test_context.rs

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