Invalid CommonJS output when transforming a single import declaration into multiple

Bug Report

I've created a TypeScript transformer that transforms a single barrel import declaration into multiple deep import declarations.

Eg changing this:

import { A, B } from 'pkg';
console.log(A, B);

Into something like this:

import { A } from 'pkg/a';
import { B } from 'pkg/b';
console.log(A, B);

This works great when emitting ES modules but not when emitting CommonJS.

🔎 Search Terms

Transform, import, esm, cjs

🕗 Version & Regression Information

Tested with 4.9.5 but I suspect that most versions have this behaviour.

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⏯ Playground Link

Since Playground doesn't have support for transforms I don't have a playground link.

💻 Code

Not sure what to post here, any custom transform that replaces a single import declaration into multiple behave this way.

🙁 Actual behavior

When calling ts.setOriginalNode(newNode, node) for all new import declarations when emitted CJS code uses the same variable for all statements like this:

var pkg_1 = require('pkg/a');
var pkg_1 = require('pkg/b');
console.log(pkg_1.A, pkg_1.B);

That is, multiple new nodes having the same, single node as their original node.

When not calling ts.setOriginalNode() at all the ES output is fine but the CJS output is even more broken with something like:

var a_1 = require('pkg/a');
var b_1 = require('pkg/b');
console.log(pkg_1.A, pkg_1.B);

🙂 Expected behavior

I'm not sure how this should be handled but I would have liked to be able to connect multiple new nodes to a single original node and have the CommonJS transform see that and use different require variables. With output that looks something like this:

var pkg_1 = require('pkg/a');
var pkg_2 = require('pkg/b');
console.log(pkg_1.A, pkg_2.B);

Riproduci il transformer personalizzato che suddivide un import in più dichiarazioni, quindi confronta l’emissione di CommonJS e degli ES module mentre tracci il modo in cui ts.setOriginalNode() influisce sui binding require generati. Il lavoro è completato quando l’output CommonJS usa variabili require distinte e aggiorna in modo coerente ogni riferimento importato, senza compromettere l’output degli ES module.