Error: Cannot find module 'typesafe-i18n/formatters'

[nn1k4]

Now the error appears in developer mode.

yarn dev
Error when evaluating SSR module /src/i18n/formatters.ts:
Error: Cannot find module 'typesafe-i18n/formatters' from 'D:/app/src/i18n'

"typesafe-i18n": "^2.36.0"
"@sveltejs/kit": "^1.0.0-next.138",

[ivanhofer]

This seems like an issue within vite. I need to investigate it further when I have more time.
Meanwhile you can copy the formatter functions from here or write your own.

[nikolay-borzov]

I assume the error happens because .cjs and .mjs extensions might not be resolved within your configuration.

[ivanhofer]

vite does not resolve .cjs and .mjs file extension in ssr mode. I will open a PR next time I'm in front of my laptop.

[ivanhofer]

I opened an Issue in the vite repository: vitejs/vite#4452

Workaround:

• go to node_modules/vite/dist/node/chunks
• look for the variable ssrExtensions in one of the dep-*.js files
• add '.cjs' to the array

Then you should be able to run your application again.
It's a one-time fix and only effects your development environment (as far as I can see). Production builds should not be affected.

[es-lynn]

Hi, I'm experiencing this issue after upgrading to npm v7 with Jest.

Using npm v6, I had no issues resolving when running my Jest tests.

After using npm v7 and upgrading my package.lock, I'm no longer able to run my Jest tests.

Cannot find module 'typesafe-i18n/adapters/adapter-react' from 'src/i18n/i18n-react.tsx'

   Require stack:
      src/i18n/i18n-react.tsx
      src/app/AppContext.tsx
      src/components/Button.test.tsx

      2 | /* eslint-disable */
      3 |
    > 4 | import { initI18nReact } from 'typesafe-i18n/adapters/adapter-react'

When I rename the .cjs file to .js, it works fine.

Using the following:

• npm: 7.21.0
• ts-jest: 26.5.4
• react-scripts: 4.0.3

[es-lynn]

^regarding the above, I needed a quick fix so I did the following:

1. Delete package-lock.json
2. Downgrade to npm v6
3. npm install with v6 to generate lockfile
4. Upgrade to npm v7
5. npm install with v7 to upgrade lockfile

[ivanhofer]

Thanks @aelesia for providing a solution.

As far as I can tell, "older" npm packages don't always resolve files correctly.
This package should be compatible with cjs and modern esm formats. I'ts hard to provide a solution that works with everything that is out there.. and I really don't want to split this project and provide it's own npm package for each framework.

I think I have configured the package resolving correct, but maybe I have missed something that can be added to support additional frameworks? If someone has additional input to this question, I would be happy :)

[mullwaden]

Having a similar issue with Jest. I think it might be worth restructuring how the package is imported (not exactly sure how though)

[ivanhofer]

@mullwaden have you tried the experimental ESM Support?
https://jestjs.io/docs/ecmascript-modules

[mullwaden]

Hmm not sure I want to add experimental flags, its a pretty big setup we have. In our case it was the import of the locale detection that was causing issues. I set it to only generate types and made my own base file as we are not using that feature anyway:

import { i18n as initI18n } from "typesafe-i18n";

import type {
  Translation,
  TranslationFunctions,
  Formatters,
  Locales,
} from "./i18n-types";
import { initFormatters } from "./formatters";
import en from "./en";

export const getTranslationForLocale = () => en as Translation;

const i18n = initI18n<Locales, Translation, TranslationFunctions, Formatters>(
  getTranslationForLocale,
  initFormatters
);

export default i18n.en;

[ivanhofer]

Good solution!
Jest does not support the modernexports field from package.json and so every import from a object in a sub-folder of typesafe-i18n will fail.

I have found a few issues on that topic.
jestjs/jest#9771
jestjs/jest#10422
jestjs/jest#2702

There are also mentioned a few workarounds, but I haven't checkt if any of these work.

[ivanhofer]

The issue vitejs/vite#4452 was fixed in vite version 2.5.2 and therefore also in SvelteKit version 1.0.0-next.160.
Can anyone confirm that the issue is resolved when using the latest version of SvelteKit?
This would make typesafe-i18n again compatible with SvelteKit.

Regarding the issue with jest: can anyone share a repo where I can reproduce the issue?

[ivanhofer]

Closing this issue since the original issue was resolved a few months ago.
I think the Jest issue is still there, but I don't know how to reproduce it.
If anyone still has problems, please open a new issue with a detailed description.