Use the capture_io method from minitest

Author: trevorturk

test/test_helper.rb

@@ -161,14 +161,18 @@ def now
   self.fake_time = nil
 end
 
-def capture_stderr
-  # The output stream must be an IO-like object. In this case we capture it in
-  # an in-memory IO object so we can return the string value. You can assign any
-  # IO object here.
-  previous_stderr, $stderr = $stderr, StringIO.new
+# From minitest/unit
+def capture_io
+  require 'stringio'
+
+  orig_stdout, orig_stderr         = $stdout, $stderr
+  captured_stdout, captured_stderr = StringIO.new, StringIO.new
+  $stdout, $stderr                 = captured_stdout, captured_stderr
+
   yield
-  $stderr.string
+
+  return captured_stdout.string, captured_stderr.string
 ensure
-  # Restore the previous value of stderr (typically equal to STDERR).
-  $stderr = previous_stderr
+  $stdout = orig_stdout
+  $stderr = orig_stderr
 end

test/worker_test.rb

@@ -642,14 +642,14 @@ def self.perform( run_time, rescue_time=nil )
     end
 
     test "displays warning when not using term_child" do
-      stderr = capture_stderr { @worker.work(0) }
+      stdout, stderr = capture_io { @worker.work(0) }
 
       assert stderr.match(/^WARNING:/)
     end
 
     test "it does not display warning when using term_child" do
       @worker.term_child = "1"
-      stderr = capture_stderr { @worker.work(0) }
+      stdout, stderr = capture_io { @worker.work(0) }
 
       assert !stderr.match(/^WARNING:/)
     end