Extract database and settings modules

js/modules/database.js

@@ -0,0 +1,33 @@
+/* global indexedDB */
+
+// Module for interacting with IndexedDB without Backbone IndexedDB adapter
+// and using promises. Revisit use of `idb` dependency as it might cover
+// this functionality.
+
+exports.open = (name, version) => {
+  const request = indexedDB.open(name, version);
+  return new Promise((resolve, reject) => {
+    request.onblocked = () =>
+      reject(new Error('Database blocked'));
+
+    request.onupgradeneeded = event =>
+      reject(new Error('Unexpected database upgrade required:' +
+        `oldVersion: ${event.oldVersion}, newVersion: ${event.newVersion}`));
+
+    request.onerror = event =>
+      reject(event.target.error);
+
+    request.onsuccess = (event) => {
+      const connection = event.target.result;
+      resolve(connection);
+    };
+  });
+};
+
+exports.completeTransaction = transaction =>
+  new Promise((resolve, reject) => {
+    transaction.addEventListener('abort', event => reject(event.target.error));
+    transaction.addEventListener('error', event => reject(event.target.error));
+    transaction.addEventListener('complete', () => resolve());
+  });
+