From 664adc4bb79da02f7687212d0db7fd34ba53f226 Mon Sep 17 00:00:00 2001
From: Katsuma Ito <katsumai@gmail.com>
Date: Thu, 9 Sep 2021 11:35:26 +0900
Subject: [PATCH] [ESLint Plugin] Add `next/script` support for
 `no-unwanted-polyfillio` rule

---
 .../lib/rules/no-unwanted-polyfillio.js       | 16 +++++++++-
 .../no-unwanted-polyfillio.test.ts            | 29 +++++++++++++++++++
 2 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/packages/eslint-plugin-next/lib/rules/no-unwanted-polyfillio.js b/packages/eslint-plugin-next/lib/rules/no-unwanted-polyfillio.js
index fa83aba9523b3b..3ea29be4ebcefe 100644
--- a/packages/eslint-plugin-next/lib/rules/no-unwanted-polyfillio.js
+++ b/packages/eslint-plugin-next/lib/rules/no-unwanted-polyfillio.js
@@ -74,8 +74,22 @@ module.exports = {
   },
 
   create: function (context) {
+    let scriptImport = null
+
     return {
-      'JSXOpeningElement[name.name=script][attributes.length>0]'(node) {
+      ImportDeclaration(node) {
+        if (node.source.value === 'next/script') {
+          scriptImport = node.specifiers[0].local.name
+        }
+      },
+      JSXOpeningElement(node) {
+        if (node.name.name !== 'script' && node.name.name !== scriptImport) {
+          return
+        }
+        if (node.attributes.length === 0) {
+          return
+        }
+
         const srcNode = node.attributes.find(
           (attr) => attr.type === 'JSXAttribute' && attr.name.name === 'src'
         )
diff --git a/test/unit/eslint-plugin-next/no-unwanted-polyfillio.test.ts b/test/unit/eslint-plugin-next/no-unwanted-polyfillio.test.ts
index f8c57f42bb19b4..4c2996d55ebbd9 100644
--- a/test/unit/eslint-plugin-next/no-unwanted-polyfillio.test.ts
+++ b/test/unit/eslint-plugin-next/no-unwanted-polyfillio.test.ts
@@ -38,6 +38,16 @@ ruleTester.run('unwanted-polyfillsio', rule, {
           );
         }
     }`,
+    `import Script from 'next/script';
+
+      export function MyApp({ Component, pageProps }) {
+          return (
+            <div>
+              <Component {...pageProps} />
+              <Script src='https://polyfill.io/v3/polyfill.min.js?features=IntersectionObserver' />
+            </div>
+          );
+    }`,
   ],
 
   invalid: [
@@ -82,5 +92,24 @@ ruleTester.run('unwanted-polyfillsio', rule, {
         },
       ],
     },
+    {
+      code: `import NextScript from 'next/script';
+
+      export function MyApp({ Component, pageProps }) {
+          return (
+            <div>
+              <Component {...pageProps} />
+              <NextScript src='https://polyfill.io/v3/polyfill.min.js?features=Array.prototype.copyWithin' />
+            </div>
+          );
+    }`,
+      errors: [
+        {
+          message:
+            'No duplicate polyfills from Polyfill.io are allowed. Array.prototype.copyWithin is already shipped with Next.js. See: https://nextjs.org/docs/messages/no-unwanted-polyfillio.',
+          type: 'JSXOpeningElement',
+        },
+      ],
+    },
   ],
 })