Question

我刚刚开始了解 Javascript 承诺的工作原理。我理解这些概念和一些代码。但在下面的代码片段中，我没有看到“then()”或“catch()”，所以我不太确定如何修改它，以便在成功时调用另一个异步方法。

const gulp = require('gulp');
const build = require('@microsoft/sp-build-web');
const spsync = require('gulp-spsync-creds').sync;
const sppkgDeploy = require('node-sppkg-deploy');

build.task("deploySharepointApps", {
  execute: async () => {
    const appList = require("./config/apps.json");

    if (!pluginList) {
      return;
    }
    
    for (const { name, sites } of appList.apps) {
      const folderLocation = `./apps/${name}`;

      for (const site of sites) {
   
        await new Promise((resolve) => {
          gulp
            .src(folderLocation)
            .pipe(
              spsync({
                username: creds.username,
                password: creds.password,
                site: coreOptions.siteUrl + site,
                libraryPath: coreOptions.appCatalog,
                publish: true,
              })
            )
            .on("finish", resolve);
        });
      }
    }
  },
});

当此代码循环并复制/上传应用程序时，我想使用此代码部署相同的应用程序：

  return sppkgDeploy.deploy({
    username: uname, 
    password: pswd,
    absoluteUrl: catURL
    filename: filename,
    skipFeatureDeployment: false,
    verbose: true
  });

你能指出我如何“链接”这个的正确方向吗？现在我正在尝试看看是否可以在 .on 之后添加 .then。

编辑 1

我尝试像这样更改内部 for 循环：

        for (const site of sites) {
            // Here await each gulp pipeline to finish before moving on to the next.
            await new Promise((resolve) => {
              gulp
                .src(folderLocation)
                .pipe(
                  spsync({
                    username: uname,
                    password: pswd,
                    site: coreOptions.siteUrl + site,
                    libraryPath: coreOptions.appCatalog,
                    publish: true,
                  })
                )
                .on("finish", resolve);
            });

            await sppkgDeploy.deploy({
              username: uname,
              password: pswd,
              absoluteUrl: catURL,
              filename: name,
              skipFeatureDeployment: false,
              verbose: true,
            });
        }//end for

它因错误而爆炸：

dev3:spfx-plugins admin$ gulp upload-sequential
Build target: DEBUG
[16:00:41] Using gulpfile /src/spfx-plugins/gulpfile.js
[16:00:41] Starting gulp
[16:00:41] Starting 'upload-sequential'...
[16:00:41] Uploading test.sppkg
[16:00:42] Upload successful 1679ms
[16:00:43] Published file 403ms
(node:69005) UnhandledPromiseRejectionWarning: Failed to call the API URL: https://<mydomain>.sharepoint.com/sites/<mysite>/AppCatalog/_api/site?$select=Id
(node:69005) 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(). (rejection id: 1)
(node:69005) [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.
About to exit with code: 0
Process terminated before summary could be written, possible error in async code not continuing!
Trying to exit with exit code 1

所以我包装添加了一个 try/catch 但我从来没有在 catch 中结束。以下是当前代码的样子：

build.task("deploySharepointApps", {
  execute: async () => {
    try 
    {
       const appList = require("./config/apps.json");

       for (const { name, sites } of pluginList.plugins) {
         for (const site of sites) {
         [original code]

          await sppkgDeploy.deploy({
             username: uname,
             password: pswd,
             absoluteUrl: catURL,
             filename: name,
             skipFeatureDeployment: false,
             verbose: true,
           });
          } // end for
        } //end for
    } catch (error) {
        console.log('inside the error handler');
    }

Answer 1

编辑 1：我认为流 (pipe) 部分存在一些错误，因此在该部分添加了错误处理，从您的日志中我看到至少有 1 个应用程序已成功发布，因此我相信 {{1} } 部分将允许您检查进一步的错误。 reject 应该与 UnhandledPromiseRejectionWarning 部分一起修复。

reject

我会使用 for (const site of sites) { // Here await each gulp pipeline to finish before moving on to the next. await new Promise((resolve, reject) => { gulp .src(folderLocation) .pipe( spsync({ username: uname, password: pswd, site: coreOptions.siteUrl + site, libraryPath: coreOptions.appCatalog, publish: true, }) ) .on('error', (error) => { console.log('spsync error:', error); reject(error); }) .on("finish", resolve()); }); await sppkgDeploy.deploy({ username: uname, password: pswd, absoluteUrl: catURL, filename: name, skipFeatureDeployment: false, verbose: true, }); }//end for 来完成，因为您位于标记为 await 的块内，而不是使用 async。当您调用 then/catch 时，您只会在该 await 代码解析时执行下一行代码，或者如果它拒绝，它会转到 await 块，如下所示：

catch

请注意，由于您使用的是 const gulp = require("gulp"); const build = require("@microsoft/sp-build-web"); const spsync = require("gulp-spsync-creds").sync; const sppkgDeploy = require("node-sppkg-deploy"); build.task("deploySharepointApps", { execute: async () => { const appList = require("./config/apps.json"); if (!pluginList) { return; } try { for (const { name, sites } of appList.apps) { const folderLocation = `./apps/${name}`; for (const site of sites) { await new Promise((resolve) => { gulp .src(folderLocation) .pipe( spsync({ username: creds.username, password: creds.password, site: coreOptions.siteUrl + site, libraryPath: coreOptions.appCatalog, publish: true, }) ) // Notice the resolve() here .on("finish", resolve()); }); } } await sppkgDeploy.deploy({ username: uname, password: pswd, absoluteUrl: catURL, filename: filename, skipFeatureDeployment: false, verbose: true, }); } catch (error) { console.log(err); } }, });，因此 await new Promise(...) 将是最后执行的操作。如果 sppkgDeploy.deploy(...) 抛出错误，您将点击 await new Promise(...) 块，而不是运行代码进行部署

第一个完成后如何调用另一个异步函数？

1 个答案: