A "Benny
test" is a type of regression testing in software development where you prerecord inputs to a game you're working on and then
play them back at high speed to
check if your
code changes causes any adverse effects on the behaviour of the game. The term specifically references Yakkety Sax, the closing theme of the The Benny Hill Show, which is played while showing characters running very fast around the screen.
The term was coined by Jon Blow, the author of Braid and The Witness, during development of his Sokoban-inspired game.