Thanks for the fix! My solution works now.

Hi! Thanks for the feedback! I've just taken a look and realised I was unintentionally passing the same array to the user code, as I was to the test code. (Which means if you were manipulating the array, it would affect the test result)
Hopefully I've fixed this now, could you try and submit your solution again and mark as resolved if this has fixed the issue for you?

Thanks!

I'm pretty sure the 'Should work for random names' test is bugged:

TypeError: user.toLowerCase is not a function
    at /workspace/node/test.js:312:34
    at Array.map (<anonymous>)
    at solution (test.js:311:30)
    at Context.<anonymous> (test.js:305:52)
    at process.processImmediate (node:internal/timers:471:21)

I've checked many times whether I was causing the error, but everything seemed fine on my part. It's preventing me from passing all the tests.