Undefined method 'scan' for nil:NilClass (NoMethodError)

Question

Stuck on this one, this layout is for a chef inspec test but leveraging ruby to grab the contents of a file. However with this test I'm not actually testing against a file, so I'm trying to understand how to account for that, heres the code:

%w(/etc/bashrc /etc/profile).each do |path|
file(path).content.scan(/^\s*umask\s+(\d{3})\b/).flatten.each do |umask| 
 BASELINE = '0027'
 (1..3).each do |i| # leading char is '0' octal indicator
    describe umask[i].to_i do
        it { should be <= BASELINE[i].to_i }
     end
    end
   end
  end
end

Here is the line giving me trouble

file(path).content.scan(/^\s*umask\s+(\d{3})\b/).flatten.each do |umask|

score 0 · Answer 1 · answered Aug 17 '16 at 15:51

You can change file(path).content to a string that matches whatever the file content is.

"Sample_string".scan(/^\s*umask\s+(\d{3})\b/).flatten.each do |umask|

The reason is file(path).content returns nil if you are not testing against a real file. And nil does not have the scan method, which is why you are getting the error.

Mrigesh Priyadarshi · Accepted Answer · 2016-08-19T06:26:25.057

As far as the error is concerned, i.e., "Undefined method 'scan' for nil:NilClass", this error would only come up, while doing inspec run, if the files, which are being passed, are either not present or not readable on the file system.

Also, The information provided is not complete, as it is unclear that what is the umask set in both files, i.e, is it 3 digits or 4 digits ones?

Because while doing scan you are looking for 3 digit umask "scan(/^\sumask\s+(\d{3})\b/)*" and you have set "BASELINE = '0027'" which is 4 digit one. So, it would definitely going to have a problem.

If you have "umask 027" in the files, then, it should be: Check BASELINE = '027', searching 3 digit umask

%w(/etc/bashrc /etc/profile).each do |path|
  file(path).content.scan(/^\s*umask\s+(\d{3})\b/).flatten.each do |umask| 
   BASELINE = '027'
   (1..3).each do |i| # leading char is '0' octal indicator
      describe umask[i].to_i do
        it { should be <= BASELINE[i].to_i }
      end
   end
 end
end

Else you have "umask 0027" in the files, then, it should be:

Check scan(/^\s*umask\s+(\d{4})\b/), searching 4 digit umask

%w(/etc/bashrc /etc/profile).each do |path|
  file(path).content.scan(/^\s*umask\s+(\d{4})\b/).flatten.each do |umask| 
   BASELINE = '027'
   (1..3).each do |i| # leading char is '0' octal indicator
      describe umask[i].to_i do
        it { should be <= BASELINE[i].to_i }
      end
   end
 end
end

Undefined method 'scan' for nil:NilClass (NoMethodError)

2 Answers2