Invalid execArgv for worker threads causes a subsequent TypeError

[guimard]

Hi,

when launching ava with node --disable-proto=throw, it first produces this error:

$ node --disable-proto=throw /usr/bin/ava

file:///usr/share/nodejs/ava/lib/api.js:312
                                for (const error_ of error.errors) {
                                                           ^

TypeError: error.errors is not iterable
    at Api.run (file:///usr/share/nodejs/ava/lib/api.js:312:32)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async loadCli (file:///usr/share/nodejs/ava/lib/cli.js:489:21)

Node.js v18.10.0

With a little hook, we can see the real error (which has no errors property):

AggregateError: 
    Error [ERR_WORKER_INVALID_EXEC_ARGV]: Initiated Worker with invalid execArgv flags: --disable-proto=throw
        at createWorker (file:///usr/share/nodejs/ava/lib/fork.js:24:12)
        at loadFork (file:///usr/share/nodejs/ava/lib/fork.js:84:39)
        at pMap.concurrency.concurrency (file:///usr/share/nodejs/ava/lib/api.js:289:20)
        at /usr/share/nodejs/p-map/index.js:57:28
    at next (/usr/share/nodejs/p-map/index.js:43:14)
    at /usr/share/nodejs/p-map/index.js:67:7
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)

Ava version: 5.0.1

[novemberborn]

Strange, an AggregateError should have an errors: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/AggregateError

Thanks for the reproduction though, should be fixable.

[guimard]

@novemberborn : hi, note that there are two errors here, one when reporting error, and the "proto" error itself

[novemberborn]

The --disable-proto error is not an issue with AVA. That flag is incompatible with worker threads. You'll have to set workerThreads: false in the AVA config to make it use child processes.

[kapouer]

v8 arguments on the main threads are passed on to workers, but passing the same v8 arguments explicitely triggers that error. Node.js is not smart enough here, see nodejs/node#41103.

Only correct workaround would be for ava to whitelist which flags are allowed on the workers, until it is fixed in Node.js

[novemberborn]

Only correct workaround would be for ava to whitelist which flags are allowed on the workers, until it is fixed in Node.js

This is too much of an edge case for us to implement. Disabling worker threads should do the trick.

[Bives89]

To fix the issue, you will need to remove the --disable-proto=throw flag when running AVA. If you need to disable the ability to modify object prototypes, you can use the --no-proto flag instead.

You can run AVA with the following command:
$ node /usr/bin/ava