@mintlify/previewing/dist/local-preview/setupNext.js

Preview Mintlify docs locally

import fse from 'fs-extra';
import { pathToFileURL } from 'node:url';
import { CLIENT_PATH, NEXT_CONFIG_PATH, NEXT_ROUTER_SERVER_PATH, NEXT_SIDE_EFFECT_PATH, } from '../constants.js';
/**
 * When creating a standalone build, next.js outputs a server.js file that can be used as
 * an entry point into the server. However, because we want to customize some parts of the
 * http server (adding a socket.io server, serving the whole public directory), we
 * create the server ourselves, and just reproduce the setup that next.js would do.
 *
 * Because we need to directly import from node_modules files, this solution seems very hacky,
 * but it is arguably no more hacky than using the server.js that ships with the standalone
 * build.
 *
 * This function attempts to replicate the behavior of two next.js files:
 * - environment setup from server.js
 * - initialization of the request handler from start-server.ts
 *
 * Links:
 * - [standalone build](https://nextjs.org/docs/pages/api-reference/next-config-js/output#automatically-copying-traced-files)
 * - [server.js](https://github.com/vercel/next.js/blob/492156b4c5e2559b2a280f7d483cd85a8e8742a9/packages/next/src/build/utils.ts#L2108-L2113) (created programmatically)
 * - [start-server.ts](https://github.com/vercel/next.js/blob/59e5ccb225189d366f57f1b204c5f44053a434ce/packages/next/src/server/lib/start-server.ts#L416-L429)
 *
 * @returns the request handler provided by next.js
 */
export const setupNext = async () => {
    const hostname = process.env.HOSTNAME || 'localhost';
    const { config } = await JSON.parse(fse.readFileSync(NEXT_CONFIG_PATH, 'utf8'));
    process.env.__NEXT_PRIVATE_STANDALONE_CONFIG = JSON.stringify(config);
    // The server.js provided by next.js's standalone build does a similar import of this file.
    // Not sure what side effects are being created, but want to change as little as possible.
    // Also, Windows requires us to use `pathToFileURL` (see #899)
    await import(pathToFileURL(NEXT_SIDE_EFFECT_PATH).href);
    const { initialize } = await import(pathToFileURL(NEXT_ROUTER_SERVER_PATH).href);
    // requestHandler was returned as an array in Next 14, and as an object in Next 15
    // this lets us support both version for old (<=0.0.1326) and new (>=0.0.1327) versions of the client app
    const result = await initialize({
        dir: CLIENT_PATH,
        dev: false,
        hostname,
        minimalMode: true,
    });
    return Array.isArray(result) ? result[0] : result.requestHandler;
};