This would be great 👍 Especially now that NodeJS also supports ESM.

Switching from require/module.exports to import/export and the generation of a CommonJS variant from it is certainly the most future-oriented solution, but seems to involve some adjustments, due to some (unconventional) module management.

I see many require('...') calls inside of functions, which are assumed to run synchronously. One could replace these with dynamic imports (in case the delayed import was really necessary -- like with process.env.NODE_PG_FORCE_NATIVE), but this will also introduce asynchronous behaviour, that needs to be addressed.

In some cases, this also introduced circular dependencies, like pg\lib\index.js -> pg-pool\index.js -> pg\lib\index.js.

A more complicated case is something like

if (...) {
// ...
} else {
  Object.defineProperty(module.exports, 'native', {
    // ...
    get() {
      Object.defineProperty(module.exports, 'native', {
        // ...
      })
      // ...
    },
  })
}

where the export definition is not only delayed, but also later overwritten.