support facts added by symbol

lib/puppet-lint/plugins/check_ghostbuster_facts.rb

@@ -28,8 +28,8 @@ def check
     return if m.nil?
 
     File.foreach(path) do |line|
-      if line.match?(/Facter.add\(["']([^"']+)["']\)/)
-        fact_name = line.match(/Facter.add\(["']([^"']+)["']\)/).captures[0]
+      if line =~ /Facter.add\(["':](?<fact>[^"'\)]+)["']?\)/
+        fact_name = Regexp.last_match(:fact)
 
         found = false
 

spec/fixtures/modules/foo/lib/facter/asym.rb

@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+# Fact is a symbol
+Facter.add(:asym) do
+  setcode do
+    'asym'
+  end
+end

spec/puppet-lint/plugins/ghostbuster_facts_spec.rb

@@ -53,5 +53,17 @@
         expect(problems.size).to eq(0)
       end
     end
+
+    context 'when added fact is a symbol and unused' do
+      let(:path) { './spec/fixtures/modules/foo/lib/facter/asym.rb' }
+
+      it 'detects one problem' do
+        expect(problems.size).to eq(1)
+      end
+
+      it 'creates a warning' do
+        expect(problems).to contain_warning('Fact asym seems unused')
+      end
+    end
   end
 end