feat(server-side): custom default config path

[intpp]

To solve issues like this one: nrwl/nx#4983, and to not create hacky functions I suggest the following change.

It doesn't break anything but it adds the ability to set the default config path.

It will allow you to simply use the package in NX monorepo with the changes from the dynamic path example.

[adrai]

cool...

[adrai]

included in v13.1.0

[quanglam2807]

This change broke production on Vercel but I don't know why:

2023-02-02T19:25:02.237Z	2c59565a-3cdb-45fb-a5ce-772f5d58ebcb	ERROR	Error: next-i18next was unable to find a user config
    at _callee$ (/var/task/node_modules/next-i18next/dist/commonjs/serverSideTranslations.js:93:19)
    at tryCatch (/var/task/node_modules/@babel/runtime/helpers/regeneratorRuntime.js:44:17)
    at Generator.<anonymous> (/var/task/node_modules/@babel/runtime/helpers/regeneratorRuntime.js:125:22)
    at Generator.next (/var/task/node_modules/@babel/runtime/helpers/regeneratorRuntime.js:69:21)
    at asyncGeneratorStep (/var/task/node_modules/@babel/runtime/helpers/asyncToGenerator.js:3:24)
    at _next (/var/task/node_modules/@babel/runtime/helpers/asyncToGenerator.js:22:9)
    at /var/task/node_modules/@babel/runtime/helpers/asyncToGenerator.js:27:7
    at new Promise (<anonymous>)
    at /var/task/node_modules/@babel/runtime/helpers/asyncToGenerator.js:19:12
    at serverSideTranslations (/var/task/node_modules/next-i18next/dist/commonjs/serverSideTranslations.js:157:17) {
  page: '/apps/popular/page/[page]'
}
RequestId: 2c59565a-3cdb-45fb-a5ce-772f5d58ebcb Error: Runtime exited with error: exit status 1
Runtime.ExitError

[adrai]

just tested if our simple example deploys on Vercel... and seems to work without any issues: https://github.com/i18next/next-i18next/tree/master/examples/simple

[quanglam2807]

Thanks, @adrai. I did more testing. It seems like it only affects dynamic routes. You can re-produce the issue with this repo: https://github.com/quanglam2807/next-i18next-simple-test/blob/main/pages/pages/%5Bpage%5D.tsx

[adrai]

@intpp can you have a look at it?

[adrai]

@quanglam2807 this is really strange... to me this looks like to be a Vercel issue... do you want to try to open an issue/discussion here? https://github.com/vercel/community/discussions

[adrai]

@quanglam2807 It seems like, as soon as the serverSideTranlsations file accesses process.env the error occurs: c6ccf41#diff-78da8fd247ac10bc4179e3dad343177bb6bf49923dcc4bd6cab86babfae025bfL27
I've now "reverted" the changes of this PR and released v13.1.4 (which basically is like v13.0.3)

@intpp it would be nice if you could investigate why this happens with the Vercel team/support

[quanglam2807]

Thank you, @adrai. I also suspected the same thing but oddly enough, calling process.env.I18NEXT_DEFAULT_CONFIG_PATH directly in getStaticProps worked.

[intpp]

I'll check

[intpp]

@adrai Hi. I did some research on the problem. It causes by the library https://github.com/vercel/nft, which is used by the Next.js' build command.

https://nextjs.org/docs/advanced-features/output-file-tracing

During next build, Next.js will use https://github.com/vercel/nft to statically analyze import, require, and fs usage to determine all files that a page might load.

When we use process.env in the variables as a value (not an expression), it can't calculate the possible path for the default value.

It works if we set I18NEXT_DEFAULT_CONFIG_PATH later.

let DEFAULT_CONFIG_PATH = './next-i18next.config.js'

// Added
if (process.env.I18NEXT_DEFAULT_CONFIG_PATH) {
  DEFAULT_CONFIG_PATH = process.env.I18NEXT_DEFAULT_CONFIG_PATH
}

export const serverSideTranslations = async (
  initialLocale: string,
  namespacesRequired: string[] | undefined = undefined,
  configOverride: UserConfig | null = null,
  extraLocales: string[] | false = false
): Promise<SSRConfig> => {
  if (typeof initialLocale !== 'string') {
    throw new Error(
      'Initial locale argument was not passed into serverSideTranslations'
    )
  }

  let userConfig = configOverride

  const configPath = path.resolve(DEFAULT_CONFIG_PATH)

  if (
    !userConfig &&
    fs.existsSync(configPath)
  ) {
    userConfig = await import(configPath)
  }

  if (userConfig === null) {
    throw new Error(`next-i18next was unable to find a user config at ${configPath}`)
  }

It works for a single application and a monorepo if next-i18next.config.js is in the same directory as next.config.js. But you must copy it manually to your build directory when it doesn't.

I have published the test version https://www.npmjs.com/package/intpp-next-i18next?activeTab=explore with the change and tested it on Vercel - It works (https://github.com/intpp/i18next-demo).

I'll create a new PR with the change.