1#![deny(missing_docs)]
2
3use crate::{
4 div, Action, AnyView, AnyWindowHandle, AppCell, AppContext, AsyncAppContext,
5 BackgroundExecutor, ClipboardItem, Context, Entity, EventEmitter, ForegroundExecutor,
6 IntoElement, Keystroke, Model, ModelContext, Pixels, Platform, Render, Result, Size, Task,
7 TestDispatcher, TestPlatform, TestWindow, TextSystem, View, ViewContext, VisualContext,
8 WindowContext, WindowHandle, WindowOptions,
9};
10use anyhow::{anyhow, bail};
11use futures::{Stream, StreamExt};
12use std::{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}
29
30impl Context for TestAppContext {
31 type Result<T> = T;
32
33 fn new_model<T: 'static>(
34 &mut self,
35 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
36 ) -> Self::Result<Model<T>>
37 where
38 T: 'static,
39 {
40 let mut app = self.app.borrow_mut();
41 app.new_model(build_model)
42 }
43
44 fn update_model<T: 'static, R>(
45 &mut self,
46 handle: &Model<T>,
47 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
48 ) -> Self::Result<R> {
49 let mut app = self.app.borrow_mut();
50 app.update_model(handle, update)
51 }
52
53 fn update_window<T, F>(&mut self, window: AnyWindowHandle, f: F) -> Result<T>
54 where
55 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
56 {
57 let mut lock = self.app.borrow_mut();
58 lock.update_window(window, f)
59 }
60
61 fn read_model<T, R>(
62 &self,
63 handle: &Model<T>,
64 read: impl FnOnce(&T, &AppContext) -> R,
65 ) -> Self::Result<R>
66 where
67 T: 'static,
68 {
69 let app = self.app.borrow();
70 app.read_model(handle, read)
71 }
72
73 fn read_window<T, R>(
74 &self,
75 window: &WindowHandle<T>,
76 read: impl FnOnce(View<T>, &AppContext) -> R,
77 ) -> Result<R>
78 where
79 T: 'static,
80 {
81 let app = self.app.borrow();
82 app.read_window(window, read)
83 }
84}
85
86impl TestAppContext {
87 /// Creates a new `TestAppContext`. Usually you can rely on `#[gpui::test]` to do this for you.
88 pub fn new(dispatcher: TestDispatcher) -> Self {
89 let arc_dispatcher = Arc::new(dispatcher.clone());
90 let background_executor = BackgroundExecutor::new(arc_dispatcher.clone());
91 let foreground_executor = ForegroundExecutor::new(arc_dispatcher);
92 let platform = TestPlatform::new(background_executor.clone(), foreground_executor.clone());
93 let asset_source = Arc::new(());
94 let http_client = util::http::FakeHttpClient::with_404_response();
95 let text_system = Arc::new(TextSystem::new(platform.text_system()));
96
97 Self {
98 app: AppContext::new(platform.clone(), asset_source, http_client),
99 background_executor,
100 foreground_executor,
101 dispatcher: dispatcher.clone(),
102 test_platform: platform,
103 text_system,
104 }
105 }
106
107 /// returns a new `TestAppContext` re-using the same executors to interleave tasks.
108 pub fn new_app(&self) -> TestAppContext {
109 Self::new(self.dispatcher.clone())
110 }
111
112 /// Simulates quitting the app.
113 pub fn quit(&self) {
114 self.app.borrow_mut().shutdown();
115 }
116
117 /// Schedules all windows to be redrawn on the next effect cycle.
118 pub fn refresh(&mut self) -> Result<()> {
119 let mut app = self.app.borrow_mut();
120 app.refresh();
121 Ok(())
122 }
123
124 /// Returns an executor (for running tasks in the background)
125 pub fn executor(&self) -> BackgroundExecutor {
126 self.background_executor.clone()
127 }
128
129 /// Returns an executor (for running tasks on the main thread)
130 pub fn foreground_executor(&self) -> &ForegroundExecutor {
131 &self.foreground_executor
132 }
133
134 /// Gives you an `&mut AppContext` for the duration of the closure
135 pub fn update<R>(&self, f: impl FnOnce(&mut AppContext) -> R) -> R {
136 let mut cx = self.app.borrow_mut();
137 cx.update(f)
138 }
139
140 /// Gives you an `&AppContext` for the duration of the closure
141 pub fn read<R>(&self, f: impl FnOnce(&AppContext) -> R) -> R {
142 let cx = self.app.borrow();
143 f(&*cx)
144 }
145
146 /// Adds a new window. The Window will always be backed by a `TestWindow` which
147 /// can be retrieved with `self.test_window(handle)`
148 pub fn add_window<F, V>(&mut self, build_window: F) -> WindowHandle<V>
149 where
150 F: FnOnce(&mut ViewContext<V>) -> V,
151 V: 'static + Render,
152 {
153 let mut cx = self.app.borrow_mut();
154 cx.open_window(WindowOptions::default(), |cx| cx.new_view(build_window))
155 }
156
157 /// Adds a new window with no content.
158 pub fn add_empty_window(&mut self) -> AnyWindowHandle {
159 let mut cx = self.app.borrow_mut();
160 cx.open_window(WindowOptions::default(), |cx| cx.new_view(|_| EmptyView {}))
161 .any_handle
162 }
163
164 /// Adds a new window, and returns its root view and a `VisualTestContext` which can be used
165 /// as a `WindowContext` for the rest of the test. Typically you would shadow this context with
166 /// the returned one. `let (view, cx) = cx.add_window_view(...);`
167 pub fn add_window_view<F, V>(&mut self, build_window: F) -> (View<V>, &mut VisualTestContext)
168 where
169 F: FnOnce(&mut ViewContext<V>) -> V,
170 V: 'static + Render,
171 {
172 let mut cx = self.app.borrow_mut();
173 let window = cx.open_window(WindowOptions::default(), |cx| cx.new_view(build_window));
174 drop(cx);
175 let view = window.root_view(self).unwrap();
176 let cx = Box::new(VisualTestContext::from_window(*window.deref(), self));
177 // it might be nice to try and cleanup these at the end of each test.
178 (view, Box::leak(cx))
179 }
180
181 /// returns the TextSystem
182 pub fn text_system(&self) -> &Arc<TextSystem> {
183 &self.text_system
184 }
185
186 /// Simulates writing to the platform clipboard
187 pub fn write_to_clipboard(&self, item: ClipboardItem) {
188 self.test_platform.write_to_clipboard(item)
189 }
190
191 /// Simulates reading from the platform clipboard.
192 /// This will return the most recent value from `write_to_clipboard`.
193 pub fn read_from_clipboard(&self) -> Option<ClipboardItem> {
194 self.test_platform.read_from_clipboard()
195 }
196
197 /// Simulates choosing a File in the platform's "Open" dialog.
198 pub fn simulate_new_path_selection(
199 &self,
200 select_path: impl FnOnce(&std::path::Path) -> Option<std::path::PathBuf>,
201 ) {
202 self.test_platform.simulate_new_path_selection(select_path);
203 }
204
205 /// Simulates clicking a button in an platform-level alert dialog.
206 pub fn simulate_prompt_answer(&self, button_ix: usize) {
207 self.test_platform.simulate_prompt_answer(button_ix);
208 }
209
210 /// Returns true if there's an alert dialog open.
211 pub fn has_pending_prompt(&self) -> bool {
212 self.test_platform.has_pending_prompt()
213 }
214
215 /// Simulates the user resizing the window to the new size.
216 pub fn simulate_window_resize(&self, window_handle: AnyWindowHandle, size: Size<Pixels>) {
217 self.test_window(window_handle).simulate_resize(size);
218 }
219
220 /// Returns all windows open in the test.
221 pub fn windows(&self) -> Vec<AnyWindowHandle> {
222 self.app.borrow().windows().clone()
223 }
224
225 /// Run the given task on the main thread.
226 pub fn spawn<Fut, R>(&self, f: impl FnOnce(AsyncAppContext) -> Fut) -> Task<R>
227 where
228 Fut: Future<Output = R> + 'static,
229 R: 'static,
230 {
231 self.foreground_executor.spawn(f(self.to_async()))
232 }
233
234 /// true if the given global is defined
235 pub fn has_global<G: 'static>(&self) -> bool {
236 let app = self.app.borrow();
237 app.has_global::<G>()
238 }
239
240 /// runs the given closure with a reference to the global
241 /// panics if `has_global` would return false.
242 pub fn read_global<G: 'static, R>(&self, read: impl FnOnce(&G, &AppContext) -> R) -> R {
243 let app = self.app.borrow();
244 read(app.global(), &app)
245 }
246
247 /// runs the given closure with a reference to the global (if set)
248 pub fn try_read_global<G: 'static, R>(
249 &self,
250 read: impl FnOnce(&G, &AppContext) -> R,
251 ) -> Option<R> {
252 let lock = self.app.borrow();
253 Some(read(lock.try_global()?, &lock))
254 }
255
256 /// sets the global in this context.
257 pub fn set_global<G: 'static>(&mut self, global: G) {
258 let mut lock = self.app.borrow_mut();
259 lock.set_global(global);
260 }
261
262 /// updates the global in this context. (panics if `has_global` would return false)
263 pub fn update_global<G: 'static, R>(
264 &mut self,
265 update: impl FnOnce(&mut G, &mut AppContext) -> R,
266 ) -> R {
267 let mut lock = self.app.borrow_mut();
268 lock.update_global(update)
269 }
270
271 /// Returns an `AsyncAppContext` which can be used to run tasks that expect to be on a background
272 /// thread on the current thread in tests.
273 pub fn to_async(&self) -> AsyncAppContext {
274 AsyncAppContext {
275 app: Rc::downgrade(&self.app),
276 background_executor: self.background_executor.clone(),
277 foreground_executor: self.foreground_executor.clone(),
278 }
279 }
280
281 /// Simulate dispatching an action to the currently focused node in the window.
282 pub fn dispatch_action<A>(&mut self, window: AnyWindowHandle, action: A)
283 where
284 A: Action,
285 {
286 window
287 .update(self, |_, cx| cx.dispatch_action(action.boxed_clone()))
288 .unwrap();
289
290 self.background_executor.run_until_parked()
291 }
292
293 /// simulate_keystrokes takes a space-separated list of keys to type.
294 /// cx.simulate_keystrokes("cmd-shift-p b k s p enter")
295 /// in Zed, this will run backspace on the current editor through the command palette.
296 /// This will also run the background executor until it's parked.
297 pub fn simulate_keystrokes(&mut self, window: AnyWindowHandle, keystrokes: &str) {
298 for keystroke in keystrokes
299 .split(" ")
300 .map(Keystroke::parse)
301 .map(Result::unwrap)
302 {
303 self.dispatch_keystroke(window, keystroke.into(), false);
304 }
305
306 self.background_executor.run_until_parked()
307 }
308
309 /// simulate_input takes a string of text to type.
310 /// cx.simulate_input("abc")
311 /// will type abc into your current editor
312 /// This will also run the background executor until it's parked.
313 pub fn simulate_input(&mut self, window: AnyWindowHandle, input: &str) {
314 for keystroke in input.split("").map(Keystroke::parse).map(Result::unwrap) {
315 self.dispatch_keystroke(window, keystroke.into(), false);
316 }
317
318 self.background_executor.run_until_parked()
319 }
320
321 /// dispatches a single Keystroke (see also `simulate_keystrokes` and `simulate_input`)
322 pub fn dispatch_keystroke(
323 &mut self,
324 window: AnyWindowHandle,
325 keystroke: Keystroke,
326 is_held: bool,
327 ) {
328 self.test_window(window)
329 .simulate_keystroke(keystroke, is_held)
330 }
331
332 /// Returns the `TestWindow` backing the given handle.
333 pub fn test_window(&self, window: AnyWindowHandle) -> TestWindow {
334 self.app
335 .borrow_mut()
336 .windows
337 .get_mut(window.id)
338 .unwrap()
339 .as_mut()
340 .unwrap()
341 .platform_window
342 .as_test()
343 .unwrap()
344 .clone()
345 }
346
347 /// Returns a stream of notifications whenever the View or Model is updated.
348 pub fn notifications<T: 'static>(&mut self, entity: &impl Entity<T>) -> impl Stream<Item = ()> {
349 let (tx, rx) = futures::channel::mpsc::unbounded();
350 self.update(|cx| {
351 cx.observe(entity, {
352 let tx = tx.clone();
353 move |_, _| {
354 let _ = tx.unbounded_send(());
355 }
356 })
357 .detach();
358 cx.observe_release(entity, move |_, _| tx.close_channel())
359 .detach()
360 });
361 rx
362 }
363
364 /// Retuens a stream of events emitted by the given Model.
365 pub fn events<Evt, T: 'static + EventEmitter<Evt>>(
366 &mut self,
367 entity: &Model<T>,
368 ) -> futures::channel::mpsc::UnboundedReceiver<Evt>
369 where
370 Evt: 'static + Clone,
371 {
372 let (tx, rx) = futures::channel::mpsc::unbounded();
373 entity
374 .update(self, |_, cx: &mut ModelContext<T>| {
375 cx.subscribe(entity, move |_model, _handle, event, _cx| {
376 let _ = tx.unbounded_send(event.clone());
377 })
378 })
379 .detach();
380 rx
381 }
382
383 /// Runs until the given condition becomes true. (Prefer `run_until_parked` if you
384 /// don't need to jump in at a specific time).
385 pub async fn condition<T: 'static>(
386 &mut self,
387 model: &Model<T>,
388 mut predicate: impl FnMut(&mut T, &mut ModelContext<T>) -> bool,
389 ) {
390 let timer = self.executor().timer(Duration::from_secs(3));
391 let mut notifications = self.notifications(model);
392
393 use futures::FutureExt as _;
394 use smol::future::FutureExt as _;
395
396 async {
397 loop {
398 if model.update(self, &mut predicate) {
399 return Ok(());
400 }
401
402 if notifications.next().await.is_none() {
403 bail!("model dropped")
404 }
405 }
406 }
407 .race(timer.map(|_| Err(anyhow!("condition timed out"))))
408 .await
409 .unwrap();
410 }
411}
412
413impl<T: Send> Model<T> {
414 /// Block until the next event is emitted by the model, then return it.
415 pub fn next_event<Evt>(&self, cx: &mut TestAppContext) -> Evt
416 where
417 Evt: Send + Clone + 'static,
418 T: EventEmitter<Evt>,
419 {
420 let (tx, mut rx) = futures::channel::mpsc::unbounded();
421 let _subscription = self.update(cx, |_, cx| {
422 cx.subscribe(self, move |_, _, event, _| {
423 tx.unbounded_send(event.clone()).ok();
424 })
425 });
426
427 // Run other tasks until the event is emitted.
428 loop {
429 match rx.try_next() {
430 Ok(Some(event)) => return event,
431 Ok(None) => panic!("model was dropped"),
432 Err(_) => {
433 if !cx.executor().tick() {
434 break;
435 }
436 }
437 }
438 }
439 panic!("no event received")
440 }
441}
442
443impl<V: 'static> View<V> {
444 /// Returns a future that resolves when the view is next updated.
445 pub fn next_notification(&self, cx: &TestAppContext) -> impl Future<Output = ()> {
446 use postage::prelude::{Sink as _, Stream as _};
447
448 let (mut tx, mut rx) = postage::mpsc::channel(1);
449 let mut cx = cx.app.app.borrow_mut();
450 let subscription = cx.observe(self, move |_, _| {
451 tx.try_send(()).ok();
452 });
453
454 let duration = if std::env::var("CI").is_ok() {
455 Duration::from_secs(5)
456 } else {
457 Duration::from_secs(1)
458 };
459
460 async move {
461 let notification = crate::util::timeout(duration, rx.recv())
462 .await
463 .expect("next notification timed out");
464 drop(subscription);
465 notification.expect("model dropped while test was waiting for its next notification")
466 }
467 }
468}
469
470impl<V> View<V> {
471 /// Returns a future that resolves when the condition becomes true.
472 pub fn condition<Evt>(
473 &self,
474 cx: &TestAppContext,
475 mut predicate: impl FnMut(&V, &AppContext) -> bool,
476 ) -> impl Future<Output = ()>
477 where
478 Evt: 'static,
479 V: EventEmitter<Evt>,
480 {
481 use postage::prelude::{Sink as _, Stream as _};
482
483 let (tx, mut rx) = postage::mpsc::channel(1024);
484 let timeout_duration = Duration::from_millis(100); //todo!() cx.condition_duration();
485
486 let mut cx = cx.app.borrow_mut();
487 let subscriptions = (
488 cx.observe(self, {
489 let mut tx = tx.clone();
490 move |_, _| {
491 tx.blocking_send(()).ok();
492 }
493 }),
494 cx.subscribe(self, {
495 let mut tx = tx.clone();
496 move |_, _: &Evt, _| {
497 tx.blocking_send(()).ok();
498 }
499 }),
500 );
501
502 let cx = cx.this.upgrade().unwrap();
503 let handle = self.downgrade();
504
505 async move {
506 crate::util::timeout(timeout_duration, async move {
507 loop {
508 {
509 let cx = cx.borrow();
510 let cx = &*cx;
511 if predicate(
512 handle
513 .upgrade()
514 .expect("view dropped with pending condition")
515 .read(cx),
516 cx,
517 ) {
518 break;
519 }
520 }
521
522 cx.borrow().background_executor().start_waiting();
523 rx.recv()
524 .await
525 .expect("view dropped with pending condition");
526 cx.borrow().background_executor().finish_waiting();
527 }
528 })
529 .await
530 .expect("condition timed out");
531 drop(subscriptions);
532 }
533 }
534}
535
536use derive_more::{Deref, DerefMut};
537#[derive(Deref, DerefMut, Clone)]
538/// A VisualTestContext is the test-equivalent of a `WindowContext`. It allows you to
539/// run window-specific test code.
540pub struct VisualTestContext {
541 #[deref]
542 #[deref_mut]
543 cx: TestAppContext,
544 window: AnyWindowHandle,
545}
546
547impl<'a> VisualTestContext {
548 /// Provides the `WindowContext` for the duration of the closure.
549 pub fn update<R>(&mut self, f: impl FnOnce(&mut WindowContext) -> R) -> R {
550 self.cx.update_window(self.window, |_, cx| f(cx)).unwrap()
551 }
552
553 /// Create a new VisualTestContext. You would typically shadow the passed in
554 /// TestAppContext with this, as this is typically more useful.
555 /// `let cx = VisualTestContext::from_window(window, cx);`
556 pub fn from_window(window: AnyWindowHandle, cx: &TestAppContext) -> Self {
557 Self {
558 cx: cx.clone(),
559 window,
560 }
561 }
562
563 /// Wait until there are no more pending tasks.
564 pub fn run_until_parked(&self) {
565 self.cx.background_executor.run_until_parked();
566 }
567
568 /// Dispatch the action to the currently focused node.
569 pub fn dispatch_action<A>(&mut self, action: A)
570 where
571 A: Action,
572 {
573 self.cx.dispatch_action(self.window, action)
574 }
575
576 /// Read the title off the window (set by `WindowContext#set_window_title`)
577 pub fn window_title(&mut self) -> Option<String> {
578 self.cx.test_window(self.window).0.lock().title.clone()
579 }
580
581 /// Simulate a sequence of keystrokes `cx.simulate_keystrokes("cmd-p escape")`
582 /// Automatically runs until parked.
583 pub fn simulate_keystrokes(&mut self, keystrokes: &str) {
584 self.cx.simulate_keystrokes(self.window, keystrokes)
585 }
586
587 /// Simulate typing text `cx.simulate_input("hello")`
588 /// Automatically runs until parked.
589 pub fn simulate_input(&mut self, input: &str) {
590 self.cx.simulate_input(self.window, input)
591 }
592
593 /// Simulates the user blurring the window.
594 pub fn deactivate_window(&mut self) {
595 if Some(self.window) == self.test_platform.active_window() {
596 self.test_platform.set_active_window(None)
597 }
598 self.background_executor.run_until_parked();
599 }
600
601 /// Simulates the user closing the window.
602 /// Returns true if the window was closed.
603 pub fn simulate_close(&mut self) -> bool {
604 let handler = self
605 .cx
606 .update_window(self.window, |_, cx| {
607 cx.window
608 .platform_window
609 .as_test()
610 .unwrap()
611 .0
612 .lock()
613 .should_close_handler
614 .take()
615 })
616 .unwrap();
617 if let Some(mut handler) = handler {
618 let should_close = handler();
619 self.cx
620 .update_window(self.window, |_, cx| {
621 cx.window.platform_window.on_should_close(handler);
622 })
623 .unwrap();
624 should_close
625 } else {
626 false
627 }
628 }
629}
630
631impl Context for VisualTestContext {
632 type Result<T> = <TestAppContext as Context>::Result<T>;
633
634 fn new_model<T: 'static>(
635 &mut self,
636 build_model: impl FnOnce(&mut ModelContext<'_, T>) -> T,
637 ) -> Self::Result<Model<T>> {
638 self.cx.new_model(build_model)
639 }
640
641 fn update_model<T, R>(
642 &mut self,
643 handle: &Model<T>,
644 update: impl FnOnce(&mut T, &mut ModelContext<'_, T>) -> R,
645 ) -> Self::Result<R>
646 where
647 T: 'static,
648 {
649 self.cx.update_model(handle, update)
650 }
651
652 fn read_model<T, R>(
653 &self,
654 handle: &Model<T>,
655 read: impl FnOnce(&T, &AppContext) -> R,
656 ) -> Self::Result<R>
657 where
658 T: 'static,
659 {
660 self.cx.read_model(handle, read)
661 }
662
663 fn update_window<T, F>(&mut self, window: AnyWindowHandle, f: F) -> Result<T>
664 where
665 F: FnOnce(AnyView, &mut WindowContext<'_>) -> T,
666 {
667 self.cx.update_window(window, f)
668 }
669
670 fn read_window<T, R>(
671 &self,
672 window: &WindowHandle<T>,
673 read: impl FnOnce(View<T>, &AppContext) -> R,
674 ) -> Result<R>
675 where
676 T: 'static,
677 {
678 self.cx.read_window(window, read)
679 }
680}
681
682impl VisualContext for VisualTestContext {
683 fn new_view<V>(
684 &mut self,
685 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
686 ) -> Self::Result<View<V>>
687 where
688 V: 'static + Render,
689 {
690 self.window
691 .update(&mut self.cx, |_, cx| cx.new_view(build_view))
692 .unwrap()
693 }
694
695 fn update_view<V: 'static, R>(
696 &mut self,
697 view: &View<V>,
698 update: impl FnOnce(&mut V, &mut ViewContext<'_, V>) -> R,
699 ) -> Self::Result<R> {
700 self.window
701 .update(&mut self.cx, |_, cx| cx.update_view(view, update))
702 .unwrap()
703 }
704
705 fn replace_root_view<V>(
706 &mut self,
707 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
708 ) -> Self::Result<View<V>>
709 where
710 V: 'static + Render,
711 {
712 self.window
713 .update(&mut self.cx, |_, cx| cx.replace_root_view(build_view))
714 .unwrap()
715 }
716
717 fn focus_view<V: crate::FocusableView>(&mut self, view: &View<V>) -> Self::Result<()> {
718 self.window
719 .update(&mut self.cx, |_, cx| {
720 view.read(cx).focus_handle(cx).clone().focus(cx)
721 })
722 .unwrap()
723 }
724
725 fn dismiss_view<V>(&mut self, view: &View<V>) -> Self::Result<()>
726 where
727 V: crate::ManagedView,
728 {
729 self.window
730 .update(&mut self.cx, |_, cx| {
731 view.update(cx, |_, cx| cx.emit(crate::DismissEvent))
732 })
733 .unwrap()
734 }
735}
736
737impl AnyWindowHandle {
738 /// Creates the given view in this window.
739 pub fn build_view<V: Render + 'static>(
740 &self,
741 cx: &mut TestAppContext,
742 build_view: impl FnOnce(&mut ViewContext<'_, V>) -> V,
743 ) -> View<V> {
744 self.update(cx, |_, cx| cx.new_view(build_view)).unwrap()
745 }
746}
747
748/// An EmptyView for testing.
749pub struct EmptyView {}
750
751impl Render for EmptyView {
752 fn render(&mut self, _cx: &mut crate::ViewContext<Self>) -> impl IntoElement {
753 div()
754 }
755}