add tests for non glob dirs audit

Library/Homebrew/rubocops/lines_cop.rb

@@ -255,11 +255,14 @@ module RuboCop
               problem "\"#{m.source}\" is deprecated, use a comparison to MacOS.version instead"
             end
           end
-          #
-          # dirPattern(body_node) do |m|
-          #   next unless m =~ /\[("[^\*{},]+")\]/
-          #   problem "Dir(#{Regexp.last_match(1)}) is unnecessary; just use #{Regexp.last_match(1)}"
-          # end
+
+          find_instance_method_call(body_node, "Dir", :[]) do |m|
+            path = parameters(m).first
+            next if !path.str_type?
+            next unless match = regex_match_group(path, /^[^\*{},]+$/)
+            problem "Dir([\"#{string_content(path)}\"]) is unnecessary; just use \"#{match[0]}\""
+          end
+
           #
           # fileUtils_methods= FileUtils.singleton_methods(false).map { |m| Regexp.escape(m) }.join "|"
           # find_method_with_args(body_node, :system, /fileUtils_methods/) do |m|

Library/Homebrew/test/rubocops/lines_cop_spec.rb

@@ -552,6 +552,29 @@ describe RuboCop::Cop::FormulaAudit::Miscellaneous do
         expect_offense(expected, actual)
       end
     end
+
+    it "with non glob DIR" do
+      source = <<-EOS.undent
+        class Foo < Formula
+          desc "foo"
+          url 'http://example.com/foo-1.0.tgz'
+          rm_rf Dir["src/{llvm,test,librustdoc,etc/snapshot.pyc}"]
+          rm_rf Dir["src/snapshot.pyc"]
+        end
+      EOS
+
+      expected_offenses = [{  message: "Dir([\"src/snapshot.pyc\"]) is unnecessary; just use \"src/snapshot.pyc\"",
+                              severity: :convention,
+                              line: 5,
+                              column: 13,
+                              source: source }]
+
+      inspect_source(cop, source)
+
+      expected_offenses.zip(cop.offenses).each do |expected, actual|
+        expect_offense(expected, actual)
+      end
+    end
   end
   def expect_offense(expected, actual)
     expect(actual.message).to eq(expected[:message])