Open Synapse - Redirecting $stdout for fun and profit

Redirecting $stdout for fun and profit

I was looking at Tom’s Chronic library and noticed this little bit of overridden code where he adds an extra space after every call to Object#p:

alias p_orig p

def p(val)
  p_orig val
  puts
end

It made me wonder how someone would write a test to cover this code and I remembered another post Tom wrote a while ago. Instead of redirecting the code to /dev/null, it’s possible to redirect it to an IO object and then check the object after the call.

describe Object, :p do
  it "prints things out" do
    old_stdout = $stdout.dup
    tempio = StringIO.new

    $stdout = tempio
    p "foo"
    $stdout = old_stdout

    tempio.string.should == "\"hello world\"\n\n"
  end
end

Ruby really is awesome…

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