SOURCE

const tree = [
    {
        id: 1,
        name: "张三",
        children: [{
            id: 2,
            name: "李四",
            children: []
        }]
    }
]

const ok = setNames(tree);

console.log(ok);

function setNames(arr) {
    const arrs = arr.map(item => {
        item.names="gege";
        if(item.children && item.children.length) {
            item.children = setNames(item.children);
        }
        return item;
    })
    return arrs;
}