Sometimes a linter is not enough. Trying its best, it will point out to the end of file. That's ok if the file is short enough to go through it and spot it. Hoewever, sometimes that's not the case and the error is not so obvious. It's in these cases where one has to apply other techniques.
Instead of going through all the code line by line, what about using your Text Editor Fold/Unfold? For Sublime Text you have the option of folding different lvels of code.
Consider the following code:
module A
method one
end