From c206d89ec28f8c729f77595bf60828b92f407aa0 Mon Sep 17 00:00:00 2001
From: Sukka <isukkaw@gmail.com>
Date: Thu, 7 Mar 2024 00:42:53 +0800
Subject: [PATCH] feat(eslint): enhance `no-unwanted-polyfill` w/ new endpoints
 (#62719)

The PR adds the new `polyfill.io` instance endpoint (from Fastly and
Cloudflare) to the `eslint-plugin-next`'s `no-unwanted-polyfillio`
rules, so these new endpoints can be detected by the rule.

---

`polyfill.io` was acquired by **a China-based CDN company** "Funnull",
see [the announcement from the `polyfill.io` domain owner's
Twitter](https://x.com/JakeDChampion/status/1761315227008643367) and
https://github.com/polyfillpolyfill/polyfill-service/issues/2834.
Despite Funnull's claims of operating in the United States, the
predominance of Simplified Chinese on its website suggests otherwise,
and it turns out that **"Funnull" is notorious for providing service for
the betting and pornography industries**.

[The original creator of the `polyfill.io` has voiced his concern on
Twitter](https://twitter.com/triblondon/status/1761852117579427975). And
since the acquisition, numerous issues have emerged
(https://github.com/polyfillpolyfill/polyfill-service/issues/2835,
https://github.com/polyfillpolyfill/polyfill-service/issues/2838,
https://github.com/alist-org/alist/issues/6100), rendering the
`polyfill.io` service **extremely unstable**. Since then, Fastly
([Announcement](https://community.fastly.com/t/new-options-for-polyfill-io-users/2540))
and Cloudflare
([Announcement](https://blog.cloudflare.com/polyfill-io-now-available-on-cdnjs-reduce-your-supply-chain-risk))
has hosted their own instances of `polyfill.io` service.

---------

Co-authored-by: Steven <steven@ceriously.com>
---
 examples/script-component/pages/polyfill.tsx           |  2 +-
 .../src/rules/no-unwanted-polyfillio.ts                |  7 ++++++-
 .../eslint-plugin-next/no-unwanted-polyfillio.test.ts  | 10 ++++++++++
 3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/examples/script-component/pages/polyfill.tsx b/examples/script-component/pages/polyfill.tsx
index bee31995b5..add9af5200 100644
--- a/examples/script-component/pages/polyfill.tsx
+++ b/examples/script-component/pages/polyfill.tsx
@@ -32,7 +32,7 @@ export default function Polyfill() {
     <>
       {/* We ensure that intersection observer is available by polyfilling it */}
       <Script
-        src="https://polyfill.io/v3/polyfill.min.js?features=IntersectionObserverEntry%2CIntersectionObserver"
+        src="https://polyfill-fastly.io/v3/polyfill.min.js?features=IntersectionObserverEntry%2CIntersectionObserver"
         strategy="beforeInteractive"
       />
 
diff --git a/packages/eslint-plugin-next/src/rules/no-unwanted-polyfillio.ts b/packages/eslint-plugin-next/src/rules/no-unwanted-polyfillio.ts
index 35ebf0acf1..fc575e9919 100644
--- a/packages/eslint-plugin-next/src/rules/no-unwanted-polyfillio.ts
+++ b/packages/eslint-plugin-next/src/rules/no-unwanted-polyfillio.ts
@@ -115,7 +115,12 @@ export = defineRule({
         const src = srcNode.value.value
         if (
           src.startsWith('https://cdn.polyfill.io/v2/') ||
-          src.startsWith('https://polyfill.io/v3/')
+          src.startsWith('https://polyfill.io/v3/') ||
+          // https://community.fastly.com/t/new-options-for-polyfill-io-users/2540
+          src.startsWith('https://polyfill-fastly.net/') ||
+          src.startsWith('https://polyfill-fastly.io/') ||
+          // https://blog.cloudflare.com/polyfill-io-now-available-on-cdnjs-reduce-your-supply-chain-risk
+          src.startsWith('https://cdnjs.cloudflare.com/polyfill/')
         ) {
           const featureQueryString = new URL(src).searchParams.get('features')
           const featuresRequested = (featureQueryString || '').split(',')
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 f1383c2f67..4871505b4f 100644
--- a/test/unit/eslint-plugin-next/no-unwanted-polyfillio.test.ts
+++ b/test/unit/eslint-plugin-next/no-unwanted-polyfillio.test.ts
@@ -48,6 +48,16 @@ ruleTester.run('unwanted-polyfillsio', rule, {
             </div>
           );
     }`,
+    `import Script from 'next/script';
+
+      export function MyApp({ Component, pageProps }) {
+          return (
+            <div>
+              <Component {...pageProps} />
+              <Script src='https://polyfill-fastly.io/v3/polyfill.min.js?features=IntersectionObserver' />
+            </div>
+          );
+    }`,
   ],
 
   invalid: [