```ruby
# encoding: utf-8

require 'helper'

class TestAddressCHFR < Test::Unit::TestCase
  def test_ch_fr_canton
    assert_match /\A[- a-zàâäèéêëîïôœùûüÿç]+\z/i, FFaker::AddressCHFR.canton
  end
end
```

Fix rubocop warning about Ambiguous regexp literal.
user
```ruby
# encoding: utf-8

require 'helper'

class TestAddressCHFR < Test::Unit::TestCase
  def test_ch_fr_canton
    assert_match(/\A[- a-zàâäèéêëîïôœùûüÿç]+\z/i, FFaker::AddressCHFR.canton)
  end
end
```
assistant