commonjs: Object.defineProperty(exports, "__esModule", …) leaves unbound exports when module is wrapped #2041

• Rollup Plugin Name: @rollup/plugin-commonjs
• Rollup Plugin Version: 29.0.3
• Rollup Version: 4.68.0
• Operating System (or Browser): macOS (Darwin 25.3.0 arm64)
• Node Version: v24.14.1
• Link to reproduction (⚠️ read below): https://gist.github.com/trackoor/07b920471d1e187149c88f0ab2fbd597

Expected Behavior

When a CommonJS module's only reference to exports is a top-level Object.defineProperty(exports, "__esModule", { value: true }) and the module also references module, m.js should either receive (module, exports) in the wrapper or have exports rewritten, matching Node's CommonJS wrapper where both module and exports are in scope.

Actual Behavior

The module is wrapped in (function (module) { ... }()) without passing exports or rewriting the defineProperty call. Running the generated ES bundle throws ReferenceError: exports is not defined in ES module scope because requireM emits a free exports identifier inside the wrapper:

(function (module) {
	Object.defineProperty(exports, "__esModule", { value: true });
	console.log('object'); 
} ());

Additional Information

// m.js
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
console.log(typeof module.exports);

// entry.js
require("./m.js");

// build.mjs
import { rollup } from "rollup";
import commonjs from "@rollup/plugin-commonjs";

const bundle = await rollup({ input: "entry.js", plugins: [commonjs()] });
const { output } = await bundle.generate({ format: "es" });
console.log(output[0].code);

The CallExpression handler for __esModule skips exports without marking uses.exports = true, so wrapping triggered by uses.module omits exports from the wrapper parameters.

Credit: https://ucsbplse.github.io/