src/language-js/print/array.js/printArrayItems
function printArrayItems(path, options, printPath, print) {
  const printedElements = [];
  let separatorParts = [];

  path.each((childPath) => {
    printedElements.push(separatorParts, group(print()));

    separatorParts = [",", line];
    if (
      childPath.getValue() &&
      isNextLineEmpty(childPath.getValue(), options)
    ) {
      separatorParts.push(softline);
    }
  }, printPath);

  return printedElements;
}