Reverting to undefined loader breaks library depending on this behavior

[joyheron]

Hi,

I am working on a project which has pirates as a transitive dependency, and now get an exception after upgrading from 4.0.1 to 4.0.3. The commit which seems to cause my problems seems to be this one:

cf74daf

As far as I can tell, the error occurs in this library here which uses @babel/register which uses pirates as a dependency: https://github.com/complate/complate-fractal/blob/master/src/transpiler.js#L6

The code that I am having problems with is as follows:

require('@babel/register')({
  extensions: ['.jsx'],
  ignore: [], // activates transpilation for third-party modules
  presets: ['@babel/preset-env'],
  plugins: [
    ['@babel/plugin-transform-react-jsx', {
      pragma: 'createElement',
      pragmaFrag: 'Fragment'
    }]
  ]
})
// activate support for ES6 import/export syntax (required for non-JSX ES6 modules, notably complate-stream)
require = require('esm')(module) // eslint-disable-line no-global-assign

I believe this worked previously because for extensions which are not explicitly specified here, the default used to be to use the default JS loader. As far as I can tell, the require('esm')(module) line now throws an error if there are any imports on the path which do not use a known extension. If I pass in ['.jsx', '.mjs', '.cjs'] as extensions in L6 of that file, then the error no longer occurs for my project.

I am willing to make a PR to the complate-fractal project to change that line there, but it feels like the wrong place to correct it because I actually would prefer to use the JavaScript loader to load .cjs and .mjs files. Here it is also not possible to leave off the extensions because then babel tries to register the JSX loader for all the .js files as well and that causes problems when loading some dependencies (e.g. prettier). For me, specifying the .cjs and .mjs in the extension list here also feels like a smell -- currently the code will work if I modify that, but if in the future my transitive dependencies are updated to include imports from different file extensions, then there is a likelihood that this will break in the code again.

Here is my demo project which currently throws an error when running: https://github.com/joyheron/complate-fractal-demo
I've created a branch to demonstrate that downgrading the pirates version to 4.0.1 solves the issue: https://github.com/joyheron/complate-fractal-demo/tree/complate-fractal-works-with-pirates-4.0.1

[danez]

Sorry for the late reply, I'm checking this now.

[github-actions]

🎉 This issue has been resolved in version 4.0.5 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[joyheron]

Thank you for the fix! I've done an update and verified that my project works again with pirates: 4.0.5