An example of how one might add FlexUnit CI to a Rakefile

flexunit_rakefile.rb

desc "Compile the test harness"
mxmlc "bin/SomeProjectRunner.swf" do |t|
  t.input = "src/FlexUnitRunner.mxml"
  t.library_path << "lib/FlexUnit.swc"
end

desc "Compile and run the test harness"
fdb :cruise do |t|
  t.file = "bin/SomeProjectRunner.swf"
  t.test_result_prelude = "WhateverYouEmitBeforeXMLResultString"
  t.test_result_closing = "WhateverYouEmitAfterXMLResultString"
  t.test_result_file = "WhateverFileYouWantYourResultsWrittenTo"
end

file "#{wherever_you_want_to_move_your_results}" do
  FileUtils.mv "WhateverFileYouWantYourResultsWrittenTo", wherever_you_want_to_move_your_results
end

desc "Move the test results elsewhere"
task :move_results => wherever_you_want_to_move_your_results