async_hooks: async hook stack assertion shadows "Maximum call stack size exceeded"

[ilyaigpetrov]

• Node Version: v8.2.1
• Platform: Linux 4.10.0-33-generic #37~16.04.1-Ubuntu SMP Fri Aug 11 14:07:24 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
• node-fetch@1.7.3

My product is not affected by this bug, but I report it anyway because it's still a bug and may affect someone else.

'use strict';

const fetch = require('node-fetch');

// Function name `fetch` clashes with required `fetch`!
const FooBar = async function fetch(url, encoding) {

 const res = fetch(url); // Programmer forgot `await` here!
 const text = await res.text();

};

(async function () {
 return await FooBar('https://github.com');
})();

$ node foobar.js 
Error: async hook stack has become corrupted (actual: 0, expected: 1)
 1: node::Start(uv_loop_s*, int, char const* const*, int, char const* const*) [node]
 2: node::Start(int, char**) [node]
 3: __libc_start_main [/lib/x86_64-linux-gnu/libc.so.6]
 4: 0x8ec861 [node]

Expected

User-friendly error message is expected, not this stack error.

[addaleax]

/cc @nodejs/async_hooks

I can reproduce this with master

[refack]

I think is mostly a stack overflow issue; fetch is being reassigned on L6, then called recursivly on L8:

6: const FooBar = async function fetch(url, encoding) {
7:
8: const res = fetch(url); // Programmer forgot `await` here!

But I agree the error should be RangeError: Maximum call stack size exceeded and not the C++ assertion error.

[addaleax]

Standalone reproduction:

async function fn() {
 fn();
 throw new Error();
}

(async function() { await fn(); })()

Edit: Without the throw, this fails silently, so there’s definitely more going on here.

[AndreasMadsen]

#15454 skips the sanity check when async_hooks is disabled. It is not exactly a fix for this, but it is related.

[trevnorris]

Thank you. Looking into it.

[trevnorris]

Thanks for reporting this. Quick update, this has to do w/ Promises and async_hooks not being enabled:

(node::node_async_ids) ids = (async_id = 2.8803866749967284E-310, trigger_id = 8.8796076974385372E-311)
(node::Environment *) env = 0x00007fffffffc608 

whereas:

require('async_hooks').createHook({ init() { } }).enable();

async function fn() {
 fn();
 throw new Error();
}

(async function() { await fn(); })()

gives:

/tmp/15448.js:3
async function fn() {
 ^

RangeError: Maximum call stack size exceeded
 at <anonymous>
 at fn (/tmp/15448.js:3:18)
 at fn (/tmp/15448.js:4:3)
 at fn (/tmp/15448.js:4:3)
 at fn (/tmp/15448.js:4:3)
 at fn (/tmp/15448.js:4:3)
 at fn (/tmp/15448.js:4:3)
 at fn (/tmp/15448.js:4:3)
 at fn (/tmp/15448.js:4:3)
 at fn (/tmp/15448.js:4:3)

[trevnorris]

There also seems to be a discrepancy depending on when this runs:

process.nextTick(() => {
 async function fn() {
 fn();
 throw new Error();
 }
 (async function() { await fn(); })()
});

produces

(node:PID) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: ID): Error

over 4,000 times, and has an exit code of 0. Also investigating that.

EDIT: nix that. Simply changing the script to

async function fn() {
 fn();
 throw new Error();
}
(async function() { await fn(); })()
process._rawDebug('------ AFTER -----');

outputs the same as above.

[trevnorris]

Have a fix at #15553. Thanks for the bug report.