diff --git a/crates/oxc_linter/src/rules.rs b/crates/oxc_linter/src/rules.rs
index a0ffe90b63cb1..ace2312e0385f 100644
--- a/crates/oxc_linter/src/rules.rs
+++ b/crates/oxc_linter/src/rules.rs
@@ -308,6 +308,7 @@ mod nextjs {
pub mod no_sync_scripts;
pub mod no_title_in_document_head;
pub mod no_typos;
+ pub mod no_unwanted_polyfillio;
}
oxc_macros::declare_all_lint_rules! {
@@ -582,4 +583,5 @@ oxc_macros::declare_all_lint_rules! {
nextjs::no_title_in_document_head,
nextjs::no_typos,
nextjs::no_document_import_in_page,
+ nextjs::no_unwanted_polyfillio,
}
diff --git a/crates/oxc_linter/src/rules/nextjs/no_unwanted_polyfillio.rs b/crates/oxc_linter/src/rules/nextjs/no_unwanted_polyfillio.rs
new file mode 100644
index 0000000000000..cdff0ddc3b4c4
--- /dev/null
+++ b/crates/oxc_linter/src/rules/nextjs/no_unwanted_polyfillio.rs
@@ -0,0 +1,275 @@
+use oxc_ast::{
+ ast::{JSXAttributeItem, JSXAttributeName, JSXAttributeValue, JSXElementName, JSXIdentifier},
+ AstKind,
+};
+use oxc_diagnostics::{
+ miette::{self, Diagnostic},
+ thiserror::{self, Error},
+};
+use oxc_macros::declare_oxc_lint;
+use oxc_semantic::AstNode;
+use oxc_span::Span;
+use phf::{phf_set, Set};
+
+use crate::{context::LintContext, rule::Rule};
+
+#[derive(Debug, Error, Diagnostic)]
+#[error("eslint-plugin-next(no-unwanted-polyfillio): No duplicate polyfills from Polyfill.io are allowed. {0} already shipped with Next.js.")]
+#[diagnostic(
+ severity(warning),
+ help("See https://nextjs.org/docs/messages/no-unwanted-polyfillio")
+)]
+struct NoUnwantedPolyfillioDiagnostic(String, #[label] pub Span);
+
+#[derive(Debug, Default, Clone)]
+pub struct NoUnwantedPolyfillio;
+
+declare_oxc_lint!(
+ /// ### What it does
+ /// Prevent duplicate polyfills from Polyfill.io.
+ ///
+ /// ### Why is this bad?
+ /// You are using polyfills from Polyfill.io and including polyfills already shipped with Next.js. This unnecessarily increases page weight which can affect loading performance.
+ ///
+ /// ### Example
+ /// ```javascript
+ ///
+ ///
+ ///
+ /// ```
+ NoUnwantedPolyfillio,
+ correctness
+);
+
+// Keep in sync with next.js polyfills file : https://github.com/vercel/next.js/blob/master/packages/next-polyfill-nomodule/src/index.js
+const NEXT_POLYFILLED_FEATURES: Set<&'static str> = phf_set! {
+ "Array.prototype.@@iterator",
+ "Array.prototype.at",
+ "Array.prototype.copyWithin",
+ "Array.prototype.fill",
+ "Array.prototype.find",
+ "Array.prototype.findIndex",
+ "Array.prototype.flatMap",
+ "Array.prototype.flat",
+ "Array.from",
+ "Array.prototype.includes",
+ "Array.of",
+ "Function.prototype.name",
+ "fetch",
+ "Map",
+ "Number.EPSILON",
+ "Number.Epsilon",
+ "Number.isFinite",
+ "Number.isNaN",
+ "Number.isInteger",
+ "Number.isSafeInteger",
+ "Number.MAX_SAFE_INTEGER",
+ "Number.MIN_SAFE_INTEGER",
+ "Number.parseFloat",
+ "Number.parseInt",
+ "Object.assign",
+ "Object.entries",
+ "Object.fromEntries",
+ "Object.getOwnPropertyDescriptor",
+ "Object.getOwnPropertyDescriptors",
+ "Object.is",
+ "Object.keys",
+ "Object.values",
+ "Reflect",
+ "Set",
+ "Symbol",
+ "Symbol.asyncIterator",
+ "String.prototype.codePointAt",
+ "String.prototype.endsWith",
+ "String.fromCodePoint",
+ "String.prototype.includes",
+ "String.prototype.@@iterator",
+ "String.prototype.padEnd",
+ "String.prototype.padStart",
+ "String.prototype.repeat",
+ "String.raw",
+ "String.prototype.startsWith",
+ "String.prototype.trimEnd",
+ "String.prototype.trimStart",
+ "URL",
+ "URL.prototype.toJSON",
+ "URLSearchParams",
+ "WeakMap",
+ "WeakSet",
+ "Promise",
+ "Promise.prototype.finally",
+ "es2015", // Should be covered by babel-preset-env instead.
+ "es2016", // contains polyfilled 'Array.prototype.includes', 'String.prototype.padEnd' and 'String.prototype.padStart'
+ "es2017", // contains polyfilled 'Object.entries', 'Object.getOwnPropertyDescriptors', 'Object.values', 'String.prototype.padEnd' and 'String.prototype.padStart'
+ "es2018", // contains polyfilled 'Promise.prototype.finally' and ''Symbol.asyncIterator'
+ "es2019", // Contains polyfilled 'Object.fromEntries' and polyfilled 'Array.prototype.flat', 'Array.prototype.flatMap', 'String.prototype.trimEnd' and 'String.prototype.trimStart'
+ "es5", // Should be covered by babel-preset-env instead.
+ "es6", // Should be covered by babel-preset-env instead.
+ "es7", // contains polyfilled 'Array.prototype.includes', 'String.prototype.padEnd' and 'String.prototype.padStart'
+};
+
+impl Rule for NoUnwantedPolyfillio {
+ fn run<'a>(&self, node: &AstNode<'a>, ctx: &LintContext<'a>) {
+ if let AstKind::JSXOpeningElement(jsx_el) = node.kind() {
+ let JSXElementName::Identifier(JSXIdentifier { name: tag_name, .. }) = &jsx_el.name
+ else {
+ return;
+ };
+
+ if tag_name.as_str() != "script" {
+ let next_script_import_local_name =
+ ctx.semantic().module_record().import_entries.iter().find_map(|entry| {
+ if entry.module_request.name().as_str() == "next/script" {
+ Some(entry.local_name.name())
+ } else {
+ None
+ }
+ });
+ if !matches!(next_script_import_local_name, Some(import) if tag_name.as_str() == import.as_str())
+ {
+ return;
+ }
+ }
+
+ if jsx_el.attributes.len() == 0 {
+ return;
+ }
+
+ let Some(JSXAttributeItem::Attribute(src)) = jsx_el.attributes.iter().find(|attr| {
+ matches!(
+ attr,
+ JSXAttributeItem::Attribute(jsx_attr)
+ if matches!(
+ &jsx_attr.name,
+ JSXAttributeName::Identifier(id) if id.name.as_str() == "src"
+ )
+ )
+ }) else {
+ return;
+ };
+
+ if let Some(JSXAttributeValue::StringLiteral(src_value)) = &src.value {
+ if src_value.value.as_str().starts_with("https://cdn.polyfill.io/v2/")
+ || src_value.value.as_str().starts_with("https://polyfill.io/v3/")
+ {
+ let Ok(url) = url::Url::parse(src_value.value.as_str()) else {
+ return;
+ };
+
+ let Some((_, features_value)) =
+ url.query_pairs().find(|(key, _)| key == "features")
+ else {
+ return;
+ };
+ let unwanted_features: Vec<&str> = features_value
+ .split(',')
+ .filter(|feature| NEXT_POLYFILLED_FEATURES.contains(feature))
+ .collect();
+ if !unwanted_features.is_empty() {
+ ctx.diagnostic(NoUnwantedPolyfillioDiagnostic(
+ format!(
+ "{} {}",
+ unwanted_features.join(", "),
+ if unwanted_features.len() > 1 { "are" } else { "is" }
+ ),
+ src.span,
+ ));
+ }
+ }
+ }
+ }
+ }
+}
+
+#[test]
+fn test() {
+ use crate::tester::Tester;
+
+ let pass = vec![
+ r"import {Head} from 'next/document';
+
+ export class Blah extends Head {
+ render() {
+ return (
+
+
Hello title
+
+
+ );
+ }
+ }",
+ r"import {Head} from 'next/document';
+
+ export class Blah extends Head {
+ render() {
+ return (
+
+
Hello title
+
+
+ );
+ }
+ }",
+ r"
+ import Script from 'next/script';
+
+ export function MyApp({ Component, pageProps }) {
+ return (
+
+
+
+
+ );
+ }",
+ ];
+
+ let fail = vec![
+ r"import {Head} from 'next/document';
+
+ export class Blah extends Head {
+ render() {
+ return (
+
+
Hello title
+
+
+ );
+ }
+ }",
+ r"
+ export class Blah {
+ render() {
+ return (
+
+
Hello title
+
+
+ );
+ }
+ }",
+ r"import NextScript from 'next/script';
+
+ export function MyApp({ Component, pageProps }) {
+ return (
+
+
+
+
+ );
+ }",
+ r"import {Head} from 'next/document';
+
+ export class ES2019Features extends Head {
+ render() {
+ return (
+
+
Hello title
+
+
+ );
+ }
+ }",
+ ];
+
+ Tester::new(NoUnwantedPolyfillio::NAME, pass, fail).test_and_snapshot();
+}
diff --git a/crates/oxc_linter/src/snapshots/no_unwanted_polyfillio.snap b/crates/oxc_linter/src/snapshots/no_unwanted_polyfillio.snap
new file mode 100644
index 0000000000000..01dfbec3d445b
--- /dev/null
+++ b/crates/oxc_linter/src/snapshots/no_unwanted_polyfillio.snap
@@ -0,0 +1,41 @@
+---
+source: crates/oxc_linter/src/tester.rs
+expression: no_unwanted_polyfillio
+---
+ ⚠ eslint-plugin-next(no-unwanted-polyfillio): No duplicate polyfills from Polyfill.io are allowed. WeakSet, Promise, Promise.prototype.finally, es2015, es5, es6 are already shipped with Next.js.
+ ╭─[no_unwanted_polyfillio.tsx:7:1]
+ 7 │ Hello title
+ 8 │
+ · ────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
+ 9 │
+ ╰────
+ help: See https://nextjs.org/docs/messages/no-unwanted-polyfillio
+
+ ⚠ eslint-plugin-next(no-unwanted-polyfillio): No duplicate polyfills from Polyfill.io are allowed. Array.prototype.copyWithin is already shipped with Next.js.
+ ╭─[no_unwanted_polyfillio.tsx:6:1]
+ 6 │ Hello title
+ 7 │
+ · ────────────────────────────────────────────────────────────────────────────────
+ 8 │
+ ╰────
+ help: See https://nextjs.org/docs/messages/no-unwanted-polyfillio
+
+ ⚠ eslint-plugin-next(no-unwanted-polyfillio): No duplicate polyfills from Polyfill.io are allowed. Array.prototype.copyWithin is already shipped with Next.js.
+ ╭─[no_unwanted_polyfillio.tsx:6:1]
+ 6 │
+ 7 │
+ · ────────────────────────────────────────────────────────────────────────────────
+ 8 │
+ ╰────
+ help: See https://nextjs.org/docs/messages/no-unwanted-polyfillio
+
+ ⚠ eslint-plugin-next(no-unwanted-polyfillio): No duplicate polyfills from Polyfill.io are allowed. Object.fromEntries is already shipped with Next.js.
+ ╭─[no_unwanted_polyfillio.tsx:7:1]
+ 7 │ Hello title
+ 8 │
+ · ────────────────────────────────────────────────────────────────────────
+ 9 │
+ ╰────
+ help: See https://nextjs.org/docs/messages/no-unwanted-polyfillio
+
+