Style/VariableName doesn't seem to work with method parameters

[mateusmedeiros]

I don't know if this is intended behaviour, but if it is, I think it should be changed (unless there's a specific cop for that, in which case I'd really like to know which it is, because I couldn't find any).

If I have the following method in a ruby script:

def downloadAnother(urlFileHash)
  variableWithCamelCase = 2
  urlFileHash.each do |url, file|
    puts "downloading #{url} to #{file}"
  end
end

Rubocop will report 3 offenses from this method:

C: Use snake_case for method names.
def downloadAnother(urlFileHash)
    ^^^^^^^^^^^^^^^

W: Useless assignment to variable - variableWithCamelCase.
  variableWithCamelCase = 2
  ^^^^^^^^^^^^^^^^^^^^^

C: Use snake_case for variable names.
  variableWithCamelCase = 2
  ^^^^^^^^^^^^^^^^^^^^^

But I was expecting Style/VariableName to also detect offenses in parameters names, like this:

C: Use snake_case for variable names.
def downloadAnother(urlFileHash)
                    ^^^^^^^^^^^

This is the original method I had for which rubocop is reporting no offense at all:

def download(urlFileHash)
  urlFileHash.each do |url, file|
    puts "Downloading #{url} to the file #{file}..."
    File.open(file, 'wb') do |saved_file|
      open(url, 'rb') do |read_file|
        saved_file.write(read_file.read)
      end
    end
  end
end

I installed rubocop straight from master and it still reports no offense.
Here is my rubocop -V:

0.34.2 (using Parser 2.2.3.0, running on ruby 2.2.3 x86_64-linux)

Thanks in advance.

[jonas054]

Makes sense. Let Style/VariableName check parameter names too.

[kjvarga]

This still isn't catching bad variable names in arguments passed to a method, and it doesn't catch bad let variable definitions (thought I think that one is understandable). The problem there is that in a lot of specs we define the variable using let and then it gets passed to a method when it's used, but this rule isn't catching either of those scenarios, leaving a big blind spot. It does catch bad parameters in a method definition, and bad variable assignments.

[kjvarga]

Created issue: #7275