As u/rednosewolf notes, a "swimming test" wasn't used in the Salem witch trials.

If there's an interest in the "test"'s origins, I would humbly offer up an older answer I wrote, plus a follow-up comment. The original "trials by water" were part of a form of justice known as trials by ordeal that were common in the early to high Middle Ages in parts of Europe, originating in 6th century Frankish law, and petering out in usage during the 13th century after the Fourth Lateran Council of 1215 discouraged participation in such trials.

"Swimmings did continue as an unofficial practice in Germany in the early modern era, and spread back to the British Isles, and to the English colonies in America. But it seems that the closest to Salem that they got was a "swimming" in Connecticut contemporaneous with the Salem trials.

Six people were accused of witchcraft in Connecticut in 1692, but only two - Mercy Disborough and Elizabeth Clauson (sometimes written as Closon, Clason or Clawson) were actually brought before a court to be tried. Disborough and Clauson were "ducked" (given the water treatment) - in Disborough's case at her own request - and found to float, and this evidence was presented in court. Ultimately the jury were unable to reach a verdict, and appealed to the Connecticut General Court for guidance. The General Court received advice in turn from a gathering of Connecticut ministers who in no uncertain terms that a conviction "onviction of witchcraft "is unlawful! & sinfull & therefor it cannot afford any evidence"

When the Court of Oyer and Terminer reconvened, it found Disborough guilty and sentenced her to death, while it acquitted Clauson (most likely because of a massive affadavit signed defending her reputation). Disborough's sentence was appealed on a technicality (a juror was missing for the second half of the trial), and ultimately the General Court reprieved her while defending the court proceedings, but prohibited any further witchcraft trials for good measure.

So: duckings/swimmings/trials by water were done to accused witches, even in 1692. But they were not done in Salem, generally not fatal, vociferously opposed by religious authorities, of dubious evidential value in no small part because of the arbitrary nature of the "result", and more often than not part of acquittals as guilty verdicts.

ETA - Reverend Increase Mather of Massachusetts Bay had also some strong words against the use of "duckings", from eight years prior to the 1692 trials:

"This practice has no foundation in nature, nor in Scripture. If the water will bear none but witches, this must need proceed either from some natural or some supernatural cause. No natural cause is, or can be, assigned why the bodies of such persons should swim rather than of any other. The Bodies of Witches have not lost their natural properties; they have weight in them as well as others. Moral changes and viciousness of mind, make no alteration as to these natural properties which are inseparable from the body. .lt is not devine, for the Scripture does no where appoint any such course to be taken to find out whether persons are in league with the devil or no. It remains, then, that the experiment is diabolical."

I think this passage is particularly interesting because it reminds me a bit of the issue around Mary Sibley using a "witch cake" test in Salem in 1692. Even though this was a sort of "counter magic" to determine if some of the supposedly afflicted girls were under the influence of a witch, the act itself was publicly and privately denounced by the Reverend Samuel Parris of Salem, who also blamed the act for unleashing diabolical forces in the village. Which is to say, a lot of the "tests" used on witches and for witchcraft were not just denounced by religious authorities, but considered actually worse than the supposed instances of witchcraft that they were looking for.

As for Salem, the 'swimming test', to my knowledge, was not used. The only extrajudicial torture used was pressing---which led to the death of the prisoner Giles Corey. Most of the "evidence" presented was so called "spectral" --- the accused appearing as a malevolent spirit to the 'afflicted' or misfortunes befalling the 'afflicted' after animosity with the accused. As for the 'swimming' test--- it had been used in Europe, but had fallen out of favour. In England, the "Swimming test' was offically banned by the reign of James I but often occurred as a localized mob action. By extension, the ban had reached the colonies as well. The opportunity for manipulation of the test was taken as the reason for its ban. The accused were bound before being immersed, and those holding the ropes could, and did, pull the accused to whichever 'verdict' they chose. Also, there was a serious debate among theologians and philosophers concerning what evidence could be allowed, with many coming down on the side of ending the physical , so called 'testing' methods like swimming or hot iron testing. The primary physical test became the search for witch's marks but that is another question in itself. The Salem Trials are interesting to read about from several different viewpoints. I would suggest starting with In the Devil's Snare by Mary Beth Norton and A Storm of Witchcraft by Emerson Baker. Baker's is more of a minute by minute exploration but still valuable. Norton makes some excellent observations about the causes of the panic, and, in my humble opionon, presents the best theory concerning the reasons behind the outbreak and it's targets. For a work that documents a similar outbreak in England, try Witchfinder by Malcolm Gaskill. It's imminently readable but difficult to find. Finally, if you can get a copy of Early Modern European Witchcraft edited by Ankarloo and Henningson, it's worth the time and effort. Also, i think you can find ' Guide to Grand-Jury Men' by Richard Bernard online. That book was written in 1630 as a guide book for how to approach witchtrials. There is also a section in Bradley Chapin's Criminal Justice in Colonial America 1606-1660 which covers early witch trials and their relative rarity in the colonies (as opposed to England) it also covers evidence that was allowed or excluded. It's a interesting yet horrifying subject to read about.

Edited to correct a spelling error.