better linting (#72)

Improve linting and fix linting errors

Signed-off-by: Philip Molares <philip.molares@udo.edu>
Signed-off-by: Tilman Vatteroth <tilman.vatteroth@tu-dortmund.de>

src/service-worker.ts

@@ -15,61 +15,50 @@ const isLocalhost = Boolean(
     // [::1] is the IPv6 localhost address.
     window.location.hostname === '[::1]' ||
     // 127.0.0.0/8 are considered localhost for IPv4.
-    window.location.hostname.match(
-      /^127(?:\.(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}$/
-    )
-);
+    new RegExp(/^127(?:\.(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}$/).exec(window.location.hostname)
+)
 
 type Config = {
   onSuccess?: (registration: ServiceWorkerRegistration) => void;
   onUpdate?: (registration: ServiceWorkerRegistration) => void;
 };
 
-export function register(config?: Config) {
+export function register (config?: Config):void {
   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.href
-    );
+    )
     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/facebook/create-react-app/issues/2374
-      return;
+      return
     }
 
     window.addEventListener('load', () => {
-      const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`;
+      const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`
 
       if (isLocalhost) {
         // This is running on localhost. Let's check if a service worker still exists or not.
-        checkValidServiceWorker(swUrl, config);
-
-        // Add some additional logging to localhost, pointing developers to the
-        // service worker/PWA documentation.
-        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'
-          );
-        });
+        checkValidServiceWorker(swUrl, config)
       } else {
         // Is not localhost. Just register service worker
-        registerValidSW(swUrl, config);
+        registerValidSW(swUrl, config)
       }
-    });
+    })
   }
 }
 
-function registerValidSW(swUrl: string, config?: Config) {
+function registerValidSW (swUrl: string, config?: Config) {
   navigator.serviceWorker
     .register(swUrl)
     .then(registration => {
       registration.onupdatefound = () => {
-        const installingWorker = registration.installing;
+        const installingWorker = registration.installing
         if (installingWorker == null) {
-          return;
+          return
         }
         installingWorker.onstatechange = () => {
           if (installingWorker.state === 'installed') {
@@ -80,70 +69,70 @@ function registerValidSW(swUrl: string, config?: Config) {
               console.log(
                 'New content is available and will be used when all ' +
                   'tabs for this page are closed. See https://bit.ly/CRA-PWA.'
-              );
+              )
 
               // Execute callback
               if (config && config.onUpdate) {
-                config.onUpdate(registration);
+                config.onUpdate(registration)
               }
             } else {
               // At this point, everything has been precached.
               // It's the perfect time to display a
               // "Content is cached for offline use." message.
-              console.log('Content is cached for offline use.');
+              console.log('Content is cached for offline use.')
 
               // Execute callback
               if (config && config.onSuccess) {
-                config.onSuccess(registration);
+                config.onSuccess(registration)
               }
             }
           }
-        };
-      };
+        }
+      }
     })
     .catch(error => {
-      console.error('Error during service worker registration:', error);
-    });
+      console.error('Error during service worker registration:', error)
+    })
 }
 
-function checkValidServiceWorker(swUrl: string, config?: Config) {
+function checkValidServiceWorker (swUrl: string, config?: Config) {
   // Check if the service worker can be found. If it can't reload the page.
   fetch(swUrl, {
     headers: { 'Service-Worker': 'script' }
   })
     .then(response => {
       // Ensure service worker exists, and that we really are getting a JS file.
-      const contentType = response.headers.get('content-type');
+      const contentType = response.headers.get('content-type')
       if (
         response.status === 404 ||
         (contentType != null && contentType.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();
-          });
-        });
+          return registration.unregister().then(() => {
+            window.location.reload()
+          })
+        }).catch(() => console.log('Service worker not ready'))
       } else {
         // Service worker found. Proceed as normal.
-        registerValidSW(swUrl, config);
+        registerValidSW(swUrl, config)
       }
     })
     .catch(() => {
       console.log(
         'No internet connection found. App is running in offline mode.'
-      );
-    });
+      )
+    })
 }
 
-export function unregister() {
+export function unregister ():void {
   if ('serviceWorker' in navigator) {
     navigator.serviceWorker.ready
       .then(registration => {
-        registration.unregister();
+        return registration.unregister()
+      })
+      .catch((error:Error) => {
+        console.error(error.message)
       })
-      .catch(error => {
-        console.error(error.message);
-      });
   }
 }