CODEWITHSUNDEEP
rubychef-infracookbooklwrp
arney
arney

Reputation: 845

How to write regression tests for custom Chef resources?

Given the minimal example

# resources/novowel.rb
resource_name :novowel
property :name, String, name_property: true, regex: /\A[^aeiou]\z/

I would like to write the unit tests in spec/unit/resources/novowel_spec.rb

to ensure that the name property still works correctly even if the regex is changed for some reason.

I browsed several top notch Chef cookbooks but could not find references for such testing.

How can it be done? Feel free to provide more complex examples with explicitly subclassing Chef::Resource if that helps achieve the task.

Update 1: Could it be that Chef does NOT FAIL when a property does not fit the regex? Clearly this should not work:

link '/none' do
  owner  'r<oo=t'
  to     '/usr'
end

but chef-apply (12.13.37) does not complain about r<oo=t not matching owner_valid_regex. It simply converges as if owner would not have been provided.

Upvotes: 0

Views: 281

Answers (2)

arney
arney

Reputation: 845

We wrap the DSL inside a little Ruby in order to know the name of the resource's Ruby class:

# libraries/no_vowel_resource.rb
require 'chef/resource'

class Chef
  class Resource
    class NoVowel < Chef::Resource
      resource_name :novowel
      property :letter, String, name_property: true, regex: /\A[^aeiou]\z/
      property :author, String, regex: /\A[^aeiou]+\z/
    end
  end
end

and now we can use RSpec with

# spec/unit/libraries/no_vowel_resource_spec.rb
require 'spec_helper'

require_relative '../../../libraries/no_vowel_resource.rb'

describe Chef::Resource::NoVowel do
  before(:each) do
    @resource = described_class.new('k')
  end

  describe "property 'letter'" do
    it "should accept the letter 'k'" do
      @resource.letter = 'k'
      expect(@resource.letter).to eq('k')
    end

    it "should accept the character '&'" do
      @resource.letter = '&'
      expect(@resource.letter).to eq('&')
    end

    it "should NOT accept the vowel 'a'" do
      expect { @resource.letter = 'a' }.to raise_error(Chef::Exceptions::ValidationFailed)
    end

    it "should NOT accept the word 'mm'" do
      expect { @resource.letter = 'mm' }.to raise_error(Chef::Exceptions::ValidationFailed)
    end
  end

  describe "property 'author'" do
    it "should accept a String without vowels" do
      @resource.author = 'cdrngr'
      expect(@resource.author).to eq('cdrngr')
    end

    it "should NOT accept a String with vowels" do
      expect { @resource.author = 'coderanger' }.to raise_error(Chef::Exceptions::ValidationFailed)
    end
  end
end

Upvotes: 0

coderanger
coderanger

Reputation: 54249

You would use ChefSpec and RSpec. I've got examples in all of my cookbooks (ex. https://github.com/poise/poise-python/tree/master/test/spec/resources) but I also use a bunch of custom helpers on top of plain ChefSpec so it might not be super helpful. Doing in-line recipe code blocks in the specs makes it waaaay easier. I've started extracting my helpers out for external use in https://github.com/poise/poise-spec but it's not finished. The current helpers are in my Halite gem, see the readme there for more info.

Upvotes: 2

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