Repro and resolve issue 1418 (#1419)

* Repro of issue #1418

* Resolves #1418

* Opting out the new test when addons are active
or where we have a workaround for buggy browser to not delete stores

src/classes/version/schema-helpers.ts

@@ -292,12 +292,8 @@ export function createMissingTables(newSchema: DbSchema, idbtrans: IDBTransactio
 }
 
 export function deleteRemovedTables(newSchema: DbSchema, idbtrans: IDBTransaction) {
-  for (var i = 0; i < idbtrans.db.objectStoreNames.length; ++i) {
-    var storeName = idbtrans.db.objectStoreNames[i];
-    if (newSchema[storeName] == null) {
-      idbtrans.db.deleteObjectStore(storeName);
-    }
-  }
+  [].slice.call(idbtrans.db.objectStoreNames).forEach(storeName =>
+    newSchema[storeName] == null && idbtrans.db.deleteObjectStore(storeName));
 }
 
 export function addIndex(store: IDBObjectStore, idx: IndexSpec) {

test/tests-upgrading.js

@@ -218,7 +218,7 @@ test("upgrade", (assert) => {
         db.version(6).stores({ store1: "++id,*email" });
         db.version(7).stores({ store2: "uuid" });
         // Deleting a version.
-        db.version(8).stores({ store1: null });
+        db.version(8).stores({store1: null });
         return db.open().then(() => {
             ok(true, "Could upgrade to version 8 - deleting an object store");
             checkVersion(8);
@@ -826,3 +826,45 @@ promisedTest(
     }
   }
 );
+
+
+promisedTest(
+    "Issue 1418 - Not deleting all object stores",
+    async () => {
+      if (!supports("deleteObjectStoreAfterRead")) {
+        ok(true, "Skipping this test - buggy browser.");
+        return;
+      }
+      if (Dexie.addons.length > 0) {
+        ok(true, "Skipping this test - default addons are acitve and can add more object stores");
+        return;
+      }
+      const DBNAME = "issue1418";
+      await Dexie.delete(DBNAME);
+      let db = new Dexie(DBNAME);
+      db.version(1).stores({
+        a: '++',
+        b: '++',
+        c: '++',
+        d: '++',
+        e: '++'          
+      });
+      await db.open();
+      equal(db.idbdb.objectStoreNames.length, 5, "There are 5 object stores");
+      db.close();
+
+      db = new Dexie(DBNAME);
+      db.version(2).stores({
+        a: null,
+        b: null,
+        c: null,
+        d: null,
+        e: '++'
+      });
+      await db.open();
+      equal(db.idbdb.objectStoreNames.length, 1, "There is only one object store now");
+      db.close();
+      await Dexie.delete(DBNAME);
+    }
+  );
+