migration_modifiers_down.js

var COLLECTION_NAME_LINE_ITEM = "line-items";
var LINEITEM_FIELD_OPTIONS = "options";

var OPTION_TYPE_GROUP = "group";
var OPTION_ADD = "add";
var OPTION_PRICE = "price";
var OPTION_PERCENTAGE = "percentage";

function mapOptions(option) {
  if (option.type === OPTION_TYPE_GROUP) {
    return {
      ...option,
      elements: option.elements.map(mapOptions),
    };
  }

  if (option.options) {
    return {
      ...option,
      options: option.options.map((item) => {
        const { modifiers, ...rest } = item;
        if (modifiers.price && modifiers.price.operation === OPTION_ADD) {
          return {
            ...rest,
            price: modifiers.price.value,
            mod: OPTION_PRICE,
          };
        }
        if (
          modifiers.price &&
          modifiers.price.operation === OPTION_PERCENTAGE
        ) {
          return {
            ...rest,
            percentage: modifiers.price.value,
            mod: OPTION_PERCENTAGE,
          };
        }
        return rest;
      }),
    };
  }
  return option;
}

var lineItemCursor = db.getCollection(COLLECTION_NAME_LINE_ITEM).find({
  [LINEITEM_FIELD_OPTIONS]: { $exists: true },
  $where: "this." + LINEITEM_FIELD_OPTIONS + ".length > 0",
});

while (lineItemCursor.hasNext()) {
  var el = lineItemCursor.next();

  if (
    !el[LINEITEM_FIELD_OPTIONS] ||
    (Array.isArray(el[LINEITEM_FIELD_OPTIONS]) &&
      el[LINEITEM_FIELD_OPTIONS].length === 0)
  ) {
    continue;
  }

  var optionGroupElements = el[LINEITEM_FIELD_OPTIONS].map(mapOptions);

  db.getCollection(COLLECTION_NAME_LINE_ITEM).updateOne(
    { _id: el._id },
    { $set: { [LINEITEM_FIELD_OPTIONS]: optionGroupElements } }
  );
}

migration_modifiers_up.js

var COLLECTION_NAME_LINE_ITEM = "line-items";
var LINEITEM_FIELD_OPTIONS = "options";

var OPTION_TYPE_GROUP = "group";
var OPTION_ADD = "add";
var OPTION_PERCENTAGE = "percentage";

function mapOptions(option) {
  if (option.type === OPTION_TYPE_GROUP) {
    return {
      ...option,
      elements: option.elements.map(mapOptions),
    };
  }

  if (option.options) {
    return {
      ...option,
      options: option.options.map((item) => {
        const { price, percentage, mod, ...rest } = item;
        if (price || percentage) {
          return {
            ...rest,
            modifiers: {
              price: {
                operation:
                  item.mod && item.mod === OPTION_PERCENTAGE
                    ? OPTION_PERCENTAGE
                    : OPTION_ADD,
                value: percentage || price,
              },
            },
          };
        }
        return {
          ...item,
          modifiers: item.modifiers || {},
        };
      }),
    };
  }
  return option;
}

var lineItemCursor = db.getCollection(COLLECTION_NAME_LINE_ITEM).find({
  [LINEITEM_FIELD_OPTIONS]: { $exists: true },
  $where: "this." + LINEITEM_FIELD_OPTIONS + ".length > 0",
});

while (lineItemCursor.hasNext()) {
  var el = lineItemCursor.next();

  if (
    !el[LINEITEM_FIELD_OPTIONS] ||
    (Array.isArray(el[LINEITEM_FIELD_OPTIONS]) &&
      el[LINEITEM_FIELD_OPTIONS].length === 0)
  ) {
    continue;
  }

  var optionGroupElements = el[LINEITEM_FIELD_OPTIONS].map(mapOptions);

  db.getCollection(COLLECTION_NAME_LINE_ITEM).updateOne(
    { _id: el._id },
    { $set: { [LINEITEM_FIELD_OPTIONS]: optionGroupElements } }
  );
}