HWIA delegates to to_hash symbolize_keys and stringify_keys and bang methods are not in the api

Signed-off-by: NJeremy Kemper <jeremy@bitsweat.net>

activesupport/lib/active_support/hash_with_indifferent_access.rb

@@ -111,8 +111,10 @@ def delete(key)
       super(convert_key(key))
     end
 
-    def stringify_keys!; self end
-    def symbolize_keys!; self end
+    undef :stringify_keys!
+    def stringify_keys; to_hash.stringify_keys end
+    undef :symbolize_keys!
+    def symbolize_keys; to_hash.symbolize_keys end
     def to_options!; self end
 
     # Convert to a Hash with String keys.

activesupport/test/core_ext/hash_ext_test.rb

@@ -60,6 +60,40 @@ def test_stringify_keys!
     assert_equal @strings, @mixed.dup.stringify_keys!
   end
 
+  def test_symbolize_keys_for_hash_with_indifferent_access
+    assert_equal @symbols, @symbols.with_indifferent_access.symbolize_keys
+    assert_equal @symbols, @strings.with_indifferent_access.symbolize_keys
+    assert_equal @symbols, @mixed.with_indifferent_access.symbolize_keys
+  end
+
+  def test_symbolize_keys_bang_for_hash_with_indifferent_access
+    assert_raise(NoMethodError) { @symbols.with_indifferent_access.dup.symbolize_keys! }
+    assert_raise(NoMethodError) { @strings.with_indifferent_access.dup.symbolize_keys! }
+    assert_raise(NoMethodError) { @mixed.with_indifferent_access.dup.symbolize_keys! }
+  end
+
+  def test_symbolize_keys_preserves_keys_that_cant_be_symbolized_for_hash_with_indifferent_access
+    assert_equal @illegal_symbols, @illegal_symbols.with_indifferent_access.symbolize_keys
+    assert_raise(NoMethodError) { @illegal_symbols.with_indifferent_access.dup.symbolize_keys! }
+  end
+
+  def test_symbolize_keys_preserves_fixnum_keys_for_hash_with_indifferent_access
+    assert_equal @fixnums, @fixnums.with_indifferent_access.symbolize_keys
+    assert_raise(NoMethodError) { @fixnums.with_indifferent_access.dup.symbolize_keys! }
+  end
+
+  def test_stringify_keys_for_hash_with_indifferent_access
+    assert_equal @strings, @symbols.with_indifferent_access.stringify_keys
+    assert_equal @strings, @strings.with_indifferent_access.stringify_keys
+    assert_equal @strings, @mixed.with_indifferent_access.stringify_keys
+  end
+
+  def test_stringify_keys_bang_for_hash_with_indifferent_access
+    assert_raise(NoMethodError) { @symbols.with_indifferent_access.dup.stringify_keys! }
+    assert_raise(NoMethodError) { @strings.with_indifferent_access.dup.stringify_keys! }
+    assert_raise(NoMethodError) { @mixed.with_indifferent_access.dup.stringify_keys! }
+  end
+
   def test_indifferent_assorted
     @strings = @strings.with_indifferent_access
     @symbols = @symbols.with_indifferent_access
@@ -213,11 +247,11 @@ def test_indifferent_hash_with_array_of_hashes
   def test_stringify_and_symbolize_keys_on_indifferent_preserves_hash
     h = HashWithIndifferentAccess.new
     h[:first] = 1
-    h.stringify_keys!
+    h = h.stringify_keys
     assert_equal 1, h['first']
     h = HashWithIndifferentAccess.new
     h['first'] = 1
-    h.symbolize_keys!
+    h = h.symbolize_keys
     assert_equal 1, h[:first]
   end