/**
 * 字符串填充
 * @param type sting 填充左侧还是右侧
 * @param sourceStr string 原字符串
 * @param len number 填充后长度
 * @param charStr string 填充的字符
 * @returns string
 */
export const strPad = (type: 'left' | 'right', sourceStr: string, len: number, charStr: string): string => {
  let retStr = '';

  if (sourceStr.length > len) return sourceStr;

  if (type === 'left') {
    // leftPad
    retStr = new Array(len - sourceStr.length + 1).join(charStr) + sourceStr;
  } else {
    // rightPad
    retStr = sourceStr + new Array(len - sourceStr.length + 1).join(charStr);
  }
  return retStr;
};