Google Chrome Indexdb - redundant code

Question

I am tryint yo understand some code from an opensource project that handles indexDB commands within a Google Chrome application.

The code is as follows :

        var db = pm.indexedDB.db;
        var trans = db.transaction([pm.indexedDB.TABLE_DRIVE_CHANGES], "readwrite");
        var store = trans.objectStore(pm.indexedDB.TABLE_DRIVE_CHANGES);

        var boundKeyRange = IDBKeyRange.only(driveChange.id);
        var request = store.put(driveChange);

        request.onsuccess = function (e) {
            callback(driveChange);
        };

        request.onerror = function (e) {
            console.log(e.value);
        };

Although the app works, to me it seems that the following line is redundant code

       var boundKeyRange = IDBKeyRange.only(driveChange.id);

Or am I missing something? The variable 'boundKeyRange' is never referenced anywhere.

Answer 1

Unless boundKeyRange is used later, you're not missing something. IDBKeyRange.only just creates an IDBKeyRange object, and if that object isn't used in some IndexedDB request, it does absolutely nothing.