Support Rollup input extension .jsx

[sisp]

Current Behavior

The file src/index.jsx is not recognized as a Rollup input:

https://github.com/palmerhq/tsdx/blob/943648edb06cd131f2c1751120cd1301804b480b/src/index.ts#L64-L69

Expected behavior

It should be possible to have the file src/index.jsx as the Rollup input.

Suggested solution(s)

async function jsOrTs(filename: string) {
  const extension = (await isFile(resolveApp(filename + '.ts')))
    ? '.ts'
    : (await isFile(resolveApp(filename + '.tsx')))
    ? '.tsx'
    : (await isFile(resolveApp(filename + '.jsx')))
    ? '.jsx'
    : '.js';

  return resolveApp(`${filename}${extension}`);
}

Your environment

Software	Version(s)
TSDX	0.6.1
TypeScript	3.5.1
Browser	Chromium
npm/Yarn	npm
Operating System	Ubuntu 18.04

[sisp]

Related to the this issue, TSDX currently does not seem to support importing *.js(x) files from *.ts(x) files because rollup-plugin-typescript2 is not configured to process *.js(x) files.

https://github.com/palmerhq/tsdx/blob/943648edb06cd131f2c1751120cd1301804b480b/src/createRollupConfig.ts#L146-L162

The fixed configuration looks like this:

typescript({
  // everything from above, plus ...
  include: ['*.(t|j)s+(|x)', '**/*.(t|j)s+(|x)'] // default is ["*.ts+(|x)", "**/*.ts+(|x)"]
})

[swyxio]

tsdx is quite evidently a typescript-first project. not a priority for me to support .js{x} but lets see what jared says

[sisp]

That's true, but I was thinking to align tsdx's features with CRA and CRA with --typescript set also resolves .js{x} files.

[agilgur5]

I'm not having this issue, but I think if tsdx supports .js it should also support .jsx. That would also add better support for gradual migrations to TS.

[myklt]

Isn't the problem here that Typescript doesn't support .jsx as a file extension for files containing jsx? As far as I know only .tsx is supported. More details: microsoft/TypeScript#30503

[agilgur5]

Wanted to update folks on this issue as this was discussed in #443 as well and I've made a few related PRs to improve JSX support.

Per #443, TSDX actually already supports JSX, you just need to make sure your tsconfig.json has compilerOptions.allowJs set to true and that your include picks it up. TSDX does not by default allow JS or JSX but does support them when they are configured.

Isn't the problem here that Typescript doesn't support .jsx as a file extension for files containing jsx? As far as I know only .tsx is supported. More details: microsoft/TypeScript#30503

I'm not sure if this is the case or is still the case, but it works in TSDX. That might only be because TSDX runs Babel on top of rollup-plugin-typescript2, but I'm not really sure

There were some bugs related to JSX support, but those might not necessarily have caused issues for all JSX users. Related fixes:

• (fix): ensure Babel presets are merged #473 fixes an issue where custom Babel presets (like @babel/preset-react) weren't always properly merged with TSDX defaults
• (fix): check for JSX extension for entry files #474 fixes the specific issue here in the OP, JSX extensions for entry files, with OP's suggested solution