Unknown Fatal Error if code is not an int

[bevand10]

rollup/cli/run/watch-cli.ts

Line 156 in 3520da5

if (code) process.exit(code);

Given the input value to this function (code) is not always an int, this line fails but does not report a true/underlying error reason to the user.

I had a scenario where my OS ran out of watcher capacity. That caused the input to the exit function to not be a number:

Sending the received value (code) to process.exit causes this error:

TypeError: The "code" argument must be of type number. Received an instance of Error
    at process.set [as exitCode] (node:internal/bootstrap/node:123:9)
    at process.exit (node:internal/process/per_thread:188:24)
    at process.close (.../node_modules/rollup/dist/shared/watch-cli.js:505:23)
    at process.emit (node:events:514:28)
    at process.emit (.../node_modules/source-map-support/source-map-support.js:516:21)
    at processEmit [as emit] (.../node_modules/rollup/dist/shared/watch-cli.js:336:34)
    at process._fatalException (node:internal/process/execution:159:25)
    at processPromiseRejections (node:internal/process/promises:289:13)
    at processTicksAndRejections (node:internal/process/task_queues:96:32)

Here's the full function:

async function close(code: number | null | undefined): Promise<void> {
		process.removeListener('uncaughtException', closeWithError);
		// removing a non-existent listener is a no-op
		process.stdin.removeListener('end', close);

		if (watcher) await watcher.close();
		if (configWatcher) configWatcher.close();
		if (code) process.exit(code);
	}

In my case, the code value passed to the function is an Error object (as alluded to in the error message), not a number, not null and not undefined:

{
  "errno": -28,
  "syscall": "watch",
  "code": "ENOSPC",
  "path": "/home/me/mydir/rollup.config.js",
  "filename": "/home/me/mydir/rollup.config.js"
}

When I added console.error(code) to debug the scenario (I hacked node_modules/rollup/dist/shared/watch-cli.js), the message emitted was converted to a string by Error.toString(), to:

Error: ENOSPC: System limit for number of file watchers reached, watch '/home/me/mydir/rollup.config.js'

That of course revealed the true problem I had/have, but the default error stack/messaging did not, as the Error object was being type-converted to a string before dispatch to process.exit, thus hiding the actual fault.