Run Django test until fail Bash function

testuntilfail.sh

testuntilfail () {
    if [ $# -eq 0 ]
    then
        echo "Django test path must be specified"
    else
        RUNS_BEFORE_FAILURE=0
        while [ $? = 0 ]; do
            let RUNS_BEFORE_FAILURE=RUNS_BEFORE_FAILURE+1
            echo "Beginning run number: $RUNS_BEFORE_FAILURE"
            ./manage.py test $1
        done
    fi
    echo "Failed after $RUNS_BEFORE_FAILURE runs"
}