我有几组承诺，如何解析每组 "sequentially"？

Question

有一个图书馆叫做 p-limit that is built for this purpose, but it's written in ESM, so it's a hassle to deal with. I figured, how hard could it be to implement my own? So I came up with this implementation:

(async() => {
    const promisedAxiosPosts = _.range(0, 100).map(async(item, index) => {
      console.log(`${index}: starting`);
      return Promise.resolve();
    });

    let i = 0;
    for (const promisedAxiosPostGroup of _.chunk(promisedAxiosPosts, 10)) {
      console.log(`***********************
GROUP ${i}
SIZE ${promisedAxiosPostGroup.length}
***********************`);
      await Promise.all(promisedAxiosPostGroup);
      i++;
    }
  }

)().catch((e) => {
  throw e;
})

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为什么不等待每个块完成后再继续下一个块？

我认为 map 可能是罪魁祸首，但我不知道如何：它 returns 一个 Promise<void>[]；如果它在函数上 awaiting，它不会返回 void[]（不确定这是否是一回事）？

Answer 1

为此，您需要 return 一个函数，该函数在调用时 return 是一个承诺。函数(athunk)延迟实际动作的执行

数组分块后，调用当前块中的函数，使用Promise.all()等待所有promise resolve:

(async() => {
    const pendingPosts = _.range(0, 100).map((item, index) => {
      return () => { // the thunk
        console.log(`${index}: starting`);

        // a simulation of the action - an api call for example
        return new Promise(resolve => {
          setTimeout(() => resolve(), index * 300);
        });
      }
    });

    let i = 0;
    for (const pendingChunk of _.chunk(pendingPosts, 10)) {
      console.log(`***********************
GROUP ${i}
SIZE ${pendingChunk.length}
***********************`);
      await Promise.all(pendingChunk.map(p => p())); // invoke the thunk to call the action
      i++;
    }
  }

)().catch((e) => {
  throw e;
})

.as-console-wrapper { max-height: 100% !important; top: 0; }

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我有几组承诺，如何解析每组 "sequentially"？

I have groups of promises, how do I resolve each group "sequentially"?

javascript

promise

async-await

typescript

lodash