Allow deep merging of hash values for nested with_options. [#490 state:resolved]

Signed-off-by: Pratik Naik <pratiknaik@gmail.com>

5 files changed, 63 insertions, 10 deletions

diff --git a/activesupport/lib/active_support/core_ext/hash.rb b/activesupport/lib/active_support/core_ext/hash.rb
index 6cbd9dd378..a6065ab48e 100644
--- a/activesupport/lib/active_support/core_ext/hash.rb
+++ b/activesupport/lib/active_support/core_ext/hash.rb
@@ -1,10 +1,11 @@
-%w(keys indifferent_access reverse_merge conversions diff slice except).each do |ext|
+%w(keys indifferent_access deep_merge reverse_merge conversions diff slice except).each do |ext|
   require "active_support/core_ext/hash/#{ext}"
 end
 
 class Hash #:nodoc:
   include ActiveSupport::CoreExtensions::Hash::Keys
   include ActiveSupport::CoreExtensions::Hash::IndifferentAccess
+  include ActiveSupport::CoreExtensions::Hash::DeepMerge
   include ActiveSupport::CoreExtensions::Hash::ReverseMerge
   include ActiveSupport::CoreExtensions::Hash::Conversions
   include ActiveSupport::CoreExtensions::Hash::Diff
diff --git a/activesupport/lib/active_support/core_ext/hash/deep_merge.rb b/activesupport/lib/active_support/core_ext/hash/deep_merge.rb
new file mode 100644
index 0000000000..f8842ba57a
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/hash/deep_merge.rb
@@ -0,0 +1,23 @@
+module ActiveSupport #:nodoc:
+  module CoreExtensions #:nodoc:
+    module Hash #:nodoc:
+      # Allows for deep merging
+      module DeepMerge
+        # Returns a new hash with +self+ and +other_hash+ merged recursively.
+        def deep_merge(other_hash)
+          self.merge(other_hash) do |key, oldval, newval|
+            oldval = oldval.to_hash if oldval.respond_to?(:to_hash)
+            newval = newval.to_hash if newval.respond_to?(:to_hash)
+            oldval.class.to_s == 'Hash' && newval.class.to_s == 'Hash' ? oldval.deep_merge(newval) : newval
+          end
+        end
+
+        # Returns a new hash with +self+ and +other_hash+ merged recursively.
+        # Modifies the receiver in place.
+        def deep_merge!(other_hash)
+          replace(deep_merge(other_hash))
+        end
+      end
+    end
+  end
+end
diff --git a/activesupport/lib/active_support/option_merger.rb b/activesupport/lib/active_support/option_merger.rb
index 1a4ff9db9a..c77bca1ac9 100644
--- a/activesupport/lib/active_support/option_merger.rb
+++ b/activesupport/lib/active_support/option_merger.rb
@@ -10,16 +10,8 @@ module ActiveSupport
 
     private
       def method_missing(method, *arguments, &block)
-        merge_argument_options! arguments
+        arguments << (arguments.last.respond_to?(:to_hash) ? @options.deep_merge(arguments.pop) : @options.dup)
         @context.send!(method, *arguments, &block)
       end
-
-      def merge_argument_options!(arguments)
-        arguments << if arguments.last.respond_to? :to_hash
-          @options.merge(arguments.pop)
-        else
-          @options.dup
-        end
-      end
   end
 end
diff --git a/activesupport/test/core_ext/hash_ext_test.rb b/activesupport/test/core_ext/hash_ext_test.rb
index 26e65075eb..5d2053f106 100644
--- a/activesupport/test/core_ext/hash_ext_test.rb
+++ b/activesupport/test/core_ext/hash_ext_test.rb
@@ -245,6 +245,16 @@ class HashExtTest < Test::Unit::TestCase
     assert(!indiff.keys.any? {|k| k.kind_of? String}, "A key was converted to a string!")
   end
 
+  def test_deep_merge
+    hash_1 = { :a => "a", :b => "b", :c => { :c1 => "c1", :c2 => "c2", :c3 => { :d1 => "d1" } } }
+    hash_2 = { :a => 1, :c => { :c1 => 2, :c3 => { :d2 => "d2" } } }
+    expected = { :a => 1, :b => "b", :c => { :c1 => 2, :c2 => "c2", :c3 => { :d1 => "d1", :d2 => "d2" } } }
+    assert_equal expected, hash_1.deep_merge(hash_2)
+
+    hash_1.deep_merge!(hash_2)
+    assert_equal expected, hash_1
+  end
+
   def test_reverse_merge
     defaults = { :a => "x", :b => "y", :c => 10 }.freeze
     options  = { :a => 1, :b => 2 }
diff --git a/activesupport/test/option_merger_test.rb b/activesupport/test/option_merger_test.rb
index 509c6d3bad..0d72314880 100644
--- a/activesupport/test/option_merger_test.rb
+++ b/activesupport/test/option_merger_test.rb
@@ -38,6 +38,33 @@ class OptionMergerTest < Test::Unit::TestCase
     end
   end
 
+  def test_nested_method_with_options_containing_hashes_merge
+    with_options :conditions => { :method => :get } do |outer|
+      outer.with_options :conditions => { :domain => "www" } do |inner|
+        expected = { :conditions => { :method => :get, :domain => "www" } }
+        assert_equal expected, inner.method_with_options
+      end
+    end
+  end
+
+  def test_nested_method_with_options_containing_hashes_overwrite
+    with_options :conditions => { :method => :get, :domain => "www" } do |outer|
+      outer.with_options :conditions => { :method => :post } do |inner|
+        expected = { :conditions => { :method => :post, :domain => "www" } }
+        assert_equal expected, inner.method_with_options
+      end
+    end
+  end
+
+  def test_nested_method_with_options_containing_hashes_going_deep
+    with_options :html => { :class => "foo", :style => { :margin => 0, :display => "block" } } do |outer|
+      outer.with_options :html => { :title => "bar", :style => { :margin => "1em", :color => "#fff" } } do |inner|
+        expected = { :html => { :class => "foo", :title => "bar", :style => { :margin => "1em", :display => "block", :color => "#fff" } } }
+        assert_equal expected, inner.method_with_options
+      end
+    end
+  end
+
   # Needed when counting objects with the ObjectSpace
   def test_option_merger_class_method
     assert_equal ActiveSupport::OptionMerger, ActiveSupport::OptionMerger.new('', '').class