element 下拉框加一個自定義選項

<el-select v-model="value" clearable placeholder="請選擇">
    <el-option
      v-for="item in options"
      :key="item.value"
      :label="item.name"
      :value="item.value">
    </el-option>
  </el-select>
           

js部分：

data() {
    return {
       options: [{
           value: '1',
           name: '測試'
         }, {
           value: '2',
           name: '測試2'
         }, {
           value: '3',
           name: '測試3'
          }],
       value: ''
      }
   },
  mounted(){
      this.options.unshift({value: "all", name: "全部"})
  }