Node 20: errors with util.inspect.custom raised in loader thread not serialized/deserialized correctly

[danrr]

Version

v20.2.0

Platform

No response

Subsystem

No response

What steps will reproduce the bug?

Throw an error with a custom inspect symbol in worker thread, which is then serialised and deserialised to be displayed by main thread.

Investigating a bug in ts-node (TypeStrong/ts-node#2026) I ran into some issues with how errors in (loader) worker threads are handled.

1. util.inspect.custom is only checked in own properties (https://github.com/nodejs/node/blob/main/lib/internal/error_serdes.js#L137), ignoring it if the error was created using a class constructor (see https://github.com/TypeStrong/ts-node/blob/7af5c48864b60576e471da03c064f325ce37d850/src/index.ts#L432-L464)
2. Errors with custom inspect methods are not displayed correctly by call to internalBinding('errors').triggerUncaughtException

node:internal/process/esm_loader:42
      internalBinding('errors').triggerUncaughtException(
                                ^
[Object: null prototype] {
  [Symbol(nodejs.util.inspect.custom)]: [Function: [nodejs.util.inspect.custom]]
}

3. Errors defined by classes inheriting from Error don't appear to trigger the check here: https://github.com/nodejs/node/blob/main/lib/internal/error_serdes.js#L120

let a = new Error("hmm?")
Object.prototype.toString(a)
> "[object Object]"

How often does it reproduce? Is there a required condition?

Every time an error is raised in loader worker thread.

What is the expected behavior? Why is that the expected behavior?

Errors using custom inspect symbol raised in threads should serialise correctly

What do you see instead?

[Symbol(nodejs.util.inspect.custom)]: [Function: [nodejs.util.inspect.custom]]

Additional information

No response

[aduh95]

The title says "loader thread", but I assume that's true for any worker thread, right?

[danrr]

One of the issues seems specific to the error handling code in process/esm_loader. Others seem to affect all error serialisation.

[aduh95]

Can you share a minimal repro?

[danrr]

@aduh95 would the repro I made for node-ts do?

TypeStrong/ts-node-repros#33

[aduh95]

A minimal repro would ideally not include any code to be downloaded from the internet, ideally a list of commands that can be copy pasted from the web browser to a terminal.

[aduh95]

1. util.inspect.custom is only checked in own properties

I've opened #48306 to address this.

2. Errors with custom inspect methods are not displayed correctly by call to internalBinding('errors').triggerUncaughtException

It has nothing to do with the custom inspect method, triggerUncaughtException will not run any JS, it generates the error message using v8::Exception::createMessage so I think what you see is the expected output.

node/src/node_errors.cc

Lines 1005 to 1017 in 6700aac

	static void TriggerUncaughtException(const FunctionCallbackInfo<Value>& args) {
	Isolate* isolate = args.GetIsolate();
	Environment* env = Environment::GetCurrent(isolate);
	Local<Value> exception = args[0];
	Local<Message> message = Exception::CreateMessage(isolate, exception);
	if (env != nullptr && env->abort_on_uncaught_exception()) {
	ReportFatalException(
	env, exception, message, EnhanceFatalException::kEnhance);
	Abort();
	}
	bool from_promise = args[1]->IsTrue();
	errors::TriggerUncaughtException(isolate, exception, message, from_promise);
	}

3. Errors defined by classes inheriting from Error don't appear to trigger the check here: https://github.com/nodejs/node/blob/main/lib/internal/error_serdes.js#L120

let a = new Error("hmm?")
Object.prototype.toString(a)
> "[object Object]"

You forgot .call, try e.g. Object.prototype.toString.call(new class A extends TypeError{}).

---

I'm not sure what this ticket is about, could you please share a minimal repro that includes steps to reproduce the issue (without needing to download code from the internet), the expected output, and what you see instead please?