Files inside the routes/ folder can export middlewares that run before any rendering happens. They are expected to be available as a named export called handler. This rule checks for when the export was incorrectly named handlers instead of handler.

Invalid:

export const handlers = {
  GET() {},
  POST() {},
};
export function handlers() {}
export async function handlers() {}

Valid:

export const handler = {
  GET() {},
  POST() {},
};
export function handler() {}
export async function handler() {}

Components inside the routes/ folder in a fresh app are exclusively rendered on the server. They are not rendered in the client and setting an event handler will have no effect.

Note that this rule only applies to server components inside the routes/ folder, not to fresh islands or any other components.

Invalid:

<button onClick={() => {}} />
<button onclick={() => {}} />
<my-custom-element foo={() => {}} />

Valid:

<button />
<my-custom-element />