Create validation function; create test based on broken subscribe call

lib/octocatalog-diff/catalog-diff/cli/catalogs.rb

@@ -234,6 +234,7 @@ module OctocatalogDiff
         # @return [Boolean] true if catalog is valid, false otherwise
         def catalog_validator(catalog = nil, _logger = @logger)
           return false unless catalog.is_a?(OctocatalogDiff::Catalog)
+          catalog.validate_references
           catalog.valid?
         end
       end

lib/octocatalog-diff/catalog.rb

@@ -174,8 +174,54 @@ module OctocatalogDiff
       !@catalog.nil?
     end
 
+    # Determine if all of the (before, notify, require, subscribe) targets are actually in the catalog.
+    # Raise a ReferenceValidationError for any found to be missing.
+    # Uses @options[:validate_references] to influence which references are checked.
+    def validate_references
+      # Skip out early if no reference validation has been requested.
+      unless @options[:validate_references].is_a?(Array) && @options[:validate_references].any?
+        return
+      end
+
+      # Iterate over all the resources and check each one that has one of the attributes being checked.
+      # Keep track of all references that are missing for ultimate inclusion in the error message.
+      missing = []
+      resources.each do |x|
+        @options[:validate_references].each do |r|
+          next unless x.key?('parameters')
+          next unless x['parameters'].key?(r)
+          next if catalog_contains_all_resources?(x['parameters'][r])
+          missing << { source: x, target_type: r, target_value: x['parameters'][r] }
+        end
+      end
+      return if missing.empty?
+
+      # At this point there is at least one broken/missing reference. Format an error message and
+      # raise.
+      message = missing.inspect
+      raise ReferenceValidationError, message
+    end
+
     private
 
+    # Private method: Determine if a catalog contains resource or resources, which may
+    # have been passed in as an array or a string. (If multiple resources are passed, the
+    # logic is AND.)
+    # @param resources_to_check [String / Array] Resources to check
+    # @return [Boolean] true if all resources are in catalog; false otherwise
+    def catalog_contains_all_resources?(resources_to_check)
+      rtc_array = resources_to_check.is_a?(Array) ? resources_to_check : [resources_to_check]
+      rtc_array.each do |res|
+        unless res =~ /\A([\w:]+)\[(.+)\]\z/
+          raise CatalogError, "Resource #{res} is not in the expected format"
+        end
+        type = Regexp.last_match(1)
+        title = Regexp.last_match(2)
+        return false if resource(type: type, title: title).nil?
+      end
+      true
+    end
+
     # Private method: Choose backend based on passed-in options
     # @param options [Hash] Options passed into constructor
     # @return [Object] OctocatalogDiff::Catalog::<whatever> object

spec/octocatalog-diff/fixtures/repos/reference-validation/hieradata/roles/broken-subscribe.yaml

@@ -0,0 +1,9 @@
+---
+  classes:
+    - test::before_callers
+    - test::before_targets
+    - test::notify_callers
+    - test::notify_targets
+    - test::require_callers
+    - test::require_targets
+    - test::subscribe_callers

spec/octocatalog-diff/fixtures/repos/reference-validation/modules/test/manifests/subscribe_callers.pp

@@ -1,6 +1,22 @@
 class test::subscribe_callers {
-  exec { 'subscribe caller':
+  exec { 'subscribe caller 1':
     command   => '/bin/true',
     subscribe => Exec['subscribe target'],
   }
+
+  exec { 'subscribe caller 2':
+    command   => '/bin/true',
+    subscribe => [
+      Exec['subscribe target'],
+      Exec['subscribe target 2']
+    ]
+  }
+
+  exec { 'subscribe caller 3':
+    command   => '/bin/true',
+    subscribe => [
+      Exec['subscribe caller 1'],
+      Exec['subscribe target']
+    ]
+  }
 }

spec/octocatalog-diff/fixtures/repos/reference-validation/modules/test/manifests/subscribe_targets.pp

@@ -2,4 +2,8 @@ class test::subscribe_targets {
   exec { 'subscribe target':
     command => '/bin/true',
   }
+
+  exec { 'subscribe target 2':
+    command => '/bin/true',
+  }
 }

spec/octocatalog-diff/integration/reference_validation_spec.rb

@@ -64,7 +64,18 @@ describe 'validation of references' do
     end
   end
 
-  context 'with broken require' do
+  context 'with broken subscribe' do
+    before(:all) do
+      @result = OctocatalogDiff::Spec.reference_validation_catalog('broken-subscribe', %w(subscribe))
+    end
+
+    it 'should not succeed' do
+      expect(@result.exitcode).to eq(-1), OctocatalogDiff::Integration.format_exception(@result)
+    end
+
+    it 'should raise ReferenceValidationError' do
+      expect(@result.exception).to be_a_kind_of(OctocatalogDiff::Catalog::ReferenceValidationError)
+    end
   end
 
   context 'with broken before' do