Gist do post "Testes no Codeigniter com CIUnit" no meu blog Link: http://willmendesnetoprojects.wordpress.com/2013/02/21/testes-no-codeigniter-com-ciunit/

phpunit.xml.dist

<?xml version="1.0" encoding="UTF-8"?>

<phpunit
    colors="true"
    stopOnFailure="false"
    backupGlobals="false"
    backupStaticAttributes="false"
    convertErrorsToExceptions="true"
    convertNoticesToExceptions="true"
    convertWarningsToExceptions="true"
    processIsolation="false"
    syntaxCheck="false"
    cacheTokens="true"
    verbose="false"
    bootstrap="application/third_party/CIUnit/bootstrap_phpunit.php">
    <testsuites>
        <testsuite name="CITools Test Suite">
            <directory>./tests/</directory>
        </testsuite>
    </testsuites>
    <filter>
        <whitelist>
            <directory>./system/</directory>
        </whitelist>
    </filter>
</phpunit>