Fixing a TypeScript error complaining of missing default export

[derek-pavao]

Was getting the following error in my TypeScript 2.7.2 project

 error TS1192: Module '"/Users/dpavao/Projects/web2/node_modules/i18next-localstorage-backend/index"' has no default export.

The following PR fixes that error

[jamuhl]

@VincentLanglet @rosskevin -> could this be merged

[VincentLanglet]

@dotDeeka @rosskevin It's weird.

In my recent project I use :

import i18next from 'i18next';
import LanguageDetector from 'i18next-browser-languagedetector';
import Backend from 'i18next-xhr-backend';
import { initReactI18next } from 'react-i18next';

export default i18next
  .use(Backend)
  .use(LanguageDetector)
  .use(initReactI18next)
  .init({ ...  });

With no error.

And if you look at the definition of browser-languagedetector here or xhr-backend here, you can see namespace, class and module are defined the same way than here. There is also chained-backend here.

[VincentLanglet]

I just tried yarn add i18next-localstorage-backend.

import i18next from 'i18next';
import LanguageDetector from 'i18next-browser-languagedetector';
import Backend from 'i18next-localstorage-backend';
import { initReactI18next } from 'react-i18next';

export default i18next
  .use(Backend)
  .use(LanguageDetector)
  .use(initReactI18next)
  .init({ ...  });

With no typescript error.

Edit: ok, I had these option in my tsconfig.json

"module": "esnext",
"moduleResolution": "node",
"allowSyntheticDefaultImports": true,
"esModuleInterop": true,

[rosskevin]

The PR is correct because the js code has a default export. TS users will see different behavior in userland depending on their allowSyntheticDefaultImports https://www.typescriptlang.org/docs/handbook/compiler-options.html

[VincentLanglet]

@rosskevin Indeed. We/I need to do the same for at least

• browser-languagedetector
• xhr-backend
• chained-backend

I won't do this this night, but if not done, I'll try to take time for it tomorrow.

[derek-pavao]

@VincentLanglet I thought I had allowSyntheticImports: true in my tsconfig file, but apparently not. Thanks for making me look. 👍

[jamuhl]

published in i18next-localstorage-backend@2.1.1

[VincentLanglet]

@jamuhl @dotDeeka @rosskevin I still have doubt in this PR

Look at https://github.com/DefinitelyTyped/DefinitelyTyped/issues/33097#issuecomment-464127582

A true default export is

module.exports.default =

Here we have

module.exports =

I think we should revert this PR, since there si no default export.

[derek-pavao]

@VincentLanglet, so if you guys reverted this, what would be my solution? To just allowSyntheticImports: true ?

[VincentLanglet]

Yes

Or use import * as Backend from ...

[jamuhl]

I think we got the same problem here as with i18next: https://github.com/i18next/i18next/pull/1204

There is a default export using the files from build -> /dist/es or `/dist/commonjs``

but not for node.js env (where this module is useless i would say) /index.js where it takes the default as main export module.exports = require('./dist/commonjs/index.js').default;

[VincentLanglet]

@jamuhl

Since the file index.js only export this way

module.exports = require('./dist/commonjs/index.js').default;

I think the good utilisation of this module is

Import * as Backend from ...

[jamuhl]

Not sure...it really depends on your environment -> /index.js is only pulled by node.js, while eg. webpack will pull https://github.com/i18next/i18next-localstorage-backend/blob/master/package.json#L7

No idea what typescript does but Import * as Backend from ... in Javascript world would be not correct.

[VincentLanglet]

I thought Import * as Backend from ... would work the same way Import * as React from 'react', I didn't know about the effect of the line "jsnext:main": "dist/es/index.js"

Maybe we have too to do the improvement

module.exports = main;
module.exports.default = main;

Don't really know, i'm not expert in module resolution...

[VincentLanglet]

@jamuhl I'll have these 3 PR to merge, after we're sure what we're doing.

https://github.com/i18next/i18next-browser-languageDetector/pull/165 https://github.com/i18next/i18next-xhr-backend/pull/298 https://github.com/i18next/i18next-chained-backend/pull/6

[jamuhl]

Yes...adding

module.exports = main;
module.exports.default = main;

would not hurt i guess