diff options
Diffstat (limited to 'activesupport/test/core_ext')
-rw-r--r-- | activesupport/test/core_ext/hash/transform_keys_test.rb | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/activesupport/test/core_ext/hash/transform_keys_test.rb b/activesupport/test/core_ext/hash/transform_keys_test.rb index 99af274614..962d3a30b6 100644 --- a/activesupport/test/core_ext/hash/transform_keys_test.rb +++ b/activesupport/test/core_ext/hash/transform_keys_test.rb @@ -43,4 +43,20 @@ class TransformKeysTest < ActiveSupport::TestCase original.transform_keys!.with_index { |k, i| [k, i].join.to_sym } assert_equal({ a0: 'a', b1: 'b' }, original) end + + test "transform_keys returns a Hash instance when self is inherited from Hash" do + class HashDescendant < ::Hash + def initialize(elements = nil) + super(elements) + (elements || {}).each_pair{ |key, value| self[key] = value } + end + end + + original = HashDescendant.new({ a: 'a', b: 'b' }) + mapped = original.transform_keys { |k| "#{k}!".to_sym } + + assert_equal({ a: 'a', b: 'b' }, original) + assert_equal({ a!: 'a', b!: 'b' }, mapped) + assert_equal(::Hash, mapped.class) + end end |