fix: next dynamic with jest

Author: huozhi

packages/next/build/babel/plugins/react-loadable-plugin.ts

@@ -31,6 +31,8 @@ import {
 
 import { relative as relativePath } from 'path'
 
+const isTest = process.env.NODE_ENV === 'test'
+
 export default function ({
   types: t,
 }: {
@@ -166,7 +168,7 @@ export default function ({
 
           if (!dynamicImports.length) return
 
-          options.node.properties.push(
+          !isTest && options.node.properties.push(
             t.objectProperty(
               t.identifier('loadableGenerated'),
               t.objectExpression([

test/unit/fixtures/stub-components/hello.js

@@ -0,0 +1,5 @@
+import React from 'react'
+
+export default function Hello() {
+  return <div>hello</div>
+}

test/unit/next-dynamic.test.js

@@ -0,0 +1,16 @@
+/**
+ * @jest-environment jsdom
+ */
+import React from 'react'
+import { act, render } from '@testing-library/react'
+import dynamic from 'next/dynamic'
+
+describe('next/dynamic', () => {
+  it('test link with unmount', () => {
+    const App = dynamic(() => import('./fixtures/stub-components/hello'))
+    act(() => {
+      const { unmount } = render(<App />)
+      unmount()
+    })
+  })
+})