react-jsx does not work with Preact

[Klukies]

Hi

Error

I've recently made the switch to microbundle for a project that uses Preact and TypeScript. Following the docs, and me having the latest version of TypeScript, I put the following in my tsconfig:

{
  "compilerOptions": {
    "jsx": "react-jsx",
    "jsxImportSource": "preact",
    //...
  }
}

However when building with microbundle I get the following error: rpt2: options error TS5089: Option 'jsxFactory' cannot be specified when option 'jsx' is 'react-jsx'. This seems weird behaviour as I have not specified the jsxFactory.

Combined with this I also get an error about the 'jsxFragmentFactory' having to be provided to use JSX Fragments, but I presume that is due to the fact the the jsxFactory is somehow incorrect.

I tried hardcoding the values from the config in my script (without success) by doing the following

microbundle --jsx react-jsx --jsxImportSource preact

Possible solution

I've been able to get microbundle working if I switch back to the tsconfig for older versions of TypeScript, so I'll be opting into this behaviour for now. For reference this is what the old config is:

{
  "compilerOptions": {
    "jsx": "react",
    "jsxFactory": "h",
    "jsxFragmentFactory": "Fragment",
    //...
  }
}

[rschristian]

Hmm, we set jsxFactory by default, and I guess rpt2 doesn't realize this needs to be removed if the tsconfig.json sets the jsx key to react-jsx.

https://github.com/developit/microbundle/blob/81088002d3581a093e177407308a934331b6b843/src/index.js#L518-L535

It's likely an upstream issue, but I haven't yet had time to delve into rpt2 yet to double check on that.

Thanks for providing the work around in case anyone else runs into this in the meantime.

[fuunnx]

Another workaround that worked for me (with React 17), is to provide an empty string for jsxFactory and jsxFragmentFactory :

{
    "jsx": "react-jsx",
    "jsxFactory": "",
    "jsxFragmentFactory": ""
}