helper script to generate sveltekit url functions

generate-url-functions.js

import { readFile, writeFile, stat, mkdir } from 'node:fs/promises';
import { join } from 'node:path';
import { format } from 'prettier';
const fileText = await readFile(
  '.svelte-kit/types/route_meta_data.json',
  'utf-8'
);
const routes = JSON.parse(fileText);
const routeIds = Object.keys(routes).sort();
const paramRx = /\[{1,2}([^\]]+)\]{1,2}/g;

const funcDecls = routeIds.map((id) => {
  const params = Array.from(id.matchAll(paramRx)).map((s) =>
    {
      return {
        param: s[1].replace(/^\.+/, ''),
        optional: s[0].indexOf('[[') === 0
      }
    }
  );
  const allParamsOptional = params.find(p => !p.optional) === undefined;

  const paramsDecl =
    params.length === 0
      ? ''
      : `
    params: {${params.map((p) => `${p.param}${p.optional ? '?' : ''}: string;`).join('')}} ${allParamsOptional ? '={}' : ''}
  `.trim();
  return `'${id}': (${paramsDecl}): string => resolveRoute('${id}', ${paramsDecl.length > 0 ? 'params' : '{}'})`;
});

const ts = `
import {resolveRoute} from '$app/paths';

export const appUrls = {${funcDecls.join(',')}}
`;
const folderPath = join('src', 'lib', 'app-urls');
const filePath = join(folderPath, 'app-urls-generated.ts');
const prettified = await format(ts, {
  singleQuote: true,
  trailingComma: 'none',
  filepath: filePath
});
try {
  await stat(folderPath);
} catch (error) {
  mkdir(folderPath);
}
await writeFile(filePath, prettified);