Temporary fix for full cache storage (codesandbox#713)

* Fix QuotaExceeded on service worker

* Add estimator

* Better clearing mechanism

Author: CompuIves

packages/common/registerServiceWorker.js

@@ -73,6 +73,35 @@ function registerValidSW(swUrl, sendNotification) {
                 );
               }
             }
+          } else if (installingWorker.state === 'redundant') {
+            if ('storage' in navigator && 'estimate' in navigator.storage) {
+              navigator.storage.estimate().then(results => {
+                const percentUsed = results.usage / results.quota * 100;
+                // Let's assume that if we're using 95% of our quota, then this failure
+                // was due to quota exceeded errors.
+                // TODO: Hardcoding a threshold stinks.
+                if (percentUsed >= 0.95) {
+                  // Get rid of the existing SW so that we're not stuck
+                  // with the previously cached content.
+                  registration.unregister();
+
+                  // Let's assume that we have some way of doing this without inadvertantly
+                  // blowing away storage being used on the origin by something other than
+                  // our service worker.
+                  // I don't think that the Clear-Site-Data: header helps here, unfortunately.
+                  self.caches.keys().then(names => {
+                    names.forEach(name => {
+                      self.caches.delete(name);
+                    });
+                  });
+
+                  // TODO clear indexeddb
+                }
+              });
+            } else {
+              // What about browsers that don't support navigator.storage.estimate()?
+              // There's no way of guessing why the service worker is redundant.
+            }
           }
         };
       };