Initial commit

src/serviceWorker.ts

@@ -0,0 +1,107 @@
+const isLocalhost = Boolean(
+  window.location.hostname === 'localhost' ||
+    window.location.hostname === '[::1]' ||
+    window.location.hostname.match(/^127(?:\.(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}$/)
+);
+
+type Config = {
+  onSuccess?: (registration: ServiceWorkerRegistration) => void;
+  onUpdate?: (registration: ServiceWorkerRegistration) => void;
+};
+
+export function register(config?: Config) {
+  if (process.env.NODE_ENV === 'production' && 'serviceWorker' in navigator) {
+    const publicUrl = new URL(
+      (process as { env: { [key: string]: string } }).env.PUBLIC_URL,
+      window.location.href
+    );
+    if (publicUrl.origin !== window.location.origin) {
+      return;
+    }
+
+    window.addEventListener('load', () => {
+      const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`;
+
+      if (isLocalhost) {
+        checkValidServiceWorker(swUrl, config);
+
+        navigator.serviceWorker.ready.then(() => {
+          console.log(
+            'This web app is being served cache-first by a service ' +
+              'worker. To learn more, visit https://bit.ly/CRA-PWA'
+          );
+        });
+      } else {
+        registerValidSW(swUrl, config);
+      }
+    });
+  }
+}
+
+function registerValidSW(swUrl: string, config?: Config) {
+  navigator.serviceWorker
+    .register(swUrl)
+    .then(registration => {
+      registration.onupdatefound = () => {
+        const installingWorker = registration.installing;
+        if (installingWorker == null) {
+          return;
+        }
+        installingWorker.onstatechange = () => {
+          if (installingWorker.state === 'installed') {
+            if (navigator.serviceWorker.controller) {
+              console.log(
+                'New content is available and will be used when all ' +
+                  'tabs for this page are closed. See https://bit.ly/CRA-PWA.'
+              );
+
+              if (config && config.onUpdate) {
+                config.onUpdate(registration);
+              }
+            } else {
+              console.log('Content is cached for offline use.');
+
+              if (config && config.onSuccess) {
+                config.onSuccess(registration);
+              }
+            }
+          }
+        };
+      };
+    })
+    .catch(error => {
+      console.error('Error during service worker registration:', error);
+    });
+}
+
+function checkValidServiceWorker(swUrl: string, config?: Config) {
+  fetch(swUrl)
+    .then(response => {
+      const contentType = response.headers.get('content-type');
+      if (
+        response.status === 404 ||
+        (contentType != null && contentType.indexOf('javascript') === -1)
+      ) {
+        navigator.serviceWorker.ready.then(registration => {
+          registration.unregister().then(() => {
+            window.location.reload();
+          });
+        });
+      } else {
+        registerValidSW(swUrl, config);
+      }
+    })
+    .catch(() => {
+      console.log(
+        'No internet connection found. App is running in offline mode.'
+      );
+    });
+}
+
+export function unregister() {
+  if ('serviceWorker' in navigator) {
+    navigator.serviceWorker.ready.then(registration => {
+      registration.unregister();
+    });
+  }
+}