Improve detection missing WhatIf support

[bheuvel]

From output of Whatif-run, do not replace line break by space, as this breaks the match if the break was done within a word.

[jaym]

@bheuvel Thanks!
Looks good, could you add a simple unit test for this? It goes in
.\spec\unit\util\dsc\local_configuration_manager_spec.rb

[bheuvel]

My first rspec unit test. Seems no problem, but two remarks/questions/opinions;

Do you want a separate test for the WhatIf; one (as currently) without the "unfortunate" linebreak, and one with the linebreak? So test both explicitly. Or just enter the "unfortunate" linebreak in the current test, which will effectively, yet implicitly, test both.

Second, due to pull #2190, the test_configuration will allways return a warning, and not an error. Having 5 minutes experience with this, it seems to me that this kinda invalidates some tests (at least that specific test line, used multiple times) using '.not_to raise_error', as it never will. So reliable testing different failure (all warning) scenario's doesn't seem reliable.
For example testing the "unfortunate" linebreak without the actual code adjustment, resulted in a good test; the code returned the "generic" PowerShell cmdlet error, which returns a warning, which is good enough for the 'missing WhatIf' test.

Resolution for that would be to use:

expect(Chef::Log).to receive(:warn).with('Received error while testing configuration due to resource not supporting \'WhatIf\'')

is that a good idea?

[jaym]

I don't generally like testing logging. I think a better way to do this would be to pull the regex out into its own function, similar to output_has_dsc_module_failure?. Then, you can test just that function

it 'should match whatif failure' do
  lcm.send(:output_has_whatif_failure?, no_whatif_lcm_output).should be_true
end

[adamedx]

@bheuvel, let us know if you're able to make the refactoring change to avoid the expectation on logging. @jdmundrawala, you start on it please let @bheuvel know to avoid duplicate work.

[bheuvel]

@jdmundrawala , @adamedx , sorry, due to personal stuff (am) out of the running. Won't be able to assist/contribute :(

[jaym]

Thanks Bob.
I'm closing this PR as I merged it with #2264