Alternative test setup for ruby-processing uses capture_io from minitest

basic.rb

def setup
  size(300, 300)
  frame_rate(10)
end

def draw  
  if frame_count == 3
    puts "ok"
    exit
  end
end

draw.rb

def setup
  size(300, 300)  
end

def draw
  begin
    unknown_method()
  rescue NoMethodError => e
    puts e
    exit
  end
end

graphics.rb

def setup
  size(100, 100, P3D)
  puts Java::Processing::opengl::PGraphicsOpenGL.OPENGL_VERSION
  exit
end

p2d.rb

def setup
  size(300, 300, P2D)
  frame_rate(10)
end

def draw  
  if frame_count == 3
    puts "ok"
    exit
  end
end

p3d.rb

def setup
  size(300, 300, P3D)
  frame_rate(10)
end

def draw  
  if frame_count == 3
    puts "ok"
    exit
  end
end

rp5_test.rb

gem "minitest"      # don't use bundled minitest
require "minitest/autorun"

Minitest::Test = MiniTest::Unit::TestCase unless defined?(Minitest::Test) 

Dir.chdir(File.dirname(__FILE__))

class Rp5Test < Minitest::Test
  
  def test_normal    
    out, err = capture_io do
      open("|../bin/rp5 run basic.rb", "r") do |io|
        while l = io.gets
          puts(l.chop) 
        end      
      end
    end
    assert_match %r%ok%, out, "Failed Basic Sketch"    
  end
  
  def test_p2d    
    out, err = capture_io do
      open("|../bin/rp5 run p2d.rb", "r") do |io|
        while l = io.gets
          puts(l.chop) 
        end      
      end
    end
    assert_match %r%ok%, out, "Failed P2D sketch"     
  end
  
  def test_p3d    
    out, err = capture_io do
      open("|../bin/rp5 run p3d.rb", "r") do |io|
        while l = io.gets
          puts(l.chop) 
        end      
      end
    end
    assert_match %r%ok%, out, "Failed P3D sketch"     
  end
  
  def test_graphics    
    out, err = capture_io do
      open("|../bin/rp5 run graphics.rb", "r") do |io|
        while l = io.gets
          puts(l.chop) 
        end      
      end
    end
    assert out[0].to_i >= 3, "Graphics capability #{out} may be sub-optimal" 
  end
  
  def test_setup_exception
    out, err = capture_io do
      open("|../bin/rp5 run setup.rb", "r") do |io|
        while l = io.gets
          puts(l.chop) 
        end      
      end
    end
    assert out.index("undefined method `unknown_method'"), "Failed to raise exception?" 
  end
  
  def test_draw_exception
    out, err = capture_io do
      open("|../bin/rp5 run draw.rb", "r") do |io|
        while l = io.gets
          puts(l.chop) 
        end      
      end
    end
    assert out.index("undefined method `unknown_method'"), "Failed to raise exception?"
  end  
end

setup.rb

def setup
  size(300, 300)
  begin
    unknown_method()
  rescue NoMethodError => e
    puts e
    exit
  end
end

def draw
end