javascript - ES6 Promises 在 catch 之前返回

Question

我怎样才能实现 saveThings() 的调用者获得精确的错误描述(A 或 B)。目前，我对 A 类型的拒绝被 catch() 子句捕获，因此调用者总是以消息 B 结束......

saveThings() {
    return api.post(endpoint, data)
    .then( response => {
        if ( !response )
            reject({message: 'error of type A - faulty response'});

        resolve('all went well');
    })
    .catch( err => {
        throw new Error('error of type B - call failed');
    });
}

Answer 1

您会想要use .then(…, …) instead of .then(…).catch(…) :

return api.post(endpoint, data).then(response => {
    if (!response)
        throw {message: 'error of type A - faulty response'};
    return 'all went well';
}, err => {
    throw new Error('error of type B - call failed');
});