如何实现 create-react-app 的自动更新？

如何解决如何实现 create-react-app 的自动更新？

我有一个反应应用程序并启用了注册服务工作者。我想在 React 应用程序有更新时向用户显示一条自定义消息。然后应用程序将在客户端自动更新。现在我必须清除浏览器缓存才能获得最新版本。这个过程很烦人。我有一个流动的 Service Worker 文件。

/*
 * In production,we register a service worker to serve assets from local cache.
 * This lets the app load faster on subsequent visits in production,and gives
 * it offline capabilities. However,it also means that developers (and users)
 * will only see deployed updates on the "N+1" visit to a page,since prevIoUsly
 * cached resources are updated in the background.
 * To learn more about the benefits of this model
 * This link also includes instructions on opting out of this behavior.
 *
 */

const isLocalhost = Boolean(
  window.location.hostname === "localhost" ||
    // [::1] is the IPv6 localhost address.
    window.location.hostname === "[::1]" ||
    // 127.0.0.1/8 is considered localhost for IPv4.
    window.location.hostname.match(
      /^127(?:\.(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}$/
    )
);

function registerValidSW(swUrl) {
  navigator.serviceWorker
    .register(swUrl)
    .then((registration) => {
      const _registration = registration;
      _registration.onupdatefound = () => {
        const installingWorker = _registration.installing;
        installingWorker.onstatechange = () => {
          if (installingWorker.state === "installed") {
            if (navigator.serviceWorker.controller) {
              // At this point,the old content will have been purged and
              // the fresh content will have been added to the cache.
              // It's the perfect time to display a "New content is
              // available; please refresh." message in your web app.
            } else {
              // At this point,everything has been precached.
              // It's the perfect time to display a
              // "Content is cached for offline use." message.
            }
          }
        };
      };
    })
    .catch(() => {});
}

function checkValidServiceWorker(swUrl) {
  // Check if the service worker can be found. If it can't reload the page.
  fetch(swUrl)
    .then((response) => {
      // Ensure service worker exists,and that we really are getting a JS file.
      if (
        response.status === 404 ||
        response.headers.get("content-type").indexOf("javascript") === -1
      ) {
        // No service worker found. Probably a different app. Reload the page.
        navigator.serviceWorker.ready.then((registration) => {
          registration.unregister().then(() => {
            window.location.reload();
          });
        });
      } else {
        // Service worker found. Proceed as normal.
        registerValidSW(swUrl);
      }
    })
    .catch(() => {});
}

export default function register() {
  if (process.env.NODE_ENV === "production" && "serviceWorker" in navigator) {
    // The URL constructor is available in all browsers that support SW.
    const publicUrl = new URL(process.env.PUBLIC_URL,window.location);
    if (publicUrl.origin !== window.location.origin) {
      // Our service worker won't work if PUBLIC_URL is on a different origin
      // from what our page is served on. This might happen if a CDN is used to
      // serve assets; see https://github.com/facebookincubator/create-react-app/issues/2374
      return;
    }

    window.addEventListener("load",() => {
      const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`;

      if (isLocalhost) {
        // This is running on localhost. Lets check if a service worker still exists or not.
        checkValidServiceWorker(swUrl);

        // Add some additional logging to localhost,pointing developers to the
        // service worker/PWA documentation.
        navigator.serviceWorker.ready.then(() => {});
      } else {
        // Is not local host. Just register service worker
        registerValidSW(swUrl);
      }
    });
  }
}

export function unregister() {
  if ("serviceWorker" in navigator) {
    navigator.serviceWorker.ready.then((registration) => {
      registration.unregister();
    });
  }
}