call initUIEvent with the correct view

src/event/createEvent.ts

@@ -47,7 +47,7 @@ export function createEvent<K extends EventType>(
   const {EventType, defaultInit} = eventMap[type]
   const event = new (getEventConstructors(window)[EventType])(type, defaultInit)
   eventInitializer[EventType].forEach(f =>
-    f(event as never, (init ?? {}) as never),
+    f(event as never, {view: window, ...init} as never),
   )
 
   return event as FixedDocumentEventMap[K]

tests/event/createEvent.ts

@@ -0,0 +1,45 @@
+import {createEvent} from '#src/event/createEvent'
+import {render} from '#testHelpers'
+
+function setupInput() {
+  return render(`<input/>`).element
+}
+
+describe('UIEvents receive the window as `view`', () => {
+  test.each([
+    ['keydown', 'KeyboardEvent'],
+    ['keyup', 'KeyboardEvent'],
+    ['mousedown', 'MouseEvent'],
+    ['mouseup', 'MouseEvent'],
+    ['click', 'PointerEvent'],
+    ['pointerdown', 'PointerEvent'],
+    ['pointerup', 'PointerEvent'],
+    ['focus', 'FocusEvent'],
+    ['blur', 'FocusEvent'],
+    ['input', 'InputEvent'],
+    ['beforeinput', 'InputEvent'],
+  ] as const)('`%s` (%s) has `view === window`', type => {
+    const element = setupInput()
+
+    const event = createEvent(type, element) as UIEvent
+
+    expect(event.view).toBe(window)
+  })
+})
+
+test('non-UIEvents do not expose `view`', () => {
+  const element = setupInput()
+
+  const event = createEvent('change', element)
+
+  expect((event as unknown as UIEvent).view).toBe(undefined)
+})
+
+test('an explicitly provided `view` is not overwritten', () => {
+  const element = setupInput()
+  const otherWindow = {} as Window
+
+  const event = createEvent('click', element, {view: otherWindow})
+
+  expect(event.view).toBe(otherWindow)
+})