src/language-js/printer-estree.js/printAssignmentRight
function printAssignmentRight(rightNode, printedRight, canBreak, options) {
  if (hasLeadingOwnLineComment(options.originalText, rightNode, options)) {
    return indent(concat([hardline, printedRight]));
  }

  if (canBreak) {
    return indent(concat([line, printedRight]));
  }

  return concat([" ", printedRight]);
}