Run multiple test-cases at the same time.

multi_testcases.rb

def wrong_result(meth, args, expected, real)
  $stderr.puts "test #{meth}(#{args.map(&:inspect).join(',')}) expected to be #{expected} but was #{real}"
end

def failed_test(meth, args, expected, exception)
  $stderr.puts "test #{meth}(#{args.map(&:inspect).join(',')}) expected to be #{expected} but raised an error #{exception}"
end


def test_method(meth, test_cases)
  test_cases.each do |args, expected|
    begin
      arglist = args.is_a?(Array) ? args : [args]
      result = send(meth, *arglist)
      wrong_result(meth, arglist, expected, result)  unless result == expected
    rescue => e
      failed_test(meth, arglist, expected, e)
    end
  end
end

def det(mat)
  mat ? 1 : 0
end

def atan2(y,x)
  raise 'Fail-Fail-Fail!' unless x
  y ? 1 : 0
end


test_method :det, 'nonempty' => 1, nil => 0, 'test with wrong result' => 0
test_method :atan2, ['nonempty', 'nobody cares'] => 1, [nil, 'nobody cares'] => 0, ['test with wrong result', 'nobody cares'] => 0, ['failing test', nil] => 1