如何处理承诺链中的多个错误？

It seems like we have a very similar stack. My solution was to handle everything server-side. You'll need to give your lambda functions the appropriate IAM permissions to access Cognito. The code below is a little long. I use async/await, which really cleans things up for me. You'll need to use Lambda with node 8 to use async/await though.

我验证所有内容都与客户端的正确格式匹配（即电子邮件实际上是电子邮件，密码长度正确）。我意识到可能出现的唯一错误是来自 Cognito 的“现有用户”错误。这个想法是：在您尝试使用 Stripe 注册该用户之前测试该用户是否存在。没有办法“测试”用户的信用卡是否对 Stripe 有效。要么全有要么全无。如果有效，它将通过，否则，您将收到错误消息。如果通过，您可以使用 Cognito 注册用户，知道您不应该收到错误（您已经在客户端验证了电子邮件和密码，并且您知道该用途尚不存在）。

作为参考，这里是cognito的aws-sdk。

const AWS = require('aws-sdk');
const cognito = new AWS.CognitoIdentityServiceProvider({
  region: "region",
  userPoolId: "cognito_user_pool_id",
});

module.exports.signUpUser = (payload) => {
  const usernamePayload = {
    UserPoolId: "cognito_user_pool_id",
    Username: payload.email,
  };

  // I use emails for usernames.

    new Promise((resolve, reject) => {
      cognito.adminGetUser(usernamePayload, (error, response) => {
        if (error && error.code === 'UserNotFoundException') {
          resolve(false);
        } else if (error) {
          reject(error);
        } else {
          // if adminGetUser doesn't fail, it means the username exists
          resolve(true);
        }
      });
    }).then((usernameExists) => {
      if (!usernameExists) {
        // run stripe API stuff
        // always run before sign up below to catch stripe errors
        // and return those errors to client
        // before you sign up the user to Cognito

        // since you've already verified the user does not exist
        // it would be rare for an error to come up here
        // as long as you validate passwords and emails client-side
        const signUpPayload = {
          ClientId: "cognito_user_pool_client_id",
          Username: payload.email,
          Password: payload.password,
          UserAttributes: [
            {
              Name: 'email',
              Value: payload.email,
            },
          ],
        };

          new Promise((resolve, reject) => {
            cognito.signUp(signUpPayload, (error, response) => {
              if (error) {
                reject(error);
              } else {
                resolve(response);
              }
            });
          }).catch((error) => {
            // you should hopefully encounter no errors here
            // once you get everything setup correctly
            console.log(error);
          })
      } else {
        // means username already exists, send error to client
        // saying username exists
      }
    }).catch((error) => {
      // may want to dispatch this error to client
      console.log(error);
    });

  return null;
};