It is forbidden to take such tests on the Holy Shabat. However, to take a convenience and claim that you are doing it as a Mitzvah is not very admirable.
In the Universe of Economics people might do the same thing.
In addition to being oppressive slavery was an important economic factor. During periods when slavery was not needed we claimed that we do not keep slaves because the Torah makes it difficult.
In Perashat Mishpatim it says:The prophet Yirmiyahu (34) discusses this subject. It is usually read as the Haftarah for Perashat Mishpatim.
When you buy a Hebrew slave you should make him work for six years and on the seventh you must free him.
Tzidkiyahu was the last Davidic King. During his reign the First Bet Hamikdash was burned down.
Yirmiyahu 34 - 8The later commentators say that the covenant to free the slaves was done during the first siege of Jerusalem. During the war many plantation owners had fled with their family and slaves to Jerusalem. During the long siege the slaves had nothing to do. The owners had become poor and little food was to be found.
The words which were sent to Yirmiyahu from G-d, after Tzidkiyahu made a covenant with the whole nation in Jerusalem to call for freedom. That each person should send away his Slave and each person should send away his maidservant the Jew and the Jewess, to set them free, not to make his fellow Jew work anymore. All of the ministers and the nation who came into the covenant that each man should free his Slave and each man should free his maidservant who are Jewish not to make them work anymore, They listened and they sent the them away. Afterwards, They went back and returned the slaves and the maidservants which that had freed, they captured them to be slaves and maidservants.
At this point everybody just happened to remember that the Torah forbids enslaving a fellow Jew for longer than a few years. In a Temple ceremony all of the slave owners made a covenant with King Tzidkiyahu to free all of the Slaves. They celebrated this as a reawakening of themselves to G-d's rules.
One commentator even says that Tzidkiyahu himself needed recruits for the army. Only Freemen could be drafted. Freeing the slaves also benefited the draft.
After the Siege was over the plantation owners went back to their farms. They realized that they lacked man power. In order to solve this problem they went and captured their freed slaves.
I am sure that the plantation owners rationalized this too as being a Mitzvah. When freeing the slaves they did not return the slaves inheritance land which is called for under the laws of Yovel. They did not keep the laws of Yovel either. This left the freed slaves penniless and without employment. By re-enslaving them "the slaves would be spared certain starvation."
It is not good to use a mere convenience and claim that you are following a great Mitzvah. However, a Mitzvah is still a Mitzvah.
The Prophet later says in Pasuk 16 - 17He uses the same word
Vetashuvu - And you Returned today to and the what is right in my eyes... Vetashuvu - And you Returned today and desecrated my name...
Vetashuvuwhich means to return both for the Return to the Mitzvah of freeing the slaves and for the terrible transgression of capturing and re-enslaving them. In other words they made Tshuvah for their previous hard heartedness. Then they made Tshuvah from performing this Mitzvah and actually regretted performing the Mitzvah of freeing their slaves.