This won't work as there are missing leading zeroes for decimals 1 to 15.

It works incorrectly with rgb(8, 64, 8), your result is 8408, you need 084008. How did you pass the random test?

Not working with 128, 12, 111

rgb(5,5,5);
its gives worng answer

Not an issue

Yeah, it's a bit shortcoming.
but I like the func toHex in func rgb, which keep not expose the inner func to the out scope!

your elses are redundant, you could get rid off them.

Don't working with rgb(1,1,1). Return "111" but correct ="010101"

what part pf the description is unclear ? more test cases coming up

Poor description.

Unclear description, need more testcases.

Targaryen error, unclear description, no tests.