js 中的tree型数组如何去重与合并？

Question

假设数据是这样的，不难发现，其中父级roleCode有重复的，子级roleCode也有重复的，如何做到把重复的去掉，同时，又可以把不重复的合并到一起呢？

testTreeData: [
{
      roleCode: 'staff',
      roleNameCn: '员工',
      children: [
        {
          roleCode: 'staff_01',
          roleNameCn: '员工_01',
          children: [
            {
              roleCode: 'staff_01_01',
              roleNameCn: '员工_01_01'
            }
          ]
        }
      ]
    },
    {
      roleCode: 'staff',
      roleNameCn: '员工',
      children: [
        {
          roleCode: 'staff_02',
          roleNameCn: '员工_02',
          children: [
            {
              roleCode: 'staff_02_01',
              roleNameCn: '员工_02_01'
            },
            {
              roleCode: 'staff_02_02',
              roleNameCn: '员工_02_02'
            }
          ]
        }
      ]
    },
    {
      roleCode: 'staff',
      roleNameCn: '员工',
      children: [
        {
          roleCode: 'staff_02',
          roleNameCn: '员工_02',
          children: [
            {
              roleCode: 'staff_webank_02_03',
              roleNameCn: '员工_02_03'
            },
            {
              roleCode: 'staff_webank_02_04',
              roleNameCn: '员工_02_04'
            }
          ]
        }
      ]
    },
    {
      roleCode: 'aaaaaaaa',
      roleNameCn: '员工aaa'
    },
    {
      roleCode: 'bbbbbbbb',
      roleNameCn: '员工bbb'
    }
]`

Answer 1

const result = []
testTreeData.forEach(child => merge(result, child))
function merge (source, child) {
  const curItem = source.find(item => item.roleCode === child.roleCode)
  if (!curItem) {
    source.push(child)
  } else {
    if (curItem.children && child.children) {
      child.children.forEach(childData => merge(curItem.children, childData))
    }
  }
}

Answer 2

树结构变成普通数组（一维数组），然后去重就简单了