Question

我正在努力工作。我无法进行第二次异步调用：

it.only('can delete an S3 bucket for a given PR', async() => {
  let result
  const options = { branch: '11'}
    // this runs and completes just fine (as you can see in the webstorm pic)
    await Deploy.createPRBucket(options, (error, stdout, stderr) => {
      console.log(`created error: ${error}`)
      console.log(`created stdout: ${stdout}`)
      console.log(`created stderr: ${stderr}`)
      result = JSON.parse(stdout)
      console.log("added")
    })

    // it never hits my console log and bombs before that right after the createPRBucket call resolves
    console.log("deleting...")
    await Deploy.deletePRBucket(options.branch, (error, stdout, stderr) => {
      console.log(`deleted error: ${error}`)
      console.log(`deleted stdout: ${stdout}`)
      console.log(`deleted stderr: ${stderr}`)
      expect(stdout).to.exist
    })
})

守则：

export async function createPRBucket (options, callback){
  try {
    await exec(`aws s3api create-bucket --bucket ${options.branch} --region us-west-2 --create-bucket-configuration LocationConstraint=us-west-2`,
      (error, stdout, stderr) => {
      console.error(`exec error: ${error}`);
      console.log(`stdout: ${stdout}`);
      console.log(`stderr: ${stderr}`);

      callback(error, stdout, stderr)
      // process.exit(0)
    })
    let error, stdout, stderr

  }
  catch(err) {
    console.log(`there was a problem creating this bucket: ${err}`)
    // process.exit(1)
  }
}

export async function deletePRBucket(branch, callback){

    await exec(`aws s3 rb s3://xxx-${branch} --force`,
      (error, stdout, stderr) => {
        console.error(`exec error: ${error}`);
        console.log(`stdout: ${stdout}`);
        console.log(`stderr: ${stderr}`);

        callback(error, stdout, stderr)
        // process.exit(0)
      })
}

这是我在WebStorm中看到的内容：注意：图片显示我有(done) =>和done()，但由于我使用async () =>，我们已将其删除。无论哪种方式，我都会遇到同样的问题，同样的错误。

同样注意我可以在我的测试中在第一个await调用（createPRBranch）的回调中放置一个断点，它就可以了。但是如果我在第二次调用中设置断点（等待deletePRBranch），则第二次调用永远不会被触发，也不会解析该调用。

Answer 1

鉴于exec是一个util.promisifed child_process.exec

it.only('can delete an S3 bucket for a given PR', async() => {
    let result;
    const options = { branch: '11' };
        // this runs and completes just fine (as you can see in the webstorm pic)
    let {stdout, stderr} = await Deploy.createPRBucket(options);
    console.log(`created error: ${error}`);
    console.log(`created stdout: ${stdout}`);
    console.log(`created stderr: ${stderr}`);
    result = JSON.parse(stdout);
    console.log("added");
    console.log("deleting...");

    ({stdout, stderr} = await Deploy.deletePRBucket(options.branch));
    console.log(`deleted error: ${error}`);
    console.log(`deleted stdout: ${stdout}`);
    console.log(`deleted stderr: ${stderr}`);
    expect(stdout).to.exist
})

导出的函数可以简单地 - 注意，不需要async因为它们已经返回Promise

export function createPRBucket(options) {
    return exec(`aws s3api create-bucket --bucket ${options.branch} --region us-west-2 --create-bucket-configuration LocationConstraint=us-west-2`);
}

export function deletePRBucket(branch) {
    return exec(`aws s3 rb s3://xxx-${branch} --force`);
}

promisified exec返回的承诺解决了

{ stdout: "...", stderr: "..." }

注意：我还没有针对exec的错误情况进行测试 - 错误对象是

{ 
  killed: true or false, 
  code: a number?, 
  signal: null (not sure what else can be here, 
  cmd: "the original command line that was run"
}

的解释

({stdout, stderr} = await Deploy.deletePRBucket(options.branch));

当使用没有声明的对象文字解构赋值时，赋值语句周围的（..）是必需的语法。

{a，b} = {a：1，b：2}不是有效的独立语法，因为左侧的{a，b}被视为块而不是对象文字。< / p>
然而，（{a，b} = {a：1，b：2}）是有效的，因为var {a，b} = {a：1，b：2}

注意：你的（..）表达式需要以分号开头，或者它可以用来执行前一行的函数。

来源：MDN Docs

摩卡 - 运行和解析两个异步/等待调用

1 个答案: