SWC has stopped working in one of my projects

[djalbat]

Describe the bug

I use SWC in dozens of projects but bizarrely it has stopped working in just one. It fails to transpile JSX despite the correct JSX flag being present in the .swcrc file, again like dozens of other projects.

I think the easiest thing to do is to just clone the project and have a look. So:

git clone git@github.com:djalbat/reaction-with-style.git

Then the usual:

npm run install

And then just build:

npm run build-debug

I get errors like:

swc failed:

  x Expression expected
    ,-[lib/example.js:16:1]
 16 | 
 17 | ReactDOM.render(
 18 | 
 19 |     <View/>
    :     ^
 20 | 
 21 |   ,
 22 |   bodyDOMElement
    `----

Clearly a problem with JSX.

Input code

ReactDOM.render(

    <View/>

  ,
  bodyDOMElement
);

Config

{
    "jsc": {
        "parser": {
            "syntax": "ecmascript",
            "jsx": true
        }
    },
    "module": {
        "type": "commonjs"
    }
}

Playground link (or link to the minimal reproduction)

https://play.swc.rs/?version=1.3.100&code=H4sIAAAAAAAAAwtKTUwucfH31StKzUtJLdLg4lIAApuwzNRyfTsQRweIk%2FJTKoFqXHNSc1PzSrg0rbkAjfPNzzcAAAA%3D&config=H4sIAAAAAAAAA1WPSw7DIAwF9zkF8rrbdtE79BAWdSIifrKJVBTl7iUE0maH3xsz8jooBbNoeKq1PMsQkYX4nEsi2Sf8lARIOxTNJia49XaWvRrRCtVoOxpIyBOluiX3hoMNQajjLXPGmzH%2FC3VwkUnkCu4o%2BsnSVTc0JbjwXmrZDkk50qF%2FwA%2FqsvNjMPLqm4kXGrYvhlQioBQBAAA%3D

SWC Info output

No response

Expected behavior

It should transpile just fine!

Actual behavior

See above.

Version

"@swc/core": "^1.2.50"

Additional context

Note that in the playground link, if you toggle the JSX flag then you get the behaviour that I have outlined.

So the problem seems to be that SWC is ignoring the configuration file for some reason.

[kdy1]

Please provide a minimal reproduction.
I can't repro with your repository, and if you know the first version that breaks, it would also help

[djalbat]

My sincere apologies, this is my oversight.

I fixed the problem after opening this issue by pinning the @swc/core version to one I knew that worked, specifically 1.2.50. I then committed this change so this is the one you would have tried.

I have just tried to replicate the bug by cloning the repository again and doing the following:

npm install @swc/core@latest

However I now cannot replicate it either.

I also stupidly did not supply you with the exact SWC version when I opened this issue. Not the one in the package.json file but the actual one that got installed when I ran npm install. So now I guess we are stuck.

I did not imagine the bug, however. It seemed to be a case of SWC not reading the configuration file, or at least not reading it properly, because it was not compiling the JSX.

I will leave the issue closed. It is up to you if you want to pursue this any further. In a meantime I have pinned the version in all of my repositories, around fifty in all:

"@swc/core": "1.2.50"

At some later date I will un-pin it again and if the bug resurfaces then I will let you know.