Jest modifies require.extensions

[wrumsby]

I'm writing a shareable ESLint config that uses eslint-plugin-unicorn which uses this module.

Inspired by Test Your ESLint config I'm testing my config with Jest.

I was seeing failures around being able to load the eslint-plugin-unicorn rules and after looking at the code here and looking across tools I was using the problem I'm experiencing seems to be caused by jestjs/jest#281.

While the problem is "caused by" Jest it seems like a difficult issue for Jest to resolve and I wondered if a solution might be possible in import-modules, e.g.

var extensions = Object.assign({}, {
    // Jest will redefine require.extensions to be {}
    // so add back default implementation(s) if not available
    '.js': require('default-require-extensions/js')
  }, require.extensions);

for (const ext of Object.keys(extensions)) {
  ...

A change like the above would mean that I get the default js implementation back and rules for eslint-plugin-unicorn load.

This is pretty similar to #1, but continues to use require.extensions.

[sindresorhus]

Sure, PR welcome.