feat: add support for projects with "type": "module" in package.json

[y-hsgw]

{
  "main": "./dist/index.js",
  "type": "module",
  ...
}

Fixed an issue where the following error occurred with a package.json using "type": "module":

require() of ES Module  ***/dist/index.js not supported.
Instead change the require of ***/dist/index.js to a dynamic import() which is available in all CommonJS modules.

#504 might be somewhat related to this.

[bmish]

Thanks for working on this. This is an important fix/support to add.

Is it possible to test this? Perhaps a new test fixture test/fixtures/esm and a test file lib/generate/esm-test.ts.

Also, do you know of a real-world eslint plugin example using ESM? I'll want to test this manually on one.

[bmish]

The test looks good.

[bmish]

1. I'd like to manually test this on a real-world plugin if you know of any. If you aren't sure, I will look for one later.
2. I believe this partially resolves Support ESM #504, handling module + main but not module + exports. We can try to handle module + exports later.

[y-hsgw]

Also, do you know of a real-world eslint plugin example using ESM? I'll want to test this manually on one.

Sorry, nothing comes to mind right away.
However, in this case, I tested it within a repository I created for experimental purposes, and it seems to generate without any issues.

[ljharb]

(to be clear, type module has nothing to do with ESM support; it just changes how .js is parsed)