Merge pull request #466 from matrix-org/rav/improve_indexeddb_errors

Improve error reporting from indexeddbstore.clearDatabase

src/store/indexeddb-local-backend.js

@@ -163,8 +163,27 @@ LocalIndexedDBStoreBackend.prototype = {
      * @return {Promise} Resolved when the database is cleared.
      */
     clearDatabase: function() {
-        console.log("Removing indexeddb instance: ", this._dbName);
-        return promiseifyRequest(this.indexedDB.deleteDatabase(this._dbName));
+        return new q.Promise((resolve, reject) => {
+            console.log(`Removing indexeddb instance: ${this._dbName}`);
+            const req = this.indexedDB.deleteDatabase(this._dbName);
+
+            req.onblocked = () => {
+                reject(new Error(
+                    "unable to delete indexeddb because it is open elsewhere",
+                ));
+            };
+
+            req.onerror = (ev) => {
+                reject(new Error(
+                    "unable to delete indexeddb: " + ev.target.error,
+                ));
+            };
+
+            req.onsuccess = () => {
+                console.log(`Removed indexeddb instance: ${this._dbName}`);
+                resolve();
+            };
+        });
     },
 
     /**

src/store/indexeddb.js

@@ -150,7 +150,7 @@ IndexedDBStore.prototype.deleteAllData = function() {
     return this.backend.clearDatabase().then(() => {
         console.log("Deleted indexeddb data.");
     }, (err) => {
-        console.error("Failed to delete indexeddb data: ", err);
+        console.error(`Failed to delete indexeddb data: ${err}`);
         throw err;
     });
 };