webstorm 开发 typescript 常见问题总结

ESLint中no-param-reassign错误

不改变原对象(数组)并重新给字段赋值，适用于ESLint4.0.0规则

Assignment to property of function parameter ‘item’

不能增加/删除对象属性

以上两个问题常用解决方法如下：

function defineProperty(obj, key, val) {  
    // 返回object对象
    return Object.defineProperty(obj, key,
      {value: val,
        writable: true,
        configurable: true,
        enumerable: true,
      }
    );
}
function setObjectValue(obj, key, val){
    return Reflect.set(obj, key, val);// 返回是否设置成功
}

const tmp = {aa: "aa1", bb: "bb1", cc: "cc1"};
function handle(tmp) {
    // tmp.aa = "aa2";   // error: no-param-reassign
    defineProperty(tmp, "aa", "aa2");      // 方案3(适用于数组字段赋值)
    
    // tmp.bb = "bb2";     // error: no-param-reassign
    setObjectValue(tmp, "bb", "bb2");    // 方案2(适用于数组字段赋值)
    
    // tmp.cc = "cc2";     // error: no-param-reassign
    const tmpp = tmp;     // 方案1
    tmpp.cc = "cc2";
}
handle(tmp);

const arr = [tmp];
function handleArr(arr, index){
    setObjectValue(arr[index], "aa", "aa3");
    //defineProperty(arr[index], "aa", "aa3");
}
handleArr(arr, 0);

console.log(tmp);  // {aa: "aa2", bb: "bb2", cc: "cc2"}
console.log(arr);