Deep-merge nested hashes

Author: georgeclaghorn

CHANGELOG.md

@@ -4,6 +4,7 @@ Unreleased
 ----------
 
 * Requires Rails 5+ and Ruby 2.2+
+* Nested hashes are deep-merged
 
 2.9.1
 -----

lib/jbuilder.rb

@@ -275,7 +275,7 @@ def _merge_values(current_value, updates)
     elsif ::Array === current_value && ::Array === updates
       current_value + updates
     elsif ::Hash === current_value && ::Hash === updates
-      current_value.merge(updates)
+      current_value.deep_merge(updates)
     else
       raise MergeError.build(current_value, updates)
     end

test/jbuilder_test.rb

@@ -1,5 +1,6 @@
 require 'test_helper'
 require 'active_support/inflector'
+require 'active_support/core_ext/hash/deep_merge'
 require 'jbuilder'
 
 def jbuild(*args, &block)
@@ -159,6 +160,25 @@ class JbuilderTest < ActiveSupport::TestCase
     assert_equal 32, result['author']['age']
   end
 
+  test 'nested blocks are additive' do
+    result = jbuild do |json|
+      json.author do
+        json.name do
+          json.first 'David'
+        end
+      end
+
+      json.author do
+        json.name do
+          json.last 'Heinemeier Hansson'
+        end
+      end
+    end
+
+    assert_equal 'David', result['author']['name']['first']
+    assert_equal 'Heinemeier Hansson', result['author']['name']['last']
+  end
+
   test 'support merge! method' do
     result = jbuild do |json|
       json.merge! 'foo' => 'bar'