Return value of yielded block in File.atomic_write

Staying true to Ruby convention, we now return the value of the yielded
block from `File.atomic_write {...}`. This mimics the behavior of MRI's
`File.open {...}`.

1 files changed, 10 insertions, 0 deletions

diff --git a/activesupport/test/core_ext/file_test.rb b/activesupport/test/core_ext/file_test.rb
index 2c04e9687c..cde0132b97 100644
--- a/activesupport/test/core_ext/file_test.rb
+++ b/activesupport/test/core_ext/file_test.rb
@@ -57,6 +57,16 @@ class AtomicWriteTest < ActiveSupport::TestCase
     File.unlink(file_name) rescue nil
   end
 
+  def test_atomic_write_returns_result_from_yielded_block
+    block_return_value = File.atomic_write(file_name, Dir.pwd) do |file|
+      "Hello world!"
+    end
+
+    assert_equal "Hello world!", block_return_value
+  ensure
+    File.unlink(file_name) rescue nil
+  end
+
   private
     def file_name
       "atomic.file"