fix: Avoid act() re-entrant when dispatching events

src/__tests__/event-wrapper-nesting.js

@@ -0,0 +1,47 @@
+import * as React from 'react'
+import {render, screen, fireEvent} from '../'
+
+let mockActDepth = 0
+let mockMaxActDepth = 0
+jest.mock('react', () => {
+  const actual = jest.requireActual('react')
+  return {
+    ...actual,
+    act: jest.fn(cb => {
+      mockActDepth++
+      mockMaxActDepth = Math.max(mockMaxActDepth, mockActDepth)
+      try {
+        return actual.act(cb)
+      } finally {
+        mockActDepth--
+      }
+    }),
+  }
+})
+
+function Nested() {
+  return (
+    <>
+      <input
+        aria-label="outer"
+        onFocus={() =>
+          fireEvent.change(screen.getByLabelText('inner'), {
+            target: {value: 'changed'},
+          })
+        }
+      />
+      <input aria-label="inner" />
+    </>
+  )
+}
+
+test('eventWrapper does not nest `act` for a re-entrant event dispatch', () => {
+  render(<Nested />)
+  expect(screen.getByLabelText('inner').value).toBe('')
+
+  mockMaxActDepth = 0
+  fireEvent.focus(screen.getByLabelText('outer'))
+
+  expect(screen.getByLabelText('inner').value).toBe('changed')
+  expect(mockMaxActDepth).toBe(1)
+})

src/pure.js

@@ -27,6 +27,8 @@ function jestFakeTimersAreEnabled() {
   return false
 }
 
+let inEventWrapper = false
+
 configureDTL({
   unstable_advanceTimersWrapper: cb => {
     return act(cb)
@@ -58,11 +60,19 @@ configureDTL({
     }
   },
   eventWrapper: cb => {
-    let result
-    act(() => {
-      result = cb()
-    })
-    return result
+    if (inEventWrapper) {
+      return cb()
+    }
+    inEventWrapper = true
+    try {
+      let result
+      act(() => {
+        result = cb()
+      })
+      return result
+    } finally {
+      inEventWrapper = false
+    }
   },
 })