Why my string comparison isn't working in bash?

I've a script that does something like this:

set -xmyJson="echo '{\"data\":\"true\"}'"commandOutput=$(eval $myJson | jq '.data')echo $commandOutputwhile :do    if [[ $commandOutput == "true" ]]    then        break    fi    sleep 1doneecho "Done"

However, my string comparison never works. The only way I managed this to work was putting '"true"' in the string comparison. It seems that is something related to the eval. Since I've set the x flag here is the output of this script:

+ myJson='echo '\''{"data":"true"}'\'''++ eval echo ''\''{"data":"true"}'\'''+++ echo '{"data":"true"}'++ jq .data+ commandOutput='"true"'+ echo '"true"'"true"+ :+ [[ "true" == \t\r\u\e ]]+ sleep 1+ :+ [[ "true" == \t\r\u\e ]]+ sleep 1+ :+ [[ "true" == \t\r\u\e ]]+ sleep 1

It seems that the string at the right side is being always scaped, if this is the case why is this happening?