Dropbox 的 `filesGetTemporaryLink` 抛出无法捕获的 `UnhandledPromiseRejectionWarning` 并终止 Node.js

Question

要下载 link 托管在 Dropbox 上的文件，我使用的是 Dropbox JavaScript API (7.0.0):

export const fileDownload = async function fileDownload(fileUUID) {

    let isSucceeded;
    let message;
    let file;
    const dbx = _dropboxFactory();

    try {
        const operationResult = await dbx.filesGetTemporaryLink({
            path: `/${CONFIG_STORAGE.uploader.assetsPath}/${fileUUID}`
        });

        if ("OK" === http.STATUS_CODES[operationResult.status].toUpperCase()) {

            file = Object.freeze({
                length: operationResult?.result?.metadata?.size,
                link: operationResult?.result?.link,
                mime: mime.lookup(operationResult?.result?.metadata?.name),
                name: operationResult?.result?.metadata?.name
            });
            isSucceeded = true;
            message = SYS_MESSAGES.storageFileDownloadSucceeded.code;

        } else {
            isSucceeded = false;
            message = SYS_MESSAGES.storageFileDownloadFailed.code;
        }
    } catch (err) {
        file = "error";
        isSucceeded = false;
        message = "FIL_NOT_FOUND";
    }

    const downloadResult = Object.freeze({
        file,
        isSucceeded,
        message
    });

    return downloadResult;

};

问题是当文件的 path 错误时，我得到一个 Node.js 异常：

(node:9156) UnhandledPromiseRejectionWarning: #<Object>

(node:9156) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag --unhandled-rejections=strict (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 2)

(node:9156) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

我测试了几个选项，得出的结论是问题出在：

const operationResult = await dbx.filesGetTemporaryLink({
    path: `/${CONFIG_STORAGE.uploader.assetsPath}/${fileUUID}`
});

我无法理解的是，为什么 Node.js 声称 «未处理的承诺拒绝» 或 «未使用 [= 处理的承诺16=]» 并在生成它的代码被 try-catch?

包装时抛出 UnhandledPromiseRejectionWarning 异常

开始 Node.js 15.x.x，未处理的承诺拒绝将以非零退出代码终止 Node.js 进程。因此，如何避免UnhandledPromiseRejectionWarning?

临时解决方法：

到运行 Node.js 带有标志 --unhandled-rejections=warn.
这将防止 Node.js 进程在 UnhandledPromiseRejectionWarning.

时以非零退出代码终止

Answer 1

尝试将您的 fileResponse 函数更改为类似这样的内容。您将 async/await 与 .then().catch() 样式语法混淆了。

只需将您的函数包装在 try-catch

中

async function getDocument() {
  try {
    const response = await fetch(`${http() + ip}/downloadDocument`, {
      body: JSON.stringify({fileUUID: oModel.oData[0].documentFile}),
      cache: "no-cache",
      credentials: "same-origin",
      headers: {
        "Content-Type": "application/json"
      },
      method: "POST",
      mode: "cors"
    });

    const data = await response.json();
    
    return data;
  } catch(err) {
    console.log(err);
  }
}

Answer 2

问题出在 Dropbox 库中，Dropbox 团队已在 7.1.0 版本中解决。升级后问题中的代码正常工作。

Dropbox 的 `filesGetTemporaryLink` 抛出无法捕获的 `UnhandledPromiseRejectionWarning` 并终止 Node.js

Dropbox's `filesGetTemporaryLink` throws an uncatchable `UnhandledPromiseRejectionWarning` and terminates Node.js

javascript

unhandled-exception

dropbox

node.js

unhandled-promise-rejection

临时解决方法：