feature: Add iframe support for user.keyboard typing

src/utils/focus/getActiveElement.ts

@@ -1,4 +1,5 @@
 import {isDisabled} from '../misc/isDisabled'
+import {isElementType} from '../misc/isElementType'
 
 export function getActiveElement(
   document: Document | ShadowRoot,
@@ -10,6 +11,11 @@ export function getActiveElement(
     if (activeElementInShadowTree) {
       return activeElementInShadowTree
     }
+  } else if (activeElement && isElementType(activeElement, 'iframe')) {
+    const contentDocument = (activeElement as HTMLIFrameElement).contentDocument
+    if (contentDocument) {
+      return getActiveElement(contentDocument)
+    }
   }
   // Browser does not yield disabled elements as document.activeElement - jsdom does
   if (isDisabled(activeElement)) {

tests/keyboard/index.ts

@@ -190,3 +190,26 @@ customElements.define(
     }
   },
 )
+
+test('typing on focused element with iframe', async () => {
+  let iframe: HTMLIFrameElement
+  let iframeButton: HTMLElement
+  const {user} = setup(
+    '<div id="iframe-container"></div>',
+  )
+  iframe = document.createElement('iframe')
+  window.document.body.appendChild(iframe)
+  iframeButton = iframe.contentWindow!.document.createElement('button')
+  iframe.contentWindow!.document.body.appendChild(iframeButton)
+  let keydown = jest.fn()
+  let keyup = jest.fn()
+  iframeButton.addEventListener('keydown', keydown)
+  iframeButton.addEventListener('keyup', keyup)
+
+  iframeButton.focus()
+  await user.keyboard('[Space]')
+  expect(keydown).toHaveBeenCalled()
+  expect(keyup).toHaveBeenCalled()
+
+  iframe.remove()
+})