Please, fix a small typo in description: not "and array" but "an array"

When I submit my solution I've got a strange otput:

TypeError: object is not a function
  at justify
  at .:136:11
  at Array.forEach
  at .:134:11
  at .:154:3
  
      
74 Passed
0 Failed
1 Errors

I can't understand why I have error with Array.forEach because my code if convert it to JavaScript doesn't include any Array.forEach. Can anybody help me?

It's strange but tests work differently when I click 'Run test' and 'Submit'.
I had my tests failed with incorrect argument when I use raise unless ... but same tests had passed when I click 'Submit'!