取消正在运行的Promise技巧详解

import React, { useEffect } from 'react';
import { history } from 'umi';
const Test = props => {
  useEffect(() => {
    new Promise((resolve, reject) => {
        // 模拟接口请求时间
        setTimeout(() => {
            resolve()
        }, 4000);
    }).then(res => {
        return new Promise((resolve1) => {
             // 模拟接口请求时间
            setTimeout(() => {
                resolve1()
            }, 1000);
        })
    }).then(() => {
        // Promise 执行完后页面跳转
        history.push('/test1')
    })
  }, []);
  const go = () => {
    history.push('/user/login')
  }
  return (
    <div>
      <button onClick={go}>go to</button>
      Test
    </div>
  );
}
export default Test;

class CancelablePromise<T> {
  /**
   * 构造器
   * @param executor Promise中的 executor
   * @param abortSignal AbortController中的signal对象
   * @returns 
   */
  constructor(executor: (resolve: (value: T | PromiseLike<T>) => void, reject: (reason?: any) => void) => void, abortSignal: AbortSignal) {
    // 记录reject和resolve方法
    let _reject: any = null;
    let _resolve: any = null;
    let _isExecResolve = false;
    // 创建和执行Promise
    const cancelablePromise = new Promise<T>((resolve, reject) => {
      _reject = reject;
      _resolve = (value: T) => {
        _isExecResolve = true;
        resolve(value);
      };
      return executor(_resolve, reject);
    });
    // 监听Signal的abourt事件
    abortSignal.addEventListener('abort', () => {
      if (_isExecResolve) {
        return;
      }
      // 抛出错误
      const error = new DOMException('user cancel promise', CancelablePromise.CancelExceptionName );
      _reject( error );
    } );
    return cancelablePromise;
  }
  // 取消后抛出的异常名称
  static CancelExceptionName = 'CancelablePromise AbortError';
}
export default CancelablePromise;

import React, { useEffect } from 'react';
import { history } from 'umi';
import CancelablePromise from '../utils/CancelablePromise';
const Test = props => {
  useEffect(() => {
   let abortController = new AbortController();
    new CancelablePromise((resolve, reject) => {
        // 模拟接口请求时间
        setTimeout(() => {
            resolve()
        }, 4000);
    }, abortController.signal).then(res => {
        return new CancelablePromise((resolve1) => {
             // 模拟接口请求时间
            setTimeout(() => {
                resolve1()
            }, 1000);
        }, abortController.signal)
    }).then(() => {
        // Promise 执行完后页面跳转
        history.push('/test1')
    })
    return () => {
        // 取消请求
        abortController.abort();
    }
  }, []);
  const go = () => {
    history.push('/user/login')
  }
  return (
    <div>
      <button onClick={go}>go to</button>
      Test
    </div>
  );
}
export default Test;

import React, { useEffect } from 'react';
import { history } from 'umi';
import CancelablePromise from '../utils/CancelablePromise';
const Test = props => {
  useEffect(() => {
      let abortController = new AbortController();
     const exec = async function () {
      try {
        await new CancelablePromise((resolve) => {
          setTimeout(() => {resolve();}, 5000);
        }, abortController.signal, 'one')
        await new CancelablePromise((resolve1) => {
          setTimeout(() => {resolve1();}, 5000);
        }, abortController.signal, 'del')
        history.push('/test')
      } catch (error) {
        // 取消之后会抛出异常
        if (CancelablePromise.CancelExceptionName === error.name) {
          console.log('promise 终止了。。。')
        }
      }
    }
    exec();
    return () => {
        // 取消请求
        abortController.abort();
    }
  }, []);
}

if (CancelablePromise.CancelExceptionName === error.name) {
  console.log('promise 终止了。。。')
}