(PA-5807) Ignore yumrepo files managed by Puppet file resource

[cthorn42]

Previously we attempted to manage every repo that was found in the yumrepos directory. If one of those repos was a Puppet File resource, yumrepo would manage the yumrepo the Puppet File resource was creating. This casued some idepontecy issues.
This change will make it so yumrepo will not attempt to manage any file resource it finds that is found in the yumrepo directory.

[joshcooper]

Since instances is a public provider method that overrides https://github.com/puppetlabs/puppet/blob/82ad86ea21ecf20a956db6bf46140940caccd0cc/lib/puppet/provider.rb#L382 it's surprising for this method to have a different signature than its parent. Since the instances method may be called in two different contexts (during prefetch or when running puppet resource yumrepo) I'd recommend creating a private class method containing all of the old instances code and then call it with different arguments from instances and prefetch, something like:

Suggested change

	def self.instances(resources = nil)
	def self.instances
	instances_with_resources
	end
	def self.instances_with_resources(resources = nil)
	# existing instances code
	end
	private_class_method :instances_with_resources
	def self.prefetch(resources)
	repos = instances_with_resources(resources)
	...
	end

[joshcooper]

Since resources is a Hash, you could extract the values directly:

-    current_yumrepo_inis = []
-    resources&.each do |key|
-      current_yumrepo_inis << key[1]
+    current_yumrepo_inis = resources&.values

Also to avoid resources defaulting to nil while current_yumrepo_inis defaults to [], I'd default the former to:

def self.instances_with_resources(resources = [])

Then you can drop all of the safe nav operators

[joshcooper]

We can stop enumerating over current_yumrepo_inis as soon as we find the first File resource with path file. A common idiom to short-circuit is to do:

-          current_yumrepo_inis.each do |index|
-            index_virtual = false if index.catalog.resource('File', file)
-          end
+          index_virtual = !current_yumrepo_inis.any? { |index| index.catalog.resource('File', file) }

[joshcooper]

Could you add a test to show if a file is managed by both a file and yumrepo, then the latter doesn't purge it? I think this has to be done as a beaker test given the way the rspec tests are currently structured.