let movingPiece = document.querySelector(
"#" + getSquareId(move.start) + " > img.piece"
);
+ // For some unknown reasons Opera get "movingPiece == null" error
+ // TOOO: is it calling 'animate()' twice ? One extra time ?
+ if (!movingPiece) return;
// HACK for animation (with positive translate, image slides "under background")
// Possible improvement: just alter squares on the piece's way...
const squares = document.getElementsByClassName("board");