Merge pull request #25 from nilo85/master

Added:keep_array_duplicates option + test

lib/deep_merge/core.rb

@@ -34,6 +34,8 @@ class InvalidParameter < StandardError; end
   #      Set to string value to run "Array::join" then "String::split" against all arrays
   #   :merge_hash_arrays      DEFAULT: false
   #      Set to true to merge hashes within arrays
+  #   :keep_array_duplicates  DEFAULT: false
+  #      Set to true to preserve duplicate array entries
   #   :merge_debug            DEFAULT: false
   #      Set to true to get console output of merge process for debugging
   #
@@ -64,7 +66,13 @@ class InvalidParameter < StandardError; end
   #   dest   = {:x => [{:z => 2}]}
   #   dest.deep_merge!(source, {:merge_hash_arrays => true})
   #   Results: {:x => [{:y => 1, :z => 2}]}
-  # 
+  #
+  # :keep_array_duplicates => merges arrays within hashes but keeps duplicate elements
+  #   source = {:x => {:y => [1,2,2,2,3]}}
+  #   dest   = {:x => {:y => [4,5,6]}}
+  #   dest.deep_merge!(source, {:keep_array_duplicates => true})
+  #   Results: {:x => {:y => [1,2,2,2,3,4,5,6]}}
+  #
   # There are many tests for this library - and you can learn more about the features
   # and usages of deep_merge! by just browsing the test examples
   def self.deep_merge!(source, dest, options = {})
@@ -84,6 +92,8 @@ def self.deep_merge!(source, dest, options = {})
     merge_hash_arrays = options[:merge_hash_arrays] || false
     # request to extend existing arrays, instead of overwriting them
     extend_existing_arrays = options[:extend_existing_arrays] || false
+    # request that arrays keep duplicate elements
+    keep_array_duplicates = options[:keep_array_duplicates] || false
 
     di = options[:debug_indent] || ''
     # do nothing if source is nil
@@ -168,6 +178,8 @@ def self.deep_merge!(source, dest, options = {})
             end
             list += source[dest.count..-1] if source.count > dest.count
             dest = list
+          elsif keep_array_duplicates
+            dest = dest.concat(source)
           else
             dest = dest | source
           end

test/test_deep_merge.rb

@@ -622,5 +622,15 @@ def test_deep_merge
     hash_src = {"item" => s2 }
     DeepMerge::deep_merge!(hash_src, hash_dst)
     assert_equal({"item" => ""}, hash_dst)
+
+    ######################################
+    # tests for "keep_array_duplicates" option
+    hash_src = {"item" => ["2", "3"]}
+    hash_dst = {"item" => ["1", "2"]}
+    DeepMerge::deep_merge!(hash_src, hash_dst, {:keep_array_duplicates => true})
+    assert_equal({"item" => ["1", "2", "2", "3"]}, hash_dst)
+
+
+
   end # test_deep_merge
 end