@next/next/inline-script-id

Next.js uses the id of an inline <Script> to keep track of it, so the code runs once instead of again after each navigation. A script with a src is tracked by its URL. An inline script doesn't have one, so it needs an id.

A script is inline if it has children or a dangerouslySetInnerHTML prop. The rule follows the name you give to the default import of next/script.

Configure

Off by default. To turn it on:

[lint.rules]
"@next/next/inline-script-id" = "error" # or "warn"

Examples

Reported:

import Script from "next/script";

export default function Page() {
  return <Script>{`window.startedAt = Date.now();`}</Script>;
}

import Script from "next/script";

export default function Page() {
  return <Script dangerouslySetInnerHTML={{ __html: "window.startedAt = Date.now();" }} />;
}

Not reported:

import Script from "next/script";

export default function Page() {
  return (
    <>
      <Script id="started-at">{`window.startedAt = Date.now();`}</Script>
      <Script src="https://example.com/widget.js" />
    </>
  );
}

If you spread a variable into the props, the id might be in there, so the element isn't reported:

import Script from "next/script";

export default function Tracker(props) {
  return <Script {...props}>{`window.startedAt = Date.now();`}</Script>;
}