Add @next/next/no-unwanted-polyfillio rule

__tests__/__fixtures__/@next/next/no-unwanted-polyfillio.correct.js

@@ -0,0 +1,11 @@
+export default function Page() {
+  return (
+    <div>
+      <script
+        async
+        defer
+        src='https://polyfill.io/v3/polyfill.min.js?features=something-that-will-never-exist'
+      />
+    </div>
+  )
+}

__tests__/__fixtures__/@next/next/no-unwanted-polyfillio.incorrect.js

@@ -0,0 +1,7 @@
+export default function Page() {
+  return (
+    <div>
+      <script async defer src='https://polyfill.io/v3/polyfill.min.js?features=es2019' />
+    </div>
+  )
+}

__tests__/next.js

@@ -31,3 +31,19 @@ describe('@next/next/no-sync-scripts', () => {
     expect(result.messages[0].message).toBe('A synchronous script tag can impact your webpage\'s performance')
   })
 })
+
+describe('@next/next/no-unwanted-polyfillio', () => {
+  it('correct', async () => {
+    const result = await lintFixture('@next/next/no-unwanted-polyfillio.correct.js')
+
+    expect(result.errorCount).toBe(0)
+  })
+
+  it('incorrect', async () => {
+    const result = await lintFixture('@next/next/no-unwanted-polyfillio.incorrect.js')
+
+    expect(result.messages).toHaveLength(1)
+    expect(result.messages[0].ruleId).toBe('@next/next/no-unwanted-polyfillio')
+    expect(result.messages[0].message).toBe('You\'re requesting polyfills from polyfill.io which are already shipped with NextJS. Please remove es2019 from the features list.')
+  })
+})

index.js

@@ -82,6 +82,7 @@ module.exports = {
 
     // Next.js
     '@next/next/no-css-tags': 'error',
-    '@next/next/no-sync-scripts': 'error'
+    '@next/next/no-sync-scripts': 'error',
+    '@next/next/no-unwanted-polyfillio': 'error'
   }
 }