yum.repo with should_not exist fails with NoMethodError: undefined method `[]' for nil:NilClass

[shoekstra]

Description

While converting a cookbook from Serverspec to Inspec I found testing for a yum repo using yum.repo that does not exist causes Inspec to break.

InSpec and Platform Version

1.11.0 (ChefDK 1.2.22)

Replication Case

Using the original resource from my serverspec test:

File:

describe yumrepo('internal') do
  it { should exist }
  it { should be_enabled }
end

describe yumrepo('epel') do
  it { should_not exist }
end

Output:

[DEPRECATION] `yumrepo(reponame)` is deprecated.  Please use `yum.repo(reponame)` instead.
[DEPRECATION] `yumrepo(reponame)` is deprecated.  Please use `yum.repo(reponame)` instead.
[DEPRECATION] `yumrepo(reponame)` is deprecated.  Please use `yum.repo(reponame)` instead.

Target:  docker://6f0853576e7fe411561c21959ea58963057ae63da3a7b539bda877bba8bd8933


  Yum Repository
     ✔  should exist
     ✔  should be enabled
  Yum Repository
     ✔  should not exist

Test Summary: 3 successful, 0 failures, 0 skipped

Using the new yum.repo('name') format.

File:

describe yum.repo('internal') do
  it { should exist }
  it { should be_enabled }
end

describe yum.repo('epel') do
  it { should_not exist }
end

Output:

[root@localhost /]# inspec exec test.rb
/opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/inspec-1.16.1/lib/resources/yum.rb:139:in `to_s': undefined method `[]' for nil:NilClass (NoMethodError)
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/rspec-core-3.5.4/lib/rspec/core/metadata.rb:180:in `build_description_from'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/rspec-core-3.5.4/lib/rspec/core/metadata.rb:133:in `populate'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/rspec-core-3.5.4/lib/rspec/core/metadata.rb:258:in `create'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/rspec-core-3.5.4/lib/rspec/core/example_group.rb:420:in `set_it_up'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/rspec-core-3.5.4/lib/rspec/core/example_group.rb:384:in `subclass'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/rspec-core-3.5.4/lib/rspec/core/example_group.rb:258:in `block in define_example_group_method'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/inspec-1.16.1/lib/inspec/runner_rspec.rb:27:in `example_group'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/inspec-1.16.1/lib/inspec/runner.rb:238:in `get_check_example'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/inspec-1.16.1/lib/inspec/runner.rb:264:in `block in register_rule'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/inspec-1.16.1/lib/inspec/runner.rb:263:in `each'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/inspec-1.16.1/lib/inspec/runner.rb:263:in `flat_map'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/inspec-1.16.1/lib/inspec/runner.rb:263:in `register_rule'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/inspec-1.16.1/lib/inspec/runner.rb:94:in `block in load'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/inspec-1.16.1/lib/inspec/runner.rb:93:in `each'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/inspec-1.16.1/lib/inspec/runner.rb:93:in `load'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/inspec-1.16.1/lib/inspec/runner.rb:100:in `run'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/inspec-1.16.1/lib/inspec/base_cli.rb:82:in `run_tests'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/inspec-1.16.1/lib/inspec/cli.rb:158:in `exec'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/thor-0.19.1/lib/thor/command.rb:27:in `run'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/thor-0.19.1/lib/thor/invocation.rb:126:in `invoke_command'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/thor-0.19.1/lib/thor.rb:359:in `dispatch'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/thor-0.19.1/lib/thor/base.rb:440:in `start'
        from /opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/inspec-1.16.1/bin/inspec:12:in `<top (required)>'
        from /usr/bin/inspec:22:in `load'
        from /usr/bin/inspec:22:in `<main>'

Confirmed using the shell:

inspec> describe yumrepo('epel') do
inspec>   it { should_not exist }
inspec> end
[DEPRECATION] `yumrepo(reponame)` is deprecated.  Please use `yum.repo(reponame)` instead.

Profile: inspec-shell
Version: (not specified)

  Yum Repository
     ✔  should not exist

Test Summary: 1 successful, 0 failures, 0 skipped

inspec> describe yum.repo('epel') do
inspec>   it { should_not exist }
inspec> end
after_eval hook failed: NoMethodError: undefined method `[]' for nil:NilClass
/opt/inspec/embedded/lib/ruby/gems/2.3.0/gems/inspec-1.16.1/lib/resources/yum.rb:139:in `to_s'
(see _pry_.hooks.errors to debug)

[adamleff]

@shoekstra thanks for submitting this issue, and for your patience! I have submitted PR #1593 to fix this problem.

[shoekstra]

@adamleff no worries, looks good! Thanks for picking this up 👍