src/language-js/comments.js/handleIgnoreComments
function handleIgnoreComments({ comment, enclosingNode, followingNode }) {
  if (
    isPrettierIgnoreComment(comment) &&
    enclosingNode &&
    enclosingNode.type === "TSMappedType" &&
    followingNode &&
    followingNode.type === "TSTypeParameter" &&
    followingNode.constraint
  ) {
    enclosingNode.prettierIgnore = true;
    comment.unignore = true;
    return true;
  }
}