[GR-19220] Add spec for use of :base in Dir#glob and tag it (#2377)

PullRequest: truffleruby/2730

Author: eregon

spec/ruby/core/dir/glob_spec.rb

@@ -29,6 +29,23 @@
                %w!file_one.ext file_two.ext!
   end
 
+  it 'returns matching file paths when supplied :base keyword argument' do
+    dir = tmp('dir_glob_base')
+    file_1 = "#{dir}/lib/bloop.rb"
+    file_2 = "#{dir}/lib/soup.rb"
+    file_3 = "#{dir}/lib/mismatched_file_type.txt"
+    file_4 = "#{dir}/mismatched_directory.rb"
+
+    touch file_1
+    touch file_2
+    touch file_3
+    touch file_4
+
+    Dir.glob('**/*.rb', base: "#{dir}/lib").sort.should == ["bloop.rb", "soup.rb"].sort
+  ensure
+    rm_r dir
+  end
+
   it "calls #to_path to convert multiple patterns" do
     pat1 = mock('file_one.ext')
     pat1.should_receive(:to_path).and_return('file_one.ext')