Patch SimpleCov to reuse code for coverage merger

scripts/merge-simplecov

 #!/usr/bin/env ruby
-begin
-  load File.expand_path('../spring', __FILE__)
-rescue LoadError => e
-  raise unless e.message.include?('spring')
-end
 
 require 'simplecov'
 
-def read(file)
-  return unless File.exist?(file)
-  data = File.read(file)
-  return if data.nil? || data.length < 2
-  data
-end
-
-def load(file)
-  begin
-    JSON.parse(read(file))
-  rescue
-    {}
-  end
-end
-
-def files
-  Dir.glob(File.join(SimpleCov.coverage_path, '*', '.resultset.json'))
-end
-
-def resultsfiles
-  files.map { |file| load(file) }
-end
-
-def resultsets
-  resultsfiles.reduce({}, :merge)
-end
-
-def all_results
-  results = []
-  resultsets.each do |command_name, data|
-    result = SimpleCov::Result.from_hash(command_name => data)
-    # Only add result if the timeout is above the configured threshold
-    if (Time.now - result.created_at) < SimpleCov.merge_timeout
-      results << result
+module SimpleCov
+  module ResultMerger
+    class << self
+      def resultset_files
+        Dir.glob(File.join(SimpleCov.coverage_path, '*', '.resultset.json'))
+      end
+
+      def resultset_hashes
+        resultset_files.map do |path|
+          begin
+            JSON.parse(File.read(path))
+          rescue
+            {}
+          end
+        end
+      end
+
+      def resultset
+        resultset_hashes.reduce({}, :merge)
+      end
     end
   end
-  results
-end
-
-def merged_result
-  merged = {}
-  results = all_results
-  results.each do |result|
-    merged = result.original_result.merge_resultset(merged)
-  end
-  result = SimpleCov::Result.new(merged)
-  # Specify the command name
-  result.command_name = results.map(&:command_name).sort.join(", ")
-  result
 end
 
 # Ignore CI environment
@@ -64,4 +32,4 @@ ENV['CI_BUILD_NAME'] = nil
 
 require_relative '../spec/simplecov_env'
 
-merged_result.format!
+SimpleCov::ResultMerger.merged_result.format!