compilePackages: `module.exports = class` loses the class method table — static AND prototype methods read `undefined` (breaks stack-utils → ink)

[proggeramlug]

Summary

A compiled (compilePackages) CommonJS module that exports a class via module.exports = SomeClass loses the class's entire method table — both static methods and prototype (instance) methods come back undefined. The class is importable and callable as a constructor, but it's effectively bare.

Concretely with stack-utils@2.x (a transitive dep of ink via <ErrorOverview>):

import StackUtils from 'stack-utils';
console.log(typeof StackUtils);                    // 'function'    ✓
console.log(typeof StackUtils.nodeInternals);      // 'undefined'   ✗  (static method)
console.log(typeof StackUtils.prototype?.clean);   // 'undefined'   ✗  (instance/prototype method)
new StackUtils();                                  // TypeError: undefined is not iterable

Node prints function / function / function, and new StackUtils() succeeds.

stack-utils/index.js is a textbook shape:

class StackUtils {
  constructor (opts) {
    ...
    if ('internals' in opts === false) {
      opts.internals = StackUtils.nodeInternals();   // ← static call from ctor
    }
    ...
  }
  static nodeInternals () { return [...natives]; }
  clean (stack, indent = 0) { ... }
  // ...more instance methods...
}
module.exports = StackUtils;   // line 344 — CJS default-export of the class

Because StackUtils.nodeInternals is undefined, the constructor's internal call collapses to spreading undefined, surfacing as TypeError: undefined is not iterable during new StackUtils().

How it surfaced (ink end-to-end, #348)

This is the ink wall immediately after the react-reconciler SIGBUS fix (#4902). Module-init eval-order tracing through ink stops at ink/build/components/ErrorOverview.js, whose top level runs:

const stackUtils = new StackUtils({ cwd: cwd(), internals: StackUtils.nodeInternals() });

→ undefined is not iterable, before any user code. So importing ink throws at init.

Minimal repro environment

• stack-utils@2.x, in compilePackages + allow.compilePackages: ["*"], PERRY_TREE_SHAKE=1, perry.define NODE_ENV=production. No correctness escape hatches.
• Perry @ origin/main (post-fix(runtime): reject unregistered box pointers in js_box_set/get (#4898) #4902 / fix(codegen,runtime): entry-initialize boxed slots — eliminate undef box-pointer operands (#4926) #4931).

Scope / suggested triage

• The breakage is method access on the class object (both Ctor.staticFn and Ctor.prototype.method read back undefined), not the constructor itself — new runs the ctor body. So the class's static + prototype method tables aren't attached to the object that module.exports = Ctor publishes.
• Likely specific to the CJS module.exports = <class> export path (the class is defined at top level, exported at the bottom). Worth checking whether the exported binding is a re-wrapped/forwarded copy of the class that drops its method side-tables, vs. the original class identity.
• Probably the same family as compiled-package instance methods not callable (dayjs.format, chalk.green) — prototype-method dispatch gap #838 (compiled-package instance methods not callable — dayjs/chalk prototype-dispatch gap), but here the methods are entirely absent (typeof … === 'undefined'), not merely non-dispatching, and statics are affected too.

Impact

• Any compilePackages CJS module doing module.exports = class { … } and relying on its methods. stack-utils is the immediate one; the pattern is extremely common.
• ink end-to-end (Compile ink (React-based TUI framework) end-to-end via perry.compilePackages #348): this blocks import 'ink' at init via <ErrorOverview>. After it, ink's next gate is yoga-layout's WASM runtime (out-of-scope).

Related

• Compile ink (React-based TUI framework) end-to-end via perry.compilePackages #348 (ink end-to-end — where this surfaced)
• compiled-package instance methods not callable (dayjs.format, chalk.green) — prototype-method dispatch gap #838 (compiled-package instance methods not callable — likely same family)
• fix(runtime): reject unregistered box pointers in js_box_set/get (#4898) #4902/fix(codegen,runtime): entry-initialize boxed slots — eliminate undef box-pointer operands (#4926) #4931 (the react-reconciler init crash cleared to reach this wall)