Generating SPA routes for NGINX to respond status code 404 correctly.

generate-spa-nginx-routes.js

// generate-spa-nginx-routes.js
// SPDX-License-Identifier: MIT (https://ncurl.xyz/s/Kkn2DQsNR)

// nginx.conf example:
//
//   include routes_params;
//   ...
//   location / {
//     try_files $uri $uri/ $routes =404;
//   }
//   ...
//

import {writeFileSync} from 'node:fs';
import {routes} from './src/router/index.js';

const escapeRegExp = (str) => str.replace(/[.*+?^${}()|[\\]/g, '\\$&');

const generatedPaths = new Set();
const generateNginxRules = (routes, basePath = '', content = '') => routes.map((route) => {
  if (route.path.includes(':pathMatch')) {
    return '';
  }

  const fullPath = route.path.startsWith('/') ?
    route.path :
    (basePath + '/' + route.path).replace(/\/+/g, '/');

  if (!generatedPaths.has(fullPath) && !route.redirect) {
    if (fullPath.includes(':')) {
      const pattern = `^${fullPath.replace(/:[^/]+/g, '[^/]+').replace(/\/?$/, '')}(/)?$`;
      content += `\t~${pattern} /index.html;\n`;
    } else {
      const pattern = `^${escapeRegExp(fullPath.replace(/\/?$/, ''))}(/)?$`;
      content += `\t~${pattern} /index.html;\n`;
    }
    generatedPaths.add(fullPath);
  }

  if (route.children) {
    return generateNginxRules(route.children, fullPath, content);
  }

  return content;
}).join('');

const mapContent = `# Auto-generated by generate-spa-nginx-routes.js
map $uri $render {
\tdefault "";
${generateNginxRules(routes)}
}`;

const routesFilePath = new URL(
  'routes_params',
  import.meta.url,
);
writeFileSync(routesFilePath, mapContent);