try/catch 不执行或捕获错误

Question

我正在尝试制作一个帮助命令，并在发生错误时返回一条消息，这意味着如果用户关闭了DM并通知他们，但似乎不起作用。它继续发送原始消息，如果出现错误，则不执行catch函数。我对javascript还很陌生，所以也许我只是做错了或者打错了什么。

try {
message.author.send('Here's a list of my commands:')
message.author.send('Commands')
message.channel.send('I sent you a dm with all the commands. If you haven't received it, check if your dms are open.')
} catch (error) {
message.channel.send('Couldn't send you a message. Are your dms open?')

Answer 1

send返回一个promise，因此您需要.catch作为promise，或者将async/await与try/catch块一起使用。

promise是一个表示异步操作的对象，因此它内部发生的错误不会被try/catch块捕获。

message.author.send('Here's a list of my commands:')
message.author.send('Commands')
message.channel.send('I sent you a dm with all the commands. If you haven't received it, check if your dms are open.')
.catch((error) => {
message.channel.send('Couldn't send you a message. Are your dms open?')
});

如果你使用async/await，那么altnernative是这样的：

async function whatever() {
... 
try {
await message.author.send('Here's a list of my commands:')
await message.author.send('Commands')
await message.channel.send('I sent you a dm with all the commands. If you haven't received it, check if your dms are open.')
} catch (err) {
await message.channel.send('Couldn't send you a message. Are your dms open?')
}
}