Whoever wrote the tests might have been lazy and chose to use random integers as keys to not implement a random string generator. If you are parsing the string manually, this makes the task harder, but it can be solved in a trivial way if you use a rather notorious language feature instead.

I don't understand why the sample test requires a symbol({:a=>1, :b=>2, :c=>3}), and attemping tests don't(Expected: {85=>42, 97=>67, 2=>29, 1=>81}).

The error message is unclear, what it means is that your output is wrong. Print the input string and your hash before returning it to see whether they're the same.

Test.assert_equals should be used instead.

STDERR
/runner/frameworks/ruby/cw-2.rb:38:in expect': Not expected values (Test::Error) from main.rb:24:in block in '
from main.rb:19:in times' from main.rb:19:in '

I can't figure what I need to fix in my code with this error...