问题

我有以下的地图和筛选功能在异步中运行。

console.log('kycPendingProviders:', kycPendingProviders)
const incompleteKYCClaims = kycPendingProviders
  .map(async (p) => {
    const provider = await getProviderOrThrow(p.tin)
    console.log('provider:', provider)

    // 检查提交当前KYC的人
    if (provider.kycSubmissionInfo?.submissionRequest.submitterUUID !== currentUserID) return Promise.reject()

    return toProviderRelationshipClaims({ tin: p.tin, role: ProviderUserSubRoles.ky, status: 'KYCInDraft' })
  })
  .filter((claim) => claim) as unknown as Array<ProviderRelationshipClaims>
console.log('incompleteKYCClaims:', incompleteKYCClaims)

尝试了`if (provider.kycSubmissionInfo?.submissionRequest.submitterUUID !== currentUserID) return` 和 `filter` 将会移除 `undefined` 条目的想法以及 `if (provider.kycSubmissionInfo?.submissionRequest.submitterUUID !== currentUserID) return Promise.reject()` 版本。

当条件不满足时，我得到的结果是 `[ Promise { <pending> } ]`，而我需要在后续的 `filter()` 中将 `undefined` 值从结果数组中移除。

我有一个使用 `for of` 循环的版本，那个版本似乎工作正常。为什么 `map()` 在这里不返回一个值 [这里是`undefined`]，而是一个未决的 promise？我该如何解决这个问题？

谢谢


<details>
<summary>英文:</summary>

I have the below map and filter functions doing async inside.

      console.log(&#39;kycPendingProviders:&#39;, kycPendingProviders)
      const incompleteKYCClaims = kycPendingProviders
        .map(async (p) =&gt; {
          const provider = await getProviderOrThrow(p.tin)
          console.log(&#39;provider:&#39;, provider)
        
          // check who submitted the current KYC
          if (provider.kycSubmissionInfo?.submissionRequest.submitterUUID !== currentUserID) return Promise.reject()
    
          return toProviderRelationshipClaims({ tin: p.tin, role: ProviderUserSubRoles.ky, status: &#39;KYCInDraft&#39; })
        })
        .filter((claim) =&gt; claim) as unknown as Array&lt;ProviderRelationshipClaims&gt;
      console.log(&#39;incompleteKYCClaims:&#39;, incompleteKYCClaims)

Tried both `if (provider.kycSubmissionInfo?.submissionRequest.submitterUUID !== currentUserID) return` with the idea that `filter` will remove `undefined` entries and `if (provider.kycSubmissionInfo?.submissionRequest.submitterUUID !== currentUserID) return Promise.reject()` versions.

When the condition is not met, I am getting as a result `[ Promise { &lt;pending&gt; } ]` while I need an `undefined` value to be removed from the results array by the subsequent `filter()`.

I have a version with `for of` loop. That seemed to be working correctly. Why is `map()` not returning a value [here `undefined`], but a pending promise? How do I fix this?

Thank you

</details>


# 答案1
**得分**: 1

要解决这个问题并获得所需的行为，您可以使用Promise.all()来等待map()返回的所有promise，然后在已解析的值上使用filter()函数。这里是一个示例：

```javascript
console.log('kycPendingProviders:', kycPendingProviders);

const incompleteKYCClaims = await Promise.all(
  kycPendingProviders.map(async (p) => {
    const provider = await getProviderOrThrow(p.tin);
    console.log('provider:', provider);

    if (provider.kycSubmissionInfo?.submissionRequest.submitterUUID !== currentUserID) {
      return undefined; // 或者 null，或者表示删除的任何其他值
    }

    return toProviderRelationshipClaims({ tin: p.tin, role: ProviderUserSubRoles.ky, status: 'KYCInDraft' });
  })
);

const filteredKYCClaims = incompleteKYCClaims.filter((claim) => claim !== undefined) as Array<ProviderRelationshipClaims>;
console.log('filteredKYCClaims:', filteredKYCClaims);

希望这对您有所帮助。

console.log('kycPendingProviders:', kycPendingProviders);
const incompleteKYCClaims = await Promise.all(
kycPendingProviders.map(async (p) => {
const provider = await getProviderOrThrow(p.tin);
console.log('provider:', provider);
if (provider.kycSubmissionInfo?.submissionRequest.submitterUUID !== currentUserID) {
return undefined; // or null, or any other value that signifies removal
}
return toProviderRelationshipClaims({ tin: p.tin, role: ProviderUserSubRoles.ky, status: 'KYCInDraft' });
})
);
const filteredKYCClaims = incompleteKYCClaims.filter((claim) => claim !== undefined) as Array<ProviderRelationshipClaims>;
console.log('filteredKYCClaims:', filteredKYCClaims);