Winston Log File and Worker thread behavior

[capttrousers]

I have a custom Winston app logger setup that I use to write debug logs to a file (file transport), and with the default worker thread AVA behavior, the logs weren't being sent to the log file, but they were being sent to the console transport.

I thought I was able to fix the issue by upgrading to v4 and setting "workerThreads": false in my package.json ava config but Im still getting weird logging behavior, specifically to the file transport only.

Here's a simple example of my logger:

let LOGGER_INSTANCE;
export const setupLogger = () => {
  if (LOGGER_INSTANCE !== null && LOGGER_INSTANCE !== undefined) {
    return LOGGER_INSTANCE;
  }

  let local_logger = winston.createLogger({
    level: "debug",
    format: winston.format.simple(),
    exitOnError: false,
    transports: [
      new winston.transports.File({ filename:  'logs/app.log', level: "debug"}),
      new winston.transports.Console({ level: "info"}),
    ],
  });
  return local_logger;
}
LOGGER_INSTANCE = setupLogger();

export { LOGGER_INSTANCE as LOGGER }

And then in the app modules (or even the test spec files themselves)

import { LOGGER } from "./utils/logger.js"

export const someMethod = async () => { 
  LOGGER.debug("something");
  LOGGER.debug("something else")
}

I can get the first something logged, but the second log statement something else isnt logged to the file transport, but it is logged to the console transport.
If I add an arbitrary log statement to the test case itself, then the logging in the app just isnt sent to the file. If I remove the logging from the test case, the first log statement in the app works but none of the rest do.

I've tested that this does work when normally running the app, so it seems to be something with the AVA test runner, maybe reporters, and maybe worker threads? Or maybe something with how module export/import works in JS that I don't understand?
Or maybe the test runner is exiting so quickly that the logs are getting written?
How can I avoid this, if thats the case?

Thanks!

[capttrousers]

I think this might just be that AVA runs my simple tests so fast, that the log file is never written to before the process/worker thread is torn down.

If I add an await for the logger's "finish" event, it seems like my log files are written to as expected.

import events from node:events

test.after.always('guaranteed cleanup', async (t) => {
    try {
        await events.once(LOGGER, "finish");
    } catch (e) {}
});

I still get an error in the after hook: guaranteed cleanup Promise returned by test never resolved

I wonder if there's a way to make ava wait for the log to finish writing everything.

[novemberborn]

There is #1718 which proposes we wait until the event loop is drained.

However AVA should already wait for all hooks to complete.

The error indicates that the worker was killed regardless. Was there a timeout or did you interrupt execution?