Add printf_spec

spec/lib/metasploit/framework/obfuscation/crandomizer/code_factory/printf_spec.rb

@@ -0,0 +1,26 @@
+require 'metasploit/framework/obfuscation/crandomizer/code_factory'
+
+RSpec.describe Metasploit::Framework::Obfuscation::CRandomizer::CodeFactory::Printf do
+
+  subject(:printf) do
+    described_class.new
+  end
+
+  describe '#stub' do
+    it 'is a string' do
+      expect(subject.send(:stub).class).to be(String)
+    end
+
+    it 'has a printf' do
+      expect(subject.send(:stub)).to match(/printf\(.+\)/)
+    end
+
+    it 'has a stub() function' do
+      expect(subject.send(:stub)).to match(/void stub()/)
+    end
+
+    it 'depends on printf' do
+      expect(subject.dep).to eq(['printf'])
+    end
+  end
+end