While the quality of the Joy-Cons are still being debated in court, the existence of the Joy-Cons themselves has won in a separate court case. Gamevice, a manufacturer of mobile gaming accessories, took both Nintendo of America and Nintendo of Japan to court in 2018, making the accusation that the Switch Joy-Cons were infringing upon their snap-on mobile controller patents. This hadn't been their first lawsuit against the company either, where they filed a lawsuit against Nintendo for the Joy-Cons also infringing upon their Wikipad device. That case was both filed and dismissed in 2017.
The second case that Gamevice brought against Nintendo, in regards to their patents, was also dismissed, but Gamevice stubbornly appealed the decision, maintaining that Nintendo infringed upon their patents on 19 different occasions. Now, a final decision has been made in court, with Nintendo coming out as the victor. The Patent Trial and Appeal Board threw out all 19 claims against Nintendo, as they proved that controllers that can clip on or fasten to tablet-like devices are unpatentable. According to the legal document provided in the source, Gamevice made no effort to argue against Nintendo's evidence nor the final court ruling.