Node.js中Promise未处理的拒绝报错的常见原因及解决方案

const fetchData = () => {
    return new Promise((resolve, reject) => {
        reject(new Error('Failed to fetch data'));
    });
};

fetchData()
    .then(data => console.log(data)); // 缺少.catch()处理拒绝

const fetchDataAsync = async () => {
    const data = await fetchData(); // 如果fetchData()拒绝，没有try/catch处理
    console.log(data);
};

fetchDataAsync();

const fetchDataSync = () => {
    return new Promise((resolve, reject) => {
        throw new Error('Failed to fetch data'); // 同步抛出错误
    });
};

fetchDataSync()
    .then(data => console.log(data)); // 缺少.catch()处理拒绝

const fetchData = () => {
    return new Promise((resolve, reject) => {
        reject(new Error('Failed to fetch data'));
    });
};

fetchData()
    .then(data => console.log(data))
    .catch(error => console.error('Error:', error.message)); // 使用.catch()处理拒绝

const fetchDataAsync = async () => {
    try {
        const data = await fetchData();
        console.log(data);
    } catch (error) {
        console.error('Error:', error.message); // 使用try/catch捕获错误
    }
};

fetchDataAsync();

process.on('unhandledRejection', (reason, promise) => {
    console.error('Unhandled Rejection at:', promise, 'reason:', reason);
    // 在这里可以记录日志或执行其他错误处理逻辑
});

const fetchData = () => {
    return new Promise((resolve, reject) => {
        reject(new Error('Failed to fetch data'));
    });
};

fetchData()
    .then(data => console.log(data)); // 即使没有.catch()，也能通过unhandledRejection事件捕获

const fetchData1 = () => Promise.resolve('Data 1');
const fetchData2 = () => Promise.reject(new Error('Failed to fetch data 2'));
const fetchData3 = () => Promise.resolve('Data 3');

Promise.all([fetchData1(), fetchData2(), fetchData3()])
    .then(results => console.log(results))
    .catch(error => console.error('Error:', error.message)); // 捕获Promise.all中的拒绝