Export types for "conventional files"

[ravinggenius]

Goals

Make it easier to enable accurate auto-complete when implementing various "well-known" router files.

Non-Goals

No response

Background

These type are only informally described on the documentation website. While I appreciate the documentation, it would more helpful and convenient to have the types formally defined as well. This way people that want to use them don't have to re-implement them every time.

Proposal

Expose the following types (maybe more). Some names could be adjusted; this is just what I have in my project.

import { NextRequest } from "next/server";
import { ReactNode } from "react";

type Params = Record<string, string | Array<string>>;

export interface DefaultProps {
	params?: Params;
}

export interface ErrorProps {
	error: Error & { digest?: string };
	reset: () => void;
}

export interface LayoutProps {
	children: ReactNode;
	params?: Params;
}

export type LayoutGenerateMetadata = (
	props: Pick<LayoutProps, "params">
) => Metadata | Promise<Metadata>;

export interface PageProps {
	params?: Params;
	searchParams?: Record<string, string | Array<string> | undefined>;
}

export type PageGenerateMetadata = (
	props: PageProps
) => Metadata | Promise<Metadata>;

interface RouteContext {
	params: Params;
}

export type RouteMethod = (
	request: NextRequest,
	{ params }: RouteContext
) => Promise<Response>;

export interface TemplateProps {
	children: ReactNode;
}

I'm happy to contribute these types and associated inline documentation (pulled from the aforementioned link).

[ravinggenius]

Honestly kinda surprised nobody seems interested in this. I actually expected it to be built into Next already.