test(fireEvent): add test spec for read-only target properties

Author: 9inpachi

src/__tests__/events.js

@@ -366,6 +366,16 @@ test('assigns clipboardData properties', () => {
   expect(clipboardData.getData('text')).toBe('example')
 })
 
+test('assigns read-only target properties', () => {
+  const node = document.createElement('div')
+  const spy = jest.fn()
+  node.addEventListener('scroll', spy)
+
+  expect(node.scrollWidth).toBe(0)
+  fireEvent.scroll(node, {target: {scrollWidth: 10}})
+  expect(node.scrollWidth).toBe(10)
+})
+
 test('fires events on Window', () => {
   const messageSpy = jest.fn()
   window.addEventListener('message', messageSpy)