Babel throws "Plugin/Preset files are not allowed to export objects, only functions."

[ktunkiewicz]

lingui 2.0.4, babel 7.0.0-beta.40

> lingui extract --clean

Extracting messages from source files…
/code/App/node_modules/@babel/core/lib/config/config-descriptors.js:158
    throw new Error("Plugin/Preset files are not allowed to export objects, only functions.");
    ^

Error: Plugin/Preset files are not allowed to export objects, only functions.
    at createDescriptor (/code/App/node_modules/@babel/core/lib/config/config-descriptors.js:158:11)
    at /code/App/node_modules/@babel/core/lib/config/config-descriptors.js:101:12
    at Array.map (<anonymous>)
    at createDescriptors (/code/App/node_modules/@babel/core/lib/config/config-descriptors.js:100:27)
    at createPresetDescriptors (/code/App/node_modules/@babel/core/lib/config/config-descriptors.js:92:10)
    at /code/App/node_modules/@babel/core/lib/config/config-descriptors.js:64:19
    at presets (/code/App/node_modules/@babel/core/lib/config/config-descriptors.js:54:25)
    at mergeChainOpts (/code/App/node_modules/@babel/core/lib/config/config-chain.js:294:68)
    at /code/App/node_modules/@babel/core/lib/config/config-chain.js:247:7
    at buildRootChain (/code/App/node_modules/@babel/core/lib/config/config-chain.js:83:20)

There's a closed issue mentioning something like this: #163

The difference is that I actually updated to 2.0.4 from 2.0.0 and got this error (while the author of issue#163 had an opposite situation - he was getting this on 2.0.2 and it was "fixed" and updated to 2.0.4)

Any ideas how to fix that?

[tricoder42]

What's the output of npm list | grep lingui command?

As a workaround, could you replace the preset with plugins and try that?

[ktunkiewicz]

❯❯❯ npm list | grep lingui
├─┬ @lingui/babel-preset-react@2.0.4
│ ├── @lingui/babel-plugin-transform-js@2.0.4
│ └── @lingui/babel-plugin-transform-react@2.0.4
├─┬ @lingui/cli@2.0.4
│ ├─┬ @lingui/babel-plugin-extract-messages@2.0.4
│ │ └── @lingui/conf@2.0.4 deduped
│ ├── @lingui/babel-plugin-transform-js@2.0.4 deduped
│ ├── @lingui/babel-plugin-transform-react@2.0.4 deduped
│ ├─┬ @lingui/conf@2.0.4
├─┬ @lingui/loader@2.0.4
│ ├── @lingui/cli@2.0.4 deduped
│ ├── @lingui/conf@2.0.4 deduped
├─┬ @lingui/react@2.0.4
│ ├─┬ @lingui/core@2.0.4

@tricoder42 not sure if you noticed that this happens when I run lingui extract --clean. How can I "replace the preset with plugins" in it?

[ktunkiewicz]

I also checked version 2.0.2 and it works fine, no errors, only when I switch to 2.0.4.

[tricoder42]

Could you please show me your .babelrc? Running lingui extract inside one of examples works fine. It's weird it worked in 2.0.2 and doesn't work now though.

[tricoder42]

I was having the same problem on one of my projects which was still using Babel 6. I updated it to Babel 7 and now lingui extract works fine. Here's my .babelrc:

{
  "presets": [
    [
      "@babel/preset-env",
      {
        "targets": {
          "browser": [
            ">1%",
            "last 4 versions",
            "Firefox ESR",
            "not ie < 9",
            "ie 11"
          ],
          "uglify": true
        },
        "modules": false
      }
    ],
    "@babel/preset-react",
    "@babel/preset-flow",
    "@lingui/babel-preset-react"
  ],
  "plugins": [
    "@babel/plugin-proposal-export-default-from",
    "@babel/plugin-syntax-dynamic-import",
    "@babel/plugin-proposal-class-properties",
    "@babel/plugin-proposal-object-rest-spread",
    "@babel/plugin-proposal-decorators"
  ],
  "env": {
    "test": {
      "plugins": [
        "@babel/plugin-transform-modules-commonjs"
      ]
    }
  }
}

... but the .babelrc in example works fine as well.

Please let me know, I'm curious what's happening.

[bs1180]

I'm having this same issue trying to use Lingui with next.js. My .babelrc consists of:

{
  "presets": [
    "next/babel",
    "@lingui/babel-preset-react"
  ]
}

I've also unsuccessfully tried:

{
  "presets": [
    "next/babel"
  ],
  "plugins": [
    "@lingui/babel-plugin-transform-js",
    "@lingui/babel-plugin-transform-react"
  ]
}

Everything is on the latest version. Thanks for any help!

[tricoder42]

@bs1180 I just tried exactly the same config and I didn't get any error.

Could you please save output of yarn list or npm list to a file and upload it here?

[bs1180]

@tricoder42 Thanks for checking - here's an example that reproduces it: https://github.com/bs1180/lingui-nextjs.

The output of yarn list | grep lingui is:

├─ @lingui/babel-plugin-extract-messages@2.0.5
│  └─ @lingui/conf@2.0.5
├─ @lingui/babel-plugin-transform-js@2.0.5
├─ @lingui/babel-plugin-transform-react@2.0.5
├─ @lingui/babel-preset-react@2.0.5
│  ├─ @lingui/babel-plugin-transform-js@2.0.5
│  └─ @lingui/babel-plugin-transform-react@2.0.5
├─ @lingui/cli@2.0.5
│  ├─ @lingui/babel-plugin-extract-messages@2.0.5
│  ├─ @lingui/babel-plugin-transform-js@2.0.5
│  ├─ @lingui/babel-plugin-transform-react@2.0.5
│  ├─ @lingui/conf@2.0.5
├─ @lingui/conf@2.0.5
├─ @lingui/core@2.0.5
├─ @lingui/react@2.0.5
│  ├─ @lingui/core@2.0.5

[ktunkiewicz]

@tricoder42 sorry for late answer, our project does not have .babelrc to start with.
So, firstly, we don't use .babelrc. Babel configuration is done through webpack config.
Secondly, we use Babel 6. Didn't migrate to Babel 7 yet.

But why should that matter for lingui? It requires babel 7 and downloads it to @babel namespace. So our node_modules have both Babel 6 and Babel7. All other lingui components work find like this.
I would expect the lingui command line tool, which is kind of a "standalone" tool, not to care about project's Babel settings...

[tricoder42]

@ktunkiewicz Messages are extracted using babel plugin, so you need full babel config. It might be a problem that we're mixing babel6 and babel7 plugins. I would suggest extract babel config from webpack one. Similar workaround is needed for create-react-app, neutrino and all other 0config tools which hard-code babel config to webpack one.

I guess we might use a different method to extract messages, but take advantage of Babel AST and write a custom babel plugin was the easiest way to start.

@bs1180 I'll take a look, thanks for the repo!

[ipeo]

I have the exact same issue

[Smolations]

@tricoder42 I am having the same issue as @bs1180. I have tried node versions of 8.x and 9.x with the same result. Also tried using the plugins instead of the preset with no change. Is there a stable version of lingui that was written to work with babel6? If so, is there feature parity between that version and the current version?

[machour]

@Smolations have you tried v2.0.2? Worked for me

[Smolations]

@machour I did try downgrading to several versions actually, but no change. You have 2.0.2 working in a next.js project?