Stop polluting ::Array and ::Hash

lib/simplecov/merge_helpers.rb

@@ -27,12 +27,9 @@ def merge_resultset(hash)
       end
 
       new_resultset.each_key do |filename|
-        new_resultset[filename] = (self[filename] || []).merge_resultset(hash[filename] || [])
+        new_resultset[filename] = (self[filename] || []).extend(SimpleCov::ArrayMergeHelper).merge_resultset(hash[filename] || [])
       end
       new_resultset
     end
   end
 end
-
-Array.send :include, SimpleCov::ArrayMergeHelper
-Hash.send :include, SimpleCov::HashMergeHelper

lib/simplecov/result.rb

@@ -24,6 +24,7 @@ class Result
     # Initialize a new SimpleCov::Result from given Coverage.result (a Hash of filenames each containing an array of
     # coverage data)
     def initialize(original_result)
+      original_result = original_result.dup.extend(SimpleCov::HashMergeHelper) unless original_result.is_a? SimpleCov::HashMergeHelper
       @original_result = original_result.freeze
       @files = SimpleCov::FileList.new(original_result.map do |filename, coverage|
         SimpleCov::SourceFile.new(filename, coverage) if File.file?(filename)

spec/merge_helpers_spec.rb

@@ -9,7 +9,7 @@
         source_fixture("app/models/user.rb") => [nil, 1, 1, 1, nil, nil, 1, 0, nil, nil],
         source_fixture("app/controllers/sample_controller.rb") => [nil, 1, 1, 1, nil, nil, 1, 0, nil, nil],
         source_fixture("resultset1.rb") => [1, 1, 1, 1],
-      }
+      }.extend(SimpleCov::HashMergeHelper)
 
       @resultset2 = {
         source_fixture("sample.rb") => [1, nil, 1, 1, nil, nil, 1, 1, nil, nil],