Allow es modules to be imported in `next-sitemap.js`.

Is your feature request related to a problem? Please describe. Right now it is not possible to import es modules in next-sitemap.js.

For example: paths.js

export const somePath = 'some/path'

next-sitemap.js

import { somePath } from './paths'

or

const { somePath } = require('./paths')

Both of these won’t work. In other words, it is in no way possible to import an es module into next-sitemap.js.

I could imagine that many next.js users have a paths.js file containing all of their app’s paths. E.g. one would import these into next-sitemap.js to exclude a path.

Describe the solution you’d like There are multiple solutions:

1. import next-sitemap.js (inside next-sitemap src code) using the import statement as opposed to using the require statement. This would effectively make next-sitemap.js an es module being able to import other es modules. Without using Babel it is necessary though to rename next-sitemap.js to next-sitemap.mjs to use the import syntax. Or adding { type: 'module' } to package.json.
2. let Babel process next-sitemap.js before executing it using the @babel-node package for example.

Describe alternatives you’ve considered The only alternative I see right now is to hardcode any values you’d like to import and thereby duplicating them. But if the values change and one forgets to update the hardcoded values in next-sitemap.js, things will obviously break…

[JarFrank]

Hi all! unfortunatly the issue still exists.

• Next: 12.1.5
• next-sitemap: 3.1.3v

I’m getting this error message:

Loaded env from C:\nextjs\.env.local
✨ [next-sitemap] Loading next-sitemap config: file:///C:/nextjs/next-sitemap.config.js
(node:5768) Warning: To load an ES module, set "type": "module" in the package.json or use the .mjs extension.
(Use `node --trace-warnings ...` to show where the warning was created)
C:\nextjs\next-sitemap.config.js:9
export default config;
^^^^^^

SyntaxError: Unexpected token 'export'
    at Object.compileFunction (node:vm:352:18)
    at wrapSafe (node:internal/modules/cjs/loader:1032:15)
    at Module._compile (node:internal/modules/cjs/loader:1067:27)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1155:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at ModuleWrap.<anonymous> (node:internal/modules/esm/translators:168:29)
    at ModuleJob.run (node:internal/modules/esm/module_job:195:25)
    at async Promise.all (index 0)
    at async ESMLoader.import (node:internal/modules/esm/loader:337:24)

[KishokanthJeganathan]

yep this is how I solved this too ^. More info - https://www.kishokanth.com/blog/how-to-fix-postbuild-error-when-using-next-sitemap