Reactively check for invalid module names

lib/msf/core/modules/loader/base.rb

@@ -362,17 +362,24 @@ class Msf::Modules::Loader::Base
   # @return [nil] if any module name along the chain does not exist.
   def current_module(module_names)
     # Don't want to trigger ActiveSupport's const_missing, so can't use constantize.
-    named_module = module_names.inject(Object) { |parent, module_name|
+    named_module = module_names.reduce(Object) do |parent, module_name|
       # Since we're searching parent namespaces first anyway, this is
       # semantically equivalent to providing false for the 1.9-only
       # "inherit" parameter to const_defined?. If we ever drop 1.8
       # support, we can save a few cycles here by adding it back.
-      if parent.const_defined?(module_name)
-        parent.const_get(module_name)
-      else
-        break
+      begin
+        if parent.const_defined?(module_name)
+          parent.const_get(module_name)
+        else
+          break
+        end
+      # HACK: This doesn't slow load time as much as checking proactively
+      rescue NameError
+        reversed_name = self.class.reverse_relative_name(module_name)
+        # TODO: Consolidate this with Msftidy#check_snake_case_filename ?
+        raise Msf::ModuleLoadError, "#{reversed_name} must be lowercase alphanumeric snake case"
       end
-    }
+    end
 
     named_module
   end

tools/dev/msftidy.rb

@@ -257,7 +257,7 @@ class Msftidy
   # This check also enforces namespace module name reversibility
   def check_snake_case_filename
     if @name !~ /^[a-z0-9]+(?:_[a-z0-9]+)*\.rb$/
-      warn('Filenames should be lowercase alphanumeric snake case.')
+      warn('Filenames must be lowercase alphanumeric snake case.')
     end
   end