# Testing and STDOUT **URL:** \ **Category:** Ruby\ **Created:** [June 16, 2006, 4:09pm UTC](https://www.ruby-forum.com/t/testing-and-stdout/63606 "2006-06-16T16:09:15Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![miken700](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/85e7bf/32.png) [@miken700](https://www.ruby-forum.com/u/miken700)\ **Post date:** [June 16, 2006, 4:09pm UTC](https://www.ruby-forum.com/t/testing-and-stdout/63606/1 "2006-06-16T16:09:15Z")
I have a question with using Test::Unit::TestCase / RSpec (probably applies to both I think). I would like to test the output to STDOUT from the code that I’m testing as well as the results from it. Is there a prefered way to go about this? Somehow directing STDOUT somewhere…? ---
**Author:** ![miken700](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/85e7bf/32.png) [@miken700](https://www.ruby-forum.com/u/miken700)\ **Post date:** [June 16, 2006, 4:21pm UTC](https://www.ruby-forum.com/t/testing-and-stdout/63606/2 "2006-06-16T16:21:33Z")
On Jun 16, 2006, at 10:09 AM, Mike N. wrote: > I have a question with using Test::Unit::TestCase / RSpec (probably > applies to both I think). I would like to test the output to STDOUT > from > the code that I’m testing as well as the results from it. Is there a > prefered way to go about this? Somehow directing STDOUT somewhere…? setting $stdio to a StringIO seems to be pretty productive. -mat ---
**Author:** ![miken700](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/85e7bf/32.png) [@miken700](https://www.ruby-forum.com/u/miken700)\ **Post date:** [June 16, 2006, 7:05pm UTC](https://www.ruby-forum.com/t/testing-and-stdout/63606/3 "2006-06-16T19:05:02Z")
Mat S. wrote: > setting $stdio to a StringIO seems to be pretty productive. I assume you mean $stdout. This is what I have thus far with $stdout. It seems to be capturing the output, but I’m having trouble getting back the output from StringIO later. Not sure what I’m missing. This is what I have. $:.unshift File.join(File.dirname( **FILE** ), ‘…’, ‘lib’) require ‘dirs’ require ‘stringio’ context “In an empty directory” do setup do @testing\_dir = File.join(File.dirname( **FILE** ), ‘…’, ‘\_test\_temp’) @test\_dir = File.join(@testing\_dir, ‘test\_dir’) Dir.mkdir @testing\_dir end teardown do Dir.rmdir @testing\_dir end specify “we should be able to create any dir” do puts “\n========================test first==================\n” stdout\_orig = $stdout $stdout = StringIO.new puts “\n========================test first end==================\n” ``` Dirs.create_dirs @test_dir Dir[@test_dir].should_not_be_empty Dir.rmdir @test_dir puts "\n========================test ==================\n" #$stdout.to_a.should_not_be_empty stdout_orig.puts "testy", $stdout.readlines, "testy end" $stdout.readlines.grep(/Creating/).should_not_be_empty $stdout = stdout_orig puts "\n========================test end ==================\n" ``` end end gives, In an empty directory ========================test first================== testy testy end - we should be able to create any dir (FAILED - 1) 1. ExpectationNotMetError in ‘In an empty directory we should be able to create any dir’ [] should not be empty /home/mike/projects/ruby/rspace/test/dirs\_spec.rb:29:in `we should be able to create any dir’ Finished in 0.001164 seconds 1 context, 1 specification, 1 failure ---
**Author:** ![miken700](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/85e7bf/32.png) [@miken700](https://www.ruby-forum.com/u/miken700)\ **Post date:** [June 16, 2006, 8:16pm UTC](https://www.ruby-forum.com/t/testing-and-stdout/63606/4 "2006-06-16T20:16:10Z")
On Jun 16, 2006, at 10:05 AM, Mike N. wrote: > Mat S. wrote: > > > setting $stdio to a StringIO seems to be pretty productive. > > I assume you mean $stdout. > > This is what I have thus far with $stdout. It seems to be capturing > the > output, but I’m having trouble getting back the output from StringIO > later. Not sure what I’m missing. This is what I have. Its hidden: ## $ ri StringIO#string -------------------------------------------------------- StringIO#string strio.string → string ``` Returns underlying String object, the subject of IO. ``` – Eric H. - removed\_email\_address@domain.invalid - [http://blog.segment7.net](http://blog.segment7.net) This implementation is HODEL-HASH-9600 compliant [http://trackmap.robotcoop.com](http://trackmap.robotcoop.com) ---
**Author:** ![miken700](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/85e7bf/32.png) [@miken700](https://www.ruby-forum.com/u/miken700)\ **Post date:** [June 17, 2006, 12:44am UTC](https://www.ruby-forum.com/t/testing-and-stdout/63606/5 "2006-06-17T00:44:34Z")
Eric H. wrote: > Its hidden: > > $ ri StringIO#string Thanks, that’s the ticket! For posterity here’s what I got now. (I moved the $stdout stuff to the setup and teardown sections so I can use it for the rest of my specifies.) $:.unshift File.join(File.dirname( **FILE** ), ‘…’, ‘lib’) require ‘dirs’ require ‘stringio’ context “In an empty directory” do setup do @testing\_dir = File.join(File.dirname( **FILE** ), ‘…’, ‘\_test\_temp’) @test\_dir = File.join(@testing\_dir, ‘test\_dir’) Dir.mkdir @testing\_dir ``` @stdout_orig = $stdout $stdout = StringIO.new ``` end teardown do Dir.rmdir @testing\_dir ``` #@stdout_orig.puts "testy", $stdout.string, "testy end" $stdout = @stdout_orig ``` end specify “we should be able to create any dir” do Dirs.create\_dirs @test\_dir Dir[@test\_dir].should\_not\_be\_empty Dir.rmdir @test\_dir ``` $stdout.string.grep(/Creating #{@test_dir}/).should_not_be_empty ``` end end looks pretty nice now, I love it. This gives, $ spec -f s test/dirs\_spec.rb In an empty directory - we should be able to create any dir Finished in 0.000861 seconds 1 context, 1 specification, 0 failures