 260        drop(cx);
 261        let view = window.root(self).unwrap();
 262        let cx = VisualTestContext::from_window(*window.deref(), self).as_mut();
 263        cx.run_until_parked();
 264
 265        // it might be nice to try and cleanup these at the end of each test.
 266        (view, cx)
 267    }
 268
 269    /// returns the TextSystem
 270    pub fn text_system(&self) -> &Arc<TextSystem> {
 271        &self.text_system
 272    }
 273
 274    /// Simulates writing to the platform clipboard
 275    pub fn write_to_clipboard(&self, item: ClipboardItem) {
 276        self.test_platform.write_to_clipboard(item)
 277    }
 278
 279    /// Simulates reading from the platform clipboard.
 280    /// This will return the most recent value from `write_to_clipboard`.
 281    pub fn read_from_clipboard(&self) -> Option<ClipboardItem> {
 282        self.test_platform.read_from_clipboard()
 283    }
 284
 285    /// Simulates choosing a File in the platform's "Open" dialog.
 286    pub fn simulate_new_path_selection(
 287        &self,
 288        select_path: impl FnOnce(&std::path::Path) -> Option<std::path::PathBuf>,
 289    ) {
 290        self.test_platform.simulate_new_path_selection(select_path);
 291    }
 292
 293    /// Simulates clicking a button in an platform-level alert dialog.
 294    #[track_caller]
 295    pub fn simulate_prompt_answer(&self, button: &str) {
 296        self.test_platform.simulate_prompt_answer(button);
 297    }
 298
 299    /// Returns true if there's an alert dialog open.
 300    pub fn has_pending_prompt(&self) -> bool {
 301        self.test_platform.has_pending_prompt()
 302    }
 303
 304    /// Returns true if there's an alert dialog open.
 305    pub fn pending_prompt(&self) -> Option<(String, String)> {
 306        self.test_platform.pending_prompt()
 307    }
 308
 309    /// All the urls that have been opened with cx.open_url() during this test.
 310    pub fn opened_url(&self) -> Option<String> {
 311        self.test_platform.opened_url.borrow().clone()
 312    }
 313
 314    /// Simulates the user resizing the window to the new size.
 315    pub fn simulate_window_resize(&self, window_handle: AnyWindowHandle, size: Size<Pixels>) {
 316        self.test_window(window_handle).simulate_resize(size);
 317    }
 318
 319    /// Causes the given sources to be returned if the application queries for screen
 320    /// capture sources.
 321    pub fn set_screen_capture_sources(&self, sources: Vec<TestScreenCaptureSource>) {
 322        self.test_platform.set_screen_capture_sources(sources);
 323    }
 324
 325    /// Returns all windows open in the test.
 326    pub fn windows(&self) -> Vec<AnyWindowHandle> {
 327        self.app.borrow().windows().clone()
 328    }
 329
 330    /// Run the given task on the main thread.
 331    #[track_caller]
 332    pub fn spawn<Fut, R>(&self, f: impl FnOnce(AsyncApp) -> Fut) -> Task<R>
 333    where
 334        Fut: Future<Output = R> + 'static,
 335        R: 'static,
 336    {
 337        self.foreground_executor.spawn(f(self.to_async()))
 338    }
 339
 340    /// true if the given global is defined
 341    pub fn has_global<G: Global>(&self) -> bool {
 342        let app = self.app.borrow();
 343        app.has_global::<G>()
 344    }
 345
 346    /// runs the given closure with a reference to the global
 347    /// panics if `has_global` would return false.
 348    pub fn read_global<G: Global, R>(&self, read: impl FnOnce(&G, &App) -> R) -> R {
 349        let app = self.app.borrow();
 350        read(app.global(), &app)
 351    }
 352
 353    /// runs the given closure with a reference to the global (if set)
 354    pub fn try_read_global<G: Global, R>(&self, read: impl FnOnce(&G, &App) -> R) -> Option<R> {
 355        let lock = self.app.borrow();
 356        Some(read(lock.try_global()?, &lock))
 357    }
 358
 359    /// sets the global in this context.
 360    pub fn set_global<G: Global>(&mut self, global: G) {
 361        let mut lock = self.app.borrow_mut();
 362        lock.update(|cx| cx.set_global(global))
 363    }
 364
 365    /// updates the global in this context. (panics if `has_global` would return false)
 366    pub fn update_global<G: Global, R>(&mut self, update: impl FnOnce(&mut G, &mut App) -> R) -> R {
 367        let mut lock = self.app.borrow_mut();
 368        lock.update(|cx| cx.update_global(update))
 369    }
 370
 371    /// Returns an `AsyncApp` which can be used to run tasks that expect to be on a background
 372    /// thread on the current thread in tests.
 373    pub fn to_async(&self) -> AsyncApp {
 374        AsyncApp {
 375            app: Rc::downgrade(&self.app),
 376            background_executor: self.background_executor.clone(),
 377            foreground_executor: self.foreground_executor.clone(),
 378        }
 379    }
 380
 381    /// Wait until there are no more pending tasks.
 382    pub fn run_until_parked(&mut self) {
 383        self.background_executor.run_until_parked()
 384    }
 385
 386    /// Simulate dispatching an action to the currently focused node in the window.
 387    pub fn dispatch_action<A>(&mut self, window: AnyWindowHandle, action: A)
 388    where
 389        A: Action,
 390    {
 391        window
 392            .update(self, |_, window, cx| {
 393                window.dispatch_action(action.boxed_clone(), cx)
 394            })
 395            .unwrap();
 396
 397        self.background_executor.run_until_parked()
 398    }
 399
 400    /// simulate_keystrokes takes a space-separated list of keys to type.
 401    /// cx.simulate_keystrokes("cmd-shift-p b k s p enter")
 402    /// in Zed, this will run backspace on the current editor through the command palette.
 403    /// This will also run the background executor until it's parked.
 404    pub fn simulate_keystrokes(&mut self, window: AnyWindowHandle, keystrokes: &str) {
 405        for keystroke in keystrokes
 406            .split(' ')
 407            .map(Keystroke::parse)
 408            .map(Result::unwrap)
 409        {
 410            self.dispatch_keystroke(window, keystroke);
 411        }
 412
 413        self.background_executor.run_until_parked()
 414    }
 415
 416    /// simulate_input takes a string of text to type.
 417    /// cx.simulate_input("abc")
 418    /// will type abc into your current editor
 419    /// This will also run the background executor until it's parked.
 420    pub fn simulate_input(&mut self, window: AnyWindowHandle, input: &str) {
 421        for keystroke in input.split("").map(Keystroke::parse).map(Result::unwrap) {
 422            self.dispatch_keystroke(window, keystroke);
 423        }
 424
 425        self.background_executor.run_until_parked()
 426    }
 427
 428    /// dispatches a single Keystroke (see also `simulate_keystrokes` and `simulate_input`)
 429    pub fn dispatch_keystroke(&mut self, window: AnyWindowHandle, keystroke: Keystroke) {
 430        self.update_window(window, |_, window, cx| {
 431            window.dispatch_keystroke(keystroke, cx)
 432        })
 433        .unwrap();
 434    }
 435
 436    /// Returns the `TestWindow` backing the given handle.
 437    pub(crate) fn test_window(&self, window: AnyWindowHandle) -> TestWindow {
 438        self.app
 439            .borrow_mut()
 440            .windows
 441            .get_mut(window.id)
 442            .unwrap()
 443            .as_mut()
 444            .unwrap()
 445            .platform_window
 446            .as_test()
 447            .unwrap()
 448            .clone()
 449    }
 450
 451    /// Returns a stream of notifications whenever the Entity is updated.
 452    pub fn notifications<T: 'static>(
 453        &mut self,
 454        entity: &Entity<T>,
 455    ) -> impl Stream<Item = ()> + use<T> {
 456        let (tx, rx) = futures::channel::mpsc::unbounded();
 457        self.update(|cx| {
 458            cx.observe(entity, {
 459                let tx = tx.clone();
 460                move |_, _| {
 461                    let _ = tx.unbounded_send(());
 462                }
 463            })
 464            .detach();
 465            cx.observe_release(entity, move |_, _| tx.close_channel())
 466                .detach()
 467        });
 468        rx
 469    }
 470
 471    /// Returns a stream of events emitted by the given Entity.
 472    pub fn events<Evt, T: 'static + EventEmitter<Evt>>(
 473        &mut self,
 474        entity: &Entity<T>,
 475    ) -> futures::channel::mpsc::UnboundedReceiver<Evt>
 476    where
 477        Evt: 'static + Clone,
 478    {
 479        let (tx, rx) = futures::channel::mpsc::unbounded();
 480        entity
 481            .update(self, |_, cx: &mut Context<T>| {
 482                cx.subscribe(entity, move |_entity, _handle, event, _cx| {
 483                    let _ = tx.unbounded_send(event.clone());
 484                })
 485            })
 486            .detach();
 487        rx
 488    }
 489
 490    /// Runs until the given condition becomes true. (Prefer `run_until_parked` if you
 491    /// don't need to jump in at a specific time).
 492    pub async fn condition<T: 'static>(
 493        &mut self,
 494        entity: &Entity<T>,
 495        mut predicate: impl FnMut(&mut T, &mut Context<T>) -> bool,
 496    ) {
 497        let timer = self.executor().timer(Duration::from_secs(3));
 498        let mut notifications = self.notifications(entity);
 499
 500        use futures::FutureExt as _;
 501        use smol::future::FutureExt as _;
 502
 503        async {
 504            loop {
 505                if entity.update(self, &mut predicate) {
 506                    return Ok(());
 507                }
 508
 509                if notifications.next().await.is_none() {
 510                    bail!("entity dropped")
 511                }
 512            }
 513        }
 514        .race(timer.map(|_| Err(anyhow!("condition timed out"))))
 515        .await
 516        .unwrap();
 517    }
 518
 519    /// Set a name for this App.
 520    #[cfg(any(test, feature = "test-support"))]
 521    pub fn set_name(&mut self, name: &'static str) {
 522        self.update(|cx| cx.name = Some(name))
 523    }
 524}
 525
 526impl<T: 'static> Entity<T> {
 527    /// Block until the next event is emitted by the entity, then return it.
 528    pub fn next_event<Event>(&self, cx: &mut TestAppContext) -> impl Future<Output = Event>
 529    where
 530        Event: Send + Clone + 'static,
 531        T: EventEmitter<Event>,
 532    {
 533        let (tx, mut rx) = oneshot::channel();
 534        let mut tx = Some(tx);
 535        let subscription = self.update(cx, |_, cx| {
 536            cx.subscribe(self, move |_, _, event, _| {
 537                if let Some(tx) = tx.take() {
 538                    _ = tx.send(event.clone());
 539                }
 540            })
 541        });
 542
 543        async move {
 544            let event = rx.await.expect("no event emitted");
 545            drop(subscription);
 546            event
 547        }
 548    }
 549}
 550
 551impl<V: 'static> Entity<V> {
 552    /// Returns a future that resolves when the view is next updated.
 553    pub fn next_notification(
 554        &self,
 555        advance_clock_by: Duration,
 556        cx: &TestAppContext,
 557    ) -> impl Future<Output = ()> {
 558        use postage::prelude::{Sink as _, Stream as _};
 559
 560        let (mut tx, mut rx) = postage::mpsc::channel(1);
 561        let subscription = cx.app.borrow_mut().observe(self, move |_, _| {
 562            tx.try_send(()).ok();
 563        });
 564
 565        let duration = if std::env::var("CI").is_ok() {
 566            Duration::from_secs(5)
 567        } else {
 568            Duration::from_secs(1)
 569        };
 570
 571        cx.executor().advance_clock(advance_clock_by);
 572
 573        async move {
 574            let notification = crate::util::timeout(duration, rx.recv())
 575                .await
 576                .expect("next notification timed out");
 577            drop(subscription);
 578            notification.expect("entity dropped while test was waiting for its next notification")
 579        }
 580    }
 581}
 582
 583impl<V> Entity<V> {
 584    /// Returns a future that resolves when the condition becomes true.
 585    pub fn condition<Evt>(
 586        &self,
 587        cx: &TestAppContext,
 588        mut predicate: impl FnMut(&V, &App) -> bool,
 589    ) -> impl Future<Output = ()>
 590    where
 591        Evt: 'static,
 592        V: EventEmitter<Evt>,
 593    {
 594        use postage::prelude::{Sink as _, Stream as _};
 595
 596        let (tx, mut rx) = postage::mpsc::channel(1024);
 597
 598        let mut cx = cx.app.borrow_mut();
 599        let subscriptions = (
 600            cx.observe(self, {
 601                let mut tx = tx.clone();
 602                move |_, _| {
 603                    tx.blocking_send(()).ok();
 604                }
 605            }),
 606            cx.subscribe(self, {
 607                let mut tx = tx.clone();
 608                move |_, _: &Evt, _| {
 609                    tx.blocking_send(()).ok();
 610                }
 611            }),
 612        );
 613
 614        let cx = cx.this.upgrade().unwrap();
 615        let handle = self.downgrade();
 616
 617        async move {
 618            crate::util::timeout(Duration::from_secs(1), async move {
 619                loop {
 620                    {
 621                        let cx = cx.borrow();
 622                        let cx = &*cx;
 623                        if predicate(
 624                            handle
 625                                .upgrade()
 626                                .expect("view dropped with pending condition")
 627                                .read(cx),
 628                            cx,
 629                        ) {
 630                            break;
 631                        }
 632                    }
 633
 634                    cx.borrow().background_executor().start_waiting();
 635                    rx.recv()
 636                        .await
 637                        .expect("view dropped with pending condition");
 638                    cx.borrow().background_executor().finish_waiting();
 639                }
 640            })
 641            .await
 642            .expect("condition timed out");
 643            drop(subscriptions);
 644        }
 645    }
 646}
 647
 648use derive_more::{Deref, DerefMut};
 649
 650use super::{Context, Entity};
 651#[derive(Deref, DerefMut, Clone)]
 652/// A VisualTestContext is the test-equivalent of a `Window` and `App`. It allows you to
 653/// run window-specific test code. It can be dereferenced to a `TextAppContext`.
 654pub struct VisualTestContext {
 655    #[deref]
 656    #[deref_mut]
 657    /// cx is the original TestAppContext (you can more easily access this using Deref)
 658    pub cx: TestAppContext,
 659    window: AnyWindowHandle,
 660}
 661
 662impl VisualTestContext {
 663    /// Provides a `Window` and `App` for the duration of the closure.
 664    pub fn update<R>(&mut self, f: impl FnOnce(&mut Window, &mut App) -> R) -> R {
 665        self.cx
 666            .update_window(self.window, |_, window, cx| f(window, cx))
 667            .unwrap()
 668    }
 669
 670    /// Creates a new VisualTestContext. You would typically shadow the passed in
 671    /// TestAppContext with this, as this is typically more useful.
 672    /// `let cx = VisualTestContext::from_window(window, cx);`
 673    pub fn from_window(window: AnyWindowHandle, cx: &TestAppContext) -> Self {
 674        Self {
 675            cx: cx.clone(),
 676            window,
 677        }
 678    }
 679
 680    /// Wait until there are no more pending tasks.
 681    pub fn run_until_parked(&self) {
 682        self.cx.background_executor.run_until_parked();
 683    }
 684
 685    /// Dispatch the action to the currently focused node.
 686    pub fn dispatch_action<A>(&mut self, action: A)
 687    where
 688        A: Action,
 689    {
 690        self.cx.dispatch_action(self.window, action)
 691    }
 692
 693    /// Read the title off the window (set by `Window#set_window_title`)
 694    pub fn window_title(&mut self) -> Option<String> {
 695        self.cx.test_window(self.window).0.lock().title.clone()
 696    }
 697
 698    /// Simulate a sequence of keystrokes `cx.simulate_keystrokes("cmd-p escape")`
 699    /// Automatically runs until parked.
 700    pub fn simulate_keystrokes(&mut self, keystrokes: &str) {
 701        self.cx.simulate_keystrokes(self.window, keystrokes)
 702    }
 703
 704    /// Simulate typing text `cx.simulate_input("hello")`
 705    /// Automatically runs until parked.
 706    pub fn simulate_input(&mut self, input: &str) {
 707        self.cx.simulate_input(self.window, input)
 708    }
 709
 710    /// Simulate a mouse move event to the given point
 711    pub fn simulate_mouse_move(
 712        &mut self,
 713        position: Point<Pixels>,
 714        button: impl Into<Option<MouseButton>>,
 715        modifiers: Modifiers,
 716    ) {
 717        self.simulate_event(MouseMoveEvent {
 718            position,
 719            modifiers,
 720            pressed_button: button.into(),
 721        })
 722    }
 723
 724    /// Simulate a mouse down event to the given point
 725    pub fn simulate_mouse_down(
 726        &mut self,
 727        position: Point<Pixels>,
 728        button: MouseButton,
 729        modifiers: Modifiers,
 730    ) {
 731        self.simulate_event(MouseDownEvent {
 732            position,
 733            modifiers,
 734            button,
 735            click_count: 1,
 736            first_mouse: false,
 737        })
 738    }
 739
 740    /// Simulate a mouse up event to the given point
 741    pub fn simulate_mouse_up(
 742        &mut self,
 743        position: Point<Pixels>,
 744        button: MouseButton,
 745        modifiers: Modifiers,
 746    ) {
 747        self.simulate_event(MouseUpEvent {
 748            position,
 749            modifiers,
 750            button,
 751            click_count: 1,
 752        })
 753    }
 754
 755    /// Simulate a primary mouse click at the given point
 756    pub fn simulate_click(&mut self, position: Point<Pixels>, modifiers: Modifiers) {
 757        self.simulate_event(MouseDownEvent {
 758            position,
 759            modifiers,
 760            button: MouseButton::Left,
 761            click_count: 1,
 762            first_mouse: false,
 763        });
 764        self.simulate_event(MouseUpEvent {
 765            position,
 766            modifiers,
 767            button: MouseButton::Left,
 768            click_count: 1,
 769        });
 770    }
 771
 772    /// Simulate a modifiers changed event
 773    pub fn simulate_modifiers_change(&mut self, modifiers: Modifiers) {
 774        self.simulate_event(ModifiersChangedEvent { modifiers })
 775    }
 776
 777    /// Simulates the user resizing the window to the new size.
 778    pub fn simulate_resize(&self, size: Size<Pixels>) {
 779        self.simulate_window_resize(self.window, size)
 780    }
 781
 782    /// debug_bounds returns the bounds of the element with the given selector.
 783    pub fn debug_bounds(&mut self, selector: &'static str) -> Option<Bounds<Pixels>> {
 784        self.update(|window, _| window.rendered_frame.debug_bounds.get(selector).copied())
 785    }
 786
 787    /// Draw an element to the window. Useful for simulating events or actions
 788    pub fn draw<E>(
 789        &mut self,
 790        origin: Point<Pixels>,
 791        space: impl Into<Size<AvailableSpace>>,
 792        f: impl FnOnce(&mut Window, &mut App) -> E,
 793    ) -> (E::RequestLayoutState, E::PrepaintState)
 794    where
 795        E: Element,
 796    {
 797        self.update(|window, cx| {
 798            window.invalidator.set_phase(DrawPhase::Prepaint);
 799            let mut element = Drawable::new(f(window, cx));
 800            element.layout_as_root(space.into(), window, cx);
 801            window.with_absolute_element_offset(origin, |window| element.prepaint(window, cx));
 802
 803            window.invalidator.set_phase(DrawPhase::Paint);
 804            let (request_layout_state, prepaint_state) = element.paint(window, cx);
 805
 806            window.invalidator.set_phase(DrawPhase::None);
 807            window.refresh();
 808
 809            (request_layout_state, prepaint_state)
 810        })
 811    }
 812
 813    /// Simulate an event from the platform, e.g. a SrollWheelEvent
 814    /// Make sure you've called [VisualTestContext::draw] first!
 815    pub fn simulate_event<E: InputEvent>(&mut self, event: E) {
 816        self.test_window(self.window)
 817            .simulate_input(event.to_platform_input());
 818        self.background_executor.run_until_parked();
 819    }
 820
 821    /// Simulates the user blurring the window.
 822    pub fn deactivate_window(&mut self) {
 823        if Some(self.window) == self.test_platform.active_window() {
 824            self.test_platform.set_active_window(None)
 825        }
 826        self.background_executor.run_until_parked();
 827    }
 828
 829    /// Simulates the user closing the window.
 830    /// Returns true if the window was closed.
 831    pub fn simulate_close(&mut self) -> bool {
 832        let handler = self
 833            .cx
 834            .update_window(self.window, |_, window, _| {
 835                window
 836                    .platform_window
 837                    .as_test()
 838                    .unwrap()
 839                    .0
 840                    .lock()
 841                    .should_close_handler
 842                    .take()
 843            })
 844            .unwrap();
 845        if let Some(mut handler) = handler {
 846            let should_close = handler();
 847            self.cx
 848                .update_window(self.window, |_, window, _| {
 849                    window.platform_window.on_should_close(handler);
 850                })
 851                .unwrap();
 852            should_close
 853        } else {
 854            false
 855        }
 856    }
 857
 858    /// Get an &mut VisualTestContext (which is mostly what you need to pass to other methods).
 859    /// This method internally retains the VisualTestContext until the end of the test.
 860    pub fn as_mut(self) -> &'static mut Self {
 861        let ptr = Box::into_raw(Box::new(self));
 862        // safety: on_quit will be called after the test has finished.
 863        // the executor will ensure that all tasks related to the test have stopped.
 864        // so there is no way for cx to be accessed after on_quit is called.
 865        let cx = Box::leak(unsafe { Box::from_raw(ptr) });
 866        cx.on_quit(move || unsafe {
 867            drop(Box::from_raw(ptr));
 868        });
 869        cx
 870    }
 871}
 872
 873impl AppContext for VisualTestContext {
 874    type Result<T> = <TestAppContext as AppContext>::Result<T>;
 875
 876    fn new<T: 'static>(
 877        &mut self,
 878        build_entity: impl FnOnce(&mut Context<T>) -> T,
 879    ) -> Self::Result<Entity<T>> {
 880        self.cx.new(build_entity)
 881    }
 882
 883    fn reserve_entity<T: 'static>(&mut self) -> Self::Result<crate::Reservation<T>> {
 884        self.cx.reserve_entity()
 885    }
 886
 887    fn insert_entity<T: 'static>(
 888        &mut self,
 889        reservation: crate::Reservation<T>,
 890        build_entity: impl FnOnce(&mut Context<T>) -> T,
 891    ) -> Self::Result<Entity<T>> {
 892        self.cx.insert_entity(reservation, build_entity)
 893    }
 894
 895    fn update_entity<T, R>(
 896        &mut self,
 897        handle: &Entity<T>,
 898        update: impl FnOnce(&mut T, &mut Context<T>) -> R,
 899    ) -> Self::Result<R>
 900    where
 901        T: 'static,
 902    {
 903        self.cx.update_entity(handle, update)
 904    }
 905
 906    fn read_entity<T, R>(
 907        &self,
 908        handle: &Entity<T>,
 909        read: impl FnOnce(&T, &App) -> R,
 910    ) -> Self::Result<R>
 911    where
 912        T: 'static,
 913    {
 914        self.cx.read_entity(handle, read)
 915    }
 916
 917    fn update_window<T, F>(&mut self, window: AnyWindowHandle, f: F) -> Result<T>
 918    where
 919        F: FnOnce(AnyView, &mut Window, &mut App) -> T,
 920    {
 921        self.cx.update_window(window, f)
 922    }
 923
 924    fn read_window<T, R>(
 925        &self,
 926        window: &WindowHandle<T>,
 927        read: impl FnOnce(Entity<T>, &App) -> R,
 928    ) -> Result<R>
 929    where
 930        T: 'static,
 931    {
 932        self.cx.read_window(window, read)
 933    }
 934
 935    fn background_spawn<R>(&self, future: impl Future<Output = R> + Send + 'static) -> Task<R>
 936    where
 937        R: Send + 'static,
 938    {
 939        self.cx.background_spawn(future)
 940    }
 941
 942    fn read_global<G, R>(&self, callback: impl FnOnce(&G, &App) -> R) -> Self::Result<R>
 943    where
 944        G: Global,
 945    {
 946        self.cx.read_global(callback)
 947    }
 948}
 949
 950impl VisualContext for VisualTestContext {
 951    /// Get the underlying window handle underlying this context.
 952    fn window_handle(&self) -> AnyWindowHandle {
 953        self.window
 954    }
 955
 956    fn new_window_entity<T: 'static>(
 957        &mut self,
 958        build_entity: impl FnOnce(&mut Window, &mut Context<T>) -> T,
 959    ) -> Self::Result<Entity<T>> {
 960        self.window
 961            .update(&mut self.cx, |_, window, cx| {
 962                cx.new(|cx| build_entity(window, cx))
 963            })
 964            .unwrap()
 965    }
 966
 967    fn update_window_entity<V: 'static, R>(
 968        &mut self,
 969        view: &Entity<V>,
 970        update: impl FnOnce(&mut V, &mut Window, &mut Context<V>) -> R,
 971    ) -> Self::Result<R> {
 972        self.window
 973            .update(&mut self.cx, |_, window, cx| {
 974                view.update(cx, |v, cx| update(v, window, cx))
 975            })
 976            .unwrap()
 977    }
 978
 979    fn replace_root_view<V>(
 980        &mut self,
 981        build_view: impl FnOnce(&mut Window, &mut Context<V>) -> V,
 982    ) -> Self::Result<Entity<V>>
 983    where
 984        V: 'static + Render,
 985    {
 986        self.window
 987            .update(&mut self.cx, |_, window, cx| {
 988                window.replace_root(cx, build_view)
 989            })
 990            .unwrap()
 991    }
 992
 993    fn focus<V: crate::Focusable>(&mut self, view: &Entity<V>) -> Self::Result<()> {
 994        self.window
 995            .update(&mut self.cx, |_, window, cx| {
 996                view.read(cx).focus_handle(cx).clone().focus(window)
 997            })
 998            .unwrap()
 999    }
1000}
1001
1002impl AnyWindowHandle {
1003    /// Creates the given view in this window.
1004    pub fn build_entity<V: Render + 'static>(
1005        &self,
1006        cx: &mut TestAppContext,
1007        build_view: impl FnOnce(&mut Window, &mut Context<V>) -> V,
1008    ) -> Entity<V> {
1009        self.update(cx, |_, window, cx| cx.new(|cx| build_view(window, cx)))
1010            .unwrap()
1011    }
1012}