auto-gen-config doesn't patch %r{/} warning correctly

[tmorris-fiksu]

To reproduce, create the file sample.rb included below. Run rubocop --auto-gen-config. rubocop --config rubocop-todo.yml gives the following warning:

...
sample.rb:2:9: C: Use %r only for regular expressions matching more than 2 '/' characters.
y.gsub!(%r{abc/xyz}, "A/Z")
        ^^^^^^^^^^^

1 file inspected, 1 offence detected
$ cat sample.rb
y = "123/abc/xyz/ijk"
y.gsub!(%r{abc/xyz}, "A/Z")
puts y
$ rubocop -V
0.18.1 (using Parser 2.1.5, running on ruby 1.9.3 x86_64-darwin12.5.0)

The generated rubocop-todo.yml includes:

# Offence count: 1
RegexpLiteral:
  MaxSlashes: 2

It should be MaxSlashes: 1 to avoid the warning.

[jonas054]

Thanks. I'll examine the problem.

[jonas054]

Let me clarify what the problem is. MaxSlashes is the maximum number of (escaped) slashes that a slash-delimited regexp is allowed to have. If there are more slashes, it should be a %r regexp. This also means that %r literals must have more slashes than MaxSlashes.

So for sample.rb above, --auto-gen-config should generate

RegexpLiteral:
  MaxSlashes: 0

For code containing %r{abc} and %r{abc/123} it should generate MaxSlashes: -1, meaning that only %r literals should be used.

For code containing %r{abc} and /abc/ it should generate Enabled: false, because there's no MaxSlashes setting that would allow both of them.