Add a meterpreter test for enumerating core commands

lib/rex/post/meterpreter/client_core.rb

@@ -104,6 +104,7 @@ class ClientCore < Extension
   def get_loaded_extension_commands(extension)
     request = Packet.create_request(COMMAND_ID_CORE_ENUMEXTCMD)
 
+    # handle 'core' as a special case since it's not a typical extension
     extension = EXTENSION_ID_CORE if extension == 'core'
     extension = Rex::Post::Meterpreter::ExtensionMapper.get_extension_id(extension) unless extension.is_a? Integer
     request.add_tlv(TLV_TYPE_UINT,   extension)

test/modules/post/test/meterpreter.rb

@@ -47,6 +47,19 @@ class MetasploitModule < Msf::Post
     super
   end
 
+  def test_core_command_id_enumeration
+    commands = []
+
+    it "should enumerate supported core commands" do
+      commands.concat(session.core.get_loaded_extension_commands('core'))
+      !commands.empty?
+    end
+
+    # 3 is arbitrary, but it's probably a good bare minimum to include enumextcmd, machine_id, and loadlib
+    it "should support 3 or more core commands" do
+      commands.length >= 3
+    end
+  end
 
   def test_sys_process
     vprint_status("Starting process tests")