test_context.rs

   1use crate::{
   2    Action, AnyView, AnyWindowHandle, App, AppCell, AppContext, AsyncApp, AvailableSpace,
   3    BackgroundExecutor, BorrowAppContext, Bounds, Capslock, ClipboardItem, DrawPhase, Drawable,
   4    Element, Empty, EventEmitter, ForegroundExecutor, Global, InputEvent, Keystroke, Modifiers,
   5    ModifiersChangedEvent, MouseButton, MouseDownEvent, MouseMoveEvent, MouseUpEvent, Pixels,
   6    Platform, Point, Render, Result, Size, Task, TestPlatform, TestScreenCaptureSource, TestWindow,
   7    TextSystem, VisualContext, Window, WindowBounds, WindowHandle, WindowOptions,
   8};
   9use anyhow::{anyhow, bail};
  10use futures::{Stream, StreamExt, channel::oneshot};
  11use scheduler::{TestScheduler, TestSchedulerConfig};
  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 scheduler: Arc<TestScheduler>,
  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 as_mut<'a, T>(&'a mut self, _: &Entity<T>) -> Self::Result<super::GpuiBorrow<'a, T>>
  67    where
  68        T: 'static,
  69    {
  70        panic!("Cannot use as_mut with a test app context. Try calling update() first")
  71    }
  72
  73    fn read_entity<T, R>(
  74        &self,
  75        handle: &Entity<T>,
  76        read: impl FnOnce(&T, &App) -> R,
  77    ) -> Self::Result<R>
  78    where
  79        T: 'static,
  80    {
  81        let app = self.app.borrow();
  82        app.read_entity(handle, read)
  83    }
  84
  85    fn update_window<T, F>(&mut self, window: AnyWindowHandle, f: F) -> Result<T>
  86    where
  87        F: FnOnce(AnyView, &mut Window, &mut App) -> T,
  88    {
  89        let mut lock = self.app.borrow_mut();
  90        lock.update_window(window, f)
  91    }
  92
  93    fn read_window<T, R>(
  94        &self,
  95        window: &WindowHandle<T>,
  96        read: impl FnOnce(Entity<T>, &App) -> R,
  97    ) -> Result<R>
  98    where
  99        T: 'static,
 100    {
 101        let app = self.app.borrow();
 102        app.read_window(window, read)
 103    }
 104
 105    fn background_spawn<R>(&self, future: impl Future<Output = R> + Send + 'static) -> Task<R>
 106    where
 107        R: Send + 'static,
 108    {
 109        self.background_executor.spawn(future)
 110    }
 111
 112    fn read_global<G, R>(&self, callback: impl FnOnce(&G, &App) -> R) -> Self::Result<R>
 113    where
 114        G: Global,
 115    {
 116        let app = self.app.borrow();
 117        app.read_global(callback)
 118    }
 119}
 120
 121impl TestAppContext {
 122    /// Creates a new `TestAppContext`. Usually you can rely on `#[gpui::test]` to do this for you.
 123    pub fn build(scheduler: Arc<TestScheduler>, fn_name: Option<&'static str>) -> Self {
 124        let background_executor = BackgroundExecutor::new(scheduler.background());
 125        let foreground_executor = ForegroundExecutor::new(scheduler.foreground());
 126        let platform = TestPlatform::new(background_executor.clone(), foreground_executor.clone());
 127        let asset_source = Arc::new(());
 128        let http_client = http_client::FakeHttpClient::with_404_response();
 129        let text_system = Arc::new(TextSystem::new(platform.text_system()));
 130
 131        Self {
 132            app: App::new_app(platform.clone(), asset_source, http_client),
 133            background_executor,
 134            foreground_executor,
 135            scheduler,
 136            test_platform: platform,
 137            text_system,
 138            fn_name,
 139            on_quit: Rc::new(RefCell::new(Vec::default())),
 140        }
 141    }
 142
 143    /// Create a single TestAppContext, for non-multi-client tests
 144    pub fn single() -> Self {
 145        Self::build(
 146            Arc::new(TestScheduler::new(TestSchedulerConfig::with_seed(0))),
 147            None,
 148        )
 149    }
 150
 151    /// The name of the test function that created this `TestAppContext`
 152    pub fn test_function_name(&self) -> Option<&'static str> {
 153        self.fn_name
 154    }
 155
 156    /// Checks whether there have been any new path prompts received by the platform.
 157    pub fn did_prompt_for_new_path(&self) -> bool {
 158        self.test_platform.did_prompt_for_new_path()
 159    }
 160
 161    /// returns a new `TestAppContext` re-using the same executors to interleave tasks.
 162    pub fn new_app(&self) -> TestAppContext {
 163        Self::build(self.scheduler.clone(), self.fn_name)
 164    }
 165
 166    /// Called by the test helper to end the test.
 167    /// public so the macro can call it.
 168    pub fn quit(&self) {
 169        self.on_quit.borrow_mut().drain(..).for_each(|f| f());
 170        self.app.borrow_mut().shutdown();
 171    }
 172
 173    /// Register cleanup to run when the test ends.
 174    pub fn on_quit(&mut self, f: impl FnOnce() + 'static) {
 175        self.on_quit.borrow_mut().push(Box::new(f));
 176    }
 177
 178    /// Schedules all windows to be redrawn on the next effect cycle.
 179    pub fn refresh(&mut self) -> Result<()> {
 180        let mut app = self.app.borrow_mut();
 181        app.refresh_windows();
 182        Ok(())
 183    }
 184
 185    /// Returns an executor (for running tasks in the background)
 186    pub fn executor(&self) -> BackgroundExecutor {
 187        self.background_executor.clone()
 188    }
 189
 190    /// Returns an executor (for running tasks on the main thread)
 191    pub fn foreground_executor(&self) -> ForegroundExecutor {
 192        self.foreground_executor.clone()
 193    }
 194
 195    #[expect(clippy::wrong_self_convention)]
 196    fn new<T: 'static>(&mut self, build_entity: impl FnOnce(&mut Context<T>) -> T) -> Entity<T> {
 197        let mut cx = self.app.borrow_mut();
 198        cx.new(build_entity)
 199    }
 200
 201    /// Gives you an `&mut App` for the duration of the closure
 202    pub fn update<R>(&self, f: impl FnOnce(&mut App) -> R) -> R {
 203        let mut cx = self.app.borrow_mut();
 204        cx.update(f)
 205    }
 206
 207    /// Gives you an `&App` for the duration of the closure
 208    pub fn read<R>(&self, f: impl FnOnce(&App) -> R) -> R {
 209        let cx = self.app.borrow();
 210        f(&cx)
 211    }
 212
 213    /// Adds a new window. The Window will always be backed by a `TestWindow` which
 214    /// can be retrieved with `self.test_window(handle)`
 215    pub fn add_window<F, V>(&mut self, build_window: F) -> WindowHandle<V>
 216    where
 217        F: FnOnce(&mut Window, &mut Context<V>) -> V,
 218        V: 'static + Render,
 219    {
 220        let mut cx = self.app.borrow_mut();
 221
 222        // Some tests rely on the window size matching the bounds of the test display
 223        let bounds = Bounds::maximized(None, &cx);
 224        cx.open_window(
 225            WindowOptions {
 226                window_bounds: Some(WindowBounds::Windowed(bounds)),
 227                ..Default::default()
 228            },
 229            |window, cx| cx.new(|cx| build_window(window, cx)),
 230        )
 231        .unwrap()
 232    }
 233
 234    /// Adds a new window with no content.
 235    pub fn add_empty_window(&mut self) -> &mut VisualTestContext {
 236        let mut cx = self.app.borrow_mut();
 237        let bounds = Bounds::maximized(None, &cx);
 238        let window = cx
 239            .open_window(
 240                WindowOptions {
 241                    window_bounds: Some(WindowBounds::Windowed(bounds)),
 242                    ..Default::default()
 243                },
 244                |_, cx| cx.new(|_| Empty),
 245            )
 246            .unwrap();
 247        drop(cx);
 248        let cx = VisualTestContext::from_window(*window.deref(), self).into_mut();
 249        cx.run_until_parked();
 250        cx
 251    }
 252
 253    /// Adds a new window, and returns its root view and a `VisualTestContext` which can be used
 254    /// as a `Window` and `App` for the rest of the test. Typically you would shadow this context with
 255    /// the returned one. `let (view, cx) = cx.add_window_view(...);`
 256    pub fn add_window_view<F, V>(
 257        &mut self,
 258        build_root_view: F,
 259    ) -> (Entity<V>, &mut VisualTestContext)
 260    where
 261        F: FnOnce(&mut Window, &mut Context<V>) -> V,
 262        V: 'static + Render,
 263    {
 264        let mut cx = self.app.borrow_mut();
 265        let bounds = Bounds::maximized(None, &cx);
 266        let window = cx
 267            .open_window(
 268                WindowOptions {
 269                    window_bounds: Some(WindowBounds::Windowed(bounds)),
 270                    ..Default::default()
 271                },
 272                |window, cx| cx.new(|cx| build_root_view(window, cx)),
 273            )
 274            .unwrap();
 275        drop(cx);
 276        let view = window.root(self).unwrap();
 277        let cx = VisualTestContext::from_window(*window.deref(), self).into_mut();
 278        cx.run_until_parked();
 279
 280        // it might be nice to try and cleanup these at the end of each test.
 281        (view, cx)
 282    }
 283
 284    /// returns the TextSystem
 285    pub fn text_system(&self) -> &Arc<TextSystem> {
 286        &self.text_system
 287    }
 288
 289    /// Simulates writing to the platform clipboard
 290    pub fn write_to_clipboard(&self, item: ClipboardItem) {
 291        self.test_platform.write_to_clipboard(item)
 292    }
 293
 294    /// Simulates reading from the platform clipboard.
 295    /// This will return the most recent value from `write_to_clipboard`.
 296    pub fn read_from_clipboard(&self) -> Option<ClipboardItem> {
 297        self.test_platform.read_from_clipboard()
 298    }
 299
 300    /// Simulates choosing a File in the platform's "Open" dialog.
 301    pub fn simulate_new_path_selection(
 302        &self,
 303        select_path: impl FnOnce(&std::path::Path) -> Option<std::path::PathBuf>,
 304    ) {
 305        self.test_platform.simulate_new_path_selection(select_path);
 306    }
 307
 308    /// Simulates clicking a button in an platform-level alert dialog.
 309    #[track_caller]
 310    pub fn simulate_prompt_answer(&self, button: &str) {
 311        self.test_platform.simulate_prompt_answer(button);
 312    }
 313
 314    /// Returns true if there's an alert dialog open.
 315    pub fn has_pending_prompt(&self) -> bool {
 316        self.test_platform.has_pending_prompt()
 317    }
 318
 319    /// Returns true if there's an alert dialog open.
 320    pub fn pending_prompt(&self) -> Option<(String, String)> {
 321        self.test_platform.pending_prompt()
 322    }
 323
 324    /// All the urls that have been opened with cx.open_url() during this test.
 325    pub fn opened_url(&self) -> Option<String> {
 326        self.test_platform.opened_url.borrow().clone()
 327    }
 328
 329    /// Simulates the user resizing the window to the new size.
 330    pub fn simulate_window_resize(&self, window_handle: AnyWindowHandle, size: Size<Pixels>) {
 331        self.test_window(window_handle).simulate_resize(size);
 332    }
 333
 334    /// Causes the given sources to be returned if the application queries for screen
 335    /// capture sources.
 336    pub fn set_screen_capture_sources(&self, sources: Vec<TestScreenCaptureSource>) {
 337        self.test_platform.set_screen_capture_sources(sources);
 338    }
 339
 340    /// Returns all windows open in the test.
 341    pub fn windows(&self) -> Vec<AnyWindowHandle> {
 342        self.app.borrow().windows()
 343    }
 344
 345    /// Run the given task on the main thread.
 346    #[track_caller]
 347    pub fn spawn<Fut, R>(&self, f: impl FnOnce(AsyncApp) -> Fut) -> Task<R>
 348    where
 349        Fut: Future<Output = R> + 'static,
 350        R: 'static,
 351    {
 352        self.foreground_executor.spawn(f(self.to_async()))
 353    }
 354
 355    /// true if the given global is defined
 356    pub fn has_global<G: Global>(&self) -> bool {
 357        let app = self.app.borrow();
 358        app.has_global::<G>()
 359    }
 360
 361    /// runs the given closure with a reference to the global
 362    /// panics if `has_global` would return false.
 363    pub fn read_global<G: Global, R>(&self, read: impl FnOnce(&G, &App) -> R) -> R {
 364        let app = self.app.borrow();
 365        read(app.global(), &app)
 366    }
 367
 368    /// runs the given closure with a reference to the global (if set)
 369    pub fn try_read_global<G: Global, R>(&self, read: impl FnOnce(&G, &App) -> R) -> Option<R> {
 370        let lock = self.app.borrow();
 371        Some(read(lock.try_global()?, &lock))
 372    }
 373
 374    /// sets the global in this context.
 375    pub fn set_global<G: Global>(&mut self, global: G) {
 376        let mut lock = self.app.borrow_mut();
 377        lock.update(|cx| cx.set_global(global))
 378    }
 379
 380    /// updates the global in this context. (panics if `has_global` would return false)
 381    pub fn update_global<G: Global, R>(&mut self, update: impl FnOnce(&mut G, &mut App) -> R) -> R {
 382        let mut lock = self.app.borrow_mut();
 383        lock.update(|cx| cx.update_global(update))
 384    }
 385
 386    /// Returns an `AsyncApp` which can be used to run tasks that expect to be on a background
 387    /// thread on the current thread in tests.
 388    pub fn to_async(&self) -> AsyncApp {
 389        AsyncApp {
 390            app: Rc::downgrade(&self.app),
 391            background_executor: self.background_executor.clone(),
 392            foreground_executor: self.foreground_executor.clone(),
 393        }
 394    }
 395
 396    /// Wait until there are no more pending tasks.
 397    pub fn run_until_parked(&mut self) {
 398        self.background_executor.run_until_parked()
 399    }
 400
 401    /// Simulate dispatching an action to the currently focused node in the window.
 402    pub fn dispatch_action<A>(&mut self, window: AnyWindowHandle, action: A)
 403    where
 404        A: Action,
 405    {
 406        window
 407            .update(self, |_, window, cx| {
 408                window.dispatch_action(action.boxed_clone(), cx)
 409            })
 410            .unwrap();
 411
 412        self.background_executor.run_until_parked()
 413    }
 414
 415    /// simulate_keystrokes takes a space-separated list of keys to type.
 416    /// cx.simulate_keystrokes("cmd-shift-p b k s p enter")
 417    /// in Zed, this will run backspace on the current editor through the command palette.
 418    /// This will also run the background executor until it's parked.
 419    pub fn simulate_keystrokes(&mut self, window: AnyWindowHandle, keystrokes: &str) {
 420        for keystroke in keystrokes
 421            .split(' ')
 422            .map(Keystroke::parse)
 423            .map(Result::unwrap)
 424        {
 425            self.dispatch_keystroke(window, keystroke);
 426        }
 427
 428        self.background_executor.run_until_parked()
 429    }
 430
 431    /// simulate_input takes a string of text to type.
 432    /// cx.simulate_input("abc")
 433    /// will type abc into your current editor
 434    /// This will also run the background executor until it's parked.
 435    pub fn simulate_input(&mut self, window: AnyWindowHandle, input: &str) {
 436        for keystroke in input.split("").map(Keystroke::parse).map(Result::unwrap) {
 437            self.dispatch_keystroke(window, keystroke);
 438        }
 439
 440        self.background_executor.run_until_parked()
 441    }
 442
 443    /// dispatches a single Keystroke (see also `simulate_keystrokes` and `simulate_input`)
 444    pub fn dispatch_keystroke(&mut self, window: AnyWindowHandle, keystroke: Keystroke) {
 445        self.update_window(window, |_, window, cx| {
 446            window.dispatch_keystroke(keystroke, cx)
 447        })
 448        .unwrap();
 449    }
 450
 451    /// Returns the `TestWindow` backing the given handle.
 452    pub(crate) fn test_window(&self, window: AnyWindowHandle) -> TestWindow {
 453        self.app
 454            .borrow_mut()
 455            .windows
 456            .get_mut(window.id)
 457            .unwrap()
 458            .as_mut()
 459            .unwrap()
 460            .platform_window
 461            .as_test()
 462            .unwrap()
 463            .clone()
 464    }
 465
 466    /// Returns a stream of notifications whenever the Entity is updated.
 467    pub fn notifications<T: 'static>(
 468        &mut self,
 469        entity: &Entity<T>,
 470    ) -> impl Stream<Item = ()> + use<T> {
 471        let (tx, rx) = futures::channel::mpsc::unbounded();
 472        self.update(|cx| {
 473            cx.observe(entity, {
 474                let tx = tx.clone();
 475                move |_, _| {
 476                    let _ = tx.unbounded_send(());
 477                }
 478            })
 479            .detach();
 480            cx.observe_release(entity, move |_, _| tx.close_channel())
 481                .detach()
 482        });
 483        rx
 484    }
 485
 486    /// Returns a stream of events emitted by the given Entity.
 487    pub fn events<Evt, T: 'static + EventEmitter<Evt>>(
 488        &mut self,
 489        entity: &Entity<T>,
 490    ) -> futures::channel::mpsc::UnboundedReceiver<Evt>
 491    where
 492        Evt: 'static + Clone,
 493    {
 494        let (tx, rx) = futures::channel::mpsc::unbounded();
 495        entity
 496            .update(self, |_, cx: &mut Context<T>| {
 497                cx.subscribe(entity, move |_entity, _handle, event, _cx| {
 498                    let _ = tx.unbounded_send(event.clone());
 499                })
 500            })
 501            .detach();
 502        rx
 503    }
 504
 505    /// Runs until the given condition becomes true. (Prefer `run_until_parked` if you
 506    /// don't need to jump in at a specific time).
 507    pub async fn condition<T: 'static>(
 508        &mut self,
 509        entity: &Entity<T>,
 510        mut predicate: impl FnMut(&mut T, &mut Context<T>) -> bool,
 511    ) {
 512        let timer = self.executor().timer(Duration::from_secs(3));
 513        let mut notifications = self.notifications(entity);
 514
 515        use futures::FutureExt as _;
 516        use smol::future::FutureExt as _;
 517
 518        async {
 519            loop {
 520                if entity.update(self, &mut predicate) {
 521                    return Ok(());
 522                }
 523
 524                if notifications.next().await.is_none() {
 525                    bail!("entity dropped")
 526                }
 527            }
 528        }
 529        .race(timer.map(|_| Err(anyhow!("condition timed out"))))
 530        .await
 531        .unwrap();
 532    }
 533
 534    /// Set a name for this App.
 535    #[cfg(any(test, feature = "test-support"))]
 536    pub fn set_name(&mut self, name: &'static str) {
 537        self.update(|cx| cx.name = Some(name))
 538    }
 539}
 540
 541impl<T: 'static> Entity<T> {
 542    /// Block until the next event is emitted by the entity, then return it.
 543    pub fn next_event<Event>(&self, cx: &mut TestAppContext) -> impl Future<Output = Event>
 544    where
 545        Event: Send + Clone + 'static,
 546        T: EventEmitter<Event>,
 547    {
 548        let (tx, mut rx) = oneshot::channel();
 549        let mut tx = Some(tx);
 550        let subscription = self.update(cx, |_, cx| {
 551            cx.subscribe(self, move |_, _, event, _| {
 552                if let Some(tx) = tx.take() {
 553                    _ = tx.send(event.clone());
 554                }
 555            })
 556        });
 557
 558        async move {
 559            let event = rx.await.expect("no event emitted");
 560            drop(subscription);
 561            event
 562        }
 563    }
 564}
 565
 566impl<V: 'static> Entity<V> {
 567    /// Returns a future that resolves when the view is next updated.
 568    pub fn next_notification(
 569        &self,
 570        advance_clock_by: Duration,
 571        cx: &TestAppContext,
 572    ) -> impl Future<Output = ()> {
 573        use postage::prelude::{Sink as _, Stream as _};
 574
 575        let (mut tx, mut rx) = postage::mpsc::channel(1);
 576        let subscription = cx.app.borrow_mut().observe(self, move |_, _| {
 577            tx.try_send(()).ok();
 578        });
 579
 580        let duration = if std::env::var("CI").is_ok() {
 581            Duration::from_secs(5)
 582        } else {
 583            Duration::from_secs(1)
 584        };
 585
 586        cx.executor().advance_clock(advance_clock_by);
 587
 588        async move {
 589            let notification = crate::util::smol_timeout(duration, rx.recv())
 590                .await
 591                .expect("next notification timed out");
 592            drop(subscription);
 593            notification.expect("entity dropped while test was waiting for its next notification")
 594        }
 595    }
 596}
 597
 598impl<V> Entity<V> {
 599    /// Returns a future that resolves when the condition becomes true.
 600    pub fn condition<Evt>(
 601        &self,
 602        cx: &TestAppContext,
 603        mut predicate: impl FnMut(&V, &App) -> bool,
 604    ) -> impl Future<Output = ()>
 605    where
 606        Evt: 'static,
 607        V: EventEmitter<Evt>,
 608    {
 609        use postage::prelude::{Sink as _, Stream as _};
 610
 611        let (tx, mut rx) = postage::mpsc::channel(1024);
 612
 613        let mut cx = cx.app.borrow_mut();
 614        let subscriptions = (
 615            cx.observe(self, {
 616                let mut tx = tx.clone();
 617                move |_, _| {
 618                    tx.blocking_send(()).ok();
 619                }
 620            }),
 621            cx.subscribe(self, {
 622                let mut tx = tx;
 623                move |_, _: &Evt, _| {
 624                    tx.blocking_send(()).ok();
 625                }
 626            }),
 627        );
 628
 629        let cx = cx.this.upgrade().unwrap();
 630        let handle = self.downgrade();
 631
 632        async move {
 633            crate::util::smol_timeout(Duration::from_secs(1), async move {
 634                loop {
 635                    {
 636                        let cx = cx.borrow();
 637                        let cx = &*cx;
 638                        if predicate(
 639                            handle
 640                                .upgrade()
 641                                .expect("view dropped with pending condition")
 642                                .read(cx),
 643                            cx,
 644                        ) {
 645                            break;
 646                        }
 647                    }
 648
 649                    rx.recv()
 650                        .await
 651                        .expect("view dropped with pending condition");
 652                }
 653            })
 654            .await
 655            .expect("condition timed out");
 656            drop(subscriptions);
 657        }
 658    }
 659}
 660
 661use derive_more::{Deref, DerefMut};
 662
 663use super::{Context, Entity};
 664#[derive(Deref, DerefMut, Clone)]
 665/// A VisualTestContext is the test-equivalent of a `Window` and `App`. It allows you to
 666/// run window-specific test code. It can be dereferenced to a `TextAppContext`.
 667pub struct VisualTestContext {
 668    #[deref]
 669    #[deref_mut]
 670    /// cx is the original TestAppContext (you can more easily access this using Deref)
 671    pub cx: TestAppContext,
 672    window: AnyWindowHandle,
 673}
 674
 675impl VisualTestContext {
 676    /// Provides a `Window` and `App` for the duration of the closure.
 677    pub fn update<R>(&mut self, f: impl FnOnce(&mut Window, &mut App) -> R) -> R {
 678        self.cx
 679            .update_window(self.window, |_, window, cx| f(window, cx))
 680            .unwrap()
 681    }
 682
 683    /// Creates a new VisualTestContext. You would typically shadow the passed in
 684    /// TestAppContext with this, as this is typically more useful.
 685    /// `let cx = VisualTestContext::from_window(window, cx);`
 686    pub fn from_window(window: AnyWindowHandle, cx: &TestAppContext) -> Self {
 687        Self {
 688            cx: cx.clone(),
 689            window,
 690        }
 691    }
 692
 693    /// Wait until there are no more pending tasks.
 694    pub fn run_until_parked(&self) {
 695        self.cx.background_executor.run_until_parked();
 696    }
 697
 698    /// Dispatch the action to the currently focused node.
 699    pub fn dispatch_action<A>(&mut self, action: A)
 700    where
 701        A: Action,
 702    {
 703        self.cx.dispatch_action(self.window, action)
 704    }
 705
 706    /// Read the title off the window (set by `Window#set_window_title`)
 707    pub fn window_title(&mut self) -> Option<String> {
 708        self.cx.test_window(self.window).0.lock().title.clone()
 709    }
 710
 711    /// Simulate a sequence of keystrokes `cx.simulate_keystrokes("cmd-p escape")`
 712    /// Automatically runs until parked.
 713    pub fn simulate_keystrokes(&mut self, keystrokes: &str) {
 714        self.cx.simulate_keystrokes(self.window, keystrokes)
 715    }
 716
 717    /// Simulate typing text `cx.simulate_input("hello")`
 718    /// Automatically runs until parked.
 719    pub fn simulate_input(&mut self, input: &str) {
 720        self.cx.simulate_input(self.window, input)
 721    }
 722
 723    /// Simulate a mouse move event to the given point
 724    pub fn simulate_mouse_move(
 725        &mut self,
 726        position: Point<Pixels>,
 727        button: impl Into<Option<MouseButton>>,
 728        modifiers: Modifiers,
 729    ) {
 730        self.simulate_event(MouseMoveEvent {
 731            position,
 732            modifiers,
 733            pressed_button: button.into(),
 734        })
 735    }
 736
 737    /// Simulate a mouse down event to the given point
 738    pub fn simulate_mouse_down(
 739        &mut self,
 740        position: Point<Pixels>,
 741        button: MouseButton,
 742        modifiers: Modifiers,
 743    ) {
 744        self.simulate_event(MouseDownEvent {
 745            position,
 746            modifiers,
 747            button,
 748            click_count: 1,
 749            first_mouse: false,
 750        })
 751    }
 752
 753    /// Simulate a mouse up event to the given point
 754    pub fn simulate_mouse_up(
 755        &mut self,
 756        position: Point<Pixels>,
 757        button: MouseButton,
 758        modifiers: Modifiers,
 759    ) {
 760        self.simulate_event(MouseUpEvent {
 761            position,
 762            modifiers,
 763            button,
 764            click_count: 1,
 765        })
 766    }
 767
 768    /// Simulate a primary mouse click at the given point
 769    pub fn simulate_click(&mut self, position: Point<Pixels>, modifiers: Modifiers) {
 770        self.simulate_event(MouseDownEvent {
 771            position,
 772            modifiers,
 773            button: MouseButton::Left,
 774            click_count: 1,
 775            first_mouse: false,
 776        });
 777        self.simulate_event(MouseUpEvent {
 778            position,
 779            modifiers,
 780            button: MouseButton::Left,
 781            click_count: 1,
 782        });
 783    }
 784
 785    /// Simulate a modifiers changed event
 786    pub fn simulate_modifiers_change(&mut self, modifiers: Modifiers) {
 787        self.simulate_event(ModifiersChangedEvent {
 788            modifiers,
 789            capslock: Capslock { on: false },
 790        })
 791    }
 792
 793    /// Simulate a capslock changed event
 794    pub fn simulate_capslock_change(&mut self, on: bool) {
 795        self.simulate_event(ModifiersChangedEvent {
 796            modifiers: Modifiers::none(),
 797            capslock: Capslock { on },
 798        })
 799    }
 800
 801    /// Simulates the user resizing the window to the new size.
 802    pub fn simulate_resize(&self, size: Size<Pixels>) {
 803        self.simulate_window_resize(self.window, size)
 804    }
 805
 806    /// debug_bounds returns the bounds of the element with the given selector.
 807    pub fn debug_bounds(&mut self, selector: &'static str) -> Option<Bounds<Pixels>> {
 808        self.update(|window, _| window.rendered_frame.debug_bounds.get(selector).copied())
 809    }
 810
 811    /// Draw an element to the window. Useful for simulating events or actions
 812    pub fn draw<E>(
 813        &mut self,
 814        origin: Point<Pixels>,
 815        space: impl Into<Size<AvailableSpace>>,
 816        f: impl FnOnce(&mut Window, &mut App) -> E,
 817    ) -> (E::RequestLayoutState, E::PrepaintState)
 818    where
 819        E: Element,
 820    {
 821        self.update(|window, cx| {
 822            window.invalidator.set_phase(DrawPhase::Prepaint);
 823            let mut element = Drawable::new(f(window, cx));
 824            element.layout_as_root(space.into(), window, cx);
 825            window.with_absolute_element_offset(origin, |window| element.prepaint(window, cx));
 826
 827            window.invalidator.set_phase(DrawPhase::Paint);
 828            let (request_layout_state, prepaint_state) = element.paint(window, cx);
 829
 830            window.invalidator.set_phase(DrawPhase::None);
 831            window.refresh();
 832
 833            (request_layout_state, prepaint_state)
 834        })
 835    }
 836
 837    /// Simulate an event from the platform, e.g. a SrollWheelEvent
 838    /// Make sure you've called [VisualTestContext::draw] first!
 839    pub fn simulate_event<E: InputEvent>(&mut self, event: E) {
 840        self.test_window(self.window)
 841            .simulate_input(event.to_platform_input());
 842        self.background_executor.run_until_parked();
 843    }
 844
 845    /// Simulates the user blurring the window.
 846    pub fn deactivate_window(&mut self) {
 847        if Some(self.window) == self.test_platform.active_window() {
 848            self.test_platform.set_active_window(None)
 849        }
 850        self.background_executor.run_until_parked();
 851    }
 852
 853    /// Simulates the user closing the window.
 854    /// Returns true if the window was closed.
 855    pub fn simulate_close(&mut self) -> bool {
 856        let handler = self
 857            .cx
 858            .update_window(self.window, |_, window, _| {
 859                window
 860                    .platform_window
 861                    .as_test()
 862                    .unwrap()
 863                    .0
 864                    .lock()
 865                    .should_close_handler
 866                    .take()
 867            })
 868            .unwrap();
 869        if let Some(mut handler) = handler {
 870            let should_close = handler();
 871            self.cx
 872                .update_window(self.window, |_, window, _| {
 873                    window.platform_window.on_should_close(handler);
 874                })
 875                .unwrap();
 876            should_close
 877        } else {
 878            false
 879        }
 880    }
 881
 882    /// Get an &mut VisualTestContext (which is mostly what you need to pass to other methods).
 883    /// This method internally retains the VisualTestContext until the end of the test.
 884    pub fn into_mut(self) -> &'static mut Self {
 885        let ptr = Box::into_raw(Box::new(self));
 886        // safety: on_quit will be called after the test has finished.
 887        // the executor will ensure that all tasks related to the test have stopped.
 888        // so there is no way for cx to be accessed after on_quit is called.
 889        let cx = Box::leak(unsafe { Box::from_raw(ptr) });
 890        cx.on_quit(move || unsafe {
 891            drop(Box::from_raw(ptr));
 892        });
 893        cx
 894    }
 895}
 896
 897impl AppContext for VisualTestContext {
 898    type Result<T> = <TestAppContext as AppContext>::Result<T>;
 899
 900    fn new<T: 'static>(
 901        &mut self,
 902        build_entity: impl FnOnce(&mut Context<T>) -> T,
 903    ) -> Self::Result<Entity<T>> {
 904        self.cx.new(build_entity)
 905    }
 906
 907    fn reserve_entity<T: 'static>(&mut self) -> Self::Result<crate::Reservation<T>> {
 908        self.cx.reserve_entity()
 909    }
 910
 911    fn insert_entity<T: 'static>(
 912        &mut self,
 913        reservation: crate::Reservation<T>,
 914        build_entity: impl FnOnce(&mut Context<T>) -> T,
 915    ) -> Self::Result<Entity<T>> {
 916        self.cx.insert_entity(reservation, build_entity)
 917    }
 918
 919    fn update_entity<T, R>(
 920        &mut self,
 921        handle: &Entity<T>,
 922        update: impl FnOnce(&mut T, &mut Context<T>) -> R,
 923    ) -> Self::Result<R>
 924    where
 925        T: 'static,
 926    {
 927        self.cx.update_entity(handle, update)
 928    }
 929
 930    fn as_mut<'a, T>(&'a mut self, handle: &Entity<T>) -> Self::Result<super::GpuiBorrow<'a, T>>
 931    where
 932        T: 'static,
 933    {
 934        self.cx.as_mut(handle)
 935    }
 936
 937    fn read_entity<T, R>(
 938        &self,
 939        handle: &Entity<T>,
 940        read: impl FnOnce(&T, &App) -> R,
 941    ) -> Self::Result<R>
 942    where
 943        T: 'static,
 944    {
 945        self.cx.read_entity(handle, read)
 946    }
 947
 948    fn update_window<T, F>(&mut self, window: AnyWindowHandle, f: F) -> Result<T>
 949    where
 950        F: FnOnce(AnyView, &mut Window, &mut App) -> T,
 951    {
 952        self.cx.update_window(window, f)
 953    }
 954
 955    fn read_window<T, R>(
 956        &self,
 957        window: &WindowHandle<T>,
 958        read: impl FnOnce(Entity<T>, &App) -> R,
 959    ) -> Result<R>
 960    where
 961        T: 'static,
 962    {
 963        self.cx.read_window(window, read)
 964    }
 965
 966    fn background_spawn<R>(&self, future: impl Future<Output = R> + Send + 'static) -> Task<R>
 967    where
 968        R: Send + 'static,
 969    {
 970        self.cx.background_spawn(future)
 971    }
 972
 973    fn read_global<G, R>(&self, callback: impl FnOnce(&G, &App) -> R) -> Self::Result<R>
 974    where
 975        G: Global,
 976    {
 977        self.cx.read_global(callback)
 978    }
 979}
 980
 981impl VisualContext for VisualTestContext {
 982    /// Get the underlying window handle underlying this context.
 983    fn window_handle(&self) -> AnyWindowHandle {
 984        self.window
 985    }
 986
 987    fn new_window_entity<T: 'static>(
 988        &mut self,
 989        build_entity: impl FnOnce(&mut Window, &mut Context<T>) -> T,
 990    ) -> Self::Result<Entity<T>> {
 991        self.window
 992            .update(&mut self.cx, |_, window, cx| {
 993                cx.new(|cx| build_entity(window, cx))
 994            })
 995            .unwrap()
 996    }
 997
 998    fn update_window_entity<V: 'static, R>(
 999        &mut self,
1000        view: &Entity<V>,
1001        update: impl FnOnce(&mut V, &mut Window, &mut Context<V>) -> R,
1002    ) -> Self::Result<R> {
1003        self.window
1004            .update(&mut self.cx, |_, window, cx| {
1005                view.update(cx, |v, cx| update(v, window, cx))
1006            })
1007            .unwrap()
1008    }
1009
1010    fn replace_root_view<V>(
1011        &mut self,
1012        build_view: impl FnOnce(&mut Window, &mut Context<V>) -> V,
1013    ) -> Self::Result<Entity<V>>
1014    where
1015        V: 'static + Render,
1016    {
1017        self.window
1018            .update(&mut self.cx, |_, window, cx| {
1019                window.replace_root(cx, build_view)
1020            })
1021            .unwrap()
1022    }
1023
1024    fn focus<V: crate::Focusable>(&mut self, view: &Entity<V>) -> Self::Result<()> {
1025        self.window
1026            .update(&mut self.cx, |_, window, cx| {
1027                view.read(cx).focus_handle(cx).focus(window)
1028            })
1029            .unwrap()
1030    }
1031}
1032
1033impl AnyWindowHandle {
1034    /// Creates the given view in this window.
1035    pub fn build_entity<V: Render + 'static>(
1036        &self,
1037        cx: &mut TestAppContext,
1038        build_view: impl FnOnce(&mut Window, &mut Context<V>) -> V,
1039    ) -> Entity<V> {
1040        self.update(cx, |_, window, cx| cx.new(|cx| build_view(window, cx)))
1041            .unwrap()
1042    }
1043}