This block seems a little aggressive.

You're shelling out to the same command twice. At the very least we should only do that once.

```ruby
spec_files.each do |spec| 
  result = `git diff --cached -G:focus #{spec}`
  puts result
  diff = result
  ...
end
```

Going even further than that, its happening in a loop. Can we drop the loop, remove the filename from the end of the command, and just execute it once?

```ruby
diff = `git diff --cached -G:focus`
passed = diff !~ /[\W\s]:focus[\W\s]/
```